Attachment 2 Supporting Information for an environmental ... · SMP Site Management Plan SSD Species Sensitivity Distribution STV Short term Trigger Value ... is seeking to amend

Attachm e n t 2

Suppo rtin g In fo rm atio n fo r an

e n viro n m e n tal autho rity (EA)

Am e n dm e n t Applicatio n

Fairvie w Arcadia Pro je ct Are a

EA (EPPG0 0 9 28 713 )

Table of Contents: 1. Introduction ............................................................................................................................... 6

2. Application Description ........................................................................................................... 8

2.1. Background ...................................................................................................................... 8

2.2. Proposed Amendments .................................................................................................. 11

2.2.1. Existing Conditions ................................................................................................. 11

2.2.2. Proposed Conditions .............................................................................................. 12

2.3. Technical Assessments .................................................................................................. 13

2.3.1. Ecotoxicity Assessment .......................................................................................... 14

2.3.2. Irrigation Assessment ............................................................................................. 15

2.3.3. CORMIX Modelling Assessment ............................................................................ 18

3. Site Description ....................................................................................................................... 20

4. Environmental Values ............................................................................................................ 21

4.1.1. Surface Water ......................................................................................................... 21

4.1.2. Wetlands (the Waterbody) ...................................................................................... 26

5. Potential Impacts and Mitigation Measures ......................................................................... 30

5.1. Surface Water and Wetlands.......................................................................................... 30

6. Legislative Considerations .................................................................................................... 32

6.1. Environmental Protection Act 1994 (EP Act).................................................................. 32

6.1.1. General requirements for an EA amendment application (s226 EP Act) ............... 32

6.1.2. CSG activities requirements for an EA amendment application (s227 EP Act) .................................................................................................................... 33

6.1.3. Requirements for amendment applications – underground water rights (S227AA EP Act) .................................................................................................... 33

6.1.4. Assessment Level Decision for amendment application (s228 EP Act) ................. 34

6.1.5. The Standard Criteria (EP Act) ............................................................................... 37

6.2. Environmental Protection Regulation 2019 (EP Reg) .................................................... 38

6.2.1. Environmental Objective Assessment .................................................................... 39

6.2.2. Waste and Resource Management Hierarchy (Waste Reduction and Recycling Act 2011) (WRR Act) .............................................................................. 41

6.2.3. Prescribed matters for particular resource activities (s24AA EP Regulation) .............................................................................................................. 41

6.3. Environmental Protection Policies (EPP) ....................................................................... 42

6.3.1. Environmental Protection (Water and Wetland Biodiversity) Policy 2019 .............. 42

6.3.2. Additional Regulatory Requirements (EPP) ........................................................... 44

List of Tables: Table 2-1: Boron Guideline Values Derived by Species Sensitivity Distribution ................................... 15

Table 2-2. Soil Water 95% Crop Species Protection Guideline ............................................................ 17

Table 2-3. Maximum Boron Release Concentration at S4 Based on 23.99ML/Day River Flow ........... 19

Table 5-1: Summary of potential impacts and mitigation measures on surface waters and wetlands . 30

Table 6-1: General Requirements EA Amendment Application (s226 EP Act) ..................................... 32

Table 6-2: Minor Amendment (Threshold) Assessment ........................................................................ 34

Table 6-3: Standard Criteria (EP Act) .................................................................................................... 37

Table 6-4: Schedule 8, Part 3, Division 1 – Water ................................................................................ 39

Table 6-5: Prescribed Documents for Application for EA for a CSG Activity (s28 EP Reg) .................. 41

Table 6-6: Environmental Protection (Water and Wetland Biodiversity) Policy 2019 ........................... 42

List of Figures: Figure 1. Location of FAPA ..................................................................................................................... 7

Figure 2. DRRS ..................................................................................................................................... 10

Santos Ltd l EA EPPG00928713 – Amendment Applicat ion l 29 October 2019 Page 2

Appendices

Appendix A Revised Boron Site-Specific Water Quality Criterion - Dawson River Release Scheme (AECOM, 2019)

Appendix B Risk Assessment Report, Boron Irrigation Water Guideline Derivation Fairview Arcadia Project Area (EHS Support, 2019)

Appendix C CORMIX Modelling Update - Dawson River Release Scheme (AECOM, 2019)

Appendix D Santos GLNG Dawson River Release Scheme, Local Water Quality Guidelines, Nov 2016


Abbreviations and Units

Acronym Description

AEP Alberta Environment and Parks

ANZG Australian and New Zealand Guidelines

ATP Authority to Prospect

BPEM Best Practice Environmental Management

CSD Crop Sensitivity Distribution

CSG Coal Seam Gas

DES Department of Environment and Science

DNRME Department of Natural Resources, Mines and Energy

DRRS Dawson River Release Scheme

DTA Direct Toxicity Assessment

EA Environmental Authority

EC/IC Effect Concentration/Inhibition Concentrations

EIS Environmental Impact Statement

EPP Environmental Protection Policy

EPBC Act Environment Protection and Biodiversity Conservation Act 1999

EP Act Environmental Protection Act 1994

ERA Environmentally Relevant Activity

ESA Environmentally Sensitive Area

ESA Ecotox Services Australasia

FAPA Fairview Arcadia Project Area

LTV Long-term Trigger Value

LWQG Local Water Quality Guidelines

NC Act Nature Conservation Act 1992

NEC No Effect Concentration

NOEC No Observable Effect Concentration

PL Petroleum Lease

PNEC Predicted No-Effect Concentration

QWQG Queensland Water Quality Guidelines

RE Regional Ecosystems

REMP Receiving Environment Monitoring Program

RO Reverse Osmosis

ROP Reverse Osmosis Plant


Acronym Description

SMP Site Management Plan

SSD Species Sensitivity Distribution

STV Short term Trigger Value

WQG Water Quality Guidelines

WQMF Water Quality Management Framework


1. Introduction

Santos TOGA Pty Ltd (Santos), on behalf of its joint venture partners (Santos TPY CSG Corp, Santos

TPY Corp, Santos Queensland Corp, Bronco Energy Pty Ltd, PAPL (Upstream) Pty Limited, Total E&P

Australia, Total E&P Australia II & KGLNG E&P Pty Ltd) is seeking to amend the Fairview Arcadia Project

Area (FAPA) Environmental Authority (EA) (EPPG00928713). EA EPPG00928713 authorises the

conduct of petroleum activities on Petroleum Lease (PLs) 90, 91, 92, 99, 100, 232 and Petroleum

Pipeline Licence (PPL) 76 and 92, situated within the FAPA (Figure 1).

This application seeks to amend the EA conditions which relate to boron limits associated with

authorised releases to the Dawson River, specifically:

• the limit(s) presented in Schedule B, Table 4 – Contaminant Limits and condition (B20); and

• the limit(s) presented in Schedule B, Table 8 – Event Based Release – Contaminant Monitoring

and condition (B31).

The holder of an EA may, at any time pursuant to section 224 of the Environmental Protection Act 1994

(EP Act), make an application to the assessing authority seeking an amendment to an EA. Santos has

prepared this document in accordance with sections 226 and 227 of the EP Act and the Department of

Environment and Sciences (DES) Guideline – Application requirements for petroleum activities.

In accordance with section 223 of the EP Act, this application is considered a minor amendment as the

proposal satisfies all of the requirements of the definition of a minor amendment (refer Section 6.1.4).


Figure 1. Location of FAPA


2. Application Description

The amendment application seeks, through the provision of scientific justification, a change to the boron

limits associated with authorised releases to the Dawson River. This change is sought due to changes

in influent boron concentrations in the coal seam gas water (produced water) and variable boron

rejection rates due to climatic and other factors in the reverse osmosis (RO) treatment process.

The need for change has resulted from:

• Changes in influent water quality associated with reservoir characteristics;

• A continued focus on brine storage management – in particular the need to minimise brine

generation which is achieved through increased operating efficiency of the RO plant. This

strategy aligns with the Queensland Government’s Coal Seam Water Management Policy

(2012), in particular Table 2 requiring feasible waste minimisation actions. This operating

strategy also achieves the ‘minimise’ element of the Waste Management Hierarchy and will

delay or prevent the construction of additional regulated brine storages; and

• The affect of seasonality (temperature) on RO membrane performance / boron rejection rates.

2.1. Background

Santos obtained an amendment to the Fairview Project Area EA in 2009 to authorise the release of

desalinated associated water from the Fairview Reverse Osmosis Plant (ROP) 1 to a tributary of the

Hutton Creek. The operation and release of desalinated associated water from ROP 1 ceased in 2014,

however the release may recommence at a later date.

Santos obtained an amendment to the FAPA EA on 31 May 2013 to authorise the release of desalinated

associated water from Fairview Reverse Osmosis Facility Number 2 (ROP 2) to a drainage feature of

the Dawson River. This release is known as the Dawson River Release Scheme (DRRS).

The DRRS includes the following elements (refer to Figure 2):

• associated water in the Hub Compressor Station No. 4 (F-HCS-04) gathering network is

collected from wells within the FAPA via gathering lines and transported to an associated water

management pond (F-HCS-04 AW Balance Dam);

• this associated water is then passed through ROP 2 for treatment (including desalinisation). The

permeate stream is stored in a dedicated desalinated water pond (HCS04DWB1). The brine

stream is stored in dedicated brine storage bonds (HCS04BA1, HCS04BB1, HCS04BC1, and

HCS04BD1);

• a 5.3 km outfall pipeline transfers the desalinated associated water from the desalinated water

pond (HCS04DWB1) to the outfall at the tributary gully at a maximum rate of 18 ML/day, which

is the total capacity of the pipe and the maximum design flow for the release scheme. The DRRS

is currently not operated as a continual release (i.e. 24 hours per day and 7 days per week).

The desalinated associated water is retained within HCS04DWB1 and batched prior to a

release. Based on the average discharge timeframe determined since the commencement, the

average release period is 7.5 release days over each 30 day period;

• the desalinated water is released as defined by the FAPA EA (condition B34), at the release

point identified in Schedule B, Table 3 – Contaminant Release Points of the FAPA EA as ROP

2. This release point is the end of the outfall pipe into the tributary gully;

• the released water flows for 2.9 km down the tributary gully before discharging into a highly

disturbed waterbody which is described as an oxbow lake (otherwise known as ‘the wetland’ by

the FAPA EA conditions) (refer to section 4.1.2 for a detailed description of the waterbody); and


• the waterbody overflows (during periods of heavy rainfall) into a downstream section of the

tributary gully, which flows for a further 1.8 km before discharging into the Dawson River at its

downstream confluence.

At the approval of the DRRS in 2013, the conditions of the FAPA EA required baseline biological

assessments and biological monitoring to be undertaken prior to the commencement of the DRRS.

Seven baseline biological assessments and biological monitoring were undertaken over a period of

approximately 24 months between 2013 and 2015 in accordance with the conditions of the FAPA EA.

Monitoring was conducted at three locations within the Waterbody (WLMP1, WLMP4 and WLMP5), two

locations within the Dawson River (DRMP1 and S4) and two controls sites (one upstream of the release

within the Dawson River (DRR1) and one within Hutton Creek (DRR2) to represent the Waterbody)

(refer to Figure 2).

A synthesis and analysis of the trends observed in the biological data and water quality monitoring data

over the monitoring surveys was used to develop local Water Quality Guidelines (LWQG) and a revised

Receiving Environment Monitoring Program (REMP) which includes locally derived trigger values for the

biological indicators.

The release of desalinated associated water from ROP 2 to the Dawson River commenced on 23rd July

2015. The commencement of the release to waters enacted the commencement of the REMP.

An amendment to the EA was authorised on 24 May 2018 removing the baseline biological assessment

and biological monitoring conditions of the EA, given their completion.


Figure 2. Authorised release of desalinated associated water from ROP 1 and ROP 2


2.2. Proposed Amendments

Santos seeks to amend the maximum limit for Boron, specifically the limit(s) presented in:

• Schedule B, Table 4 – Contaminant Limits and condition (B20); and

• Schedule B, Table 8 – Event Based Release – Contaminant Monitoring and condition (B31).

2.2.1. Existing Conditions

Schedule B, Table 4 – Contaminant Limits

Quality Characteristic

Monitoring Point (MP)

Latitude (Decimal degrees GDA94)

Longitude (Decimal degrees GDA94)

Limit Type Limit Monitoring Frequency

Boron

HCS04DWB1 -25.730 149.090 Maximum 1 mg/L Weekly during release from

ROP2

Dawson River MP1

-25.690 149.163 Maximum 1 mg/L Weekly during release from

ROP1

At the location where

contaminants are being extracted for irrigation (applies to any current or future irrigation

extraction)

- -

Maximum when irrigation

from the receiving waters is

being undertaken

0.5 mg/L

Weekly during release from

ROP2 when water is being extracted for irrigation within

the receiving environment as

defined by condition (B34)

(B20) If the quality characteristic of Boron of the release exceeds the release limit of 0.5 mg/L

specified in Schedule B, Table 4 – Contaminant Limits, all third parties that undertake irrigation

using water from the receiving waters must be notified.

Schedule B, Table 8 – Event Based Release - Contaminant Monitoring






Boron Downstream

monitoring point S1a

-25.72464 149.10405 Maximum 0.5 mg/L

Within 2 hours of commencement of release, and weekly during release thereafter


specified in and Schedule B, Table 8 – Event- based release - Contaminant monitoring, all third

parties that undertake irrigation using water from the receiving waters up to a distance of 300km

downstream must be notified.

Santos Ltd l EA EPPG00928713 – Amendment Applicat ion l 29 October 2019

Page 11

2.2.2. Proposed Conditions

Summaries of the technical assessments undertaken to support the proposed amendments are

provided in Section 2.3. Based on the outcomes of these scientific assessment the following conditions

are proposed.

Schedule B, Table 4 – Contaminant Limits






Boron

HCS04DWB1 -25.730 149.090 Maximum

4.3 mg/L at 9.0 ML/Day

3.0 mg/L at

13.5 ML/Day

2.5 mg/L at 18.0 ML/Day

Weekly during release from

ROP2

Dawson River MP1

-25.690 149.163 Maximum 2.9 mg/L Weekly during release from

ROP1

S4 - - Maximum 1.2 mg/L

Monthly, then 6 monthly after three

(3) consecutive detects <50% of

limit specified during release

from ROP2 when water is being extracted for

irrigation within the receiving

environment as defined by

condition (B34)


specified in Schedule B, Table 4 – Contaminant Limits, all third parties downstream of

monitoring point S4, that undertake irrigation using water from the receiving waters must be

notified.

Schedule B, Table 8 – Event Based Release - Contaminant Monitoring






Boron Downstream

monitoring point S1a

-25.72464 149.10405 Maximum 1.2 mg/L

Within 2 hours of commencement of release, and weekly during release thereafter


Page 12


specified in and Schedule B, Table 8 – Event- based release - Contaminant monitoring, all third

parties downstream of monitoring point S4 that undertake irrigation using water from the

receiving waters up to a distance of 300km downstream must be notified.

2.3. Technical Assessments

Multiple assessments have been undertaken to support the proposed amendments. Where applicable, these assessments have been undertaken in accordance with the Australian and New Zealand Guidelines (ANZG) for Freshwater and Marine Water Quality (2018) and the Water Quality Management Framework (WQMF).

Santos, prior to and during implementation of the DRRS, has undertaken extensive baseline and post release water quality and receiving environment monitoring. Monitoring requirements are stipulated in the REMP developed and implemented to meet EA condition requirements. To date, REMP monitoring has concluded:

• release limits have complied with the local water quality guidelines at all sites and/or are within the natural range of variation for the receiving environment;

• the physical habitat features in the waterbody have improved from baseline condition due to higher water levels and select improvements in water quality;

• the sediment quality is consistent with ambient baseline conditions and/or is comparable to that found at control sites;

• the diversity of fish recorded is the same as or higher than that recorded during the baseline monitoring program. Additionally the diversity of exotic fish has not increased compared to baseline conditions;

• the abundance, taxonomic richness, PET richness and SIGNAL-2 scores of macroinvertebrates is consistent with the guideline range or natural range of baseline condition and/or is comparable to that found at control sites;

• the same species of macrocrustaceans are being recorded as that during the baseline monitoring program. The species are breeding and the exoskeletons are in robust and good condition; and

• that given the above, the DRRS release has not negatively influenced the aquatic environmental values of the receiving environment from the baseline condition.

These findings, together with the assessments below, demonstrate that Santos has and continues to protect and enhance the values of the receiving environment, including addressing the key requirements for long-term management strategies stated within the WQMF. Through the DRRS and associated REMP monitoring, Santos has demonstrated:

• a good understanding of links between human activity and water/sediment quality;

• clearly defined community values or uses, including the setting of unambiguous management goals;

• clearly identified and appropriate water/sediment quality objectives; and

• adoption of cost-effective strategies to achieve water/sediment quality objectives.

The assessments undertaken to support the proposed amendments include:

• A review of ecotoxicity data generated for and presented within the Direct Toxicity Assessment (DTA) previously completed for the DRRS and provided to DES in 2013 as a part of the DRRS amendment application.

o Derivation of a new site-specific boron (surface) water quality guideline (WQG) in accordance with ANZG (2018) methodology.

• A review of existing Australian and New Zealand Environmental and Conservation Council (ANZECC) 2000 irrigation guidelines for boron, including assessment of limitations of the ANZECC 2000 guidelines.


Page 13

o Derivation of alternative site-specific boron irrigation water quality criteria using the ANZG (2018) methodology and recently promulgated Canadian guidance on boron developed by Alberta Environment and Parks (AEP).

• An update of the CORMIX (mixing zone) model assessment previously completed for the DRRS and provided to DES in 2013 incorporating updated surface water WQG and irrigation criteria.

A summary of each assessment is provided in the following Sections with the supporting technical documentation provided in respective Appendices.

2.3.1. Ecotoxicity Assessment

The authorisation of the DRRS on 31 May 2013 was supported by a DTA, titled Dawson River Release Scheme, Direct Toxicity Assessment (Halcrow, 2012) and supplementary addendum DTA, titled Dawson River Release Scheme, Direct Toxicity Assessment: Fish Test. Addendum to Direct Toxicity Report (Halcrow, November 2012).

The 2013 FAPA EA Amendment conditioned the DRRS with a maximum boron limit of 1 mg/L within the Dawson River which aligned with the maximum limit for ROP 1 within the Dawson River. The DTA (Halcrow, 2012) presented a Predicted No-Effect Concentration (PNEC) of 1.03mg/L, based on a safety factor of 10 applied to the No Observable Effect Concentration (NOEC) of 10.3 mg/L (reproduction NOCE for Ceriodaphnia dubia (the most sensitive species of the aquatic species tested). The limit of 1.0 mg/L was adopted from the PNEC values presented within the DTAs.

AECOM Services Pty Ltd (AECOM) were engaged by Santos to review ecotoxicity data generated for the DRRS to identify whether an adjustment can be made to the 1.0 mg/L WQG for boron in accordance with ANZG (2018) methodology. The outcome of this assessment is outlined below and provided in Appendix A.

The objectives of the AECOM assessment were as follows:

1. To review the ecotoxicity data generated for the DRRS (presented in Halcrow 2012 & 2013) and identify whether:

a) The ecotoxicity data can be relied upon to generate an amended site-specific boron WQG; and,

b) There is sufficient information available to meet the minimum ANZG (2018) requirements to derive a site-specific boron WQG.

2. Should the quality and quantity of the ecotoxicity data be deemed suitable, provide recommendations for an amended site-specific boron WQG.

To meet the requirements of Objective 1, AECOM reviewed the aforementioned DTAs and consulted both the laboratory that completed the tests (Ecotox Services Australasia [ESA]) and Dr Rick van Dam, co-author of the ANZG 2018 and Warne et al. Revised Method for Deriving Australian and New Zealand Water Quality Guideline Values for Toxicants (2018).

As part of the assessments undertaken by Halcrow, surface water was collected from the Dawson River monitoring point at Yebna Crossing (monitoring location S4) and spiked with boron (as boric acid) to represent test concentrations of 2.2, 4.4, 8.8, 17.5 and 35 mg of boron/L. ESA performed the toxicity testing, which is NATA accredited for compliance with ISO/IEC 17025. ESA calculated the effect concentration/inhibition concentrations (EC/IC) using a linear interpolation method with the statistical software package ToxCalc because the data met the ToxCalc statistical assumptions.

Based on advice from ESA and informal advice from Dr Rick van Dam, AECOM considered that the IC/EC concentration data are reliable for use in derivation of a site-specific WQG for boron.

AECOM also completed an assessment of the quality of the ecotoxicity data in accordance with approaches described in Warne et al (2018) to determine their suitability for use in WQG derivation. Based on a review of the Santos ecotoxicity data against the ANZG (2018) data screening process and scoring system the data is considered to be ‘high’ quality and suitable for guideline derivation.

Based on reliability, quality and suitability of the DTA data, AECOM derived new boron WQG in accordance with methodologies identified by Warne et al. (2018).


Page 14

AECOM generated WQGs for a variety of species protection levels (80% to 99% species protection levels) using the species sensitivity distribution (SSD) approach with the Burrlioz 2.0 software (Barry and Henderson, 2014). The input data comprised chronic IC/EC10 and chronic adjusted IC/EC10 data (from acute data).

Following the review of the DTA toxicity data and methodologies in accordance with Warne et al. (2018), and the ANZG 2018, a revised boron WQG of 2.9 mg/L for 95% species protection level was determined. Calculated boron guideline values by species sensitivity distribution is provided in Table 2-1.

Table 2-1: Boron Guideline Values Derived by Species Sensitivity Distribution

Species Protection Level

(%)

Guideline value (mg/L)

99 1.2

95 2.9

90 4.4

80 6.7

This 95% WQG is different to Halcrow’s calculation (9.3 mg/L) because the software used by AECOM is the most current version (Version 2.0) which incorporates latest ANZG (2018) guidance relating to fitting of the data. Halcrow (2012, 2013) used a Burr Type III method whereas AECOM used a log logistic fit, which resulted in the concentration differences.

The Queensland Environmental Protection (Water and Wetland Biodiversity) Policy 2019 (EPP Water) defined the Upper Dawson River Sub-basin waters (WQ1308) as ‘moderately disturbed’. The waterbody is considered to be a ‘highly disturbed’ system as discussed and reported in additional supporting information submitted to DES on 6 February 2013 (refer to Section 4.1.2). There is no boron published WQG for the protection of aquatic ecology.

Considering the land uses adjacent to the Dawson River include light to moderate grazing, and there is some development upstream of the Waterbody, AECOM recommended the adoption of the 95% species protection criteria (2.9 mg/L) as the boron site-specific (surface) water quality release criterion for the release to waters (i.e. the Dawson River). Given the ‘highly disturbed’ classification of the Waterbody, a 90% species protection criteria (4.4 mg/L) has been applied for the boron release limits within the Waterbody (refer to section 2.2.2). These species protection criteria are considered appropriate given they have been generated using high quality site-specific data via the ANZG (2018) endorsed SSD method.

Whilst Santos considers the adoption of 95% and 90% species protection appropriate for the Dawson River and Waterbody, respectively, in accordance with Warne et al (2018) and ANZG (2018), Santos proposes to adopt a boron concentration of 2.9mg/L for the site-specific boron (surface) WQG and varying concentrations for the release limit (below 4.4mg/L) dependent on the release rate (refer to section 2.2.2).

2.3.2. Irrigation Assessment

EHS Support were engaged by Santos to assess and describe the limitations of existing ANZECC 2000 crop irrigation guidelines for boron and provide a detailed derivation of alternative criteria using the ANZG (2018) methodology. The outcome of this assessment is outlined below and provided in Appendix B.

The approach used to develop site-specific boron irrigation criteria leverages the species sensitivity approach detailed in Warne et al. (2018) as well as recently promulgated Canadian guidance on boron developed by Alberta Environment and Parks (AEP).


Page 15

Released associated water mixes with surface water in a manner that is protective of aquatic receptors within the Dawson River (AECOM, 2019). Since the Dawson River is a source of irrigation water for downgradient agricultural activities, concentrations of boron at downstream points of take must also be protective of other realised beneficial uses, such as the protection of crops.

Assessment of the typical cropping activities along the Dawson River indicate that cotton farming is the dominant agricultural practice; however, wheat, chickpeas, corn and mung beans are also grown in the region. The derived irrigation values are intended to be protective of a wide range of crop types and ensure realised or future beneficial uses are protected within the basin.

The objective of the EHS Support scope was to develop boron irrigation guideline values that adequately protect crops at the point of take within the Dawson River. To achieve these objectives, EHS Support’s assessment included:

1. Review of relevant background information on the project; 2. Assessment of the current basis for ANZECC crop irrigation criteria for boron; 3. Assessment of background soil conditions using regional and site-specific datasets; 4. Literature review on boron toxicity and derive site-specific irrigation values; and 5. Make recommendations on appropriate boron irrigation guidelines for the DRRS.

The ANZECC 2000 guidelines present both short-term trigger value (STV) and long-term trigger value (LTV) irrigation guidelines for certain crop types. These STV and LTVs are based on sand culture studies by Eaton (1944) and characterised by Maas (1984), later summarised by Ayers and Westcot (1985).

Ayers and Westcot (1985) noted that the boron trigger values represent the “maximum concentrations tolerated in soil-water or saturation extract without yield or vegetative growth reductions. Boron tolerances vary depending upon climate, soil conditions and crop varieties. Maximum concentrations in the irrigation water are approximately equal to these values or slightly less.” The LTV was selected as the minimum of the STV values, which, according to ANZECC (2000) was to “protect the most sensitive species.”

The 0.5 mg/L ‘irrigation’ limit identified in the current EA was adopted by DES in 2013 to account for ANZECC 2000’s most sensitive crop types (e.g. lemon and blackberry).

During the irrigation assessment and review of the ANZECC 2000 boron irrigation criteria, a number of limitations were identified:

• Lack of experimental conditions that would enable an understanding of boron toxicity in naturally buffered silty-loam soils typical of the region – Experiments informing boron tolerance thresholds were based on sand cultures and not natural soil types that exhibit similar physical and chemical characteristics to the soil within the Dawson River valley;

• Reliance on threshold chronic effect concentration rather than preferred no effect concentrations (NEC) or percent effect/inhibition concentrations – The existing STVs and LTVs utilize threshold responses, which are the concentrations at which any reduction in growth endpoints were observed. Threshold approaches are sensitive to outliers and effects-based (ECX) or inhibitory-based concentrations (ICX) are preferred metrics for evaluating risk to organisms under the most recent testing and assessment methodologies (e.g., Warne et al. [2018]); and

• Crop-specific tolerance levels rather than statistically derived species sensitivity distributions (SSD) – Use of crop-specific thresholds may be useful for protecting known crops within the Dawson River Valley, but they do not consider protection levels for multiple crop species if agricultural practices in the valley change over time. Adopting more statistically robust methods, such as SSDs or crop sensitivity distributions (CSDs) will provide a more detailed understanding as to the percentage of crops protection at given irrigation threshold.

Crop irrigation criteria were derived based on boron toxicity information for 40 different common crop species across three different soil types. The approach adopted to redevelop boron irrigation guideline values leveraged the large toxicity dataset compiled on crop-specific data found in AEP (2015b) to calculate and estimate IC10 chronic values to assess the 95% crop protection level using the SSD framework of Warne et al. (2018).


Page 16

The general approach undertaken by EHS Support for deriving the crop guideline values was as follows:

1. Collate toxicity literature and assess its quality 2. Establish a hierarchy of preferred chronic values 3. Quantify IC10 effects for crops using USEPA Benchmark Dose Software for select data 4. Use relationship between calculated chronic effect types to develop site-specific conversion

factor to estimate IC10 effects for less conservative chronic endpoints. 5. Run crop sensitivity distributions (CSDs) using measured IC10 and estimated chronic data.

In summary, the derived soil water boron irrigation criteria using the log-logistic fit is recommended at a concentration of 1.4 mg/L soil water boron (refer to Table 2-2). The adopted approach has the following advantages over the historical approach used in ANZECC 2000:

• It considers a wider range of crops due to additional literature sources beyond those summarised by Ayers and Westcot (1985) and leverages recent, natural soil crop-specific toxicity testing data from the AEP.

• Rather than using tolerance values, which can be sensitive to outliers, the irrigation criteria is informed by IC25 data.

• The derivation approach makes use of the SSD framework. This enables decisions to be made on the basis of proportion of crops protected. For example, accepting a 95 percent crop protection guideline would mean that only two crops (blackberries and grapes) may experience a reduction in production based on the IC10 effect values.

Table 2-2. Soil Water 95% Crop Species Protection Guideline

Model Fit Type Guideline value (mg/L)

Log-Normal Fit 1.5

Log-Logistic Fit 1.4

Burr Type III Fit 1.2

EHS Support’s assessment detailed the existing guidance for boron crop irrigation values within the ANZECC framework. Although the guidelines values may be suitable for quickly determining which crops are suitable for irrigation, they do not provide a statistically defensible framework in which to make risk based decisions.

ANZECC 2000 clearly states that these “Guidelines should not be used as mandatory standards because there is significant uncertainty associated with the derivation and application of water quality guidelines” and that “be just a starting point to trigger an investigation to develop more appropriate guidelines based on the type of water resource and inherent differences in water quality across regions. For water whose environmental value is aquatic ecosystem protection, for example, the investigation should aim to develop and adapt these guidelines to suit the local area or region.”

Inherent limitations associated with the historical assessment have provided highly conservative tolerance thresholds that do not align with the current, robust scientific assessment methods such as those described by Warne et al. (2018).

A number of the key weaknesses of the studies referenced within ANZECC have been addressed by leveraging recently promulgated Canadian guidance. This new AEP guidance incorporates more recent literature and soil-specific toxicity testing across a range of natural soil types. The resulting crop sensitivity distributions (CSDs) can be used to identify the proportion of crops affected for a constant test criteria (IC10). Due to the retention of the historic (and highly conservative) sand culture studies in the CSD approach, the resulting irrigation value at the 95 percent crop protection level (1.4 mg/L) is still considered conservative in nature and protective of a wide range of crop types grown in the Dawson River Valley. These values are slightly higher than the generic screening criteria of 1.27 mg/L developed by AEP, which, if applied, would be consistent with our data assessment and provide protection to the likely range of crops grown in the area with limited-to-no reduction in productivity.


Page 17

In consideration of the above, Santos considers the adoption of Burr Type III Fit 95% species protection appropriate for crop irrigation, Santos proposes to adopt a boron concentration of 1.2mg/L for the site-specific boron irrigation WQG.

2.3.3. CORMIX Modelling Assessment

Following the ecotoxicology and irrigation assessments, AECOM were engaged by Santos to update the CORMIX (mixing zone) modelling for the DRRS. The outcome of this assessment is outlined below and provided in Appendix C.

The objectives of AECOM mixing zone study were as follows:

1. Update the CORMIX modelling conducted in 2012 to include various effluent concentrations for the following contaminants of potential concern (COPCs): boron, electrical conductivity (EC), chloride, and zinc.

2. Run the CORMIX model for various effluent release rates and river flow combinations to determine:

a) Distances to meet minimum trigger value (MTV) and EA limits for each COPC, b) Distances to achieve complete mixing and the resulting COPC concentration.

3. Use CORMIX to determine the maximum boron concentration in the effluent for various release rates at river flows of 22.13ML/day (monitoring location DRR1) and 23.99ML/day (monitoring location DRMP1) based on various S4 limits (refer to Figure 2 for these monitoring locations).

4. Use CORMIX to inform operational release rates dependent on boron effluent concentrations and water quality limits.

The CORMIX model inputs were based on the previous modelling effort in 2012 (Halcrow 2012) provided to DES to support the 2013 EA Amendment. The previous CORMIX model and the adequacy of its inputs were not reviewed as part of this assessment. The previous CORMIX models did not assess the more recently quantified 22.13ML/day and 23.99ML/day river flows (based on actual local river gaugings undertaken at monitoring locations DRR1 and DRMP1 respectively), so the model inputs for these conditions were adapted from a HEC-RAS model created for a previous DRRS assessment.

The previous CORMIX modelling set the region of interest (i.e. the region of reported results) at a distance of 10 km from the modelled discharge location (at the point that the waterbody discharges to Dawson River). This region of interest was maintained for this modelling effort. For the determination of the maximum boron effluent concentration, the CORMIX results were analysed at a location 8 km downstream of the discharge location, at monitoring location S4. The effluent concentration in CORMIX was varied until the S4 concentration limits were achieved 8 km downstream.

A revision of the original CORMIX modelling was performed to assess the mixing of the local baseflow data. Santos performed low flow gauging at monitoring locations DRR1, DRMP1 and S4 in winter 2017 and 2018. Base flow of the Dawson River at locations DRR1, DRMP1 and S4 is 22.13, 23.99 and 24.30 ML/Day, respectively. The local base flow is considerably different to the estimated baseflow reported in the original DRRS EA Amendment application and supporting information.

The revised CORMIX modelling reported complete mixing within 35m from the release location for both the current (1.0 mg/L) and proposed boron (2.9mg/L) concentrations at 22.13ML/day river flow. The proposed boron concentration (2.9 mg/L) did not achieve the minimum threshold value (MTV) for any operational DRRS release rate and the boron concentration at complete mixing ranged from 1.3 to 2.2 mg/L. The current (1.0 mg/L) boron concentration modelled at 18ML/day release rate, did not achieve the MTV and met a concentration of 0.5 mg/L within 5km.

To support the aforementioned ecotoxicological and irrigation assessments, an additional modelling assessment was conducted to determine the maximum boron release concentration to achieve the derived WQGs for aquatic ecology and irrigation.

Table 2-3 presents the maximum release concentrations and concentrations at complete mixing for various effluent release rates for the 23.99 ML/day permissible to achieve both the site-specific boron (surface) WQG (2.9mg/L) and site-specific boron irrigation WQG (1.2mg/L, measured at S4).


Page 18

Table 2-3. Maximum Boron Release Concentration at S4 Based on 23.99ML/Day River Flow

DRRS Release Rate

(ML/day)

Boron Concentration at Complete Mixing

(mg/L)

Boron Concentration at S4 (mg/L)

Maximum Boron Release

Concentration

(mg/L)

WQG 2.9 1.2 -

4.5 2.9 1.1 6.4

9 2.1 1.2 4.3

13.5 2.1 1.2 3.0

18.0 1.9 1.2 2.5

This application seeks to authorise a varied release rate (but no greater than 18ML/day) as outlined in Schedule B, Table 4 of section 2.2.2.

The release rates presented in Table 2-3 and consequently the proposed EA conditions provide flexible management of ROP 2 and the DRRS based on boron concentrations at the time of release. The volume of water into and discharged from the ROP is managed via the number of pumps operating to transfer water.

These limits achieve the 95% and 90% species protection appropriate for the Dawson River and Waterbody respectively, in accordance with Warne et al (2018) and ANZG (2018) based on the moderately disturbed and highly disturbed classification of the Dawson River and waterbody respectively.


Page 19

3. Site Description

The FAPA covers approximately 341,509 ha of tenure and is located approximately 18 km east of Injune at its southern extent and approximately 30 km north-east of Rolleston at its northern extent (refer to Figure 1). The project area is comprised of the following Authority to Prospects (ATPs) and Petroleum Leases (PLs) within Maranoa Regional Council, Central Highlands Regional Council and Banana Shire council areas:

• ATP526/PL1017

• ATP2012

• PL90

• PL91

• PL92

• PL99

• PL100

• PL232

• PL233

• PL234

• PL235

• PL236

• PL420

• PL421

• PL440

The release of desalinated associated water from ROP 1 and ROP 2 occurs within PL100 and PL232, respectively of the FAPA.

ROP 1 is located adjacent to coal seam gas well FV 77 within PL100. The release from ROP 1 into a tributary of the Hutton Creek occurs at the coordinates prescribed in Schedule B, Table 3 – Contaminant Release Points (refer to Figure 2).

ROP 2 is located adjacent to Fairview Hub Compressor Station 4 (F-HCS-04) within PL232. The release from ROP 2 into a tributary of the Dawson River occurs at the coordinates prescribed in Schedule B, Table 3 – Contaminant Release Points (refer to Figure 2).


Page 20

4. Environmental Values

The amendment is limited to water quality related EA conditions associated with the DRRS. The proposed amendment to the DRRS water quality conditions has the potential to impact upon the environmental values of water. As such, this is the only value described as a part of this amendment application.

The proposed amendment will not impact on the environmental values of groundwater, flora and fauna, land use, acoustic, land or waste. These environmental values are not discussed further.

4.1.1. Surface Water

The receiving environment for the DRRS is in the Upper Dawson River Sub-catchment, in the ‘Upper Dawson – Taroom area’, which is the reach of the Dawson River that extends from Hutton Creek to Glebe Weir. Major waterways in the area are the Dawson River, Hutton Creek and Baffle Creek.

The Upper Dawson River catchment lies on the northeast side of the continental divide and forms part of the Fitzroy River catchment, which drains toward the Tasman Sea. The catchment is not part of the Murray Darling Basin (MDB), and therefore not subject to the salt management policies and guidelines specific to the MDB.

In the downstream reaches of Hutton Creek, grazing, forestry and cropping are widespread. A number of water storages and weirs are located on the Dawson River from Taroom downstream and are used for irrigation and recreational purposes, supporting regional industry and urban communities.

Based on the definitions in the Dawson River Sub-basin Environmental Values and Water Quality Objectives EPP Water, there are two water types in the receiving environment of the DRRS:

• the Waterbody – freshwater semi permanent oxbow lake (non-flowing water); and

• the Dawson River – freshwaters within the Upper Dawson River (flowing water).

The Waterbody is a large freshwater semi permanent oxbow lake (floodplain billabong) with an approximate volume of 500ML. There are several dry gullies upstream of the Waterbody, including the gully to which the release water is discharged. An ephemeral stream connects the Waterbody with the Dawson River downstream of the Waterbody. The aquatic ecological assessment conducted in December 2012 of the Waterbody defined the Waterbody as highly disturbed. Further information on the Waterbody is provided in Section 4.1.2.

The Dawson River is a major tributary of the Fitzroy River. The Dawson River and its tributaries cover an area of approximately 50 776km2. The stretch of the Dawson River in the receiving environment has a perennial flow regime. Local flow gaugings conducted during the low flow season (winter) reported the baseflow of the Dawson River between 22.13 and 24.30 ML/day within the extent defined as the receiving environment.

Santos conducted extensive baseline water quality monitoring which has continued in the REMP at two locations along the Dawson River (DRMP1 and S4) and one upstream control site (DRR1) (refer to Figure 2). Site S4 is specified as the monitoring location for the assessment of water quality for protecting the environmental value of drinking water.

The Upper Dawson River catchment is considered to be moderately disturbed waters in accordance with the Dawson River Sub-basin Environmental Values and Water Quality Objectives, EPP Water (DERM, September 2011).


Page 21

The following environmental values are listed in the Dawson River Sub-basin Environmental Values and Water Quality Objectives, EPP Water (DERM, September 2011), relevant to the Upper Dawson River catchment:

• aquatic ecosystem

• irrigation

• farm supply/use

• stock watering

• aquaculture

• human consumption

• primary recreation

• secondary recreation

• visual appreciation

• drinking water

• industrial use; and

• cultural and spiritual values.

A brief discussion on the applicability of each potentially relevant environmental value, as identified in the EPP Water as listed above, is presented for the Dawson River in Table 2.1 of the Santos GLNG Dawson River Release Scheme, Local Water Quality Guidelines (Appendix D).

Schedule 1 of the EPP Water defines the water quality objectives to protect aquatic ecosystems within the Dawson River and associated waters. Where WQOs are not defined for an environmental value, the most stringent guideline value should be used as the default minimum trigger value.

The relevant water quality guidelines for Queensland, in order of preferred application as prescribed by the EPP Water, are:

• locally derived guideline values (refer to Appendix D);

• Dawson River Sub-basin Environmental Values and Water Quality Objectives, Basin No. 130

(part), including all waters of the Dawson River Sub-basin except the Callide Creek Catchment,

EPP Water (DERM, September 2011);

• Queensland Water Quality Guidelines (QWQG)1 which provide guidelines tailored to Queensland

regions and water types; or

• where the QWQG or local guidelines are not available, the default guidelines are the Australian

Water Quality Guidelines (AWQG)2 published by Australian and New Zealand Environment

Conservation Council (ANZECC) (2000)3.

LWQG values were submitted to DES as a part of the 2018 DRRS amendment application. Guideline values were derived for the Dawson River from water quality data from the baseline monitoring locations over the data period prescribed by the QWQGs. Amendments to Schedule B, Table 4 – Contaminant Limits were authorised by DES based on the results of baseline monitoring and the locally derived water quality guidelines. The series of diagrams on pages 24 – 25 depict the Dawson River monitoring locations during the baseline monitoring prior to the DRRS commencement and during the REMP monitoring post the DRRS commencement. These diagrams depict the results from the REMP monitoring to date (refer to section 2.3) that has found that the DRRS release has not influenced the aquatic environmental values of the receiving environment.

1 Queensland Water Quality Guidelines (2009) Department of Environment and Resource Management. Queensland

Government.

2 Australian Drinking Water Guidelines (NHMRC and ARMCANZ 1996).

3 Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC 2000).


Page 22

To date, Santos is not aware of any irrigation activities within the receiving environment as defined by condition (B34). Yebna property has a licence to extract water from the Dawson River during event-flow conditions. Santos communicates regularly with the Yebna property landholder as part of Conduct and Compensation Agreements. There are no other landholders within the extent of the receiving environment as defined by condition (B34).

A search of the Department of Natural Resources, Mines and Energy (DNRME) water entitlement dataset indicates that the closest surface water impoundment entitlement (specific purpose not stated in dataset) on the Dawson River main channel is situated more than 350km downstream.


Page 23

DRR1 - Baseline monitoring July 2014 (pre-wet) prior to release

DRR1 - Baseline monitoring Feb 2015 (post wet) prior to release

DRR1 – REMP monitoring Sept 2018 (pre-wet) post release

DRR1 – REMP monitoring April 2019 (post wet) post release

DRMP1 - Baseline monitoring July 2014 (pre-wet) prior to release

DRMP1 - Baseline monitoring Feb 2015 (post wet) prior to release

DRMP1 - REMP monitoring Sept 2018 (pre-wet) post release

DRMP1 – REMP monitoring April 2019 (post wet) post release


S4 - Baseline monitoring July 2014 (pre-wet) prior to release

S4 - Baseline monitoring Feb 2015 (post wet) prior to release

S4 - REMP monitoring Sept 2018 (pre-wet) post release

S4 – REMP monitoring April 2019 (post wet) post release


4.1.2. Wetlands (the Waterbody)

Santos completed an aquatic ecology assessment of the Waterbody by suitably qualified personnel in December 2012. This assessment included physico-chemical (water quality and flow regime) and biological indicators (habitat and biota) of the Waterbody over seasonal variations. This assessment was submitted to DES as supporting information to the DRRS amendment application authorised on 31 May 2013. The aquatic ecological assessment conducted prior to the commencement of the DRRS described the Waterbody as follows.

The Waterbody is considered to be a highly disturbed system, characterised by long, wide and deep permanent pools that narrow into the downstream section of the tributary gully. Permanent pools exist at the Waterbody, however pools and flow conditions are summer dominant and are influenced by heavy rainfall. Hydrological events influence macro-invertebrate numbers. Floods are seasonal (summer) and intermittent.

The Waterbody is characterised by high nutrient and iron concentrations, and an elevated concentration of suspended solids within the middle of the lake.

The Waterbody and surrounding landform have been adversely affected by human activity (grazing and stock access) and have little to no biological integrity. The adjacent land uses include light to moderate grazing.

The Waterbody is a riverine wetland and is considered to be a wetland of General Ecological Significance (GES) under the EPP Water.

Santos conducted extensive baseline water quality monitoring which has continued in the REMP at three locations within the Waterbody (WLMP1, WLMP4 and WLMP5) and one control site on the Hutton Creek (DRR2) (refer to Figure 2). Control site DRR2 is the closest representative of a floodplain billabong (oxbow lake) which could be identified in the region. The series of photographs on pages 27 – 29 depict the Waterbody and Hutton Creek during the baseline monitoring prior to the DRRS commencement and during the REMP monitoring post the DRRS commencement. These diagrams depict the results from the REMP monitoring to date (refer to section 2.3) that has found that the DRRS release has improved the physical habitat features in the waterbody from baseline condition due to higher water levels as a result of the release.

The following environmental values have been recognised for the Waterbody:

• freshwater aquatic ecosystem;

• stock drinking water (stock is currently allowed direct access to the river);

• human consumption of aquatic foods (e.g. freshwater fish);

• recreation (primary and secondary use); and

• cultural values (including indigenous special areas, art and artefacts; and historical settlements).

A brief discussion on the applicability of each potentially relevant environmental value, as identified in the EPP Water as listed above, is presented for the waterbody in Table 2.1 of the Santos GLNG Dawson River Release Scheme, Local Water Quality Guidelines (Appendix D).

LWQG values were submitted to DES as a part of the 2018 DRRS amendment application. LWQG values were derived for the Waterbody from water quality data over the period prescribed by the QWQGs. Amendments to Schedule B, Table 4 – Contaminant Limits were authorised by DES based on the results of baseline monitoring and the locally derived water quality guidelines. Table 4.3 of Appendix D demonstrates the highly disturbed nature of the Waterbody through a comparison of the water quality data collected over the baseline monitoring period with the Dawson River Sub-basin Environmental Values and Water Quality Objectives EPP Water. Table 4.3 highlights the elevated salinity, suspended solids and nutrient concentration of the Waterbody compared to the moderately disturbed water quality objectives recommended in the Dawson River Sub-basin Environmental Values and Water Quality Objectives, EPP Water.


WLMP1 – Baseline monitoring July 2014 (pre-wet) prior to release

WLMP1 – Baseline monitoring Feb 2015 (post wet) prior to release

WLMP1 - REMP monitoring Sept 2018 (pre-wet) post release

WLMP1 – REMP monitoring April 2019 (post wet) post release

Santos Ltd l EA EPPG00928713 – Amendment Application l 29 October 2019 Page 27


WLMP4 – Baseline monitoring Feb 2015 (post wet) prior to release


WLMP4 – REMP monitoring April 2019 (post wet) post release


WLMP 5 – Baseline monitoring Feb 2015 (post wet) prior to release


WLMP 5 – REMP monitoring April 2019 (post wet) post release


DRR2 – Baseline monitoring July 2014 (pre-wet) prior to release

DRR2 - Baseline monitoring Feb 2015 (post wet) prior to release

DRR2 - REMP monitoring Sept 2018 (pre-wet) post release

DRR2 – REMP monitoring April 2019 (post wet) post release


5. Potential Impacts and Mitigation Measures

5.1. Surface Water and Wetlands

A summary of potential impacts and associated mitigation measures on surface waters and wetlands as a result of the proposed amendments are provided in Table 5-1.

Table 5-1: Summary of potential impacts and mitigation measures on surface waters and wetlands

Potential Impact Mitigation Measure

• Toxicity to aquatic flora/fauna

• In ability to grow crops

• Contamination of drinking water

• Algal blooms

• The boron limits sought by the amendment application have been generated using high quality site specific data via the ANZG (2018) SSD method.

The ANZG (2018) recommends the adoption of the 90% and 95% species protection levels for highly disturbed and moderately disturbed waters of which the waterbody and Dawson River respectively are considered. The application of the ANZG (2018) in the determination of site specific water quality release criteria, is a part of the WQMF. The WQMF aims to ensure that through the adoption of the framework, releases to waters do not cause environmental harm. As such, the adoption of the site specific water quality release criteria will ensure that there is no increase in the level of environmental harm from the change sought by the EA amendment.

• Santos considers the adoption of the Burr Type III Fit 95% species protection appropriate for crop irrigation (1.2mg/L for the site-specific boron irrigation WQG) is appropriate. The site specific irrigation limit has been derived applying recently promulgated Canadian guidance which addresses key weaknesses of the studies referenced within ANZECC. The site specific irrigation limit is considered to provide protection to the likely range of crops grown in the area with limited to no reduction in productivity.

• Continued operation of ROP 2 in accordance with the design specifications so as to ensure the desalinated associated water continues to be:

• released in accordance with authorised release volumes; and

• compliant with receiving environment concentrations of boron in the Dawson River for the protection of 95% of species as per the DTA. This will be managed by varying release volumes dependent on the concentration of boron in the desalinated associated water release water.

• Compliance with the quality characteristic limits prescribed by Schedule B, Table 4 – Contaminant Limits and the proposed amendments;

• Submission of surface water quality monitoring in accordance with Schedule B, Table 4 – Contaminant Limits and the proposed amendments to WaTERS;

• In addition to the proposed changes to the monitoring requirements prescribed by Schedule B, Table 4 – Contaminants Limits; biannual monitoring will be conducted in accordance with Table 6.2 of the REMP;

• Compliance with all other conditions of the EA which are applicable to the DRRS (e.g. (A5 – Maintenance of plant and equipment), (A18 – monitoring undertaken by suitably qualified person), (L2 and L3 – Notification to DES and any affected drinking water service provider within 24hrs in the event that the drinking water quality parameter limit is exceeded); and


Potential Impact Mitigation Measure

• Maintain a regular request for water licence holders within the receiving environment as defined by condition (B34) with DNRME.

It is considered that the implementation of the above listed mitigation measures and the existing conditions of the EA contained within Schedule B - Water, sufficiently address the risk that may be associated with the amendment application.


6. Legislative Considerations

6.1. Environmental Protection Act 1994 (EP Act)

6.1.1. General requirements for an EA amendment application (s226 EP Act)

Section 226 of the EP Act, specifies the general requirements for an EA amendment application. Table 6-1 contains a summarised checklist of the EP Act general requirements against this proposed amendment application.

Table 6-1: General Requirements EA Amendment Application (s226 EP Act)

Section 226 and 226A EP Act Relevance to amendment application

226(1)(a) be made to the administering authority

The EA amendment application was lodged with DES who is the administering authority for the EP Act.

226(1)(b) be made in the approved form Refer to Attachment 1 of the application package, which includes the form Application to amend an environmental authority.

226(1)(c) be accompanied by the fee prescribed under a regulation

The applicable fee was paid at lodgement of the amendment application.

226(1)(d) describe the proposed amendment Refer to Section 2.2.

226(1)(e) describe the land that will be affected by the proposed amendment

Refer to Section 3.

226(1)(f) include any other document relating to the application prescribed under a regulation

Refer to the information provided throughout this supporting report.

226A(1)(a) describe any development permits in effect under the Planning Act for the carrying out of the relevant activity for the authority; and

Not applicable – No development permits are in effect under the Planning Act 2016 for the activities, which are the subject of this amendment application.

226A(1)(b) state whether each relevant activity will, if the amendment is made, comply with any eligibility criteria for the activity

Not applicable – There are currently no eligibility criteria relevant to the activities proposed by the amendment application.

226A(1)(c) if the application states that each relevant activity will, if the amendment is made, comply with any eligibility criteria for the activity— include a declaration that the statement is correct

Not applicable – There are currently no eligibility criteria relevant to the activities proposed by the amendment application.

226A(1)(d) state whether the application seeks to change a condition identified in the authority as a standard condition

Not applicable - The respective EA does not contain any standard conditions.

226A(1)(e) if the application relates to a new relevant resource tenure for the authority that is an exploration permit or GHG permit—state whether the applicant seeks an amended environmental authority that is subject to the standard conditions for the relevant activity or authority, to the extent it relates to the permit

Not applicable - The application does not relate to a new resource tenure.

226A(1)(f) include an assessment of the likely impact of the proposed amendment on the environmental values, including—


Section 226 and 226A EP Act Relevance to amendment application

226A(1)(f)(i) a description of the environmental values likely to be affected by the proposed amendment;

Refer to Section 4.

226A(1)(f)(ii) details of any emissions or releases likely to be generated by the proposed amendment;

Refer to Sections 2 and 5.

226A(1)(f)(iii) a description of the risk and likely magnitude of impacts on the environmental values;

Refer to Sections 2 and 5.

226A(1)(f)(iv) details of the management practices proposed to be implemented to prevent or minimise adverse impacts;

The prevention / minimisation of adverse impacts associated with petroleum activities is achieved through compliance with the existing conditions of the EA, by the implementation of local and international best practice and the implementation of management plans as appropriate.

Refer to Section 5.

226A(1)(f)(v) details of how the land the subject of the application will be rehabilitated after each relevant activity ceases;

N/A - The proposed amendment would not result in the authorisation of additional significant disturbance to land or change the existing rehabilitation requirements.

226A(1)(g) include a description of the proposed measures for minimising and managing waste generated by any amendments to the relevant activity;

N/A – The proposed amendment does not involve the generation of a new waste stream.

226A(1)(h) include details of any site management plan or environmental protection order that relates to the land the subject of the application;

N/A – There is no relevant site management plan or environmental protection order for the land located within the FAPA.

6.1.2. CSG activities requirements for an EA amendment application (s227 EP Act)

Section 227 of the EP Act specifies requirements for an amendment application for CSG activities as follows:

Section 227 Requirements for amendment applications—CSG activities (1) This section applies for an amendment application if—

a) relates to an EA for a CSG activity; and

b) the proposed amendment would result in changes to the management of CSG water; and

c) the CSG activity is an ineligible ERA.

(2) The application must also—

(a) state the matters mentioned in section 126(1); and

(b) comply with section 126(2).

The proposed amendments will not result in changes to the management of CSG water. The desalinated associated water will continue to be managed in accordance with the conditions of the EA and the amended release limit as proposed by this application. As such, this section of the EP Act is not relevant.

6.1.3. Requirements for amendment applications – underground water rights (S227AA EP Act)

Section 227AA of the EP Act specifies the requirements for an amendment application where the

application involves changes to the exercise of underground water rights for a petroleum lease.


Section 227AA Requirements for amendment applications—underground water rights

(1) This section applies for an amendment application if—

(a) the application relates to a site-specific environmental authority for—

(i) a resource project that includes a resource tenure that is a mineral

development licence, mining lease or petroleum lease; or

(ii) a resource activity for which the relevant tenure is a mineral development

licence, mining lease or petroleum lease; and

(b) the proposed amendment involves changes to the exercise of underground water

rights.

(2) The application must also state the matters mentioned in section 126A(2).

The proposed amendments will not involve a change in the exercise of underground water rights. As

such, this section of the EP Act is not relevant.

6.1.4. Assessment Level Decision for amendment application (s228 EP Act)

Santos considers the proposed amendment satisfies all requirements of the definition of a minor amendment (threshold) in accordance with Section 223 of the EP Act. Refer to 6.1.4, for further information with regards to the determination of this application being a minor amendment.

Table 6-2: Minor Amendment (Threshold) Assessment

Minor amendment (threshold), for an environmental authority, means an amendment that the administering authority is satisfied -

Relevance to amendment application

(i) Is not a change to a condition identified in the authority as a standard condition; and

The EA (EPPG00928713) does not identify any standard conditions.

(i) a change that is a condition conversion; or

(ii) a change that is not a condition conversion but that replaces a standard condition of the authority with a standard condition for the environmentally relevant activity to which the authority relates; and




(ii) Does not significantly increase the level of environmental harm caused by the relevant activity; and

The amendments will not significantly increase the level of environmental harm authorised under the EA. The amendment seeks to amend the EA conditions which relate to Boron, specifically:

• the limit(s) presented in Schedule B, Table 4 – Contaminant Limits and condition (B20); and

• the limit(s) presented in Schedule B, Table 8 – Event Based Release – Contaminant Monitoring and condition (B31).

The amendment proposes the adoption of the following boron concentrations in accordance with Warne et al (2018) and ANZG (2018):

• 2.9mg/L (95% species protection level) for the site-specific boron (surface) WQG;

• 1.2mg/L (95% crop species protection level) for the site-specific boron irrigation WQG (measured at S4); and

• 2.5mg/L, 3.0mg/L or 4.3mg/L release concentration dependent on the DRRS release rate (90% species protection level).

The boron limits sought by the amendment application have been generated using high quality site specific data via the ANZG (2018) SSD method.

The ANZG (2018) recommends the adoption of the 90% and 95% species protection levels for highly disturbed and moderately disturbed waters of which the waterbody and Dawson River respectively are considered. The application of the ANZG (2018) in the determination of site specific water quality release criteria, is a part of the WQMF. The WQMF aims to ensure that through the adoption of the framework, releases to waters do not cause environmental harm. As such, the adoption of the site specific water quality release criteria will ensure that there is no increase in the level of environmental harm from the change sought by the EA amendment.

Santos considers the adoption of the Burr Type III Fit 95% species protection appropriate for crop irrigation (1.2mg/L for the site-specific boron irrigation WQG). The site specific irrigation limit has been derived applying recently promulgated Canadian guidance which addresses key weaknesses of the studies referenced within ANZECC. The site specific irrigation limit is considered to provide protection to the likely range of crops grown in the area with limited to no reduction in productivity.

Refer to section 2.3 and section 5.1.




(iii) Does not change any rehabilitation objectives stated in the authority in a way likely to result in significantly different impacts on environmental values than the impacts previously permitted under the authority; and

The amendment does not seek to change any rehabilitation objectives of the EA.

(iv) Does not significantly increase the scale or intensity of the relevant activity; and

The amendment does not seek to change the release rates or volumes of desalinated associated water released as authorised by the EA.

The amendment seeks to amend the EA conditions which relate to Boron, specifically:

a) the limit(s) presented in Schedule B, Table 4 – Contaminant Limits and condition (B20); and

b) the limit(s) presented in Schedule B, Table 8 – Event Based Release – Contaminant Monitoring and condition (B31).

The application does not propose an increase in the scale or intensity of the relevant petroleum activity.

(v) Does not relate to a new relevant resource tenure for the authority that is –

(i) A new mining lease; or

(ii) A new petroleum lease; or

(iii) A new geothermal lease under the Geothermal Energy Act; or

(iv) A new GHG injection and storage lease under the GHG storage Act; and

The amendment does not relate to a new resource tenure for the authority.

(vi) Involves an addition to the surface area for the relevant activity of no more than 10% of the existing area; and

The proposed amendment does not involve an addition to the surface area for the relevant activity.

(vii) For an environmental authority for a petroleum activity –

(i) if the amendment involves constructing a new pipeline – the new pipeline does not exceed 150km; and

The amendment does not involve constructing a new pipeline of more than 150km in length.

(ii) if the amendment involves extending an existing pipeline- the extension does not exceed 10% of the existing length of the pipeline; and

The amendment does not involve extending an existing pipeline.

(viii) If the amendment relates to a new relevant resource tenure for the authority that is an exploration permit or GHG permit-the amendment application under section 224 seeks an amended environmental authority that is subject to the standard conditions for the relevant activity or authority to the extent it relates to the permit.

The amendment does not relate to a new relevant resource tenure that is an exploration permit or greenhouse gas permit


6.1.5. The Standard Criteria (EP Act)

The standard criteria (as defined by Schedule 4 of the EP Act) are required to be considered by the administering authority for both a major and minor amendment application. Refer to Table 6-3 for consideration of the standard criteria.

Table 6-3: Standard Criteria (EP Act)

Schedule 4 EP Act Relevance

(a) the following principles of environmental policy as set out in the Intergovernmental Agreement on the Environment –

(i) the precautionary principle;

(ii) intergenerational equity;

(iii) conservation of biological diversity and ecological integrity; and

The proposed amendment was contemplated within the context of intergenerational equity and sustainable development. The amendment will not result in significant or permanent impact to the existing environmental values of the FAPA as demonstrated in sections 2.3 and 5.

The release of contaminants to waters as authorised by the FAPA EA will be conducted in accordance with the conditions of the FAPA EA and the amendments sought by this application to conserve biological diversity and ecological integrity.

The proposed amendment was contemplated within the context of the precautionary principle. The release of contaminants to waters as authorised by the FAPA EA does not pose a threat of serious or irreversible environmental harm, and scientific uncertainty does not exist as to the level of potential environmental harm as demonstrated in the supporting information provided with this amendment application.

Compliance with the existing conditions of the FAPA EA concerning the release of contaminants to waters will continue to be met during the conduct of authorised activities to achieve best practice environmental management (BPEM).

(b) any Commonwealth or State government plans, standards, agreements or requirements about environmental protection or ecologically sustainable development

The proposed activities will be undertaken in accordance with the applicable requirements of the following:

• EP Act

• EPBC Act

• Petroleum and Gas (Production and Safety) Act (P&G Act)

• Nature Conservation Act 1992 (NC Act)

• Vegetation Management Act 1999 (VM Act)

• Regional Planning Interests Act 2014

(c) any relevant environmental impact study, assessment or report

Refer Santos EIS - http://www.santosglng.com/resource-library/glng-eis.aspx

(d) the character, resilience and values of the receiving environment

Refer to Section 4.

(e) all submissions made by the application and submitters

The EA amendment application is considered to be a minor amendment (refer to Table 5-2) and as such, will not be subject to public notification (refer to (i) below).


Schedule 4 EP Act Relevance

(f) Best Practice Environmental Management (BPEM) for activities under any relevant instrument, or proposed instrument, as follows-

(i) an environmental authority;

(ii) a transitional environmental program;

(iii) an environmental protection order;

(iv) a disposal permit;

(v) a development approval;

BPEM of the proposed activities will be achieved through compliance with the existing and proposed conditions of the EA and implementation of environmental management measures described in this report, refer to Section 5.

(g) financial implications of the requirements under an instrument, or proposed instrument, mentioned in paragraph (g) as they would relate to the type of activity or industry carried out, or proposed to be carried out under the instrument;

Santos will continue to provide adequate funds, equipment and staff time to comply with the conditions of the amended EA.

(h) public interest The proposed amendment is in the public interest, as it will allow for the sustainable management of associated water generated through the extraction of coal seam gas authorised by the EA. The management of associated water is critical to the continuation of the extraction of coal seam gas.

Gas produced as a result of the authorised activities will generate taxes and royalties to the Queensland State Government, which provide an ongoing source of revenue to support Government services provided to the general public.

Gas produced by the authorised activities plays an important role in the Santos export markets (i.e. Asia) as a cleaner and lower-carbon emitting alternative to coal.

Furthermore, in Australia and Queensland, gas plays an important role in domestic energy security and diversification, supporting intermittent renewable energy sources. Santos is a major supplier of natural gas to the domestic energy market, and in light of recent concerns around an east coast gas shortage; Santos has committed to diverting 30 petajoules of gas planned for export, to the east coast domestic market in 2019.

(i) site management plan (SMP) There are no relevant SMPs applicable to this amendment application.

(j) integrated environmental management system (IEMS) or proposed IEMS

The existing Santos EHSMS in conjunction with Santos management plans will be implemented for the proposed activities.

(k) other matters prescribed under a regulation

Refer to Section 6.2

6.2. Environmental Protection Regulation 2019 (EP Reg)

Section 235 of the EP Act (major amendment) and section 241 of EP Act (minor amendment), both require the administering authority to consider any relevant regulatory requirement in deciding an amendment application.

In accordance with section 48(2)(b) of the EP Reg, an amendment application is not considered an environmental management decision if it relates to an application for a minor amendment of an environmental authority. Notwithstanding, the sections of the EP Reg potentially relevant to the application are provided below.


6.2.1. Environmental Objective Assessment

Section 35 of the EP Reg describes the matters to be considered by the administering authority in

making an environmental management decision. For the purposes of this amendment application,

sections 35(1)(a) and (b), require the administering authority to:

• carry out an environmental objective assessment against the environmental objective and performance outcomes mentioned in Schedule 8, Part 3, Divisions 1 and 2. The objective assessment is also prescribed as an additional matter for the standard criteria (Schedule 4 EP Act); and

• consider the environmental values declared under the EP Reg.

The proposed amendments would protect the environmental values of air, noise, land, groundwater and

waste as the application relates to a change to the release limit for boron. In addition, there will be no

alteration of the hydrology of wetlands above the existing authorisations of EPPG00928713.

Refer to Table 6-4 for an assessment of the proposed amendment against the environmental objectives

and performance outcomes relating to water.

Table 6-4: Schedule 8, Part 3, Division 1 – Water

Schedule 8, Part 3, Division 1 EP Reg Relevance to amendment application

Water

Environmental Objective

The activity will be operated in a way that protects environmental values of water

The amendment application does not propose to change the process (rate or maximum volume) for the release of desalinated associated water from ROP 1 or ROP 2 which have been assessed and approved by DES.





The adoption of the 95% and 90% species protection levels will ensure the protection of the environmental values of water. Refer to section 2.3.



Performance Outcomes

1 There is no actual or potential discharge to waters of contaminants that may cause an adverse effect on an environment value from the operation of the activity.






The adoption of the 95% and 90% species protection levels will ensure that there are no adverse effects on the environmental value for water from the releases. Refer to section 2.3.

2 All of the following—

a) the storage and handling of contaminants will include effective means of secondary containment to prevent or minimise releases to the environment from spillage or leaks;


Refer to section 2.1 for a description of the releases.

b) contingency measures will prevent or minimise adverse effects on the environment due to unplanned releases or discharges of contaminants to water;


Refer to section 2.1 for a description of the releases and section 5.1 for the management measures in place.

c) the activity will be managed so that stormwater contaminated by the activity that may cause an adverse effect on an environmental value will not leave the site without prior treatment;



d) the disturbance of any acid sulfate soil, or potential acid sulfate soil, will be managed to prevent or minimise adverse effects on environmental values;

N/A – no acid sulfate soils have been identified.

e) acid producing rock will be managed to ensure that the production and release of acidic waste is prevented or minimised, including impacts during operation and after the environmental authority has been surrendered;

N/A – no acid producing rock has been identified.

f) any discharge to water or a watercourse or wetland will be managed so that there will be no adverse effects due to the altering of existing flow regimes for water or a watercourse or wetland;

The amendment application does not propose to change the maximum volume of desalinated associated water released from ROP 1 and ROP 2. Refer to section 2.1 for a description of the releases.



g) for a petroleum activity, the activity will be managed in a way that is consistent with the coal seam gas water management policy, including the prioritisation hierarchy for managing and using coal seam gas water and the prioritisation hierarchy for managing saline waste;

The amendment application does not propose to change the process (rate or maximum volume) of the release of desalinated associated water from ROP 1 and ROP 2. As such, the releases will be managed in a way that is consistent with the coal seam gas water management policy as they were originally assessed and authorised by DES.


h) the activity will be managed so that adverse effects on environmental values are prevented or minimised.

The management measures outlined in section 5.1 will be implemented to minimise any adverse effects on the environmental value of water from the release of desalinated associated water from ROP 1 or ROP 2.

Given that the amendment application does not propose to change the process (rate or maximum volume) for the release of desalinated associated water from ROP 1 or ROP 2 which have been assessed and authorised by DES, the management measures proposed by the original applications (as outlined in section 5.1) have not changed.


6.2.2. Waste and Resource Management Hierarchy (Waste Reduction and Recycling Act 2011) (WRR Act)

N/A – the application will not result in the generation of additional wastes or resources within the project area, and would not change existing waste or resource management.

6.2.3. Prescribed matters for particular resource activities (s24AA EP Regulation)

Section 226 of the EP Act, specifies the general requirements for an EA amendment application. This includes item (1)(n) which specifies any other documents relating to the application prescribed under a regulation. Section 28 of the EP Regulation describes the prescribed documents for an application for environmental authority for a CSG activity.

Table 6-5: Prescribed Documents for Application for EA for a CSG Activity (s28 EP Reg)

Section 28 EP Reg Relevance to amendment application

(1) For section 125(1)(o) of the Act, the documents prescribed for an application for an environmental authority for a CSG activity that is an ineligible ERA are—

(a) documents dealing with the following matters about coal seam gas water generated in connection with carrying out the CSG activity—

The amendment application does not propose to change the process (rate or maximum volume) of the release of desalinated associated water from ROP 1 and ROP 2. As such, the releases will be managed in a way that is consistent with the coal seam gas water management policy as they were originally assessed and authorised by DES.


(i) whether the proposed management of the coal seam gas water is consistent with the coal seam gas water management policy, including the prioritisation hierarchy for managing and using coal seam gas water;

(ii) if the proposed management of the coal seam gas water is inconsistent with the prioritisation hierarchy for managing and using coal seam gas water—the reason for managing the coal seam gas water in the proposed way;


Section 28 EP Reg Relevance to amendment application

(b) documents dealing with the following matters for brine or salt generated from the management of the coal seam gas water mentioned in paragraph (a)—

(i) whether the proposed management of the brine or salt is consistent with the coal seam gas water management policy, including the prioritisation hierarchy for managing saline waste;

(ii) if the proposed management of the brine or salt is inconsistent with the prioritisation hierarchy for managing saline waste—the reason for managing the coal seam gas water in the proposed way.

6.3. Environmental Protection Policies (EPP)

Section 35(1)(d) of the EP Reg requires consideration of the management hierarchy, the environmental values, the quality objectives, the management intent of all relevant EPPs and if a bilateral agreement requires the matters of national environmental significance to be considered – consider those matters. It is considered that the proposed activities will not impact on the environmental values and quality objectives of Air or Noise as described in the Environmental Protection Policies.

The amendment application does not propose a change to the activities which have been previously assessment and authorised by DES. The application seeks to amend the EA conditions which relate to the release limit for boron, as such only the EPP Water is considered relevant to this amendment application.

6.3.1. Environmental Protection (Water and Wetland Biodiversity) Policy 2019

Conditions (B14) to (B45) relate to the contaminant release of coal seam water. The amendment application does not propose to have an impact to the environmental value of water greater than that which was approved by DES in authorising the releases from ROP 1 and ROP 2.

Table 6-6: Environmental Protection (Water and Wetland Biodiversity) Policy 2019

Legislative considerations State how the legislation has been considered and any conditions proposed

Part 3, 6 (1) The environmental values of waters to be enhanced or protected under this policy are:

a) for water mentioned in schedule 1, column 1 – the environmental values stated in the document opposite the water in schedule 1, column 2; or

b) for other water – the environmental values stated in subsection (2).

Section 4 outlines the environmental values relevant to the amendment.

Part 3, 7 (1) The environmental values for wetlands to be enhanced or protected under this policy are the qualities of a wetland that support and maintain the biodiversity of the wetland, including the following—

a) (a) the health of the wetland’s ecosystems;

b) (b) the wetland’s natural state and biological integrity;

Section 4 outlines the environmental values relevant to the amendment.


c) (c) the presence of distinct or unique features, endemic plants or animals and their habitats, including threatened wildlife and near threatened wildlife under the Nature Conservation Act 1992;

d) (d) the wetland’s natural hydrological cycle;

e) (e) the natural interaction of the wetland with other ecosystems, including other wetlands.

Part 3, 8 (3) For particular water, the indicators and water quality guidelines for an environmental value are –

(a) decided using the following document

(i) site specific documents for the water;

(ii) the Queensland water quality guidelines 2009;

(iii) the Australian and New Zealand quidelines for fresh and marine water quality, 2018;

(iv) the Australian drinking water guidelines, paper 6, 2011;

(v) the Guidelines for managing risks in recreational waters, 2008; and

(vi) other relevant documents published by a recognised entity; or

b) for water mentioned in schedule 1, column 1 – the indicators stated in the document opposite the water in schedule 1, column 2





The adoption of the 95% and 90% species protection levels will ensure that there are no adverse effects on the environmental value for water from the releases.


Part 3, 9 For this policy, the environmental values for particular water are protected if the measures for all indicators do not exceed the water quality guidelines stated for the indicators

The proposed amendments will not impact on the environmental value of water greater than that which was approved by DES in authorising the release of desalinated associated water from ROP 1 and ROP 2. As outlined in the results of the REMP monitoring conducted to date, the DRRS release has not negatively influenced the aquatic environmental values of the receiving environment from the baseline condition, rather the physical habitat features in the waterbody have improved from baseline condition due to higher water levels.


Part 4, 10 The management goals for water mentioned in schedule 1, column 1 are the goals, if any, stated in the document opposite the water in schedule 1, column 2

There are no management goals prescribed in the Dawson River Sub-basin Environmental Values and Water Quality Objectives, Upper Dawson River Sub-basin waters (WQ1308), EPP Water and freshwater lakes/reservoirs.

Part 4, 11 The water quality objectives for water mentioned in Schedule 1, column 1 are:

a) the objectives stated in the document opposite the water in schedule 1, column 2; or

b) if water quality objectives for the water are not stated in the document – the set of water quality guidelines that will protect all environmental values stated in the document.

There are no water quality objectives for boron in the Dawson River Sub-basin Environmental Values and Water Quality Objectives, Upper Dawson River Sub-basin waters (WQ1308), EPP Water and freshwater lakes/reservoirs.







Refer to section 2.3.

Part 5, 14 (2) To the extent it is reasonable to do so, release of waste water or contaminants to waters must be dealt with in the following order of preference –

(a) Firstly – reduce the production of waste water or contaminants by reducing the use of water;

(b) Secondly – prevent waste and implement appropriate waste prevention measures;

(c) Thirdly—evaluate treatment and recycling options and implement appropriate treatment and recycling;

(d) Fourthly—evaluate the following options for waste water or contaminants, in the order in which they are listed—

(i) appropriate treatment and release to a waste facility or sewer;

(ii) appropriate treatment and release to land;

(iii) appropriate treatment and release to surface waters or ground waters.

The amendment application does not propose to change the process (rate or maximum volume) of the release of desalinated associated water from ROP 1 and ROP 2. As such, the releases will be managed in a way that is consistent with the management hierarchy for surface water as they were originally assessed and authorised by DES.


Part 5, 15 (2) It is the management intent for the waters that the decision to release the waste water or contaminant must ensure the following –

(b) for slightly disturbed waters – the measures for the slightly modified physical or chemical indicators are progressively improved to achieve the water quality objectives for high ecological value water

There are no water quality objectives for boron in the Dawson River Sub-basin Environmental Values and Water Quality Objectives, Upper Dawson River Sub-basin waters (WQ1308), EPP Water and freshwater lakes/reservoirs.






Refer to section 2.3.

6.3.2. Additional Regulatory Requirements (EPP)

Chapter 4, Part 3 of the EP Reg includes additional regulatory requirements, which must be considered

by the administering authority in making an environmental management decision where the

management decision relates to an activity mentioned in either section 40 or 41. However, the

amendment application does not relate to an activity mentioned in sections 40 or 41 of the EP Reg as

there is no release of water or waste to wetlands for treatment, nor does the activity involve the direct

release of waste to groundwater.


Appendix A - Revised Boron Site-Specific Water Quality Criterion - Dawson River Release Scheme (AECOM, 2019)


AECOM Services Pty Ltd

Level 8

540 Wickham Street

PO Box 1307

Fortitude Valley QLD 4006

Australia

www.aecom.com

+61 7 3553 2000 tel

+61 7 3553 2050 fax

ABN 46 000 691 690

\\aubne1fp003\projects\606x\60600415\400_tech\432_toxicity assessment\final letter\rev4\60600415-l-001-rev4 revised boron

criteria_20190911.docx Ref: 60600415

12 September 2019

Environmental Advisor Environment and Access Santos Limited32 Turbot Street BRISBANE QLD 4000

Dear ,

Revised Boron Site-Specific Water Quality Criterion - Dawson River Release Scheme

1.0 Introduction and Background

AECOM Services Pty Ltd (AECOM) was engaged by Santos Ltd (Santos) to review ecotoxicity datagenerated for the Dawson River Release Scheme (DRRS) to identify whether an adjustment can bemade to the current water quality guideline (WQG) for boron in accordance with Australian and NewZealand Guidelines (ANZG) for Fresh and Marine Water Quality (2018) methodology.

The DRRS is authorised under the Fairview Arcadia Project Area Environmental Authority (EA)(EPPG00928713) which approves release of 18 ML/day of desalinated produced water from ReverseOsmosis Plant (ROP) ROP2 to the Dawson River via a tributary gully and water body. The EAcurrently authorises a boron limit of 1 mg/L in release water based on ecotoxicity tests performed onwater samples collected from the Dawson River. Ecotox Services Australasia (ESA) performed thetoxicity testing, which is NATA accredited for compliance with ISO/IEC 170251. The ESA laboratoryreports are provided in:

· Halcrow (2012). Dawson River Release Scheme, Direct Toxicity Assessment. 13 November2012.

· Halcrow (2013). Dawson River Release Scheme, Direct Toxicity Assessment: Fish Test.Addendum to Direct Toxicity Report (Halcrow, November 2012). 11 February 2013.

Based on the 2012/2013 toxicity testing results (summarised in Section 3.0), a boron site-specificwater quality criterion of 1 mg/L was adopted for release waters in the DRRS which represents thepredicted no-effect concentration (PNEC). The PNEC was calculated by dividing the lowest noobserved effect concentration (NOEC) (i.e. 10.3 mg/L for Ceriodaphnia dubia reproduction) by 10.

2.0 Objectives

The objectives of this study are as follows:

1) To review the ecotoxicity data generated for the DRRS (presented in Halcrow 2012 & 2013) andidentify whether:

a) The ecotoxicity data can be relied upon to generate an amended site-specific boron WQG;and,

b) There is sufficient information available to meet the minimum ANZG (2018) requirements toderive a site-specific boron WQG.

2) Should the quality and quantity of the ecotoxicity data be deemed suitable, providerecommendations for an amended site-specific boron WQG.

3.0 Overview of Ecotoxicity Data

As part of the assessments undertaken by Halcrow, surface water was collected from the DawsonRiver release point at Yebna Crossing and spiked with boron (as boric acid) to represent testconcentrations of 2.2, 4.4, 8.8, 17.5 and 35 mg of boron/L. A suite of toxicity tests were performed onthe spiked waters (and two controls) including both chronic and acute endpoints for five speciesrepresentative of those occurring in the Upper Dawson River. Laboratory analysis of the river water did

1 International Organisation for Standardisation, General requirements for the competence of testing and calibration laboratories.

\\aubne1fp003\projects\606x\60600415\400_tech\432_toxicity assessment\final letter\rev4\60600415-l-001-rev4 revised boron criteria_20190911.docx

2 of 13

not detect boron concentrations above the laboratory detection limit (0.05 mg/L). The ecotoxicity testresults are presented in Table 1.

Table 1 Toxicity Test Results (Halcrow, 2013)

Freshwater Species TestNOEC

(mg/L)

LOEC

(mg/L)

EC/IC50 ±95% CL

(mg/L)

EC/IC10 ±95% CL

(mg/L)

Chironomus tepperi (midge insect)

survival (48 hour)

125.1 250.2 159.4

(142.7-178.1)

119.9

(114 – 137)

Ceriodaphnia cf dubia (crustacean)

survival (7 days)

41.3 82.5 62.6

(54.9 – 71.4)

63.3

(53.8 – 67.0)

Selanstrum capricornutum (microalgae)

growth inhibition

20.7 41.3 30.3

(28.8 – 31.4)

19.9

(14.0 – 22.9)

Ceriodaphnia cf dubia (crustacean)

reproduction (7 days)

10.3 20.6 27.5

(25.9 – 29.0)

12.1*

(6.5 – 15.89)

Lemna disperma (duckweed) growth

inhibition (7 days)

12.5 25 21.5

(15.6 – 28.8)

1.9*

(0.12 – 19.93)

Melanotaenia splendida (rainbow fish)

10-day embryo development and

survival

>35 >35 >35 >35

Notes:

NOEC = no observed effect concentration

LOEC = lowest observed effect concentration

EC/IC50 = half maximal effect/inhibition concentration determined through regression analysis of the dose response curve

EC/IC10 = 10% of maximal effect/inhibition concentration determined through regression analysis of the dose response curve

CL = confidence limit

Results expressed as Total boron (mg/L) ± confidence intervals (where applicable) as a proportion of boric acid.

*Confidence limits reported to be unreliable (refer to discussion below).

ESA calculated the effect concentration/inhibition concentrations (EC/IC) using a linear interpolationmethod with the statistical software package ToxCalc because the data met the ToxCalc statisticalassumptions. This program calculates an EC/IC concentration, and a standard deviation with 95%confidence limits. It is understood that the criteria for reliability of the confidence limits is a laboratory-specific set criterion, based on professional judgement and discussion between laboratory personnel.Two tests were reported with ‘unreliable’ confidence limits, the C. dubia (life-cycle test) and the L.disperma (growth inhibition test), because the confidence limits fell outside the test concentrations andthey overlapped other test treatments. This situation only introduces uncertainty in the results whenthe toxicity concentration at 0 mg/L is not known, such as effluent dilution studies. However, becausethe testing media was developed in the laboratory by spiking site water with boric acid, the toxicity at‘concentration 0 mg/L’ (i.e. the diluent control) is known, and therefore a confidence limit below thelowest test concentration is not of concern.

Furthermore, informal advice received from Dr Rick van Dam (co-author of the ANZG (2018) andWarne et al (2018) guidelines) indicates that the wide confidence limits reported in the C. dubia(reproduction) test does not preclude the use of the IC10 concentration (12.1 mg/L) in deriving site-specific WQGs because the intra-treatment variability is quite low and the concentration-responserelationship is monotonic (pers comms. Dr Rick van Dam, September 20192).

When compared against other published studies, the L. disperma IC10 concentration (1.9 mg/L) is atthe lower end of reported concentrations. For example, Gür et al (20163) reported approximately 10%growth inhibition (in biomass) for two Lemna species at 4 mg/L of boron. Therefore, although the

2 The informal advice was given following a review of the C. dubia ecotoxicity data, in the absence of any other data or contextsighted.3 Gur N, Tuker OC, Bocuk H. 2016. Toxicity assessment of boron (B) by Lemna minor L. and Lemna gibba L. and their possibleuse as model plants for ecological risk assessment of aquatic ecosystems with boron pollution. Chemosphere. 157:1-9.


3 of 13

reported confidence limits were wide, the L. disperma IC10 concentration is considered to be reliable,and conservative, for the derivation of site-specific WQGs (pers comms. Dr Rick van Dam, September20194).

Based on advice from the laboratory and informal advice from Dr Rick van Dam, AECOM considersthat the IC/EC concentration data are reliable for use in derivation of a site-specific WQG for boron.

The reported IC value for M. splendida was >35 mg/L (Halcrow, 2013). ANZG (2018) states thattoxicity values expressed as greater than (>) can be used, subject to determining whether they:

a) are too far outside the existing data range; and/or

b) have an overly large influence on the final WQG value.

AECOM considers that the M. splendida data is suitable for inclusion in the dataset because the IC10concentration is within the range reported for other chronic test species (1.9 mg/L to 63.3 mg/L).

4.0 Review Methodology

The following Australian guidelines and documents were relied upon when assessing the quality andquantity of the boron ecotoxicity data generated for the DRRS:

· ANZG 2018. Australian and New Zealand Guidelines for Fresh and Marine Water Quality.Australian and New Zealand Governments and Australian state and territory governments,

Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

· Batley GE, van Dam R, Warne MStJ, Chapman JC, Fox DR, Hickey CW and Stauber JL. 2018.Technical Rationale for Changes to the Method for Deriving Australian and New Zealand WaterQuality Guideline Values for Toxicants – update of 2014 version. Prepared for the revision of theAustralian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and NewZealand Governments and Australian state and territory governments, Canberra, ACT, Australia.

· Warne MStJ. 2001. Derivation of the ANZECC and ARMCANZ water quality guidelines fortoxicants. Australasian Journal of Ecotoxicology 7:123-136.

· Warne MStJ, Batley GE, van Dam RA, Chapman JC, Fox DR, Hickey CW and Stauber J. 2018.Revised Method for Deriving Australian and New Zealand Water Quality Guideline Values forToxicants – update of 2015 version. Prepared for the revision of the Australian and New ZealandGuidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments andAustralian state and territory governments, Canberra, 48 pp.

5.0 Data Review Results

5.1 Quality of the Ecotoxicity Data

The quality of the ecotoxicity data was assessed in accordance with approaches described in Warneet al (2018) to determine their suitability for use in WQG derivation. The quality of the ecotoxicity datawere screened against three main characteristics:

· Whether the Santos ecotoxicity data satisfies the classification of acute and chronic toxicity testsfor temperate species. This assessment is presented in Table 2.

· Whether the test characteristics (such as experimental design, exposure concentrations) are inaccordance with ANZG (2018) requirements. This assessment is presented in Table 3.

· The data quality ‘score’ which is generated by examining how each toxicity value was generatedwith the highest possible score being 103 for freshwater metal non-plant data. ANZG (2018)states that “toxicity data with a quality score ≥80% are classed as ‘high’ quality, data with a qualityscore of ≥ 50% to < 80% are classed as ‘acceptable’ quality while data with a quality score of<50% are classed as ‘unacceptable’ quality. Only ‘high’ and ‘acceptable’ quality data can be usedto derive GVs.” This assessment is presented in Table 4.

4 The informal advice was given following a review of the L. disperma ecotoxicity data, in the absence of any other data orcontext sighted.


4 of 13

Table 2 Classification of Acute and Chronic Toxicity Tests for Temperate Species

Toxicity Test Life StageRelevant

EndpointsTest Duration AECOM Assessment

Acute

microinvertebrate1

Adults/juveniles/

larvae

All (except

fertilisation, larval

development)

< 7 days Santos data complies. The

acute test using juvenile C.

tepperi had an endpoint of

‘lethality’ with a test duration of

48 hours.

Chronic

microinvertebrate1

Adults/juveniles/

larvae

Lethality/

immobilisation/

reproduction

≥ 7 days Santos data complies.

The two chronic tests using

juvenile C. dubia had an

endpoint of ‘lethality’ and

‘reproduction’ with a test

duration of 7 days.

Chronic microalgae Early life stages Development ≥ 48 hours Santos data complies.

The chronic test using S.

capricornutum had an

endpoint of ‘growth inhibition’

(development) with a test

duration of 72 hours.

Chronic

macrophytes

Mature All ≥ 7 days Santos data complies.

The chronic test using L.

disperma has an endpoint of

‘growth inhibition’ with a test

duration of 7 days.

Fish Embryos/larvae/

eggs

All ≥ 7 days. Santos data complies.

The chronic test using M.

splendida had an endpoint of

‘development’ and ‘survival’

with a test duration of 10 days.

Notes:

1) Microinvertebrates are defined as invertebrate species where full-grown adults are typically <2 mm long. Examples of invertebrates that meet

this criterion are some cladocerans (such as Ceriodaphnia dubia) copepods, conchostrancans, rotifer, acari, bryozoan and hydra.

Table 3 Circumstances and Types of Toxicity Data for Which WQGs Should not be Calculated

Test Characteristic Conditions for Exclusion of DataAECOM’s Assessment of Whether Data is

Suitable for Calculating WQGs

Experimental design Where the test concentrations differ

by a large amount (for example >

10-fold differences such as 1, 10,

100, 1000 and 10,000 μg/L)

Santos data complies.

The test concentrations were 2.2, 4.4, 8.8,

17.5 and 35 mg/L of boron. These test

concentrations were chosen based on a

literature review where the highest

concentration of boron used for toxicity

testing of the rainbow fish was set at 35 mg/L

of boron.

Duration of exposure If not stated or does not conform

with ANZG (2018) definition of acute

and chronic toxicity tests for

temperate species (defined in Table

1 of ANZG, 2018).


Refer to AECOM’s assessment presented in

Table 2.


5 of 13

Test Characteristic Conditions for Exclusion of DataAECOM’s Assessment of Whether Data is

Suitable for Calculating WQGs

Toxicological endpoint If not stated and/or endpoints other

than lethality, immobilisation,

growth, population growth or the

equivalent unless the endpoint has

been proven to be ecologically

relevant.


Endpoints are stated in laboratory reports

and comprise lethality, growth inhibition and

population growth.

Aqueous solubility If toxicity values are greater than

twice the aqueous solubility.


Boric acid was added to the test water

(collected from Dawson River) and the

nominal concentration of boron present was

calculated from the proportion of boron in the

boric acid (~17.5% B). The aqueous

solubility of boric acid is 57 g/L. The toxicity

values reported are not greater than boron’s

aqueous solubility.

Table 4 Scoring System for Assessing the Quality of Toxicity Data for Metals in Freshwater Non-Plants to be used inthe Derivation of Guideline Value Toxicants

No. Question AECOM Assessment

ANZG Score

(highest possible

score)

1 Was the duration of the exposure

stated?

Yes 10 (10)

2 Was the biological endpoint stated

and defined?

Yes 10 (10)

3 Was the biological effect stated (for

example, LC or NOEC)?

Yes. NOEC, LOEC, EC10, EC50, LC10, LC50,

IC50 and IC10 values reported.

5 (5)

4 Was the biological effect quantified

(for example 50% effect, 25%

effect). The effect for NOEC and

LOEC data must be quantified.

Yes 5 (5)

5 Were appropriate controls (for

example a no-toxicant control

and/or solvent control) used?

Yes. A dilute mineral water (DMW) control

and a dilution control (Dawson River water

without added boron) were tested

concurrently with the test samples.

5 (5)

6 Was each control and chemical

concentration at least duplicated?

Not stated in laboratory reports. 0 (5)

7 Were test acceptability criteria

stated or inferred (for example

mortality in controls must not

exceed a certain percentage)?

Data that fail the acceptability

criteria are automatically deems to

be of unacceptable quality and

must not be used.

Yes. Control criteria was reported to be

≥90.0% non-immobilised, ≥80% survival,

≥16.0x104 cells/mL cell density and <2.5

days frond doubling time.

5 (5)

8 Were the characteristics of the test

organism (for example length,

mass, age) stated?

Yes. The laboratory reports stated whether

they were larvae or juveniles.

5 (5)


6 of 13


ANZG Score

(highest possible

score)

9 Was the type of test media used

stated?

Yes. An ‘aqueous sample’ was stated in

the laboratory reports. The aqueous

sample comprised water collected from the

Dawson River with the addition of boron

(as boric acid).

5 (5)

10 Was the type of exposure (for

example static, flow-through)

stated?

Not stated in laboratory reports. 0 (4)

11 Were the contaminant

concentrations measured at the

beginning and end of the

exposure?

Dawson River water was measured for

‘Santos suite F’ (see Note A below) by

Australian Laboratory Services (ALS). Un-

spiked water contained non-detect

concentrations of boron (<0.05 mg/L).

Spiked test water was measured at the end

of exposure.

2 (4)

12 Were parallel reference toxicant

toxicity tests conducted?

Yes. A solution with either potassium

chloride or copper was used as the

reference toxicant test.

4 (4)

13 Was there a concentration-

response relationship either

observed or stated?

Yes. A dose-response plot is provided in

the ESA report.

4 (4)

14 Was an appropriate statistical

method or model used to determine

the toxicity? The method should be

accepted by a recognised national

or international regulatory body

such as USEPA, ASTM or OECD.

Yes. Statistical methods used to assess

the data included:

· Dunnett’s Test

· Trimmed-Karber analysis

· Maximum Likelihood Probability

analysis

· One-way Analysis of Variance

(ANOVA)

· Shapiro-Wilk’s test

· Bartlett’s test

· Steel’s Many-One rank test

Refer to Section 3.0 for a discussion on

the statistical methods used to derive the

confidence limits for C. dubia

(reproduction) and L. disperma.

4 (4)

15 For LC/EC/NEC/BEC data, was an

estimate of variability provided?

For NOEC/LOEC/MDEC/MATC

data, was the significance level

0.05 or less?

Yes. A significance level of 0.05 was stated

for NOEC/LOEC data.

4 (4)

16.1 Was pH measured at least at the

beginning and end of the toxicity

test?

Yes. Mean pH values were stated in the

ESA report (7.7 – 8.1)

3 (3)

16.2 Was hardness measured at least at

the beginning and end of the

toxicity test?

Not stated in the ESA report. Was tested in

the pre-spiked water sample.

1 (3)


7 of 13


ANZG Score

(highest possible

score)

16.3 Was alkalinity measured at least at

the beginning and end of the

toxicity test?



1 (3)

16.4 Was dissolved organic carbon

measured at least at the beginning

and end of the toxicity test?



1 (3)

16.5 Was dissolved oxygen measured at

least at the beginning and end of

the toxicity test?

Yes. Mean dissolved oxygen values were

stated in the ESA report.

3 (3)

16.6 Was conductivity measured at least

at the beginning and end of the

toxicity test?

Yes. Mean conductivity vales were stated

in the ESA report.

3 (3)

17 Was the temperature measured

and stated?

Yes. The temperature of the test water was

measured upon receipt at ESA laboratory,

and during the test.

3 (3)

18 Were test solutions, blanks and/or

controls tested for contamination or

were analytical reagent grade

chemicals or the highest possible

purity chemicals used for the

experiment?

Yes. The Dawson River sample was tested

for a range of chemicals and results

provided. The quality of the boric acid

added to the test sample is unknown.

3 (3)

Total Score 86

Total Possible Score 103

Quality Score (total score/total possible score) x 100 83.5

Notes: (A) Santos ‘suite F’ includes total and dissolved metals (Ag, Al, As, B, Ba, Be, Cd, Cr, Co, Cu, Fe, Hg, Li, Mo, Mn, Ni, Pb, Se, Sn, Sr, U, V, Zn), total

petroleum hydrocarbons, polychlorinated biphenyls, nitrogen (nitrate, nitrite, ammonia), phosphorus, sulphate, chloride, fluoride, water quality parameters (pH,

conductivity, total dissolved solids, dissolved oxygen, biological oxygen demand, turbidity, suspended solids), major cations, silica, residual alkali, total

organic carbon and dissolved organic carbon,


8 of 13

Based on a review of the Santos ecotoxicity data against the ANZG (2018) data screening process(Table 2 and Table 3) and scoring system (Table 4), the data is considered to be ‘high’ quality andsuitable for guideline derivation.

5.2 ANZG Minimum Data Requirements

When choosing data to derive WQGs, Warne et al (2018) states that:

· The preferred order of statistical estimates of chronic (and acute) toxicity to calculate site-specificWQGs is: NEC/EC/IC/LCx (where x ≤10), BEC10, EC/IC/LC15-20 and NOEC. In many cases,only chronic NOEC data will be available, and these may be used5.

· Chronic data are always preferred in the derivation of WQGs over acute data. In situations whereacute toxicity data is available, acute data can be converted to chronic data by applying an acuteto chronic ratio (ACR). In absence of an ACR for a particular toxicant, a default ACR of 10 can beapplied.

The minimum data requirements to use the species sensitivity distribution (SSD) method include atleast five species that belong to at least four different taxonomic groups as defined in Table 5. Thisrequirement is consistent with ANZECC (2000) methodology (i.e. it did not change in the updatedANZG (2018)).

Table 5 Minimum Data Requirements to use the SSD Method

Major Types of

Organisms

Organisms Considered to be Taxonomically

DifferentAECOM Assessment

Vertebrates Fish, amphibians The Santos toxicity data set

includes five species from five

taxonomic groups (fish,

crustaceans, insects, green algae

and macrophytes), which meets

the minimum requirements to use

the SSD method.

Invertebrates Crustaceans, insects, molluscs, annelids,

echinoderms, rotifers, hydra

Plants Green algae, diatoms, brown algae, red algae,

macrophytes

Others Blue-green algae (cyanobacteria), bacteria,

protozoans, coral, fungi and others

ANZG (2018) classifies datasets that contain 5-7 species as ‘adequate’, datasets with 8-14 speciesthat belong to at least four taxonomic groups are ‘good’ and datasets that contain at least 15 speciesbelonging to at least four taxonomic groups are termed ‘preferred’.

Based on this ANZG requirement, the Santos dataset is classified as ‘adequate’ and meets theminimum data requirements to use the SSD method (refer to Table 5).

6.0 Species Sensitivity Distribution Analysis

AECOM generated WQGs for a variety of species protection levels using the SSD approach with theBurrlioz 2.0 software (Barry and Henderson, 2014). The input data comprised chronic IC/EC10 andchronic adjusted IC/EC10 data (from acute data) presented in Table 6.

The C. tepperi survival toxicity test represented an acute endpoint and therefore the reported EC50concentration was divided by 10 in accordance with Warne et al. (2018) methodology that states “…adefault ACR [acute to chronic ratio] of 10 should be used [in absence of a chemical-specific ACR] toconvert acute LC/EC/IC50 values to chronic EC10/NOEC values.”

In accordance with Warne et al (2018) methodology, the lowest IC10 value reported for C. dubia waschosen to represent this species in the SSD calculations (i.e., the IC10 of 63.3 mg/L was omitted fromthe dataset).

5 The use of NOEC data to derive guideline values is to be phase out as recommended by Warne and van Dam (2008) and vanDam et al (2012a, 2012b).


9 of 13

Table 6 Toxicity Data Used to Calculate the Site-Specific Boron WQG

Ecotoxicity TestToxicity Data Used to Calculate

the Site-Specific Boron WQGEC/IC10 (mg/L)

M. splendida (rainbow fish) embryo

hatching

Chronic IC10 35

S. capricornutum (microalgae)

growth inhibition

Chronic IC10 19.9

C. dubia (crustacean) reproduction Chronic IC10 12.1

C. tepperi (crustacean) survival Converted acute EC50 15.9

L. disperma (duckweed) growth

inhibition

Chronic IC10 1.9

The species sensitivity distribution generated by Burrlioz 2.0 is shown in Figure 1 and the boronWQGs for a range of species protection levels are presented in Table 7. The Burrlioz 2.0 statisticaloutput is provided in Attachment 1.

Table 7 Boron Water Quality Guidelines Derived Using SSD Method

Species Protection Level (%) Boron Water Quality Guideline (mg/L)

80 6.7

90 4.4

95 2.9

96 2.6

97 2.2

98 1.8

99 1.2

The 95% WQG is different to Halcrow’s calculation (9.3 mg/L) because the software used by AECOMis the most current version (Version 2.0) which incorporates latest ANZG (2018) guidance relating tofitting of the data. Halcrow (2012, 2013) used a Burr Type III method whereas AECOM used a loglogistic fit, which resulted in the concentration differences. ANZG (2018) guidance recommends that alog logistic fit is used where the number of observations (i.e. EC/IC data) is less than eight, and a BurrType III is used when eight or more observations are available (the model does not give the user achoice of data fitting method). A total of six observations were available, and therefore AECOM usedthe log logistic fit of the data.

Furthermore, AECOM used the IC/EC10 data in preference to the NOEC data in accordance withupdated ANZG (2018) methodology for deriving WQGs (refer to Section 5.2).


10 of 13

Figure 1 Species Sensitivity Distribution for Boron Ecotoxicity Data (*represents a converted chronic EC10concentration)

7.0 Recommended Site-Specific Boron WQG

In accordance with the ecosystem classification defined by Queensland Environmental Protection(Water) Policy 2009 (presented in Table 8), it is likely that both the waterhole (initial receivingenvironment before releases enter Dawson River) and the Dawson River at the release point can beclassified as ‘moderately disturbed’. ANZG (2018) defines ‘moderately disturbed’ ecosystems as thosewith slightly to moderately cleared catchments or reasonably intact riparian vegetation. This includesrural streams receiving runoff from land disturbed to varying degrees by grazing or pastoralism.

Considering the land uses adjacent to the Dawson River include light to moderate grazing, and thereis some development upstream of the Horseshoe Lakes, adoption of the 95% species protectioncriteria is considered appropriate. It is noted that EHP (2011) (Table 2) lists a management intent(level of protection) for the Upper and Lower Dawson River as ‘Aquatic ecosystem – moderatelydisturbed’.

Therefore, adoption of the 95% species protection WQG (2.9 mg/L) generated using high quality site-specific data via the ANZG (2018) endorsed SSD method is considered appropriate as the boron site-specific water quality release criterion for the DRRS.

95% speciesprotection

Key

95% confidence interval

Log logistic data fit


11 of 13

Table 8 Levels of Protection for Aquatic Ecosystems (defined by Queensland Environmental Protection (Water)Policy 2009)

Water Quality

Guidelines

Ecosystem

ClassificationDescription

ANZG (2018)

Species

Protection

High

conservation or

ecological value

High ecological

value (HEV)

Waters in which the biological integrity of the water

is effectively unmodified or highly valued

99%

Slightly to

moderately

disturbed

Slightly disturbed

(SD)

Waters that have the biological integrity of high

ecological value waters but with slightly modified

physical or chemical quality

95%a

Moderately

disturbed (MD)

Waters in which the biological integrity of the water

is adversely affected by human activity to a

relatively small but measurable degree

95%a

Highly disturbed Highly disturbed

(HD)

Waters that are significantly degraded by human

activity and have lower ecological value than

slightly or moderately disturbed waters

80% or 90%a

Notes:

For highly bioaccumulating toxicants, ANZG (2018) recommends adoption of the 99% species protection regardless of the ecosystem classification. This is

not relevant for boron which is not considered to be a bioaccumulating metalloid (ATSDR, 2010).

8.0 References

ANZG. 2018. Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australianand New Zealand Governments and Australian state and territory governments, Canberra ACT,

Australia. Available at www.waterquality.gov.au/anz-guidelines

ANZECC (2000) Australia and New Zealand Guidelines for Fresh and Marine Water Quality. Australiaand New Zealand Environment and Conservation Council and Agriculture and Resource ManagementCouncil of Australia and New Zealand, Canberra, Australia.

ATSDR (2010) Toxicological Profile for Boron. Agency for Toxic Substances and Disease Registry.November 2010.

Barry S and Henderson B. 2014. Burrlioz 2.0. Commonwealth Science and Industrial ResearchOrganisation, Canberra, Australia.

Batley GE, van Dam R, Warne MStJ, Chapman JC, Fox DR, Hickey CW and Stauber JL. 2018.Technical Rationale for Changes to the Method for Deriving Australian and New Zealand WaterQuality Guideline Values for Toxicants – update of 2014 version. Prepared for the revision of theAustralian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and NewZealand Governments and Australian state and territory governments, Canberra, ACT, Australia.

EHP (2011) Department of Environment and Heritage Protection. Environmental Protection (Water)Policy 2009. Dawson River Sub-basin Environmental Values and Water Quality Objectives. Basin No.130 (part), including all waters of the Dawson River Sub-basin except the Callide Creek Catchment.September 2011.

Halcrow (2013). Dawson River Release Scheme, Direct Toxicity Assessment: Fish Test. Addendum toDirect Toxicity Report (Halcrow, November 2012). 11 February 2013.

Halcrow (2012). Dawson River Release Scheme Direct Toxicity Assessment. Document 2.1. 13 November2012.

van Dam R, Harford A and Warne MStJ. 2012a. Time to get off the fence: The need for definitiveinternational guidance for statistical analysis of ecotoxicity data. Integr. Environ. Assess. Manag.8:242-245.


12 of 13

van Dam R, Harford A and Warne MStJ. 2012b. Canada showing the lead, however, we still have aNOEC problem: Response to Van der Vliet et al. Integr. Environ. Manag. 8:399-400.

Warne MStJ. 2001. Derivation of the ANZECC and ARMCANZ water quality guidelines for toxicants.Australasian Journal of Ecotoxicology 7:123-136.

Warne MStJ and van Dam R. 2008. NOEC and LOEC data should no longer be generated or used.Australasian Journal of Ecotoxicology. 14:1-5.

Warne MTtJ, Batley GE, van Dam RA, Chapman JC, Fox DR, Hickey CW and Stauber J. 2018.Revised Method for Deriving Australian and New Zealand Water Quality Guideline Values forToxicants – update of 2015 version. Prepared for the revision of the Australian and New ZealandGuidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments andAustralian state and territory governments, Canberra, 48 pp.

9.0 Standard Limitations

AECOM Services Pty Limited (AECOM) has prepared this report in accordance with the usual careand thoroughness of the consulting profession for the use of Santos Limited and only those thirdparties who have been authorised in writing by AECOM to rely on this Report.

It is based on generally accepted practices and standards at the time it was prepared. No otherwarranty, expressed or implied, is made as to the professional advice included in this Report.

It is prepared in accordance with the scope of work and for the purpose outlined in the proposal dated17 April 2019.

Where this Report indicates that information has been provided to AECOM by third parties, AECOMhas made no independent verification of this information except as expressly stated in the Report.AECOM assumes no liability for any inaccuracies in or omissions to that information.

This Report was prepared between 18 April 2019 and 12 September 2019 and is based on theinformation reviewed at the time of preparation. AECOM disclaims responsibility for any changes thatmay have occurred after this time.

This Report should be read in full. No responsibility is accepted for use of any part of this report in anyother context or for any other purpose or by third parties. This Report does not purport to give legaladvice. Legal advice can only be given by qualified legal practitioners.

Except as required by law, no third party may use or rely on this Report unless otherwise agreed byAECOM in writing. Where such agreement is provided, AECOM will provide a letter of reliance to theagreed third party in the form required by AECOM.

To the extent permitted by law, AECOM expressly disclaims and excludes liability for any loss,damage, cost or expenses suffered by any third party relating to or resulting from the use of, orreliance on, any information contained in this Report. AECOM does not admit that any action, liabilityor claim may exist or be available to any third party.

Except as specifically stated in this section, AECOM does not authorise the use of this Report by anythird party.

It is the responsibility of third parties to independently make inquiries or seek advice in relation to theirparticular requirements and proposed use of the site.


13 of 13

Any estimates of potential costs which have been provided are presented as estimates only as at thedate of the Report. Any cost estimates that have been provided may therefore vary from actual costsat the time of expenditure.

Yours sincerelyfor AECOM AUSTRALIA PTY LTD

Human Health and Ecological Risk Assessor [email protected]

Team Lead – Water Resources & Coastal Management

encl: Attachment 1

© AECOM Services Pty Limited. All rights reserved.

No use of the contents, concepts, designs, drawings, specifications, plans etc. included in this report is permitted unless and until they are the

subject of a written contract between AECOM Services Pty Limited (AECOM) and the addressee of this report. AECOM accepts no liability of any

kind for any unauthorised use of the contents of this report and AECOM reserves the right to seek compensation for any such unauthorised use.

Document Delivery

AECOM Services Pty Limited (AECOM) provides this document in either printed format, electronic format or both. AECOM considers the printed

version to be binding. The electronic format is provided for the client’s convenience and AECOM requests that the client ensures the integrity of

this electronic information is maintained. Storage of this electronic information should at a minimum comply with the requirements of the Electronic

Transactions Act 2002.

Burrlioz 2.0 report

Toxicant: BoronInput file: C:\Users\belinda.goldsworthy\Desktop\Projects\Santos Ecotox\Revised Burllioz values_IC_EC10 chronic values labeled.txtTime read: Fri Aug 23 09:31:35 2019Units: Not specifiedModel: log logistic

Protection level informationProtect. level Guideline Value lower 95% CI upper 95% CI99% 1.2 0.17 1195% 2.9 0.54 1590% 4.4 0.91 1780% 6.7 1.5 19

notes:

Boron Site−Specific WQG (mg/L)

Percentage of species potentially affected

2.9

5

L. disperma (duckweed)

C. dubia (cladoceran)

C. tepperi* (chironomid)

S. capricornutum (microalgae)

M. splendida (fish)

020

40

60

80

100

1 10 100

Data:

Data Taxa

19.9 S. capricornutum (microalgae)12.1 C. dubia (cladoceran)1.9 L. disperma (duckweed)15.9 C. tepperi* (chironomid)35 M. splendida (fish)

Appendix B - Risk Assessment Report, Boron Irrigation Water Guideline Derivation Fairview Arcadia Project Area (EHS Support, 2019)


Risk Assessment Report Boron Irrigation Water

Guideline Derivation

Fairview Arcadia

Project Area

Prepared for: Santos TOGA Pty Ltd

Prepared by:

August 2019

Boron Irrigation Water Guideline Derivation

FAPA Boron Irrigation Water Guideline Derivation Scheme – August 2019

Table of Contents

EHS Support Pty Ltd i

Table of Contents

1 Introduction and Background ........................................................................................... 1

1.1 Purpose and Objectives ................................................................................................ 1

2 Background ..................................................................................................................... 2

2.1 Project Description ....................................................................................................... 2

3 Current Basis for ANZECC Crop Irrigation Criteria for Boron ............................................... 3

3.1 Default Guideline Values for Boron Crop Irrigation ...................................................... 3

3.2 Limitations of Boron Irrigation Default Guideline Values ............................................. 4

4 Assessment of Regional and Site-Specific Soil Conditions .................................................. 7

4.1 Regional Soil Condition ................................................................................................. 7

4.2 Soil Conditions Near the Proposed Release Location ................................................... 8

5 Boron Plant Toxicity Literature and Irrigation Criteria Derivation .................................... 10

5.1 Mechanisms of Plant Boron Use, Deficiency, and Toxicity ......................................... 10

5.2 Summary of AEP Criteria ............................................................................................. 11

5.3 Derivation of Boron Irrigation Values Based on Crop SSD Approach ......................... 12

5.3.1 Boron Crop Toxicity Literature and Quality Assessment ............................... 12

5.3.2 Hierarchy of Preferred Chronic Values .......................................................... 12

5.3.3 IC10 Effects Quantification Using USEPA Benchmark Dose Software ............ 13

5.3.4 Develop Constituent-Specific Conversion Factor Between Measured IC10 and

IC25 Values ...................................................................................................... 13

5.3.5 Crop Sensitivity Distribution Assessment ...................................................... 16

6 Conclusions ....................................................................................................................19

7 Limitations......................................................................................................................20

8 References ......................................................................................................................21

9 Appendices .....................................................................................................................22



Table of Contents

EHS Support Pty Ltd ii

List of Tables

Table 3-1 Relative tolerance of agricultural crops at differing soil water boron concentrations

from Ayers and Westcot (1985)

Table 4-1 Soil parameters for Queensland from the NGSA dataset

Table 5-1 Estimated and measured crop soil water IC10 values by soil type and receptor

(Adapted from Table D-1 in AEP [2015b])

Table 5-2 Guideline values (± 95% confidence interval) derived using a species sensitivity

approach of soil water boron IC10 values

List of Figures

Figure 4-1 NGSA sample locations

Figure 4-2 Soil characteristics near proposed release location (Horizon, 2018)

Figure 5-1 Crop species sensitivity distribution of estimated and measured IC10 values across

each soil type with three candidate model fits

Figure 5-2 Crop species sensitivity distribution of estimated and measured soil water boron IC10

values across each soil type with three candidate model fits

List of Appendices

Appendix A Boron Crop Toxicity Literature Quality Assessment

Appendix B USEPA Benchmark Dose Crop Growth-Response IC10 Evaluation

Appendix C Estimated and Measured Crop Soil Water IC10 and IC25 Values by Soil Type and

Receptor

Appendix D Burrlioz Output and Diagnostic Statistics



Acronyms

EHS Support Pty Ltd iii

Acronyms

AEP Alberta Environment and Parks

ANZECC Australian and New Zealand Environmental and Conservation Council

ATP adenosine triphosphate

BIC Bayesian information criterion

BMDS Benchmark Dose Software

CCL cumulative contaminant loading limit

CDF cumulative distribution function

DF dilution factor

DGV default guideline value

DRRS Dawson River Release Scheme

DUA domestic use aquifer

GRDC Grains Research and Development Corporation

IC inhibitory-based concentration

LOI loss on ignition (carbon content)

LTV long-term trigger value

NADH nicotinamide adenine dinucleotide

NGSA National Geophysical Survey – Australia

SSD species sensitivity distribution

STV short-term trigger value

USEPA United States Environmental Protection Agency

Trademarks, trade names, company, or product names referenced herein are used for identification purposes

only and are the property of their respective owners.



Units of Measure

EHS Support Pty Ltd iv

Units of Measure

Area

ha hectare

m2 square metres

Density

kg/m3 kilograms per cubic metre

Electrical Conductance

μS/cm micro Siemen per centimetre

dS/m deci Siemen per metre

mS/cm milli Siemen per centimetre

mV millivolt

Length

μm micrometres

cm centimetres

km kilometres

m metres

mm millimetres

Mass

μg micrograms

g grams

kg kilograms

mg milligrams

t metric tonnes

Concentration by Mass

μg/kg microgram per kilogram

mg/kg milligram per kilogram

Pressure

kPa kilopascals

Pa Pascals

Temperature

°C degrees Celsius

°F degrees Fahrenheit

K kelvin

Velocity

m/s metres per second

Amount

mol mole

M mol per litre

Volume

μL microlitres

cL centilitres

cm3 cubic centimetre

GL gigalitre

L litres

m3 cubic metre

mL millilitres

ML megalitre

Concentration by Volume

μg/L microgram per litre

mg/L milligram per litre

ppmv parts per million by volume

ppbv parts per billion by volume



Introduction and Background

EHS Support Pty Ltd 1

1 Introduction and Background

Santos TOGA Pty Ltd (Santos) on behalf of its joint venture partners (Santos TPY CSG Corp, Santos

TPY Corp, Santos Queensland Corp, Bronco Energy Pty Ltd, PAPL (Upstream) Pty Limited, Total E&P

Australia, Total E&P Australia II & KGLNG E&P Pty Ltd) is seeking to amend the Fairview Arcadia

Project Area (FAPA) Environmental Authority (EA) (EPPG00928713). EA EPPG00928713 authorises

the conduct of petroleum activities on Petroleum Lease (PLs) 90, 91, 92, 99, 100, 232 and Petroleum

Pipeline Licence (PPL) 76 and 92, situated within the FAPA.

Santos seeks to amend the conditions of the FAPA which relate to Boron, specifically conditions

(B20) and Schedule B, Table 4 – Contaminant Limits. The holder of an EA may, at any time pursuant

to section 224 of the Environmental Protection Act 1994 (EP Act), make an application to the

assessing authority seeking an amendment to an EA.

On behalf Santos, EHS Support PTY (EHS Support) has prepared this report discussing Boron

Irrigation Water Guideline Value Derivation to support the FAPA amendment. This factual report

describes limitations of existing Australian and New Zealand Environmental and Conservation

Council (ANZECC) 2000 crop irrigation guidelines for boron and provides a detailed derivation of

alternative criteria using the Australian and New Zealand ANZG (2018) methodology. The approach

used to develop site-specific boron irrigation criteria leverages the species sensitivity approach

detailed in Warne et al. (2018) - Revised method for deriving Australian and New Zealand water

quality guideline values for toxicants as well as recently promulgated Canadian guidance on boron

developed by Alberta Environment and Parks (AEP).

The EA approves release of desalinated produced water at the rate of 18 ML/day from Reverse

Osmosis Plant (ROP) ROP2 to the Dawson River via a tributary referred to herein as the Dawson

River Release Scheme (DRRS). Released produced water mixes with surface water in a manner that is

protective of aquatic receptors within the Dawson River (AECOM, 2019). Since the Dawson River is a

source of irrigation water for downgradient agricultural activities, concentrations of boron at

downstream points of take must also be protective of other realised beneficial uses, such as the

protection of crops.

Assessment of the typical cropping activities along the Dawson River indicate that cotton farming is

the dominant agricultural practice; however, wheat, chickpeas, corn and mung beans are also grown

in the region. The derived irrigation values are intended to be protective of a wide range of crop

types and ensure realised or future beneficial uses are protected within the basin.

1.1 Purpose and Objectives

The purpose of this report is to develop boron irrigation guideline values that adequately protect

crops at the point of take within the Dawson River. The specific objectives of this study include:

• Section 2 – Provides relevant background information on the project;

• Section 3 – Assess the current basis for ANZECC crop irrigation criteria for boron;

• Section 4 – Assess background soil conditions using regional and site-specific datasets;

• Section 5 – Review literature on boron toxicity and derive site-specific irrigation values; and,

• Section 6 – Summarize investigation findings and make recommendations on appropriate

boron irrigation guidelines for the DRRS.



Background


2 Background

2.1 Project Description

Santos obtained an amendment to the FAPA EA (EPPG00928713) on 31st May 2013 to authorise the

release of desalinated produced water from the Fairview reverse osmosis plant (ROP) 2 to the

Dawson River – the DRRS.

The DRRS release includes the following elements:

• Produced water in the Hub Compressor Station No. 4 (F-HCS-04) gathering network is

collected from the well pads within the FAPA via gathering lines and transported to

associated water management pond (F-HCS-04 AW Balance Dam);

• Produced water is then passed through Fairview ROP2 for treatment and subsequently

stored in desalinated water pond (HCS04DWB1) before delivery at a maximum rate of 18

ML/day to the outfall pipeline (which is the total capacity of the pipe and the maximum

design flow for the release scheme);

• A 5.3 km outfall pipeline transfers the desalinated produced water from the desalinated

water pond (HCS04DWB1) to the outfall at the tributary gully;

• Desalinated produced water is released to surface waters as defined by the FAPA EA

(condition B41), at the contaminant release point described in Schedule B, Table 3 –Contaminant release points of the FAPA EA as ROP2. This location is approximately the end

of the outfall pipe into the tributary gully;

• The released water flows for 2.9 km down the tributary gully before discharging into the

Waterbody (otherwise known as the Wetland by the FAPA EA conditions); and

• The Waterbody overflows into a downstream section of the tributary gully, which flows for a

further 1.8 km before discharging into the Dawson River at its downstream confluence.



Current Basis for ANZECC Crop Irrigation Criteria for Boron


3 Current Basis for ANZECC Crop Irrigation Criteria for Boron

The current basis for the ANZECC (2000) crop irrigation criteria for boron and limitations of the

existing guidance is discussed below.

3.1 Default Guideline Values for Boron Crop Irrigation

ANZECC (2000) provides two irrigation water default guideline values (DGVs) for boron: a long-term

trigger value (LTV) and short-term trigger value (STV). The LTV is defined as the maximum

concentration of a constituent in the irrigation water that can be tolerated assuming 100 years of

irrigation, and the STV is the maximum concentration that can be tolerated for a shorter period of

time (usually 20 years). For most irrigation criteria, STV and LTV are related based on a cumulative

contaminant loading limit (CCL) value. In ANZECC (2000), no CCL exists for boron.

The boron STVs values found in Table 9.2.18 of ANZECC (2000) presents six levels of crop tolerance

to irrigation water by common agricultural plant types. Specific plant tolerances to boron used in

Table 9.2.18 were characterized by Maas (1984) and largely sourced by Eaton (1944) – a fairly

comprehensive evaluation of crop boron toxicity using sand culture experiments. This information

was summarized by Ayers and Westcot (1985). Ayers and Westcot (1985) note that the boron trigger

values for boron represent the “maximum concentrations tolerated in soil-water or saturation

extract without yield or vegetative growth reductions. Boron tolerances vary depending upon

climate, soil conditions and crop varieties. Maximum concentrations in the irrigation water are

approximately equal to these values or slightly less.” The LTV was selected as the minimum of the

STV values, which, according to ANZECC (2000) was to “protect the most sensitive species.”

Relative crop tolerances for boron from Ayers and Westcot (1985) are summarized in Table 3-1.

Table 3-1 is very similar to Table 9.2.18 of ANZECC; however, it includes a greater number of total

crops and sub-divides the “sensitive” crop species based on two concentration ranges.

Table 3-1 Relative tolerance of agricultural crops at differing soil water boron concentrations

from Ayers and Westcot (1985)

Tolerance B Conc.

(mg/L) Crop

Very Sensitive <0.5 Lemon (Citrus limon), Blackberry (Rubus spp.)

Sensitive 0.5 – 0.75 Avocado (Persea americana), Grapefruit (Citrus X paradisi), Orange (Citrus sinensis),

Apricot (Prunus armeniaca), Peach (Prunus persica), Cherry (Prunus avium), Plum

(Prunus domestica), Persimmon (Diospyros kaki), Fig, kadota (Ficus carica), Grape

(Vitis vinifera), Walnut (Juglans regia), Pecan (Carya illinoiensis), Cowpea (Vigna

unguiculate), Onion (Allium cepa)

0.75 – 1.0 Garlic (Allium sativum), Sweet potato (Ipomoea batatas), Wheat (Triticum

eastivum), Barley (Hordeum vulgare), Sunflower (Helianthus annuus), Bean, mung

(Vigna radiata), Sesame (Sesamum indicum), Lupine (Lupinus hartwegii),

Strawberry (Fragaria spp.), Artichoke, Jerusalem (Helianthus tuberosus), Bean,

kidney (Phaseolus vulgaris), Bean, lima (Phaseolus lunatus), Groundnut/Peanut

(Arachis hypogaea)

Moderately

Sensitive

1.0 – 2.0 Pepper, red (Capsicum annuum), Pea (Pisum sativa), Carrot (Daucus carota), Radish

(Raphanus sativus), Potato (Solanum tuberosum), Cucumber (Cucumis sativus)





Tolerance B Conc.

(mg/L) Crop

Moderately

Tolerant

2.0 – 4.0 Lettuce (Lactuca sativa), Cabbage (Brassica oleracea capitate), Celery (Apium

graveolens), Turnip (Brassica rapa), Bluegrass, Kentucky (Poa pratensis), Oats

(Avena sativa), Maize (Zea mays), Artichoke (Cynara scolymus), Tobacco (Nicotiana

tabacum), Mustard (Brassica juncea), Clover, sweet (Melilotus indica), Squash

(Cucurbita pepo), Muskmelon (Cucumis melo)

Tolerant 4.0 – 6.0 Sorghum (Sorghum bicolor), Tomato (Lycopersicon lycopersicum), Alfalfa (Medicago

sativa), Vetch, purple (Vicia benghalensis), Parsley (Petroselinum crispum), Beet,

red (Beta vulgaris), Sugar beet (Beta vulgaris)

Very Tolerant 6.0 – 15.0 Cotton (Gossypium hirsutum), Asparagus (Asparagus officinalis)

3.2 Limitations of Boron Irrigation Default Guideline Values

Although the DGV irrigation values address boron tolerance for a wide range of crop types, there are

limitations to their derivation approach that warrant additional consideration in the context of the

current recommendations on deriving guideline values. For most irrigation trigger values in ANZECC

(2000), the approach included consideration of the crop being irrigated, mode of irrigation, soil

characteristics, rainfall and other water quality parameters. Australian and New Zealand (ANZ)

Guidelines on Fresh and Marine Water Quality (2018) indicate that aquatic ecosystem guideline

values may need to be considered for the receiving ecosystems in setting the overall water quality

objective of irrigation values. Limitations identified based on the review of the ANZECC (2000) boron

irrigation criteria include:

• Lack of experimental conditions that would enable of understanding of boron toxicity in

naturally buffered silty-loam soils typical of the region – Experiments informing boron

tolerance thresholds were based on sand cultures and not natural soil types that exhibit

similar physical and chemical characteristics to the soil within the Dawson River valley.

• Reliance on threshold chronic effect concentration rather than preferred no effect

concentrations (NEC) or percent effect/inhibition concentrations – The existing STVs and LTVs

utilize threshold responses, which are the concentrations at which any reduction in growth

endpoints were observed. Threshold approaches are sensitive to outliers and effects-based

(ECX) or inhibitory-based concentrations (ICX) are preferred metrics for evaluating risk to

organisms under the most recent testing and assessment methodologies (e.g., Warne et al.

[2018]).

• Crop-specific tolerance levels rather than statistically derived species sensitivity distributions

(SSD) – Use of crop-specific thresholds may be useful for protecting known crops within the

Dawson River Valley, but they do not consider protection levels for multiple crop species if

agricultural practices in the valley change over time. Adopting more statistically robust

methods, such as SSDs or crop sensitivity distributions (CSDs) will provide a more detailed

understanding as to the percentage of crops protection at given irrigation threshold.

Detailed discussion of each limitation is provided below.

Under the updated ANZECC framework, existing boron irrigation values are considered DGVs. DGVs

can be updated based on site-specific conditions. Therefore, derivation approaches adopted by

other, more recent international guidance documents that consider natural soils would be more

applicable. The proposed application of boron containing irrigation water in the Dawson River Valley

has been considered when assessing the suitability of these DGVs. In the context of irrigation water





quality, the complexities of natural soil systems are recognized in the ANZECC (2000) guidance.

Section 9.2.1 (ANZECC, 2000) summarizes the general considerations for assessment of irrigation

water quality, which include water balance, soil characteristics, crop tolerance, climatic conditions

and subsurface drainage. All of these elements were not adequately considered within the

framework of the Eaton (1944) study, and the geochemical reactions in natural soils is a key factor

affecting impacts on vegetative growth.

The use of sand culture experiments within the existing ANZECC irrigation guidance for boron is a

limitation because it does not consider the natural buffering capacity of soils. A critical determinant

in bioavailability of boron are the soil properties and geochemistry. In bulk soil, boron is most

commonly present as borate (BO3-3), where its availability is controlled by carbonates and oxides and

hydroxides of iron and aluminium, in reactions that are similar to those for phosphate in that they

are pH dependent (Park and Schlesinger, 2002). Boron in soil solution, which is a more relevant

exposure medium for plants than bulk soil, is mainly present as the neutrally charged undissociated

boric acid [B(OH)3] and borate. The logarithmic acid dissociation constant (pKa) of boric acid is 9.25

and, at neutral pH, the equilibrium is shifted greatly toward boric acid. Boron is unique among

essential nutrients for plants taken up from soil in that it is taken up by plants as a neutrally charged

species (boric acid), and not an ion. Some boron toxicity studies (e.g., Aitken and Bell, 1984) were

conducted using alkaline soils, which likely favoured the formation of borate and impeded the

mobility of boron and its uptake into plants.

Crop tolerance to boron soil water concentration summarized by Ayers and Westcot (1985) included

information from Eaton (1944), which, to date, represents one of the most comprehensive

summaries of boron deficiency and toxicity information for plants. Eaton (1944) examined over 50

species of crops in large sand cultures. The field trials published by Eaton (1944) were conducted in

outdoor sand cultures in the early 1930s. Each crop was started by seed. The sand was irrigated with

culture solutions containing trace boron (0.03 or 0.04 mg/L), as well as treated cultures with 1,5,10,

15, and 25 mg/L boron. The water also contained 6, 3, and 3 μmol/L of calcium nitrate, magnesium sulphate, and monopotassium phosphate, respectively. Sand cultures were flushed twice daily with

treated water. The use of sand columns by Eaton (1944) enabled control over experimental

conditions; however, these conditions do not align well with sandy loam and silty soil types present

within the Dawson River Valley (site and regional specific soil information is provided in Section 4).

Further, due to the limited information on effective macronutrient solution concentrations and pH,

it is unclear if resulting boron growth thresholds were low due to experimental artefacts associated

with nutrient limitation. Nevertheless, the values derived from these sand culture studies provide a

conservative estimate of the concentration of boron needed in soil water to result in changes to

crop growth and experimental findings using silty loam soils could highlight this limitation.

The current STVs rely on threshold chronic effect concentration rather than preferred no effect

concentrations (NEC) or percent effect/inhibition concentrations. Warne et al. (2018) establishes a

hierarchy of preference for selecting estimates of chronic toxicity. In order of greatest preference

these included NEC, ECX/ICX (where x is ≤ 10), 10% bounded effect concentration (BEC10), ECX/ICX

(where 10 < x ≤ 20), no observed effect concentration (NOEC), or estimated NOEC. Threshold

approaches are sensitive to outliers and study design. For example, if the hypothetical concentration

of an effect occurred at 4.9 mg/L soil water boron and the study design used the treatments

discussed in Eaton (1944) a NOEC would be determined at 1 mg/L and the LOEC would be 5.0 mg/L.

Although multiple treatments would be used in the study, none of these would contribute to the

understanding of toxicity to that particular organism. This is why the guidance proposed in Warne et

al. (2018) prefers ECX/ICX approaches. The experimental findings of Eaton (1944) support the

development of more robust statistical approaches for understanding chronic effects, but these are





not leveraged in the existing ANZECC (2000) guidance. Recent guidance promulgated by AEP makes

use of the robust assessments in sand cultures by Eaton (1944) and others. This is discussed in detail

in Section 5.2.

Lastly, the existing ANZECC guidance offers crop-specific tolerance trigger values rather than

statistically derived trigger values based on the percent of crops protected from SSDs. The more

current, risk-based approaches discussed in Warne et al. (2018) recognize that guideline values

specific to a given species (or crop) could result in issues for other species if the particular species of

interest is more resilient to the compound of interest. By leveraging data collected across several

taxonomic groups for several species, the SSDs enable an estimation of the percentage of species

protected by a guideline value. Because cotton farming is widespread within the region, a case could

be made in favour of an irrigation value of 6.0 mg/L soil water boron based on ANZECC (2000).

However, this approach would not account for potential changes in agricultural practices over time.

Nor would it be protective of less tolerant species that are not typically grown in the region. Simply

selecting an STV based on tolerance and anticipated cropping regimes does not provide a rigorous

statistical approach for risk-based decision making; therefore, adopting a method that accounts for

the sensitivity of crops to known inhibitory endpoints (e.g., growth) allows for the development of

robust irrigation trigger values.



Assessment of Regional and Site-Specific Soil Conditions


4 Assessment of Regional and Site-Specific Soil Conditions

A determinant in bioavailability of boron are the soil properties and geochemistry. This assessment

focused on understanding the physical and chemical conditions that may influence the fate and

transport and toxicity of boron using regional and site-specific data.

4.1 Regional Soil Condition

The soil quality in the region has been evaluated by the NGSA (Caritat et al., 2010). Soil samples

were collected throughout Queensland including in the vicinity of the Project Area (Figure 4-1). Soils

are primarily comprised of sand and silt with lower clay content, and total organic carbon contents

of 6.7 ± 4.1 percent (Table 4-1).

Table 4-1 Soil parameters for Queensland from the NGSA dataset

Parameter Average ± One Standard Deviation

LOI (%) 6.7 ± 4.1

Clay (%) 14.3 ± 8.8

Silt (%) 33.3 ± 15.1

Sand (%) 52.4 ± 23.3

Table Notes:

LOI = Loss on ignition

Given the critical role that soil pH plays in boron mobility, soil data collected by the NGSA, including

in the general vicinity of the project area (Table 4-1). The data review indicated that native soil in

Queensland is circumneutral (6.3 + 0.9; n = 78). The region is arid; annual rainfall in Taroom,

Queensland, located 72 km from the proposed release site, is 670 mm per year (Australian Bureau of

Meteorology, 2019). In areas of Queensland with rainfall levels less than 1000 mm per year, only 5

percent of soils have pH higher than 8.5 (soilquality.org.au). Based on the NGSA data, it is expected

that boron would be present as the neutrally charged boric acid and available for plant uptake.

However, there is some uncertainty given the wide geographic range over which the NGSA data

were collected; more site-specific data is discussed below.

Boron concentrations in uncontaminated native soils from Queensland appear to be low. The NGSA

measured total boron concentrations in Queensland soil found that concentrations in soil were

below the detection limit (1 mg/kg) in 70 of 78 samples and averaged 1.5 + 0.5 (n = 8) in the samples

with detectable concentrations. As a technical consideration, any future soil sampling may consider

chemical extraction techniques to estimate the bioavailable fraction of boron in soil. ANZECC (2000)

recommends measuring 0.01M CaCl2 extractable boron, rather than total boron as the hot 0.01M

CaCl2 extractable fraction is more comparable to the plant available fraction in soil. ANZECC (2000)

assumes that the 0.01M CaCl2 extraction from soil and total boron in aqueous samples are

equivalent.

Although native soils are likely circumneutral in Queensland, soil pH is actively managed in

agriculture, and soil pH may deviate significantly from the native state. Irrigated crops in the area are

focused mainly on cotton; however, wheat, chickpeas, corn and mung beans are also grown. A soil

pH in calcium chloride (CaCl2) of 5.2–8.0 provides optimum conditions for most agricultural plants,

including those listed above (Grains Research and Development Corporation [GRDC], 2017). Based





on the crops grown in the region, it is unlikely that soil amendments to alternative pH levels would

result in alkaline soils that could limit boron bioavailability.

Figure 4-1 NGSA sample locations

4.2 Soil Conditions Near the Proposed Release Location

Soil conditions in soils evaluated near the proposed release location are summarized below. Studies

completed by Santos in the area of the DRRS are quite heterogeneous in composition with soils in

the immediate vicinity of the Dawson River flood plain comprised largely of sandy loams (Horizon,

2018). Cropping in the area is generally biased towards soils with higher fines content due to their

inherent capacity to retain moisture and support extended growth periods. A and B horizon soil

descriptions developed by Horizon Soil Science and Engineering Pty. Ltd. (Horizon) as part of the

Report on the Soil Survey of Fairview and Arcadia Project Area in 2018 are illustrated in Figure 4-2. A

mixture of loamy sands as well as light and medium clay soils are observed in the vicinity of the

upland areas adjacent to the Dawson River. Soil chemistry at the surface was generally observed to

be neutral with a slight alkaline shift at increasing depth intervals

Based on the evidence presented above, it is likely that naturally occurring soil boron and any

additional boron added from irrigation waters at the point of take would be bioavailable to plants at

the surface. Boron is taken up by plants as the neutrally charged boric acid, and this species is

favoured at the circumneutral pH typically found in regional soils. Bulk soil boron concentrations,

although low in in native Queensland soils, are poor predictors of boron bioavailability and chemical

extraction methods can be used to reduce uncertainty regarding boron bioavailability. Although pH

will be affected by agricultural activity, it is unlikely that soil pH will be increased to the point where

boron uptake would be limited.





Figure 4-2 Soil characteristics near proposed release location (Horizon, 2018)



Boron Plant Toxicity Literature and Irrigation Criteria Derivation


5 Boron Plant Toxicity Literature and Irrigation Criteria Derivation

The Canadian Provence of Alberta has recently released a comprehensive set of Tier 1 remediation

guidelines across multiple media and receptors to better manage contaminated sites (Alberta

Environment and Parks [AEP], 2019). As part of the newly developed guidelines, updated approaches

were used for deriving environmental and human health criteria for boron (AEP, 2015a). The

promulgated Canadian guidance leverages an expanded literature review beyond the sand culture

studies conducted by Eaton (1944). Recognizing these deficiencies, the AEP contracted the

laboratory Exova to conduct toxicity testing conducted across multiple soil types to assess boron’s inhibitory capacity on crop growth. The following section summarizes the current state of

understanding of boron toxicity to crops, the approach adopted by AEP, and derivation of

preliminary irrigation criteria within the ANZECC framework.

5.1 Mechanisms of Plant Boron Use, Deficiency, and Toxicity

Boron is well recognized as an essential element for plant growth (Miwa and Fujiwara, 2010; Dell

and Huang, 1991). The element plays a key physiological role in the function of plant cellular walls.

Unlike most other essential elements taken up by plants as charged ions, the uncharged

(electroneutral) boric acid [B(OH)3] molecule in soil water is used by plants (Miwa and Fujiwara,

2010). At low concentrations of bioavailable soil boron, plants can have limited growth due to

deficiency and at high concentrations plants can have deleterious effects to growth and productivity

(Ayers and Westcot, 1985). Although the primary mechanism responsible for boron transport in

plants was believed to be passive in nature; more recent literature suggests that plants actively

sense and respond to soil boron concentrations (Miwa and Fujiwara, 2010). Since the interaction

between crop boron tolerance and the ability for a given plant species to sense and respond to soil

boron is not fully understood, the derived irrigation criteria must be conservative to a wide range of

crop and soil types whilst recognizing that “tolerance” may be a physiological adaptation linked to transport mechanisms and soil conditions.

In plants, boron deficiencies can be expressed structurally or biogeochemically. Structural

deficiencies include abnormal cell wall formation and membrane production. The specific

mechanism driving cell wall abnormality have been attributed to the inability for a cellular wall

polysaccharide (RG-II) and pectin to effectively join (Camacho-Cristóbal et al., 2008). Without the

rigid structure offered by the boron-mediated joining of RG-II and pectin, the plant cells become

stressed and elongated, and growth is inhibited. Membrane production can also be impeded by

boron deficiency; however, uncertainties of the specific mechanism still exist. Biogeochemical

factors that can be altered by boron deficiency include the inability to assimilate nitrate and reduced

production of important enzymes that moderate plant oxidative stress (Camacho-Cristobal et al.,

2008).

At high concentrations, boron can exhibit a range of toxic effects that influence the metabolic

function and growth of plants (Nable et al., 1997). The specific mechanisms of boron toxicity in

plants is not clear. Similar to processes influencing boron deficiency, toxicity may be caused by

alterations to cell wall structure, the interruption of metabolic processes involving adenosine

triphosphate (ATP) or nicotinamide adenine dinucleotide (NADH), and/or cell reproduction

disruption (Camacho-Cristóbal, 2008).





Regardless of specific mechanisms driving these interactions, plants tend to exhibit an increased

response in growth and function to the presence of some level of boron and at some tipping point

the beneficial effect of boron become deleterious.

5.2 Summary of AEP Criteria

AEP (2015a) derived direct contact values for boron using ecological direct contact toxicity data for

ornamental and crop plant species, trees and soil invertebrates. Toxicity information was sourced

from historical sand column studies (e.g., Eaton [1944], Francois [1986, 1988, 1989, 1991, 1992],

Bingham et al. [1985]) as well as soil-specific toxicity testing on six common agricultural species

(alfalfa, northern wheatgrass, cucumber, barley, carrot and durum wheat) conducted by Exova 2011-

2014 (AEP, 2015b). Additional toxicity testing was conducted on common Albertan plans including

jack pine, white spruce, bluejoint reedgrass, black spruce, and trembling aspen. IC25 values were

calculated using the United States Environmental Protection Agency (USEPA) Benchmark Dose

Software (BMDS) for historical and site-specific toxicity information. Data were expressed based on

mg/L saturated paste boron, which was deemed to be the most appropriate analytical method for

quantifying plant available soil boron (AEP, 2015a). Saturated paste boron can be converted to soil

water solution boron by multiplying by a factor of 1.27 (AEP, 2015a).

Since multiple data sources were used, some crop species had up to three data points within the SSD

developed by the AEP. This was attributed to up to three different soil types (i.e., sand column,

sandy loam, and clay loam). No advanced statistical tools were used to conduct model fitting of the

SSD. Rank percentiles were assigned, and a log-normal model was adopted to predict the

concentrations corresponding to protection of 25 percent and 50 percent of the species for IC25

effect values. A saturated paste boron concentration of 3.3 mg/L in soil was estimated to be

protective of the 25th percentile and a concentration of 7.9 mg/L was estimated to be protective of

the 50th percentile.

Information from the threshold crop tolerance values, in tandem with known IC25 SSD, was used to

develop the irrigation criteria for boron. A value of 1 mg/L (saturated paste basis) was deemed an

appropriate groundwater guideline to protect crop receptors. If expressed on the basis of soil water,

the concentration would be approximately 1.27 mg/L. At an irrigation concentration of 1.27 mg/L,

the water was deemed to pose minimal risk and was used as the basis for subsequent evaluations

(AEP, 2015a). This guideline value was multiplied by four dilution factors (DFs) to account for the

following:

1. DF1: partitioning and soil solution boron;

2. DF2: leaching towards domestic use aquifer (DUA);

3. DF3: dilution into a DUA; and

4. DF4: lateral transport.

This approach used several detailed assumptions about local hydrological conditions to inform final

irrigation water criteria development, which could be considered for the DRRS. However, in the

absence of site-specific information and a known riverine source of irrigation water, a simpler

approach was developed that does not rely on assumptions related to the water table in the region.

The section below describes the detailed derivation approach of the boron crop irrigation guideline

values for use by the FAPA.





5.3 Derivation of Boron Irrigation Values Based on Crop SSD Approach

Crop irrigation criteria were derived based on boron toxicity information for 40 different common

crop species across three different soil types. The approach adopted to redevelop boron irrigation

guide values leveraged the large toxicity dataset compiled on crop-specific data found in AEP

(2015b) to calculate and estimate IC10 chronic values to assess the 95% crop protection level using

the SSD framework of Warne et al. (2018).

The general approach for deriving the crop guideline values was as follows:

1. Collate toxicity literature and assess its quality

2. Establish a hierarchy of preferred chronic values

3. Quantify IC10 effects for crops using USEPA Benchmark Dose Software for select data

4. Use relationship between calculated chronic effect types to develop site-specific conversion

factor to estimate IC10 effects for less conservative chronic endpoints.

5. Run crop sensitivity distributions (CSDs) using measured IC10 and estimated chronic data.

Details of each step outlined above is provided in the subsequent sections.

5.3.1 Boron Crop Toxicity Literature and Quality Assessment

Boron toxicity information for crops was obtained from 10 different literature sources:

1. Exova (2011-2014)

2. Eaton (1944)

3. Bingham et al. (1985)

4. Francois (1986)

5. Francois (1988)

6. Ahmed et al. (2007)

7. Francois (1989)

8. Francois (1991)

9. Francois (1992)

10. Vlamis and Ulrich (1973).

A detailed review of the quality of the toxicity testing information provided by these studies is

provided in Appendix A - Boron Crop Toxicity Literature Quality Assessment. The approach used to

assess toxicity test quality followed that discussed in Warne et al. (2018); however, information that

was specifically relevant to aquatic toxicity testing was omitted. Data sources included in subsequent

assessments were considered to be in the high or acceptable quality class with quality scores ≥ 80%

or ≥50– <80%, respectively. The recent toxicity data from Exova (2011-2014) included in the AEP

(2015b) guidance has the greatest quality score and the work of Eaton (1944) has the lowest quality

score.

5.3.2 Hierarchy of Preferred Chronic Values

The established hierarchy of preferred chronic values described in Warne et al (2018) is listed below:

• No effect concentrations (NEC)

• x% effect/inhibition/lethal concentration (in order of preference: EC/IC/LCx) where x ≤10(wherever possible, ECx and ICx data should be used in preference to LCx data)

• 10% bounded effect concentration (BEC10)

• x% effect/inhibition concentration (EC/IC/LCx1) where x >10 and ≤20





• No observed effect concentration (NOEC)

• NOEC estimated from a chronic maximum acceptable toxicant concentration (MATC), lowest

observed effect concentration (LOEC) or median lethal/effect value (LC/EC50).

ANZECC (2000) recommends the use of a 90 percent yield to quantify irrigation water criteria.

Therefore, IC10 chronic values would be most applicable in determining appropriate boron irrigation

values within the DRRS. Taking the IC25 chronic values directly from the AEP (2018) and converting

them using the NOEC estimation conversion factors would be a plausible approach to understanding

the distribution of growth inhibition to crops due to added boron. However, this approach results in

lower reliability and measured IC10 are preferred to estimated NOECs.

5.3.3 IC10 Effects Quantification Using USEPA Benchmark Dose Software

The calculation of IC10 effects values for select crops using the Exova toxicity data found in AEP

(2015b) is discussed below. The detailed boron crop toxicity information provided in AEP (2015b)

enabled the preferred IC10 values to be measured. IC10 effects values were calculated using USEPA

Benchmark Dose Software (BMDS, Version 3.1). Calculations were performed for six select crops,

across two soil types, and four receptor endpoints. Values were calculated for each combination of

crop, soil type and receptor. The Maximum Likelihood Estimate (MLE) was calculated using the

Frequentist Restricted Hill Model. The Benchmark Response (BMR) risk type was set to Relevant

Deviation, the BMR Factor (BMRF) set to 0.1 and the confidence level set to 0.95. Normal

distribution and constant variance were used. Appendix B - USEPA Benchmark Dose Crop Growth-

Response IC10 Evaluation provides detailed summaries of the BMD model runs using input data from

Tables A-1 through A-19 in AEP (2015b).

5.3.4 Develop Constituent-Specific Conversion Factor Between Measured

IC10 and IC25 Values

The linear relationship between measured IC10 and IC25 values for toxicity data from Exova (2011-

2014) was evaluated. The resulting regression was used to determine conversion factors to estimate

IC10 values from existing, more conservative IC25 values found in AEP (2015b) (Figure 5-1).

A significant, linear relationship was observed whereby soil water IC25 values for boron could explain

83% of the variance of soil water IC10 values. Measured IC25 values from the literature could then be

reliably converted to IC10 by dividing by 1.62.





Figure 5-1 Crop species sensitivity distribution of estimated and measured IC10 values across

each soil type with three candidate model fits

Table 5-1 provides a summary of all of the estimated and measured IC10 effects values by soil type

and receptor group. Appendix C – Estimated and Measured Crop Soil Water IC10 and IC25 Values by

Soil Type and Receptor contains both chronic effect values.

Table 5-1 Estimated and measured crop soil water IC10 values by soil type and receptor

(Adapted from Table D-1 in AEP [2015b])

Crop Receptor Soil Type Source IC10 (mg/L) IC10 Value Type

Alfalfa Sand Culture 2 4.36 Estimated

Barley Sand Culture 2;3 2.96 Estimated

Beet Sand Culture 2 8.52 Estimated

Blackberry Sand Culture 2 1.17 Estimated

Broccoli Sand Culture 4 9.23 Estimated

Cabbage Sand Culture 2 10.31 Estimated

Carrot Sand Culture 2 2.93 Estimated

Cauliflower Sand Culture 4 10.66 Estimated

Celery Sand Culture 2;5 11.71 Estimated

Cherry Sand Culture 2 1.45 Estimated

Common wheat Sand Culture 3 5.14 Estimated

Corn Sand Culture 2 2.62 Estimated

Cotton Shoots Sandy Loam 6 14.12 Measured

Cow pea Sand Culture 2;7 1.81 Estimated

Garlic Sand Culture 8 8.43 Estimated

Grape Sand Culture 2 1.40 Estimated

Jerusalem Artichoke Sand Culture 2 2.10 Estimated

Kentucky bluegrass Sand Culture 2 7.14 Estimated

Kidney bean Sand Culture 2 1.94 Estimated

Lettuce Sand Culture 2;5 9.40 Estimated





Lima bean Sand Culture 2 2.21 Estimated

Mustard Sand Culture 2 13.53 Estimated

Oats Sand Culture 2 4.81 Estimated

Onion Sand Culture 8 13.70 Estimated

Parsley Sand Culture 2 7.47 Estimated

Pea Sand Culture 2 2.48 Estimated

Peach Sand Culture 2 1.72 Estimated

Potato Sand Culture 2 6.25 Estimated

Radish Sand Culture 2; 4 8.19 Estimated

Snap bean Sand Culture 7 1.92 Estimated

Sorghum Sand Culture 3 7.87 Estimated

Squash Sand Culture 9 4.22 Estimated

Strawberry Sand Culture 2 1.55 Estimated

Sugar beet Sand Culture 10 6.82 Estimated

Sweet Pea Sand Culture 2 2.27 Estimated

Tomato Sand Culture 2 7.86 Estimated

Vetch Sand Culture 2 13.09 Estimated

Alfalfa Root Clay Loam 1 40.11 Measured

Alfalfa Shoot Clay Loam 1 29.60 Measured

Alfalfa Root Sandy Loam 1 37.41 Measured

Alfalfa Shoot Sandy Loam 1 21.97 Measured

Barley Root Clay Loam 1 12.98 Measured

Barley Shoot Clay Loam 1 44.33 Measured

Barley Root Sandy Loam 1 13.67 Measured

Barley Shoot Sandy Loam 1 27.62 Measured

Carrot Root Clay Loam 1 13.84 Measured

Carrot Shoot Clay Loam 1 9.02 Measured

Carrot Root Sandy Loam 1 11.17 Measured

Carrot Shoot Sandy Loam 1 8.37 Measured

Cucumber Root Clay Loam 1 3.88 Measured

Cucumber Shoot Clay Loam 1 13.48 Measured

Cucumber Root Sandy Loam 1 1.46 Measured

Cucumber Shoot Sandy Loam 1 9.20 Measured

Durum Wheat Root Clay Loam 1 11.38 Measured

Durum Wheat Shoot Clay Loam 1 24.34 Measured

Durum Wheat Root Sandy Loam 1 7.15 Measured

Durum Wheat Shoot Sandy Loam 1 12.75 Measured

Northern Wheat Grass Root Clay Loam 1 22.19 Measured

Northern Wheat Grass Shoot Clay Loam 1 33.41 Measured

Northern Wheat Grass Root Sandy Loam 1 3.83 Measured

Northern Wheat Grass Shoot Sandy Loam 1 14.36 Measured

Table Notes:

Sources from Table D-1 (AEP, 2015b): 1 = Exova (2011-2014); 2 = Eaton (1944); 3 = Bingham et al. (1985); 4 = Francois

(1986); 5 = Francois (1988); 6 = Ahmed et al. (2007); 7 = Francois (1989); 8= Francois (1991); 9 = Francois (1992); 10 =

Vlamis and Ulrich (1973)





5.3.5 Crop Sensitivity Distribution Assessment

Using the data provided in Table 5-1 CSDs were developed using soil water boron IC10 values to

provide an estimate of soil boron toxicity across a wide range of soil types and crops. Two fitting

procedures were employed to estimate 95% crop protection levels: the Burrlioz 2.0 software and

fitdistrplus. Fitdistrplus is similar to the Burrlioz software recommended by Warne et al. (2018);

however, it provides enhanced functionality to compare model types whilst providing diagnostic

tools such as goodness-of-fit statistics and goodness-of-fit criteria (Delignette-Muller et al., 2019).A

summary of the Burrlioz output and statistical diagnostics is found in Appendix D – Burrlioz Output

and Diagnostic Statistics.

The CSD is illustrated in Figure 5-2 and resulting crop irrigation levels of protection are summarized

in Table 5-2. Since most agricultural areas are modified landscapes, the 90 percent or 95 percent

level of protection would be suitable. However, in effort to be conservative in nature, and align with

the derivation approach used for ecological receptors within the Dawson River, the 95 percent crop

protection level was selected. Three separate models were fit to the cumulative distribution function

(CDF): log-normal, log-logistic, and Burr type III. All three models had comparable performance as

determined by the Anderson-Darling test. However, the Bayesian information criterion (BIC), a

metric for evaluating the most parsimonious model, was lowest for the log-logistic distribution. The

log-logistic model fit was therefore selected as the most suitable irrigation value for 95 percent crop

protection of soil water boron. Using the CSD approach, the log-logistic soil water boron guideline

value would be 1.4 mg/L.

Table 5-2 Guideline values (± 95% confidence interval) derived using a species sensitivity

approach of soil water boron IC10 values

Model Fit Type

IC10– 95% Crop

Protection Soil

Water B (mg/L)

Log-Normal Fit 1.5 (1.0 – 2.2)

Log-Logistic Fit 1.4 (0.9 – 2.2)

Burr Type III Fit 1.2 (0.9 – 1.8)

Table Notes:

Bolded term indicates recommended IC10– 95% Crop Protection irrigation guideline value





Figure 5-2 Crop species sensitivity distribution of estimated and measured soil water boron IC10 values across each soil type with three

candidate model fits





In summary, the derived soil water boron irrigation criteria using the log-logistic fit is recommended

at a concentration of 1.4 mg/L soil water boron. The adopted approach has the following advantages

over the historical approach used in ANZECC:

• It considers a wider range of crops due to additional literature sources beyond those

summarized by Ayers and Westcot (1985) and leverages recent, natural soil crop-specific

toxicity testing data from the AEP.

• Rather than using tolerance values, which can be sensitive to outliers, the irrigation criteria

is informed by IC25 data.

• The derivation approach makes use of the SSD framework. This enables decisions to be

made on the basis of proportion of crops protected. For example, accepting a 95 percent

crop protection guideline would mean that only two crops (blackberries and grapes) may

experience a reduction in production based on the IC10 effect values.



Conclusions


6 Conclusions

This assessment has detailed the existing guidance for boron crop irrigation values within the

ANZECC framework. Although the DGVs may be suitable for quickly determining which crops are

suitable for irrigation, they do not provide a statistically defensible framework in which to make risk-

based decisions. Inherent limitations associated with the historical assessment have provided highly

conservative tolerance thresholds that do not align with the current, robust scientific assessment

methods such as those described by Warne et al. (2018).

A number of the key weaknesses of the studies referenced within ANZECC have been addressed by

leveraging recently promulgated Canadian guidance. This new AEP guidance incorporates more

recent literature and soil-specific toxicity testing across a range of natural soil types. The resulting

CSD (Figure 5-2) can be used to identify the proportion of crops affected for a constant test criteria

(IC10). Due to the retention of the historic (and highly conservative) sand culture studies in the CSD

approach, the resulting irrigation value at the 95 percent crop protection level (1.4 mg/L) is still

considered conservative in nature and protective of a wide range of crop types grown in the Dawson

River Valley. These values are slightly higher than the generic screening criteria of 1.27 mg/L

developed by AEP, which, if applied, would be consistent with our data assessment and provide

protection to the likely range of crops grown in the area with limited-to-no reduction in productivity.

In application of irrigation criteria, it is important to note a number of items consistent with the

ANZECC framework:

1. The criteria provided should be considered average irrigation water quality as impacts on

plant growth can be averaged over time. In the context of discharges of treated effluent to

the Dawson River, natural variability in flow will provide a wide range of dilutions with

discharge criteria establishment based on conservative base flow conditions.

2. Consistent with the ANZECC framework, monitoring and management are key components

for management of impacts. Modifications to discharge regime (to the Dawson River to

facilitate additional dilution), can be implemented.



Limitations


7 Limitations

EHS Support Pty Ltd (“EHS Support”) has prepared this report in accordance with the usual care and thoroughness of the consulting profession for the use of Santos TOGA Pty Ltd and only those third

parties who have been authorised in writing by EHS Support to rely on the report. It is based on

generally accepted practices and standards at the time it was prepared. No other warranty,

expressed or implied, is made as to the professional advice included in this report.

This report should be read in full. No responsibility is accepted for use of any part of this report in

any other context or for any other purpose or by third parties. This report does not purport to give

legal advice. Legal advice can only be given by qualified legal practitioners.



References


8 References

AECOM. 2019. Revised Boron Site-Specific Water Quality Criterion – Dawson River Release Scheme.

Letter from B. Goldsworthy and N. Lee to A. Lavery. 12 July 2019.

Ahmed, J.N., M. Abid, & K. Islam. 2007. Boron Toxicity in Irrigated Cotton. In The ASA-CSSA-SSSA

International Annual Meetings. (Vol. 7, pp. 296-312). November.

Alberta Environment and Parks (AEP). 2015a. Soil Remediation Guidelines for Boron: Environmental

and Human Health. Land Policy Branch, Policy and Planning Division. 146 pp.

Alberta Environment and Parks (AEP). 2015b. Soil Remediation Guidelines for Boron: Supplemental

Data Appendices. Land Policy Branch, Policy and Planning Division. 126 pp.

Alberta Environment and Parks (AEP). 2019. Alberta Tier 1 Soil and Groundwater Remediation

Guidelines. Land Policy Branch, Policy and Planning Division. 198 pp.

ANZECC, A. (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality.

Volume 3, Chapter 9. Primary Industries—Rationale and Background Information (Irrigation

and general water uses, stock drinking water, aquaculture and human consumers of aquatic

foods).

Australian Bureau of Meteorology. 2019. Climate statistics for Australian locations. Taroom Post

Office, Site 035070. Location: http://www.bom.gov.au/climate/

Ayers, R.S., and D.W. Westcot. 1985. Water Quality for Agriculture, FAO Irrigation and Drainage

Paper 29 Rev. 1. Food and Agriculture Organization of the United Nations, Rome. 174 pp.

Bingham, F.T., J.E. Strong, J.D. Rhoades, and R. Keren. 1985. An application of the Maas-Hoffman

Salinity Response Model for Boron Toxicity. Soil Science Society of America Journal. 49, 672-

674.

Camacho‐Cristóbal, J. J., J. Rexach, & A. González‐Fontes. 2008. Boron in plants: deficiency and toxicity. Journal of Integrative Plant Biology, 50(10), 1247-1255.

Caritat, P. de, M. Cooper, W. Pappas, C. Thun, and E. Webber. 2010. National Geochemical Survey of

Australia: Analytical Methods Manual. Geoscience Australia. Record 2010/15, 22 pp.

Delignette-Muller, M.L., & C. Dutang. 2015. fitdistrplus: An R package for fitting distributions. Journal

of Statistical Software, 64(4), 1-34.

Delignette-Muller, M.L., C. Dutang, R. Pouillot, J.B. Denis, & A. Siberchicot. 2019. Package

‘fitdistrplus’.

Dell, B. & L. Huang. 1997. Physiological response of plants to low boron. Plant and soil, 193(1-2),

103-120.

Eaton, F.M. 1944. Deficiency, toxicity and accumulation of boron in plants. J. Agric. Res. 69, 237–277.

http://www.bom.gov.au/climate/



References


Francois, L.E. 1986. Effect of excess boron on broccoli, cauliflower and radish. Journal of the

American Society for Horticultural Science. 111, 494-498.

Francois, L.E. 1988. Yield and quality responses of celery and crisphead lettuce to excess boron.

Journal of the American Society for Horticultural Science. 113, 538-542.

Francois, L.E. 1989. Boron tolerance of snapbean and cowpea. Journal of the American Society for

Horticultural Science. 114, 615-619.

Francois, L.E. 1991. Yield and quality responses of garlic and onion to excess boron. Horticultural

Science. 26 (5), 547-549.

Francois, L.E. 1992. Effect of excess boron on summer and winter squash. Plant and Soil. 147, 163-

170.

GRDC. 2017. GrowNotes for Wheat. Southern Region. April 24.

Maas EV. 1984. Salt tolerance of plants. In: Christie BR, ed. Handbook of plant science in agriculture.

Volume 2. Bota Raton: CRC Press, 57–75.

Miwa K. and T. Fujiwara. 2010. Boron transport in plants: co-ordinated regulation of transporters.

Ann. Bot., 105(7): 1103–1108.

Nable R.O., G.S. Banuelos, J.G. Paull. 1997. Boron toxicity. Plant Soil 193, 181–198.

Park H. and W.H. Schlesinger. 2002. Global biogeochemical cycle of boron. Global Biogeochemical

Cycles 16(4): 1-10, 2002.

Soil pH in regard to rainfall data obtained from the Soil Quality website: http://soilquality.org.au/

Vlamis, J. and A. Ulrich. 1973. Boron tolerance of sugar beets in relation to the growth and boron

content of tissues, Journal of the American Society of Sugar Beet Technologist. 17 (3) 280-

288.

Warne, Michael, Graeme Batley, Rick van Dam, John Chapman, David R. Fox, Christopher Hickey,

Jenny Stauber. 2018. Revised method for deriving Australian and New Zealand water quality

guideline values for toxicants. 10.13140/RG.2.2.36577.35686.

http://soilquality.org.au/

Boron Irrigation Water Guideline Derivation – Boron Irrigation Water Guideline Derivation

EHS Support Pty Ltd

9 Appendices


EHS Support Pty Ltd

Appendix A Boron Crop Toxicity Literature Quality Assessment

APPENDIX A ‐ TABLE A‐1Boron Crop Toxicity Literature Quality AssessmentFAPA ‐ Dawson River Release Scheme ‐ August 2019


1. EXOVA, 2011‐2014(AEP, 2015)

2. Eaton, 1944(AEP, 2015) 3. Bingham et al, 1985

Assessment Notes

ANZGScore

Assessment Notes

ANZGScore

Assessment Notes

ANZGScore

1 Was the duration of the exposure stated? Yes. 10 (10) Yes, but only at the resolution of month. 5 (10) Yes. 10 (10)

2 Was the biological endpoint stated and refined?

Yes. Growth + appearance. Appearance was qualitative.

10 (10)Yes, growth was stated but not explicitly defined.

5 (10) Yes. Plant weight. 10 (10)

3 Was the biological effect stated (for example, LC or NOEC)? Yes 5 (5) Based on AEP, 2015a. 5 (5) No. 0 (5)

4Was the biological effect quanitified (for example, 50% effect, 25% effect). The effect for NOEC and LOEC data must be quantified.

Yes 5 (5) Based on AEP, 2015a. 5 (5) No. 0 (5)

5 Were appropriate controls (for example no‐toxicant control and/or solvent control) used? Yes 5 (5)

Yes, a control concentration of boron varied by species tested.

5 (5) No. 0 (5)

6 Was each control and chemical concentration at least duplicated?

Yes. 2 replicates per treatment. 5 (5) Yes, seasonal

replication was applied. 5 (5) Yes. 4 replicates per treatment. 5 (5)

7

Were test acceptability criteria stated or inferred (for example mortality in controls must not exceed a certain percentage)? Data that fail the acceptability criteria are automatically deemed to be of unacceptable quality and must not be used.

Yes 5 (5)Test acceptability was stated, but not numerically defined.

1 (5) No. 0 (5)

8 Were the characteristics of the test organism (for example length, mass, age) stated? Yes. 5 (5)

Yes, various physiological measurements were taken and stated.

5 (5) Yes. 5 (5)

9 Was the type of test media used stated? Yes, natural soils. 5 (5) Yes, sand. 5 (5) Yes, sand. 5 (5)

10 Was the type of exposure (for example static, flow‐through) stated? Yes 5 (5) Yes 5 (5) Yes 5 (5)

11 Were the contaminant concentrations measured at the beginning and end of exposure? Unsure 0 (4)

Yes, but confirmatory analysis of elemental composition of test solutions were performed only occasionally.

2 (4) Yes. 4 (4)

12 Were parallel reference toxicant toxicity tests conducted? Yes 4 (4) No 0 (4) No 0 (4)

13 Was there a concentration‐response relationship either observed or stated? Yes. 4 (4)

Yes, a dose‐reponse plot was provided by species (Figure 3).

4 (4) Yes. 4 (4)

14

Was an appropriate statistical method or model used to determine the toxicity ? The method should be recognised national or international regulatory body such as USEPA, ASTM, or OECD.

Yes. USEPA. 4 (4)

No, a statistical evaluation of the dose‐response data was not performed.

0 (4)

No, a statistical evaluation of the dose‐response data was not performed for the purpose of deriving an effects concentration.

0 (4)

15For LC/EC/NEC/BEC data, was an estimate of variability provided? For NOEC/LOEC/MDEC/MATC data, was the significance level 0.05 or less?

Yes. 4 (4) No, these metrics were not calculated. 0 (4) No, these metrics were

not calculated. 0 (4)

16.1 Was pH measured at least at the beginning and end of the toxicity test? Yes 3 (3) Yes 3 (3) Yes 3 (3)

17 Was temperature measured and stated? Not stated. 0 (3)

Max daily air temperature was recorded for the second half of growth.

2 (3) It was controlled but not stated. 2 (3)

18

Were test solutions, blanks, and/or controls tested for contamination or were analytical reagent grade chemicals or the highest possible purity chemicals used for the experiment?

Yes, test solutions were analyzed for accuracy. 3 (3)

Occasionally the test solutions were analysed. The quality of the borate provided is unknown.

1 (3) Yes, test solutions were analyzed for accuracy. 3 (3)

Total ScoreTotal Possible ScoreQuality Score (total score/total possible score) x 100

8893.2

58

No. Question

56828863.665.9

88

Page 1 of 4



1 Was the duration of the exposure stated?


3 Was the biological effect stated (for example, LC or NOEC)?


5 Were appropriate controls (for example no‐toxicant control and/or solvent control) used?


7


8 Were the characteristics of the test organism (for example length, mass, age) stated?

9 Was the type of test media used stated?

10 Was the type of exposure (for example static, flow‐through) stated?

11 Were the contaminant concentrations measured at the beginning and end of exposure?

12 Were parallel reference toxicant toxicity tests conducted?

13 Was there a concentration‐response relationship either observed or stated?

14



16.1 Was pH measured at least at the beginning and end of the toxicity test?

17 Was temperature measured and stated?

18



No. Question 4. Francois, 1986 5. Francois, 1988 6. Ahmed et al, 2008Assessment

NotesANZGScore

Assessment Notes

ANZGScore

Assessment Notes

ANZGScore

Yes. 10 (10) Yes. 10 (10) Yes, 60 days after sowing. 10 (10)

Yes. Relative yield. 10 (10) Yes. Relative yield. 10 (10) Yes, relative dry matter yield. 10 (10)

Yes 5 (5) Yes 5 (5) Yes, the 90% yield. 5 (5)

Yes 5 (5) Yes 5 (5)

Yes, the 90% yield was provided as 5 mg/kg soil. Using the experiemntal data provided, this value was transformed to an aqueous concentration of 14.18 mg/L.

5 (5)

No 0 (5) No 0 (5) Yes 5 (5)

Yes. 4 replicates per treatment. 5 (5) Yes. 4 replicates per

treatment. 5 (5) Yes, 4 replications per. 5 (5)

No. 0 (5) No. 0 (5) No 0 (5)

Yes. 5 (5) Yes. 5 (5)


5 (5)

Yes, sand. 5 (5) Yes, sand. 5 (5) Yes, silt loam collected from the Ap horizon. 5 (5)

Yes 5 (5) Yes 5 (5) Yes 5 (5)

Yes. 4 (4) Yes. 4 (4) Yes, only at the start. 2 (4)

No 0 (4) No 0 (4) No 0 (4)

Yes. 4 (4) Yes. 4 (4)Yes, a dose‐reponse plot was provided by species (Figure 2).

4 (4)

Yes. 4 (4) Yes. 4 (4)

No, a statistical evaluation of the dose‐response data was not performed for the purpose of evaluating for a biological effect.

0 (4)

Yes. 4 (4) Yes. 4 (4) No 0 (4)

Yes 3 (3) Not stated. 0 (3) Yes 3 (3)

Not stated. 0 (3) Yes 3 (3)Yes, average air temperature was provided.

3 (3)

Yes, test solutions were analyzed for accuracy. 3 (3) Yes, test solutions were

analyzed for accuracy. 3 (3)

The test soil was tested for B and other nutrients. The purity of the added B was not provided.

2 (3)

72 72 6988 8881.8 81.8 78.4

88

Page 2 of 4









7








14





18



No. Question 7. Francois, 1989 8. Francois, 1991 9. Francois, 1992Assessment

NotesANZGScore

Assessment Notes

ANZGScore

Assessment Notes

ANZGScore

Yes. 10 (10) Yes, exact dates were provided. 10 (10) Yes. 10 (10)

Yes. Relative yield. 10 (10) Yes, relative yield. 10 (10) Yes. Relative yield. 10 (10)

Yes 5 (5) Yes, the LOEC was calculated. 5 (5) Yes 5 (5)

Yes 5 (5) Yes, the LOEC was calculated. 5 (5) Yes 5 (5)

No 0 (5)No, the use of a control was not explicitly stated.

0 (5) No 0 (5)

Yes. 4 replicates per treatment. 5 (5) Yes, at least 4

replicates. 5 (5) Yes. 4 replicates per treatment. 5 (5)

No. 0 (5) No 0 (5) No. 0 (5)

Yes. 5 (5)


5 (5) Yes. 5 (5)

Yes, sand. 5 (5) Yes, a sand‐gravel mix. 5 (5) Yes, sand. 5 (5)

Yes 5 (5) Yes 5 (5) Yes 5 (5)

Yes. 4 (4)

Yes, B concentrations were monitored over the course of the experiment.

4 (4) Yes. 4 (4)

No 0 (4) No 0 (4) No 0 (4)

Yes. 4 (4)Yes, a dose‐reponse plot was provided by species (Figure 1).

4 (4) Yes. 4 (4)

Yes. 4 (4) Yes 4 (4) Yes. 4 (4)

Yes. 4 (4) Yes, significance was <0.05. 4 (4) Yes. 4 (4)

Not stated. 0 (3) Yes 3 (3) Yes 3 (3)

Yes 3 (3) No 0 (3) Not stated. 0 (3)

Yes, test solutions were analyzed for accuracy. 3 (3) Yes, contamination was

tested for. 3 (3) Yes, test solutions were analyzed for accuracy. 3 (3)

72 72 72

81.888

81.8 81.888 88

Page 3 of 4









7








14





18



No. Question 10. Vlamis and Ulrich, 1973Assessment

NotesANZGScore

ANZGScore

Yes. 10 10 (10)

Yes. Relative yield. 10 10 (10)

Yes 5 5 (5)

Yes 5 5 (5)

No 0 0 (5)

Yes. 3 replicates per treatment. 5 5 (5)

No. 0 0 (5)

Yes. 5 5 (5)

Yes, sand. 5 5 (5)

Yes 5 5 (5)

No. 0 0 (4)

Yes 4 4 (4)

Yes. 4 4 (4)

Statistical method used, not based on modern approaches.

2 2 (4)

No. 0 0 (4)

Yes 3 3 (3)

Conditions stated 3 3 (3)

No. 0 0 (3)

668875.0

Page 4 of 4


EHS Support Pty Ltd

Appendix B USEPA Benchmark Dose Crop Growth-Response IC10

Evaluation

FAPA – Dawson River

Release Scheme

August 2019

APPENDIX B

USEPA Benchmark Dose Crop Growth-Response IC10 Evaluation

Boron Irrigation Water Guideline DerivationFIGURE B-1

Alfalfa Sandy Loam – Shoot Biomass

Crop Soil Type Receptor Model Analysis Type Restriction RiskType BMRF

BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Alfalfa Sandy Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 13.15 7.81 22.92


Release Scheme

August 2019

APPENDIX B



Alfalfa Sandy Loam – Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Alfalfa Sandy Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 24.99 17.00 32.35


Release Scheme

August 2019

APPENDIX B



Alfalfa Sandy Loam – Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Alfalfa Sandy Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 21.59 16.95 26.87


Release Scheme

August 2019

APPENDIX B



Alfalfa Sandy Loam – Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Alfalfa Sandy Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 34.15 25.57 41.00


Release Scheme

August 2019

APPENDIX B



Northern Wheat Grass Sandy Loam – Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Northern Wheat Grass Sandy Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 4.93 3.66 6.89


Release Scheme

August 2019

APPENDIX B



Northern Wheat Grass Sandy Loam – Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Northern Wheat Grass Sandy Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 1.41 0.87 2.55


Release Scheme

August 2019

APPENDIX B



Northern Wheat Grass Sandy Loam – Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Northern Wheat Grass Sandy Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 17.78 15.21 20.50


Release Scheme

August 2019

APPENDIX B



Northern Wheat Grass Sandy Loam – Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Northern Wheat Grass Sandy Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 4.64 3.07 8.13


Release Scheme

August 2019

APPENDIX B



Cucumber Sandy Loam – Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Cucumber Sandy Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 4.06 3.43 4.82


Release Scheme

August 2019

APPENDIX B



Cucumber Sandy Loam – Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Cucumber Sandy Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 1.09 0.62 2.89


Release Scheme

August 2019

APPENDIX B



Cucumber Sandy Loam – Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Cucumber Sandy Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 10.49 8.43 12.71


Release Scheme

August 2019

APPENDIX B



Cucumber Sandy Loam – Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Cucumber Sandy Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 1.22 1.07 1.63


Release Scheme

August 2019

APPENDIX B



Barley Sandy Loam – Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Barley Sandy Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 19.95 16.75 22.98


Release Scheme

August 2019

APPENDIX B



Barley Sandy Loam – Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Barley Sandy Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 11.34 8.27 14.15


Release Scheme

August 2019

APPENDIX B



Barley Sandy Loam – Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Barley Sandy Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 23.71 20.37 27.92


Release Scheme

August 2019

APPENDIX B



Barley Sandy Loam – Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Barley Sandy Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 10.26 8.92 11.76


Release Scheme

August 2019

APPENDIX B



Carrot Sandy Loam - Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Carrot Sandy Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 6.87 5.31 8.82


Release Scheme

August 2019

APPENDIX B



Carrot Sandy Loam - Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Carrot Sandy Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 6.59 4.38 8.99


Release Scheme

August 2019

APPENDIX B



Carrot Sandy Loam - Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Carrot Sandy Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 6.37 5.13 7.64


Release Scheme

August 2019

APPENDIX B



Carrot Sandy Loam - Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Carrot Sandy Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 11.08 7.74 14.10


Release Scheme

August 2019

APPENDIX B



Durum Wheat Sandy Loam - Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Durum Wheat Sandy Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 7.94 5.80 10.60


Release Scheme

August 2019

APPENDIX B



Durum Wheat Sandy Loam - Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Durum Wheat Sandy Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 2.48 1.89 3.95


Release Scheme

August 2019

APPENDIX B



Durum Wheat Sandy Loam – Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Durum Wheat Sandy Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 12.22 9.23 15.67


Release Scheme

August 2019

APPENDIX B



Durum Wheat Sandy Loam – Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Durum Wheat Sandy Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 8.82 6.49 11.89


Release Scheme

August 2019

APPENDIX B



Alfalfa Clay Loam - Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Alfalfa Clay Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 12.36 9.58 15.63


Release Scheme

August 2019

APPENDIX B



Alfalfa Clay Loam - Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Alfalfa Clay Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 20.42 15.39 25.75


Release Scheme

August 2019

APPENDIX B



Alfalfa Clay Loam - Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Alfalfa Clay Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 34.44 22.96 47.65


Release Scheme

August 2019

APPENDIX B



Alfalfa Clay Loam - Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Alfalfa Clay Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 43.00 38.80 48.73


Release Scheme

August 2019

APPENDIX B



Northern Wheatgrass Clay Loam - Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Northern Wheat Grass Clay Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 15.60 11.37 20.66


Release Scheme

August 2019

APPENDIX B



Northern Wheatgrass Clay Loam - Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Northern Wheat Grass Clay Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 20.13 10.44 31.66


Release Scheme

August 2019

APPENDIX B



Northern Wheatgrass Clay Loam - Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Northern Wheat Grass Clay Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 37.23 31.96 42.86


Release Scheme

August 2019

APPENDIX B



Northern Wheatgrass Clay Loam - Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Northern Wheat Grass Clay Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 14.95 11.29 18.74


Release Scheme

August 2019

APPENDIX B



Cucumber Clay Loam - Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Cucumber Clay Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 7.94 5.11 10.81


Release Scheme

August 2019

APPENDIX B



Cucumber Clay Loam - Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Cucumber Clay Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 3.71 2.81 4.92


Release Scheme

August 2019

APPENDIX B



Cucumber Clay Loam - Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Cucumber Clay Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 13.38 11.56 15.28


Release Scheme

August 2019

APPENDIX B



Cucumber Clay Loam - Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Cucumber Clay Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 2.42 1.91 3.75


Release Scheme

August 2019

APPENDIX B



Barley Clay Loam - Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Barley Clay Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 31.98 24.74 38.87


Release Scheme

August 2019

APPENDIX B



Barley Clay Loam - Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Barley Clay Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 5.39 3.85 7.36


Release Scheme

August 2019

APPENDIX B



Barley Clay Loam - Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Barley Clay Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 38.10 31.08 45.24


Release Scheme

August 2019

APPENDIX B



Barley Clay Loam - Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Barley Clay Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 15.13 14.11 17.02


Release Scheme

August 2019

APPENDIX B



Carrot Clay Loam - Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Carrot Clay Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 8.34 6.99 9.74


Release Scheme

August 2019

APPENDIX B



Carrot Clay Loam - Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Carrot Clay Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 6.35 2.76 10.13


Release Scheme

August 2019

APPENDIX B



Carrot Clay Loam - Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Carrot Clay Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 5.92 5.49 7.55


Release Scheme

August 2019

APPENDIX B



Carrot Clay Loam - Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Carrot Clay Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 15.53 14.12 17.51


Release Scheme

August 2019

APPENDIX B



Durum Wheat Clay Loam - Shoot Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Durum Wheat Clay Loam Shoot Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 9.19 7.77 10.76


Release Scheme

August 2019

APPENDIX B



Durum Wheat Clay Loam - Root Biomass


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Durum Wheat Clay Loam Root Biomass Hill (CV) frequentist Restricted Rel. Dev. 10% 7.61 5.54 10.16


Release Scheme

August 2019

APPENDIX B



Durum Wheat Clay Loam - Shoot Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Durum Wheat Clay Loam Shoot Length Hill (CV) frequentist Restricted Rel. Dev. 10% 29.29 26.49 32.57


Release Scheme

August 2019

APPENDIX B



Durum Wheat Clay Loam - Root Length


BMD (mg/L Sat.

Paste B)

BMDL (mg/L

Sat. Paste B)

BMDU (mg/L

Sat. Paste B)

Durum Wheat Clay Loam Root Length Hill (CV) frequentist Restricted Rel. Dev. 10% 10.38 7.11 14.67

APPENDIX B ‐ TABLE B‐1Summary of Measured Benchmark Dose Results for Crops IC10 Derivation and IC25 Values from AEP (2015b)

FAPA ‐ Dawson River Release Scheme ‐ August 2019Boron Irrigation Water Guideline Derivation

Soil Type Receptor Analysis Name BMRF

BMD Sat. Paste B (mg/L)

Mean BMD Type

IC10 Sat. Paste B (mg/L)

IC10 Soil Water B (mg/L)

IC25 Sat. Paste B (mg/L)

IC25 Soil Water B (mg/L)

[A] [B] [C] [D] [E] [F] [G] [H] [I] [J]Clay Loam Root Biomass Alfalfa Clay Loam ‐ Root Biomass 0.1 20.42Clay Loam Root Length Alfalfa Clay Loam ‐ Root Length 0.1 43.00Clay Loam Shoot Biomass Alfalfa Clay Loam ‐ Shoot Biomass 0.1 12.36Clay Loam Shoot Length Alfalfa Clay Loam ‐ Shoot Length 0.1 34.44Sandy Loam Root Biomass Alfalfa Sandy Loam ‐ Root Biomass 0.1 24.99Sandy Loam Root Length Alfalfa Sandy Loam ‐ Root Length 0.1 34.15Sandy Loam Shoot Biomass Alfalfa Sandy Loam ‐ Shoot Biomass 0.1 13.15Sandy Loam Shoot Length Alfalfa Sandy Loam ‐ Shoot Length 0.1 21.59Clay Loam Root Biomass Barley Clay Loam ‐ Root Biomass 0.1 5.39Clay Loam Root Length Barley Clay Loam ‐ Root Length 0.1 15.13Clay Loam Shoot Biomass Barley Clay Loam ‐ Shoot Biomass 0.1 31.98Clay Loam Shoot Length Barley Clay Loam ‐ Shoot Length 0.1 38.10Sandy Loam Root Biomass Barley Sandy Loam ‐ Root Biomass 0.1 11.34Sandy Loam Root Length Barley Sandy Loam ‐ Root Length 0.1 10.26Sandy Loam Shoot Biomass Barley Sandy Loam ‐ Shoot Biomass 0.1 19.95Sandy Loam Shoot Length Barley Sandy Loam ‐ Shoot Length 0.1 23.71Clay Loam Root Biomass Carrot Clay Loam ‐ Root Biomass 0.1 6.35Clay Loam Root Length Carrot Clay Loam ‐ Root Length 0.1 15.53Clay Loam Shoot Biomass Carrot Clay Loam ‐ Shoot Biomass 0.1 8.34Clay Loam Shoot Length Carrot Clay Loam ‐ Shoot Length 0.1 5.92Sandy Loam Root Biomass Carrot Sandy Loam ‐ Root Biomass 0.1 6.59Sandy Loam Root Length Carrot Sandy Loam ‐ Root Length 0.1 11.08Sandy Loam Shoot Biomass Carrot Sandy Loam ‐ Shoot Biomass 0.1 6.87Sandy Loam Shoot Length Carrot Sandy Loam ‐ Shoot Length 0.1 6.37Clay Loam Root Biomass Cucumber Clay Loam ‐ Root Biomass 0.1 3.71Clay Loam Root Length Cucumber Clay Loam ‐ Root Length 0.1 2.42Clay Loam Shoot Biomass Cucumber Clay Loam ‐ Shoot Biomass 0.1 7.94Clay Loam Shoot Length Cucumber Clay Loam ‐ Shoot Length 0.1 13.38Sandy Loam Root Biomass Cucumber Sandy Loam ‐ Root Biomass 0.1 1.09Sandy Loam Root Length Cucumber Sandy Loam ‐ Root Length 0.1 1.22Sandy Loam Shoot Biomass Cucumber Sandy Loam ‐ Shoot Biomass 0.1 4.06Sandy Loam Shoot Length Cucumber Sandy Loam ‐ Shoot Length 0.1 10.49Clay Loam Root Biomass Durum Wheat Clay Loam ‐ Root Biomass 0.1 7.61Clay Loam Root Length Durum Wheat Clay Loam ‐ Root Length 0.1 10.38Clay Loam Shoot Biomass Durum Wheat Clay Loam ‐ Shoot Biomass 0.1 9.19Clay Loam Shoot Length Durum Wheat Clay Loam ‐ Shoot Length 0.1 29.29Sandy Loam Root Biomass Durum Wheat Sandy Loam ‐ Root Biomass 0.1 2.48Sandy Loam Root Length Durum Wheat Sandy Loam ‐ Root Length 0.1 8.82Sandy Loam Shoot Biomass Durum Wheat Sandy Loam ‐ Shoot Biomass 0.1 7.94Sandy Loam Shoot Length Durum Wheat Sandy Loam ‐ Shoot Length 0.1 12.22Clay Loam Root Biomass Northern Wheatgrass Clay Loam ‐ Root Biomass 0.1 20.13Clay Loam Root Length Northern Wheatgrass Clay Loam ‐ Root Length 0.1 14.95Clay Loam Shoot Biomass Northern Wheatgrass Clay Loam ‐ Shoot Biomass 0.1 15.60Clay Loam Shoot Length Northern Wheatgrass Clay Loam ‐ Shoot Length 0.1 37.23Sandy Loam Root Biomass Northern Wheat Grass Sandy Loam ‐ Root Biomass 0.1 1.41Sandy Loam Root Length Northern Wheat Grass Sandy Loam ‐ Root Length 0.1 4.64Sandy Loam Shoot Biomass Northern Wheat Grass Sandy Loam ‐ Shoot Biomass 0.1 4.93Sandy Loam Shoot Length Northern Wheat Grass Sandy Loam ‐ Shoot Length 0.1 17.78

Table Notes:[D] BMRF ‐ Benchmark Response Factor (0.1).[E] BMD ‐ Benchmark Dose for growth inhibition at a rate of 10% (0.1) for root or shoot biomass/length expressed as saturated paste boron obtained from Appendix B Figures.[G] Saturated Paste Boron IC10 ‐ Inhibitory Concentration 10% for growth calculated as the average of biomass and length measurements for column [E].[H] Soil Water Boron IC10 ‐ Inhibitory Concentration 10% for growth by multiplying [G] by 1.27 based on mean saturated paste boron soil water boron conversion

factor provided in AEP (2015b).[I] Saturated Paste Boron IC25 ‐ Inhibitory Concentration 25% for growth from Table D‐1 in AEP (2015b).[J] Soil Water Boron IC25 ‐ Inhibitory Concentration 25% for growth by multiplying [I] by 1.27.

35.04Shoot

35.0322.19 27.6917.54Root

39.0612.75 30.8810.08Shoot

14.427.15 11.405.65Root

58.3440.11 46.12

66.2029.60 52.33

45.4137.41 35.90

35.2921.97 27.90

22.2812.98 17.61

67.0544.33 53.00

7.309.20 9.23

22.3411.38 17.66

Shoot 19.24 19.8024.34 25.05

8.263.88 6.53

Shoot 10.66 9.2013.48 11.64

4.051.46 3.20

16.349.02 20.67

16.9511.17 13.40

Shoot 6.62 11.208.37 14.17

19.9913.67 15.80

Shoot 21.83 36.0027.62 45.54

19.1113.84 15.11

11.35Shoot

Root 3.03

26.41Shoot 47.1533.41 37.27

9.063.83 7.16

24.9214.36 19.70

8.83Root

10.94Root

10.80Root

8.99Root

1.16Root

3.07Root

Shoot 7.13

Shoot 7.27

Shoot 23.40

31.71Root

Root 10.26

17.37Shoot

29.57Root

Page 1 of 1


EHS Support Pty Ltd

Appendix C Estimated and Measured Crop Soil Water IC10 and

IC25 Values by Soil Type and Receptor

APPENDIX C - TABLE C-1

Estimated and Measured Crop Soil Water IC10 and IC25 Values by Soil Type and Receptor

FAPA - Dawson River Release Scheme - August 2019


Crop Receptor Soil_Type Source IC10 (mg/L) IC10 Value Type IC25 (mg/L) IC25 Value Type

Alfalfa Sand Culture 2 4.36 Estimated 7.06 Measured

Barley Sand Culture 2;3 2.96 Estimated 4.79 Measured

Beet Sand Culture 2 8.52 Estimated 13.80 Measured

Blackberry Sand Culture 2 1.17 Estimated 1.89 Measured

Broccoli Sand Culture 4 9.23 Estimated 14.96 Measured

Cabbage Sand Culture 2 10.31 Estimated 16.70 Measured

Carrot Sand Culture 2 2.93 Estimated 4.75 Measured

Cauliflower Sand Culture 4 10.66 Estimated 17.27 Measured

Celery Sand Culture 2;5 11.71 Estimated 18.97 Measured

Cherry Sand Culture 2 1.45 Estimated 2.35 Measured

Common wheat Sand Culture 3 5.14 Estimated 8.33 Measured

Corn Sand Culture 2 2.62 Estimated 4.25 Measured

Cotton Shoots Sandy Loam 6 14.12 Measured 28.24 Estimated

Cow pea Sand Culture 2;7 1.81 Estimated 2.93 Measured

Garlic Sand Culture 8 8.43 Estimated 13.65 Measured

Grape Sand Culture 2 1.40 Estimated 2.26 Measured

Jerusalem Artichoke Sand Culture 2 2.10 Estimated 3.40 Measured

Kentucky bluegrass Sand Culture 2 7.14 Estimated 11.56 Measured

Kidney bean Sand Culture 2 1.94 Estimated 3.15 Measured

Lettuce Sand Culture 2;5 9.40 Estimated 15.23 Measured

Lima bean Sand Culture 2 2.21 Estimated 3.58 Measured

Mustard Sand Culture 2 13.53 Estimated 21.92 Measured

Oats Sand Culture 2 4.81 Estimated 7.79 Measured

Onion Sand Culture 8 13.70 Estimated 22.19 Measured

Parsley Sand Culture 2 7.47 Estimated 12.10 Measured

Pea Sand Culture 2 2.48 Estimated 4.01 Measured

Peach Sand Culture 2 1.72 Estimated 2.78 Measured

Potato Sand Culture 2 6.25 Estimated 10.13 Measured

Radish Sand Culture 2; 4 8.19 Estimated 13.26 Measured

Snap bean Sand Culture 7 1.92 Estimated 3.11 Measured

Sorghum Sand Culture 3 7.87 Estimated 12.75 Measured

Squash Sand Culture 9 4.22 Estimated 6.83 Measured

Strawberry Sand Culture 2 1.55 Estimated 2.51 Measured

Sugar beet Sand Culture 10 6.82 Estimated 11.05 Measured

Sweet Pea Sand Culture 2 2.27 Estimated 3.68 Measured

Tomato Sand Culture 2 7.86 Estimated 12.73 Measured

Vetch Sand Culture 2 13.09 Estimated 21.21 Measured

Alfalfa Root Clay Loam 1 40.11 Measured 58.34 Measured

Alfalfa Shoot Clay Loam 1 29.60 Measured 66.20 Measured

Alfalfa Root Sandy Loam 1 37.41 Measured 45.41 Measured

Alfalfa Shoot Sandy Loam 1 21.97 Measured 35.29 Measured

Barley Root Clay Loam 1 12.98 Measured 22.28 Measured

Barley Shoot Clay Loam 1 44.33 Measured 67.05 Measured

Barley Root Sandy Loam 1 13.67 Measured 19.99 Measured

Barley Shoot Sandy Loam 1 27.62 Measured 45.54 Measured

Carrot Root Clay Loam 1 13.84 Measured 19.11 Measured

Carrot Shoot Clay Loam 1 9.02 Measured 20.67 Measured

Carrot Root Sandy Loam 1 11.17 Measured 16.95 Measured

Carrot Shoot Sandy Loam 1 8.37 Measured 14.17 Measured

Cucumber Root Clay Loam 1 3.88 Measured 8.26 Measured

Cucumber Shoot Clay Loam 1 13.48 Measured 11.64 Measured

Cucumber Root Sandy Loam 1 1.46 Measured 4.05 Measured

Cucumber Shoot Sandy Loam 1 9.20 Measured 9.23 Measured

Durum Wheat Root Clay Loam 1 11.38 Measured 22.34 Measured

Durum Wheat Shoot Clay Loam 1 24.34 Measured 25.05 Measured

Durum Wheat Root Sandy Loam 1 7.15 Measured 14.42 Measured

Durum Wheat Shoot Sandy Loam 1 12.75 Measured 39.06 Measured

Northern Wheat Grass Root Clay Loam 1 22.19 Measured 35.03 Measured

Northern Wheat Grass Shoot Clay Loam 1 33.41 Measured 47.15 Measured

Northern Wheat Grass Root Sandy Loam 1 3.83 Measured 9.06 Measured

Northern Wheat Grass Shoot Sandy Loam 1 14.36 Measured 24.92 Measured

Table Notes:

(a) References from Table D-1 (AEP, 2015b): 1 = Exova (2011-2014); 2 = Eaton (1944); 3 = Bingham et al. (1985); 4 = Francois (1986);

5 = Francois (1988); 6 = Ahmed et al. (2007); 7 = Francois (1989); 8= Francois (1991); 9 = Francois (1992); 10 = Vlamis and Ulrich (1973)

(b) S Cul = Sand Culture Matrix; CL = Clay Loam; SL = Sandy Loam.

Page 1 of 1


EHS Support Pty Ltd

Appendix D Burrlioz Output and Diagnostic Statistics

Burrlioz 2.0 report

Toxicant: BoronInput file: Time read: Thu Jul 25 13:10:35 2019Units: milligrams per litreModel: Burr type III

Protection level informationProtect. level Guideline Value lower 95% CI upper 95% CI99% 0.36 0.2 1.195% 1.2 0.88 1.890% 2 1.6 2.880% 3.4 2.3 4.6

notes:

Soil Water IC10 Boron Concentration (mg/L)

Percentage of Crops Affects

020

40

60

80

100

1 10 100

APPENDIX D ‐ TABLE D‐1Model Fit Diagnostic Statistics

FAPA ‐ Dawson River Release Scheme ‐ August 2019Boron Irrigation Water Guideline Derivation

Goodness‐of‐Fit Statistics Burr Log‐Normal Log‐LogisticKolmogorov‐Smirnov 0.08761557 0.09693684 0.1106846Cramer‐von Mises 0.09022595 0.1336314 0.1435128Anderson‐Darling 0.6538827 0.87333264 0.842988

Goodness‐of‐Fit Criteria Burr Log‐Normal Log‐LogisticAkaike's Information Criterion (AIC) 413.1086 412.9573 409.2786Bayesian Information Criterion (BIC) 419.4412 417.179 413.5004

Page 1 of 1

Appendix C - CORMIX Modelling Update - Dawson River Release Scheme (AECOM, 2019)


AECOM Services Pty Ltd

Level 8

540 Wickham Street

PO Box 1307

Fortitude Valley QLD 4006

Australia

www.aecom.com

+61 7 3553 2000 tel

+61 7 3553 2050 fax

ABN 46 000 691 690

\\aubne1fp003\projects\606x\60600415\500_deliv\502_cormix letter\6. final issued 30 aug 2019\60600415 cormix_final_20190830.docx Ref: 60600415

30 August 2019

Environmental Advisor Environment and Access Santos Limited32 Turbot Street, Brisbane QLD 4000

Dear ,

CORMIX Modelling Update - Dawson River Release Scheme

1.0 Introduction and Background

AECOM Services Pty Ltd (AECOM) was engaged by Santos Ltd (Santos) to update CORMIXmodelling for the Dawson River Release Scheme (DRRS) to support an application to amend theboron limits for water listed in the existing Environmental Authority (EA).

The DRRS is authorised under the FAPA EA (EPPG00928713) which approves release of 18 ML/dayof desalinated produced water from Reverse Osmosis Plant (ROP) ROP2 to the Dawson River via atributary gully and water body. The DRRS commenced July 2015 and is currently authorised till 2025.The EA currently authorises a boron limit of 1.0 mg/L in discharge waters (as well as limiting boronconcentration to 1.0 mg/L within the receiving environment waters and 0.5 mg/L at point of irrigationtake, when irrigation water is taken). Santos is aiming to increase this number to align with revisedboron water quality guidelines. To support the proposed amendments to EA conditions and in line withthe 2018 Australian & New Zealand Guidelines for Fresh & Marine Water Quality revision (ANZG,2018), previous CORMIX mixing zone modelling (undertaken in 2012 to support the original DRRS EAapplication1) requires revising to incorporate updated inputs and scenarios.

2.0 Objectives

The objectives of this study are as follows:

1) Update the CORMIX modelling conducted in 2012 to include various effluent concentrations forthe following contaminants of potential concern (COPCs): boron, electrical conductivity (EC),chloride, and zinc.

2) Run the CORMIX model for various effluent release rates and river flow combinations todetermine:

a) Distances to meet minimum trigger value (MTV) and EA limits for each COPC,b) Distances to achieve complete mixing and the resulting COPC concentration.

3) Use CORMIX to determine the maximum boron concentration in the effluent for various releaserates at river flows of 22.13ML/day (monitoring location DRR1) and 23.99ML/day (monitoringlocation DRMP1) based on various S4 limits.

4) Use CORMIX to inform operational release rates dependent on boron effluent concentrations andwater quality limits.

1 Halcrow (2012). Dawson River Mixing Zone Modelling, CORMIX Modelling Assessment. 18 December 2012.

\\aubne1fp003\projects\606x\60600415\500_deliv\502_cormix letter\6. final issued 30 aug 2019\60600415 cormix_final_20190830.docx

2 of 22

3.0 CORMIX Model Inputs

The CORMIX model inputs were based on the previous modelling effort in 2012 (Halcrow 2012). Table1 summarises the key model inputs for the ambient parameters and Table 2 summarises the inputs forthe discharge parameters. The previous CORMIX model and the adequacy of its inputs were notreviewed as part of this project. The previous CORMIX models did not assess the 22.13ML/day and23.99ML/day river flows (based on local river gaugings undertaken at monitoring locations DRR1 andDRMP1 respectively), so the model inputs for these conditions were adapted from a HEC-RAS modelcreated for a previous DRRS assignment2.

Table 1 Key CORMIX Inputs for Ambient Parameters

ParameterRiver Flow (ML/day)

4.3A 22.13B 23.99C 378D 78,520E

River width (m) 7 12.1 12.2 26 78

Average depth (m) 0.10 0.13 0.14 0.53 6.34

Depth at discharge (m) 0.10 0.13 0.14 0.53 6.34

Channel regularity Uniform Uniform Uniform Uniform Uniform

Manning’s n 0.035 0.035 0.035 0.035 0.035

Wind velocity (m/s) 2 2 2 2 2

Surface temperature (deg C) 20 20 20 20 20

Bottom temperature (deg C) 20 20 20 20 20

Depth near discharge outlet (m) 0.1 0.1 0.1 0.5 6.0

Discharge channel depth (m) 0.1 0.1 0.1 0.3 2.0

Notes:A Low flow condition from Halcrow 2012.B Based on local river gaugings performed in winter 2017 and 2018 at monitoring location DRR1.C Based on local river gaugings performed in winter 2017 and 2018 at monitoring location DRMP1.D Mean flow condition from Halcrow 2012.E High flow condition from Halcrow 2012.

Table 2 Key CORMIX Inputs for Discharge Parameters

ParameterEffluent Release Rate (ML/day)

2.5 4.5 9.0 13.5 18.0

Discharge configuration flush flush flush flush flush

Distance from river bank to outlet (m) 0 0 0 0 0

Discharge angle (deg) 90 90 90 90 90

Bottom slope at discharge (deg) 8 8 8 8 8

Discharge channel width (m) 1 1 1 1 1

Discharge temperature (deg C) 20.8 20.8 20.8 20.8 20.8

Discharge concentration (excess %) 100 100 100 100 100

Note: 2.5 ML/day effluent release rate as per 2012 CORMIX modelling (Halcrow 2012). 4.5, 9.0, 13.5 and 18.0 ML/day effluent

release rates based on DRRS pump rates (varied according to the number of pumps operating).

2 AECOM (2016). Dawson River Mass Balance – HEC-RAS Model. 17 February 2016.


3 of 22

The previous CORMIX modelling set the region of interest (i.e. the region of reported results) at adistance of 10 km from the modelled discharge location (at the point that the waterbody discharges toDawson River). This region of interest was maintained for this modelling effort. For the determinationof the maximum boron effluent concentration, the CORMIX results were analysed at a location 8 kmdownstream of the discharge location, at monitoring location S4 (refer to Figure 1). The effluentconcentration in CORMIX was varied until the S4 concentration limits were achieved 8 kmdownstream.

The modelled COPC concentrations were based on the following:

· Historical effluent concentrations for the HCS04 Desalinated Water Balance Dam (monitoringlocation HCS04DWB1) - 95th percentile, calculated from DRRS release water from May 2015 toApril 2019;

· Waterbody monitoring sites (WLMP1 to WLMP5) - 95 percentile, calculated from five monitoringsites in the waterbody receiving environment (which discharges into Dawson River) from May2015 to April 2019; and,

· Proposed HCS04DWB1 concentration – proposed site-specific boron water quality guideline for95% species protection, based on direct toxicity assessment (DTA) and the methodologyspecified in ANZG 2018.

The detailed inputs for each COPC are summarised in Section 4.

3.1 CORMIX Model Assumptions

As mentioned in the previous modelling study3, the following assumptions apply to the CORMIXmodelling performed herein:

· It is assumed that the effluent discharge gully is aligned perpendicular to the Dawson River at itsconfluence;

· The CORMIX model assumes that the parameters of interest do not bind, settle out, or decay.For this reason, concentrations of water quality parameters will stay constant once completemixing occurs;

· CORMIX modelling assumes steady-state flow scenarios; and,

· No consideration has been given to the effect of flow inputs to the Dawson River downstream ofthe tributary gully. Boyd Creek joins the Dawson River approximately 3.75 km downstream of thetributary gully and the flow from Boyd Creek would promote further mixing of water andsubsequent impacts on water quality.

It is noted that in some of the CORMIX results tables, the results didn’t always follow a smooth trendas the release rates were gradually increased. These were particularly apparent on the resultsshowing the distances to meet effluent limits and complete mixing. Since the modelling approach wasto maintain consistent model inputs from the 2012 study, the results have been presented as is. Areview of the CORMIX model inputs for the discharge and ambient parameters has not beenconducted as part of this study.

3 Halcrow (2012). Dawson River Mixing Zone Modelling, CORMIX Modelling Assessment. 18 December 2012.

Figure 1


5 of 22

4.0 CORMIX Results

The CORMIX models were run with a discharge concentration of 100% which is the concentration inexcess of the background concentration. This generic approach was used to establish the dilutionbehaviour for each release rate and river flow combination. The effluent concentrations and DawsonRiver background concentrations, shown in Table 3, were then related to the CORMIX dilutionpredictions. Table 4 contains a summary of the discharge limits for each COPC.

The following sections summarise the CORMIX results for boron. The results are presented asdistances to meet the MTV and EA discharge limits and the distance to achieve complete mixing. Theconcentration at the complete mixing location is also presented. These results are summarised for thevarious combinations of release rates, river flows, and effluent concentrations. The CORMIX resultsfor EC, chloride and zinc are appended to this memorandum (refer to Attachment A).

The complete mixing locations shown in the results are where complete vertical mixing occurs. Theprevious Halcrow modelling also reported only the vertical mixing extent as the complete mixinglocation. Additionally, CORMIX does not account for a lateral velocity needed to calculate an adequatelateral mixing component.

Table 3 Effluent and Dawson River Background Concentrations

COPCHCS04DWB1

(95th %ile)WLMP Sites(95th %ile)

HCS04DWB1(Proposed)

BackgroundConcentration

(DRR1 95th %tile)

Boron (mg/L) 0.894 0.7 2.9 0.025 (half LOR)

EC (µS/cm) 150.6 253 NA 315.8

Chloride (mg/L) 24.75 21.1 NA 32.3

Zinc (mg/L) 0.0025 (half LOR) 0.005 NA 0.00815LOR = Limit of reporting

Table 4 CORMIX Output Comparison Concentrations

COPCMTVs DTA

(Original)EA

(Irrigation)EA (Drinking

Water)DTA

(Revised)

Boron (mg/L) 0.37 1 0.5 4 2.9

EC (µS/cm) 340 NA NA NA NA

Chloride (mg/L) 175 NA NA NA NA

Zinc (mg/L) 0.008 NA NA NA NA

4.1 River Flow Rate of 4.3ML/day

CORMIX has limitations in modelling discharge flow that exceeds the river flow rate. Therefore, allcases where the discharge flow exceeds the river flow are not modelled. For the 4.3 ML/day river flow,all of the COPC effluent concentrations are summarised in Table 5 for the 2.5 ML/day release rate.


6 of 22

Table 5 CORMIX Summary: All COPCs, All Effluent Concentrations, 4.3ML/day River Flow, 2.5ML/day Release Rate

COPCDistance toCompleteMixing (m)

Concentration at Complete Mixing

HCS04DWB1(95th %ile)

WLMP Sites(95th %ile)

HCS04DWB1(Proposed)

Boron (mg/L) 20 0.508 0.400 1.622

EC (µS/cm) 20 224.0 280.9 NA

Chloride (mg/L) 20 28.11 26.08 NA

Zinc (mg/L) 20 0.0050 0.0064 NANote: CORMIX does not allow discharge flow rates greater than the ambient river flow rate. Therefore, the 4.5, 9.0, 13.5, and 18 ML/day releaserates cannot be modelled for the 4.3 ML/day river flow condition.

4.2 Boron

The CORMIX results for boron are summarised in Table 6 to Table 8 following and Attachment B forthe mean (378 ML/day) and high (78,520 ML/day) flow scenarios. For each river flow condition, thedistance to the MTV concentration, EA limit concentration, and complete mixing are shown for eachrelease rate. The concentrations at complete mixing are also shown.

Table 6 CORMIX Summary: Boron, HCS04DWB1 (95th %ile) Effluent Concentration, 22.13ML/day River Flow

Model Scenario:BoronHCS04DWB1 (95th %ile)22.13 ML/day river flow

Distance to Meet Concentration (m)Concentrationat Complete

Mixing(mg/L)

Effluent Release Rate(ML/day)

MTV EA LimitsCompleteMixing

2.5 10 5 < 35 0.232

4.5 420 15 < 35 0.420

9.0 2420 75 < 35 0.460

13.5 8910 2500 < 35 0.646

18.0 > MTV 5000 < 35 0.693


7 of 22

Table 7 CORMIX Summary: Boron, WLMP Sites (95th %ile) Effluent Concentration, 22.13ML/day River Flow

Model Scenario:BoronWLMP Sites (95th %ile)22.13 ML/day river flow

Distance to Meet Concentration (m)Concentrationat CompleteMixing(mg/L)



2.5 5 2 < 35 0.186

4.5 20 3 < 35 0.332

9.0 75 8 < 35 0.363

13.5 4110 10 < 35 0.507

18.0 7460 710 < 35 0.544

Table 8 CORMIX Summary: Boron, HCS04DWB1 (Proposed) Effluent Concentration, 22.13ML/day River Flow

Model Scenario:BoronHCS04DWB1 (Proposed)22.13 ML/day river flow




2.5 6500 2550 < 35 0.710

4.5 > MTV > EA < 35 1.332

9.0 > MTV > EA < 35 1.463

13.5 > MTV > EA < 35 2.079

18.0 > MTV > EA < 35 2.237

4.3 Maximum Boron Concentration in Effluent

CORMIX was used to estimate the maximum boron concentration in the discharged effluent for a riverflow rate of 22.13 ML/day and 23.99 ML/day (DRMP1) while maintaining the current and proposed EAlimits for the irrigation environmental value. The targeted concentration for boron was measured atmonitoring location S4 which is approximately 8 km downstream of the discharge location. The effluentconcentration in CORMIX was varied until the targeted S4 concentration was achieved 8 kmdownstream. Table 9 and Figure 2 summarise the results of the maximum boron concentrations andconcentrations at complete mixing for various effluent release rates for the 22.13 ML/day river flow.Table 10 and Figure 3 summarise the results of the maximum boron concentrations andconcentrations at complete mixing for various effluent release rates for the 23.99 ML/day river flow.


8 of 22

Table 9 Maximum Boron Effluent Concentration to Achieve Boron Concentration Limits at Location S4 andConcentrations at Complete Mixing with a River Flow of 22.13 ML/day

Effluent ReleaseRate

(ML/day)

CORMIXDilution at S4

(8km fromDischargeLocation)

BoronConcentration at

CompleteMixing (mg/L)

BoronConcentration

Limit at S4Location (mg/L)

Maximum BoronConcentration in

Effluent

(mg/L)

2.5 9.6

1.1 0.5 4.6

2.7 1.2 11.3

2.9 1.3 ~12.2

3.4 1.5 14.2

5.2 2.3 21.9

4.5 5.5

1.2 0.5 2.6

2.9 1.2 ~6.3

3.0 1.2 6.5

3.7 1.5 8.1

5.7 2.3 12.5

9 3.3

0.8 0.5 1.6

2.0 1.2 3.9

2.5 1.5 4.9

2.9 1.8 ~5.8

3.8 2.3 7.5

13.5 2.4

0.8 0.5 1.2

2.0 1.2 2.8

2.6 1.5 3.6

2.9 1.7 ~4.0

3.9 2.3 5.5

18 2

0.8 0.5 1.0

1.8 1.2 2.4

2.3 1.5 3.0

2.9 1.9 ~3.8

3.5 2.3 4.6

Notes:1) The background concentration of boron was assumed to be 0.025 mg/L.2) Complete mixing occurs within 35m of the discharge location.3) Grey italicised values indicate a scenario whereby the boron concentration at complete mixing exceeds the site-specific boron water

quality guideline of 2.9 mg/L.4) Red values indicate interpolated values (based on an assumed linear relationship) that correspond with a concentration at complete

mixing value of 2.9 mg/L. These values have not been modelled in CORMIX.


9 of 22

Figure 2 Maximum Boron Effluent Concentration to Achieve Boron Concentration Limits at Location S4 andConcentrations and Complete Mixing with a River Flow of 22.13 ML/day

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

5.00

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

0 2 4 6 8 10 12 14 16 18 20

Bo

ron C

oncentr

ation a

t C

om

ple

te M

ixin

g (

mg

/L)

Maxi

mum

Bo

ron E

fflu

ent

Conc

entra

tio

n (

mg

/L)

Effluent Release Rate (ML/day)

S4=0.5mg/L S4=1.2mg/L S4=1.5mg/L Limit

S4=0.5mg/L S4=1.2mg/L S4=1.5mg/L

Maximum Effluent Conc.:

Conc. at Complete Mixing:

Aquatic EcologyLimit (2.9mg/L)


10 of 22

Table 10 Maximum Boron Effluent Concentration to Achieve Boron Concentration Limits at Location S4 andConcentrations at Complete Mixing with a River Flow of 23.99 ML/day

Effluent ReleaseRate

(ML/day)

CORMIXDilution at S4

(8km fromDischargeLocation)

BoronConcentration at

CompleteMixing (mg/L)

BoronConcentration

Limit at S4Location (mg/L)

Maximum BoronConcentration in

Effluent

(mg/L)

2.5 10.6

1.1 0.5 5.1

2.7 1.2 12.5

2.9 1.3 ~13.2

3.4 1.5 15.7

5.3 2.3 24.1

4.5 5.9

1.3 0.5 2.8

2.9 1.1 ~6.4

3.2 1.2 7.0

4.0 1.5 8.7

6.1 2.3 13.4

9.0 3.6

0.9 0.5 1.7

2.1 1.2 4.3

2.7 1.5 5.3

2.9 1.6 ~5.8

4.1 2.3 8.2

13.5 2.5

0.9 0.5 1.2

2.1 1.2 3.0

2.7 1.5 3.7

2.9 1.6 ~4.1

4.1 2.3 5.7

18.0 2.1

0.8 0.5 1.0

1.9 1.2 2.5

2.4 1.5 3.1

2.9 1.8 ~3.8

3.7 2.3 4.8Notes:

1) The background concentration of boron was assumed to be 0.025 mg/L.2) Complete mixing occurs within 35m of the discharge location.3) Grey italicised values indicate a scenario whereby the boron concentration at complete mixing exceeds the site-specific boron water

quality guideline of 2.9 mg/L.4) Red values indicate interpolated values (based on an assumed linear relationship) that correspond with a concentration at complete

mixing value of 2.9 mg/L. These values have not been modelled in CORMIX.


11 of 22

Figure 3 Maximum Boron Effluent Concentration to Achieve Boron Concentration Limits at Location S4 andConcentrations and Complete Mixing with a River Flow of 23.99 ML/day

5.0 CORMIX Modelling Summary

The main findings drawn from the effluent modelling are listed below for each objective identified inSection 2.0:

1) Objective: Update CORMIX modelling conducted in 2012 to include various effluentconcentrations for COPCs.

Findings: Updated CORMIX results for EC, chloride and zinc are presented in Attachment A.Boron results are presented in Section 4.2.

2) Objective: Run the CORMIX model for various effluent release rates and river flow combinationsto determine:

a) Distances to meet minimum trigger value (MTV) and EA limits for each contaminant ofpotential concern (COPC),

b) Distances to achieve complete mixing and the resulting COPC concentration.

Findings: Distances to meet MTVs, EA limits and complete mixing, and the resultingconcentration at complete mixing for EC, chloride and zinc are presented in Attachment A. Boronresults are presented in Section 4.2.

o Under a river flow rate of 22.13 ML/day, complete mixing of boron is achieved lessthan 35m from the release location, and the concentration at complete mixing is belowthe proposed site-specific boron water quality guideline for all modelled scenarios.

o For the HCS04DWB1 and WLMP 95th percentile effluent concentrations, the MTV forboron is met within 9 km of release location with the exception of HCS04DWB1 at arelease rate of 18.0 ML/day. EA limits are met within 5 km.

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

5.00

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

0 2 4 6 8 10 12 14 16 18 20

Bo

ron C

oncentr

ation a

t C

om

ple

te M

ixin

g (

mg

/L)

Maxi

mum

Bo

ron E

fflu

ent

Conc

entra

tio

n (

mg

/L)


S4=0.5mg/L S4=1.2mg/L S4=1.5mg/L Limit

S4=0.5mg/L S4=1.2mg/L S4=1.5mg/L

Maximum Effluent Conc.:

Conc. at Complete Mixing:

Aquatic EcologyLimit (2.9mg/L)


12 of 22

o For the proposed HCS04DWB1 (site-specific boron water quality guideline) effluentconcentration, boron concentrations do not reach the MTV or EA limits within the 10km model domain for the 22.13 ML/day river flow at release rates of 4.5 ML/day andgreater. At a release rate of 2.5 ML/day, the MTV was met within 6500 m and the EAlimits were met within 2550 m.

3) Objective: Use CORMIX to determine the maximum boron concentration in the effluent for variousrelease rates at river flows of 22.13ML/day (monitoring location DRR1) and 23.99ML/day(monitoring location DRMP1) based on various S4 limits.

Findings: CORMIX results which can be used to inform maximum boron effluent concentrations atvarious operational release rates and water quality limits are presented in Table 9, Table 10,Figure 2 and Figure 3.

4) Objective: Use CORMIX to inform operational release rates dependent on boron effluentconcentrations and water quality limits.

Findings: CORMIX results which can be used to inform operational release rates dependent onboron effluent concentrations and water quality limits are presented in Table 9, Table 10, Figure 2and Figure 3.

6.0 References

AECOM (2016). Dawson River Mass Balance – HEC-RAS Model. 17 February 2016.

ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian andNew Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Halcrow (2012). Dawson River Mixing Zone Modelling, CORMIX Modelling Assessment. 18 December2012.

7.0 Standard Limitations

AECOM Services Pty Limited (AECOM) has prepared this report in accordance with the usual careand thoroughness of the consulting profession for the use of Santos Limited and only those thirdparties who have been authorised in writing by AECOM to rely on this Report.

It is based on generally accepted practices and standards at the time it was prepared. No otherwarranty, expressed or implied, is made as to the professional advice included in this Report.

It is prepared in accordance with the scope of work and for the purpose outlined in the proposal dated4 June 2019.

Where this Report indicates that information has been provided to AECOM by third parties, AECOMhas made no independent verification of this information except as expressly stated in the Report.AECOM assumes no liability for any inaccuracies in or omissions to that information.

This Report was prepared between 6 June 2019 and 30 August 2019 and is based on the informationreviewed at the time of preparation. AECOM disclaims responsibility for any changes that may haveoccurred after this time.

This Report should be read in full. No responsibility is accepted for use of any part of this report in anyother context or for any other purpose or by third parties. This Report does not purport to give legaladvice. Legal advice can only be given by qualified legal practitioners.

Except as required by law, no third party may use or rely on this Report unless otherwise agreed byAECOM in writing. Where such agreement is provided, AECOM will provide a letter of reliance to theagreed third party in the form required by AECOM.

To the extent permitted by law, AECOM expressly disclaims and excludes liability for any loss,damage, cost or expenses suffered by any third party relating to or resulting from the use of, orreliance on, any information contained in this Report. AECOM does not admit that any action, liabilityor claim may exist or be available to any third party.


13 of 22

Except as specifically stated in this section, AECOM does not authorise the use of this Report by anythird party.

It is the responsibility of third parties to independently make inquiries or seek advice in relation to theirparticular requirements and proposed use of the site.

Any estimates of potential costs which have been provided are presented as estimates only as at thedate of the Report. Any cost estimates that have been provided may therefore vary from actual costsat the time of expenditure.

Yours sincerely

Team Lead -Water Resources & Coastal Management

Senior Engineer

© AECOM Services Pty Limited. All rights reserved.

No use of the contents, concepts, designs, drawings, specifications, plans etc. included in this report is permitted unless and until they are the

subject of a written contract between AECOM Services Pty Limited (AECOM) and the addressee of this report. AECOM accepts no liability of any

kind for any unauthorised use of the contents of this report and AECOM reserves the right to seek compensation for any such unauthorised use.

Document Delivery

AECOM Services Pty Limited (AECOM) provides this document in either printed format, electronic format or both. AECOM considers the printed

version to be binding. The electronic format is provided for the client’s convenience and AECOM requests that the client ensures the integrity of

this electronic information is maintained. Storage of this electronic information should at a minimum comply with the requirements of the Electronic

Transactions Act 2002.

mailto:[email protected]

mailto:[email protected]


14 of 22

Attachment A – CORMIX Results for Electrical Conductivity,Chloride and Zinc

Electrical Conductivity

The effluent and background concentrations for EC are below the MTV concentration of 340 µS/cm.Therefore, the MTV concentration will not be reached. The distances to complete mixing aresummarised on the following tables for both effluent concentrations analysed for EC.

Table 11 CORMIX Summary: EC, 22.13ML/day River Flow


Distance to CompleteMixing (m)

Concentration at Complete Mixing (µS/cm)



2.5 < 35 276.5 300.8

4.5 < 35 240.7 287.3

9.0 < 35 233.2 284.4

13.5 < 35 197.8 270.9

18.0 < 35 188.7 267.5

Table 12 CORMIX Summary: EC, 378ML/day River Flow






2.5 10 310.7 313.8

4.5 10 262.5 295.5

9.0 15 271.2 298.8

13.5 20 277.4 301.2

18.0 40 254.6 292.5

Table 13 CORMIX Summary: EC, 78,520ML/day River Flow






2.5 > 10000 315.8 315.8

4.5 > 10000 315.8 315.8

9.0 130 315.6 315.7

13.5 130 315.5 315.7

18.0 150 315.4 315.7Note: The concentration at 10km is shown for the complete mixing concentrations for the > 10km cases shown above.


15 of 22

Chloride

The effluent and background concentrations for chloride are below the MTV concentration of 175mg/L. Therefore, the MTV concentration will not be reached. The distances to complete mixing aresummarised on the following tables for both effluent concentrations analysed for chloride.

Table 14 CORMIX Summary: Chloride, 22.13ML/day River Flow



Concentration at Complete Mixing (mg/L)



2.5 < 35 30.50 29.63

4.5 < 35 28.87 27.21

9.0 < 35 28.53 26.70

13.5 < 35 26.91 24.30

18.0 < 35 26.49 23.68

Table 15 CORMIX Summary: Chloride, 378ML/day River Flow






2.5 10 32.07 31.95

4.5 10 29.86 28.69

9.0 15 30.26 29.27

13.5 20 30.54 29.70

18.0 40 29.50 28.15

Table 16 CORMIX Summary: Chloride, 78,520ML/day River Flow






2.5 > 10000 32.30 32.30

4.5 > 10000 32.30 32.30

9.0 130 32.29 32.29

13.5 130 32.29 32.28

18.0 150 32.28 32.28Note: The concentration at 10km is shown for the complete mixing concentrations for the > 10km cases shown above.


16 of 22

Zinc

The CORMIX results for zinc are summarised in the following tables. For each river flow condition, thedistance to the MTV concentration and complete mixing are shown for each release rate. Theconcentrations at complete mixing are also shown.

Table 17 CORMIX Summary: Zinc, HCS04DWB1 (95th %ile) Effluent Concentration, 22.13ML/day River Flow

Model Scenario:ZincHCS04DWB1 (95th %ile)22.13 ML/day river flow




2.5 > 10000 NA < 35 0.0068

4.5 > 10000 NA < 35 0.0056

9.0 > 10000 NA < 35 0.0053

13.5 > 10000 NA < 35 0.0041

18.0 > 10000 NA < 35 0.0038

Table 18 CORMIX Summary: Zinc, WLMP Sites (95th %ile) Effluent Concentration, 22.13ML/day River Flow

Model Scenario:ZincWLMP Sites (95th %ile)22.13 ML/day river flow




2.5 > 10000 NA < 35 0.0074

4.5 > 10000 NA < 35 0.0067

9.0 > 10000 NA < 35 0.0066

13.5 > 10000 NA < 35 0.0059

18.0 > 10000 NA < 35 0.0057

Table 19 CORMIX Summary: Zinc, HCS04DWB1 (95th %ile) Effluent Concentration, 378 ML/day River Flow

Model Scenario:ZincHCS04DWB1 (95th %ile)378 ML/day river flow




2.5 250 NA 10 0.0080

4.5 2650 NA 10 0.0063

9.0 > 10000 NA 15 0.0066

13.5 > 10000 NA 20 0.0068

18.0 > 10000 NA 40 0.0061


17 of 22

Table 20 CORMIX Summary: Zinc, WLMP Sites (95th %ile) Effluent Concentration, 378 ML/day River Flow

Model Scenario:ZincWLMP Sites (95th %ile)378 ML/day river flow




2.5 50 NA 10 0.0081

4.5 850 NA 10 0.0071

9.0 3150 NA 15 0.0073

13.5 7010 NA 20 0.0074

18.0 > 10000 NA 40 0.0070

Table 21 CORMIX Summary: Zinc, HCS04DWB1 (95th %ile) Effluent Concentration, 78,520ML/day River Flow

Model Scenario:ZincHCS04DWB1 (95th %ile)78,520 ML/day river flow




2.5 < 50 NA > 10000 0.0081

4.5 < 50 NA > 10000 0.0081

9.0 < 50 NA 130 0.0081

13.5 < 50 NA 130 0.0081

18.0 < 50 NA 150 0.0081

Note: The concentration at 10 km is shown for the complete mixing concentrations for the > 10km cases shown above.

Table 22 CORMIX Summary: Zinc, WLMP Sites (95th %ile) Effluent Concentration, 78,520ML/day River Flow

Model Scenario:ZincWLMP Sites (95th %ile)78,520 ML/day river flow




2.5 < 50 NA > 10000 0.0081

4.5 < 50 NA > 10000 0.0081

9.0 < 50 NA 130 0.0081

13.5 < 50 NA 130 0.0081

18.0 < 50 NA 150 0.0081Note: The concentration at 10k m is shown for the complete mixing concentrations for the > 10km cases shown above.


18 of 22

Conclusions:

· The effluent and background concentrations for EC and chloride are below the MTV levels.

· For zinc, the effluent is released at a concentration below the MTV, however backgroundconcentrations in the Dawson River exceed the MTV (a concentration of 0.00815 mg/L comparedwith an MTV of 0.008 mg/L). CORMIX dilution values were used to estimate how far downstreamthe effluent would return to the MTV value. It should be noted that this scenario isn’t the intendeduse of CORMIX, however we have replicated the method applied previously for comparison usinga linear background dilution equation.

- For this condition, it is estimated that the MTV value is reached within 50 m for the 78,520ML/day river flow.

- For the 378 ML/day river flow, the distance ranges from 250 m, to over 10 km for thedifferent release rates.

- The MTV is not reached within the 10 km model extent during the 22.13 ML/day river flowscenarios.


19 of 22

Attachment B – Mean and High River Flow Results

Table 23 CORMIX Summary: Boron, HCS04DWB1 (95th %ile) Effluent Concentration, 378 ML/day River Flow

Model Scenario:BoronHCS04DWB1 (95th %ile)378 ML/day river flow




2.5 1 1 10 0.052

4.5 50 1 10 0.305

9.0 2 1 15 0.260

13.5 10 3 20 0.227

18.0 30 5 40 0.347

Table 24 CORMIX Summary: Boron, WLMP Sites (95th %ile) Effluent Concentration, 378 ML/day River Flow

Model Scenario:BoronWLMP Sites (95th %ile)378 ML/day river flow




2.5 1 1 10 0.046

4.5 1 1 10 0.243

9.0 1 1 15 0.207

13.5 4 2 20 0.182

18.0 10 2 40 0.275

Table 25 CORMIX Summary: Boron, HCS04DWB1 (Proposed) Effluent Concentration, 378 ML/day River Flow

Model Scenario:BoronHCS04DWB1 (Proposed)378 ML/day river flow




2.5 10 10 10 0.114

4.5 150 75 10 0.952

9.0 500 225 15 0.802

13.5 1025 415 20 0.694

18.0 2100 1050 40 1.090


20 of 22

Table 26 CORMIX Summary: Boron, HCS04DWB1 (95th %ile) Effluent Concentration, 78,520ML/day River Flow

Model Scenario:BoronHCS04DWB1 (95th %ile)78,520 ML/day river flow




2.5 < 10 < 10 > 10000 0.025

4.5 < 10 < 10 > 10000 0.025

9.0 < 10 < 10 130 0.026

13.5 < 10 < 10 130 0.027

18.0 < 10 < 10 150 0.027Note: The concentration at 10 km is shown for the complete mixing concentrations for the > 10km cases shown above.

Table 27 CORMIX Summary: Boron, WLMP Sites (95th %ile) Effluent Concentration, 78,520ML/day River Flow

Model Scenario:BoronWLMP Sites (95th %ile)78,520 ML/day river flow




2.5 < 10 < 10 > 10000 0.025

4.5 < 10 < 10 > 10000 0.025

9.0 < 10 < 10 130 0.026

13.5 < 10 < 10 130 0.026


Table 28 CORMIX Summary: Boron, HCS04DWB1 (Proposed) Effluent Concentration, 78,520ML/day River Flow

Model Scenario:BoronHCS04DWB1 (Proposed)78,520 ML/day river flow




2.5 < 10 < 10 > 10000 0.025

4.5 < 10 < 10 > 10000 0.026

9.0 < 10 < 10 130 0.029

13.5 < 10 < 10 130 0.030



21 of 22

Figure 4 Boron Concentration at Complete Mixing for HCS04DWB1 (95th %ile) Effluent

Figure 5 Boron Concentration at Complete Mixing for WLMP Sites (95th %ile) Effluent

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0 2 4 6 8 10 12 14 16 18 20

Co

ncen

trati

on

at

Co

mp

lete

Mix

ing

(m

g/L

)


22.13ML/day river flow 378ML/day river flow 78520ML/day river flow

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0 2 4 6 8 10 12 14 16 18 20

Co

ncen

trati

on

at

Co

mp

lete

Mix

ing

(m

g/L

)




22 of 22

Figure 6 Boron Concentration at Complete Mixing for HCS04DWB1 (Proposed) Effluent

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

2.75

3.00

0 2 4 6 8 10 12 14 16 18 20

Co

nc

en

trati

on

at

Co

mp

lete

Mix

ing

(m

g/L

)



Appendix D - Santos GLNG Dawson River Release Scheme, Local Water Quality Guidelines, Nov 2016


!

! !

Santos'GLNG'

Dawson'River'Release'

Scheme''

Local'Water'Quality'Guidelines'

'

Prepared'for:'

Santos'GLNG!

frc environmental

PO!Box!2363,!Wellington!Point!!QLD!!4160!Telephone:!!+!61!3286!3850!

Facsimile:!!!!+!61!3821!7936!

frc!reference:! 150106

frc environmental

This!work!is!copyright.!!

A!person!using!frc!environmental!documents!or!data!accepts!the!risk!of:!

1! Using! the!documents!or!data! in!electronic! form!without! requesting!and!checking! them! for!accuracy!against! the!

original!signed!hard!copy!versionR!and!

2! Using!the!documents!or!data!for!any!purpose!not!agreed!to!in!writing!by!frc!environmental.!

!

Santos!GLNG!Dawson!River!Release!Scheme:!Local!Water!Quality!Guidelines!

/Volumes/Archives/Archives!

Projects/Archives_2015/150106_SAN_DRRS_Technical_Studies/Report/WQO/Current/150106RiX_WQG_2016^11^

07_TP.docx!

Document'Control'Summary'

Project!No.:! 150106!

Status:! Final!Report!

Project!Director:! Project!

Manager:!!

Title:! Santos!GLNG!Dawson!River!Release!Scheme:!Local!Water!Quality!Guidelines!

Project!Team:! B.!Cook,!C.!Forward,!A.!Bentley,!J.!Charlish!and!C.!Conacher!

Client:! Santos!GLNG!

Client!Contact:! !

Date:! 7!November!2016!

Edition:!

Checked!by:!

Issued!by:!

150105RiX_WQG!

Distribution!Record!

Santos!GLNG:! as!PDF!and!Word!.docx!

!

Revision' Revision'date' Authorised'by'

01! 15/02/2015! Ben!Cook!

02! 20/03/2015! Ben!Cook!

03! 01/04/2015! Ben!Cook!

04! 07/07/2015! Ben!Cook!

05! 29/07/2015! Ben!Cook!

06! 23/10/2016! Ben!Cook!

07! 13/01/2016! Ben!Cook!

08! 14/09/2016! Ben!Cook!

09! 07/11/2016! Ben!Cook!

frc environmental

Santos!GLNG!Dawson!River!Release!Scheme:!Local!Water!Quality!Objectives!

Contents'

1! Introduction' 1!

1.1! Purpose!and!Scope! 2!

2! Applicable'Environmental'Values'and'National,'State'and'Regional'

WQGs' 5!

3! The'QWQG'Approach'to'Developing'Local'WQGs' 14!

3.1! Defining!the!Water!Types!in!the!Receiving!Environment! 14!

3.2! Selection!of!Reference!Sites! 14!

3.3! Selecting!Appropriate!Water!Quality!Parameters! 15!

3.4! Selecting!Appropriate!Water!Quality!Data! 15!

3.5! Procedure! for! Calculating! the! Local! WQGs! from! Reference! Site!

Data! 15!

4! Developing'Local'WQGs'for'the'DRRS' 17!

4.1! Water!Types!in!the!Receiving!Environment! 17!

4.2! Selection!of!Reference!Sites! 17!

4.3! Selecting!Appropriate!Water!Quality!Parameters! 20!

4.4! Available!Water!Quality!Data! 20!

4.5! Calculated!Local!WQGs! 21!

4.6! Recommendations!for!Modifying!the!Water!Quality!Guidelines! 24!

5! Summary' 26!

6! References' 27!

Appendix!A! Published!WQGs!

Appendix!B! Number!of!Data!Points!Used!to!Calculate!Local!WQGs!

Appendix!C! Calculations!for!Local!WQGs!for!Water!Chemistry!

frc environmental

Santos!GLNG!Dawson!River!Release!Scheme:!Local!Water!Quality!Objectives!

Tables'

Table!2.1! Environmental! Values! Assessment! for! the! Waterbody! and!

Dawson!River.! 7!

Table!2.2! Comparison!of!Environmental!Values! for! the!Dawson!River!and!

Waterbody.! 11!

Table!4.1! Location!of!Reference!Sites.! 18!

Table!4.2! Calculation!of! local!water!quality!guidelines!compared!to!current!

EA!water!quality!guidelines.! 22!

Table!4.3! Local!water! quality! guidelines! developed! from! baseline! data! as!

per!the!QWQG! 25!

Maps'

Map!1.1! Water!types!relevant!to!DRRS.! 4!

Map!4.1! Reference!sites.! 19!

!

!

frc environmental

Santos!GLNG!Dawson!River!Release!Scheme:!Local!Water!Quality!Guidelines! 1!

1' Introduction'

Santos! GLNG! operates! a! number! of! gas! fields! in! the! Bowen! and! Surat! Basins.! ! The!

Fairview! Arcadia! Project! Area! (FAPA),! in! the! upper! Dawson! River! Sub^catchment! in!

central! Queensland,! is! one! of! a! number! of! Santos! GLNG! Project! areas! in! which! gas!

extraction! activities! are! being! conducted.! ! The! FAPA! is! an! operating! gas! field! and!

includes!Petroleum!Leases!90,!91,!92,!99,!100,!232,!233,!234,!235,!236,!420,!421!and!

440,! Petroleum! Pipeline! Licences! 76! and! 92,! and! Authority! to! Prospect! lease! 526P,!

covering!approximately!318,!297!ha.!

The! release! of! desalinated! produced! water! from! the! Fairview! Reverse! Osmosis! Plant!

(ROP)!2!to!the!Dawson!River!is!authorised!under!the!FAPA!Environmental!Authority!(EA)!

EPPG009287131!(formerly!PEN100178208).! !The!amendment!which!was!sought! for! the!

release!of!desalinated!produced!water! is!known!as! the!Dawson!River!Release!Scheme!

(DRRS).!!

The! Dawson! River! Release! Scheme! (DRRS)! proposes! to! release! reverse! osmosis^

treated!(desalinated)!produced!water!from!ROP2,! located!in!the!south^east!region!of!the!

FAPA,! to! a! tributary! gully! of! the! Dawson! River,! which! joins! the! Dawson! River!midway!

between! “Dawson’s! Bend”! and! “Yebna! Crossing”! (Map! 1.1).! ! This! area! between! the!

tributary! gully! of! the! Dawson! River,! which! joins! the! Dawson! River! midway! between!

“Dawson’s! Bend”! and! “Yebna! Crossing”! is! known! as! the! ‘receiving! environment’! as!

defined!by!condition!(B31)!of! the!FAPA!EA.!The!release!proposal! includes! the! following!

elements:!

!! produced!water! in! the!Hub!Compressor!Station!No.!4! (HCS4)!gathering!network!

will! be! collected! from! the! well! pads! via! gathering! lines! and! transported! to! a!

produced!water!management!pond!of!200!ML!capacity,!sized!for!10!days!storage!

at!peak!production!

!! produced! water! will! then! be! passed! through! ROP2! for! treatment,! and!

subsequently! stored! in! a! permeate! pond! of! 340!ML! capacity,! sized! for! 15! days!

storage!at!peak!production,!before!delivery!at!a!maximum!rate!of!18!ML/day!to!the!

outfall! pipeline! (which! is! the! total! capacity! of! the! pipe! and! the!maximum!design!

flow!for!the!release!scheme)!

!! desalinated!produced!water!will! be! released! to!surface!waters!as!defined!by! the!

FAPA!EA,!at! the!contaminant!release!point!described! in! the!FAPA!EA!as!ROP2.!

The! coordinates! for! the! release! location! as! those! described! in! condition! (B14)! ^!

Schedule!B,!Table!3!–!Contaminant!Release!Points!of!the!FAPA!EA!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!1! EPPG00928713,!dated!18!June!2015!

frc environmental


!! a! 5.3km! outfall! pipeline! will! transfer! the! desalinated! produced! water! from! the!

permeate!pond!to!the!proposed!outfall!at!the!tributary!gully!

!! the!released!water!will!flow!for!2.9!km!down!the!tributary!gully!before!discharging!

into!the!Waterbody,!estimated!to!have!a!volume!of!approximately!500!ML,!and!

!! the!Waterbody! overflows! into! a! downstream! section! of! the! tributary! gully,! which!

flows!for!a!further!1.8!km!before!discharging!the!Dawson!River.!

The! receiving! environment! of! the! DRRS! therefore! contains! two! water! types:! the!

Waterbody! (otherwise! known! as! the! Wetland! by! the! FAPA! EA! conditions)! and! the!

Dawson!River!(Map!1.1).!!The!assessment!of!water!quality!against!relevant!water!quality!

guidelines!(WQGs)!in!each!of!these!water!types!is!a!requirement!of!the!FAPA!EA.!

WQGs!are!numerical!concentration!limits!for!specific!water!quality!parameters!that!ensure!

that!the!environmental!values!(EV)!of!waters!are!protected.!EVs!are!the!identified!uses!of!

a! particular!watercourse! or!waterbody,! including! human! uses! for!water! (e.g.! secondary!

recreation,! stock! water)! and! environmental! uses! for! water! (e.g.! aquatic! ecosystem!

protection).!!Where!the!WQGs!for!a!watercourse!or!waterbody!are!met,!then!the!quality!of!

water!will! support! the!EVs! that! have! been! identified! for! that!watercourse! or!waterbody.!!

When!WQGs! are! endorsed! by! all! relevant! stakeholder! groups! they! can! be! scheduled!

under!the!Environmental!Protection!(Water)!Policy,!and!are!then!known!as!Water!Quality!

Objectives!(WQOs).!

WQGs!have!been!developed!at!national,!state!and!regional!levels!for!a!range!of!different!

water! quality! parameters.! ! However,! national! and! state! WQGs! are! often! not!

representative!of!water!quality!conditions!that!ensure!protection!of!aquatic!ecosystems!of!

one!or!more!water!types!in!a!certain!area!(EHP!2013c).!

The!National'Water'Quality'Guidelines!ANZECC!&!ARMCANZ!(2000b)! recommend! that!

local! WQGs! based! on! locally! collected! water! quality! data! be! developed! and! used! in!

preference!to!national!and!state!WQGs.!!!

The!Queensland'Water'Quality'Guidelines!(QWQG)!(EHP!2013c)!outline!the!procedures!

for!developing!local!WQGs!in!Queensland.!

1.1' Purpose'and'Scope'

The!purpose!of!this!document!is!to!develop!local!WQGs!(LWQGs)!for!the!Waterbody!and!

the!Dawson!River!within!the!receiving!environment!of!the!DRRS,!based!on!data!collected!

by!Santos!GLNG.!!

frc environmental


The!scope!of!this!document!is!to:!

!! overview!the!procedure!for!developing!LWQGs!!

!! summarise!the!water!quality!data!used!to!develop!the!LWQGs,!including!sampling!

locations,!sampling! frequency,!parameters!assessed!and!data!quality!assurance,!

and!

!! present! the! LWQGs! for! monitoring! of! water! quality! in! the! Waterbody! and! the!

Dawson!River!in!relation!to!DRRS.!

! !

Inju

ne R

oad

Inju

ne

Roa

d

Hutton Creek

Commis

s ion

erCre

ek

Commissio nerCreek

Commis sion

erCre

ek

Mo

lesk

inC

reek

Daw

son River

Dawson

Riv

er

DawsonRiver

Dawson River

Boy d Cre

ek

oExpedition (Limited

Depth) National Park

oHallett

State Forest

oExpedition

Resources Reserve

oBelington Hut

State Forest

oStephenton

State Forest

oBelington Hut

State Forest

Fitzroy

Basin

149.25° E

149.25° E

149.2° E

149.2° E

149.15° E

149.15° E

149.1° E

149.1° E25

.66

7°

S

25

.66

7°

S

25

.7°

S

25

.7°

S

25

.73

3°

S

25

.73

3°

S

25

.76

7°

S

25

.76

7°

S

LEGEND

Riverine Water Type

Wetland Water Type

Basin

Road Network

Local Road

Protected Area

National Park

Other Reserve

Coordinate System: GCS GDA 1994

Datum: GDA 1994

Units: Degree

Santos GLNG Local Water Quality Objectives

Fairview Project Area ±0 21

Kilometres

© Copyright Commonwealth of Australia (Geoscience Australia) 2001, 2004, 2006

© The State of Queensland (Department of Natural Resources and Mines) 2015

© The State of Queensland (Department of National Parks, Recreation, Sport and Racing) 2015

SCALED

awson Rive r

Me

riv

ale

Cre

ek

War

re go

Riv

er

Mara

no a

Riv

er

Warrego

Basin

Burnett

Basin

Fitzroy

Basin

Condamine-Balonne

Basin

MilesRoma

Tara

Surat

Mitchell

Wandoan

Yuleba

Injune

Leic

hh

ard

tH

i ghw

ay

Warrego Highway

Roma Con damine Road

Leic

hhard

tH

i ghw

ay

Ca

rnarv

on

Hig

hway

0 25 Km

Scale: 1:60,000 @ A3

SOURCES

Map 1.1:

Water types relevant to DRRS

PROJECTION2015-03-19

JC

VERSION

DATE

DRAWN BY

01

PO Box 2363

Wellington Point

Q 4160 Australia

P 07 3286 3850

E [email protected]

www.frcenv.com.au

Document Path: Y:\P rojects\2015\150106_SAN_DRRS_Technical_Studies\Mapping\Workspaces\150106_watertype_map_15- 03-19_JC.m xd

Dawson's Bend

Yebna Crossing

tributary gully

trib

uta

ry g

ully

frc environmental


2' Applicable' Environmental' Values' and' National,' State' and'

Regional'WQGs'

The!receiving!environment!for!the!DRRS!is!in!the!Upper!Dawson!River!Sub^catchment,!in!

the!‘Upper!Dawson!–!Taroom!area’,!which!is!the!reach!of!the!Dawson!River!that!extends!

from!Hutton!Creek! to!Glebe!Weir.! !The!Dawson'River'Sub–basin'Environmental'Values'

and'Water'Quality'Objectives,'Environmental'Protection'(Water)'Policy'2009'(EPP'Water)!

(Dawson! EPPR! EHP! 2013a)! identifies! the! following! environmental! values! (EVs)! for! this!

reach!of!the!Dawson!River:!

!! aquatic!ecosystem!(moderately!disturbed!waters)!

!! irrigation!

!! farm!supply/use!

!! stock!water!

!! aquaculture!

!! human!consumption!

!! primary!recreation!

!! secondary!recreation!

!! visual!appreciation!

!! drinking!water!

!! industrial!use,!and!

!! cultural!and!spiritual!values.!

A!brief!discussion!on!the!applicability!of!each!potentially!relevant!EV,!as! identified! in!the!

EPP!Water,! is!presented!for!each!water!type!(i.e.!the!Waterbody!and!the!Dawson!RiverR!

Map!1.1)! in!Table!2.1.! !A!search!of! the!DRNM!water!entitlement!dataset! (DNRM!2016)!

indicates! that! the! closest! surface! water! impoundment! entitlement! (specific! purpose! not!

stated! in! database)! on! the! Dawson! River! main! channel! is! situated! more! than! 350!km!

downstream.!

Additional!references!to!the!EVs!of!the!Upper!Dawson!River!catchment!are!detailed!in!the!

report! Environmental' Values' for' the' Fitzroy:' Community' Consultation' September' 2010!

(FBA!2010).!

A!comparison!of!the!potential!EVs!as!presented!within!the!Dawson!EPP!and!the!summary!

of!Draft!Human!Use!Environmental!Values!as!determined!through!community!consultation!

frc environmental


throughout!the!Fitzroy!Basin!(Feb^Mar!2010),!as!well!as!the!applicable!EVs!determined!by!

Santos,!are!provided!in!Table!2.2.!!!

frc environmental

Santos'GLNG'Dawson'River'Release'Scheme:'Local'Water'Quality'Guidelines' 7'

Table'2.1' Environmental'Values'Assessment'for'the'Waterbody'and'Dawson'River.'

Environmental,Value, Discussion,Applicability,/,Level,

Waterbody, Dawson,River,

Aquatic'Ecosystems' Recent'assessments'of'aquatic'ecology'of'the'Waterbody,'by'suitably'qualified'

personnel,'indicated'that'the'Waterbody'is'a'moderately'to'highly'disturbed'system,'

as'the'Waterbody'and'its'immediate'surrounds'have'been'adversely'affected'by'

human'activity'(grazing,'stock'access).''''Several'species'of'waterbird'listed'as'

Migratory'under'the'Commonwealth’s'Environment*Protection*and*Biodiversity*

Conservation*Act*1999'frequent'the'Waterbody,'although'these'species'are'unlikely'to'

be'residents'at'the'Waterbody.'

The'assessment'of'the'Dawson'River'indicated'the'presence'of'White'Throated'

Snapping'Turtle'(Elseya*albagula),'which'is'listed'as'Critically'Endangered'under'the'

Commonwealth’s'Environment*Protection*and*Biodiversity*Conservation*Act*1999.''

Applicable'–'

moderate'

Applicable'–'

moderate'to'

high'

Irrigation' There'is'currently'no'irrigation'in'the'immediate'vicinity'of'the'Waterbody,'with'the'

closest'irrigation'being'approximately'5km'to'the'west.'

There'is'a'water'supply'scheme'in'the'Dawson'River'that'supplies'water'to'irrigators,'

although'this'scheme'is'further'downstream'than'the'extent'of'the'receiving'

environment.'There'is'limited'extraction'of'water'for'irrigation'from'the'Dawson'River'

in'the'vicinity'of'the'receiving'environment.'

Not'applicable' Applicable'–'low'

Farm'Supply/Use' The'Waterbody'is'currently'not'used'for'irrigation,'nor'is'it'considered'to'be'used'to'

supplement'water'for'other'farm'based'uses'(e.g.'milking'sheds,'fruit'packing'etc.).'

There'is'limited'extraction'of'water'for'general'farm'supply'from'the'Dawson'River'in'

the'vicinity'of'the'receiving'environment.''

Not'Applicable' Applicable'–'low'

frc environmental




Stock'Watering' Stock'access'to'large'portions'of'the'Waterbody'is'permitted'and'has'been'observed.''

The'banks'of'the'Waterbody'are'severely'degraded'and'lack'riparian'vegetation'due'

to'cattle'access/activity.''

Similarly,'cattle'access'the'Dawson'River'for'water'at'numerous'places'within'and'

downstream'of'the'receiving'environment.'

Applicable'–'high' Applicable'–'

high'

Aquaculture' There'is'currently'no'aquaculture'in'or'within'the'immediate'vicinity'of'the'Waterbody'

or'the'receiving'environment'of'the'Dawson'River.'

Not'Applicable' Not'Applicable'

Human'Consumption' Human'consumption'(of'wild'or'stocked)'aquatic'species'is'considered'applicable'to'

the'Waterbody'and'the'Dawson'River.'However'it'is'noted'that'the'Waterbody'is'in'a'

remote'location'and'on'private'land,'as'such'is'not'accessible'to'the'public.'The'

likelihood'of'human'consumption'of'aquatic'species'from'the'Waterbody'is'considered'

to'be'very'low.''Similarly,'there'are'few'public'access'points'to'the'receiving'

environment'reach'of'the'Dawson'River,'although'fish'species'such'as'saratoga'(a'

nonZeating'species)'may'be'caught'by'local'landholders'in'this'reach'of'the'Dawson'

River.'

Applicable'–'low' Applicable'–'low'

Primary'Recreation' The'Waterbody'is'in'a'remote'location'and'on'private'land,'as'such'is'not'accessible'

to'the'public.'The'likelihood'of'primary'recreation'(e.g.'swimming,'etc)'within'the'

Waterbody'is'considered'to'be'very'low.'

Similarly,'public'access'to'the'receiving'environment'reach'of'the'Dawson'River'is'

limited.''It'is'possible'but'not'wellZknown'if'local'landholders'use'this'reach'of'the'

Dawson'River'for'swimming.'


frc environmental




Secondary'Recreation' The'Waterbody'is'in'a'remote'location'and'on'private'land,'as'such'it'is'not'accessible'

to'the'public.'The'likelihood'of'secondary'recreation'(e.g.'fishing,'sailing'or'other'water'

sports'etc.)'within'the'Waterbody'is'considered'to'be'very'low.'

Similarly,'the'receiving'environment'reach'of'the'Dawson'River'has'few'public'access'

points,'and'while'there'may'be'some'fishing'by'local'landholders'in'this'reach'of'the'

Dawson'River,'other'forms'of'secondary'recreation'are'unlikely.'


Visual'Appreciation' The'Waterbody'is'in'a'remote'location'and'on'private'land,'as'such'it'is'not'accessible'

to'the'public.'Visual'appreciation'of'environmental'values,'including'picnicking,'bush'

walking'etc.'are'therefore'not'considered'applicable'to'the'Waterbody.'

Similarly,'the'receiving'environment'reach'of'the'Dawson'River'has'few'public'access'

pints,'and'no'established'picnic'areas'or'parklands'are'near'this'reach'of'the'Dawson'

River.'


Drinking'Water' The'extraction'of'raw'water'from'the'Waterbody'for'drinking'water'is'not'considered'

applicable.'The'closest'residential'property'to'the'Waterbody'is'approximately'5.5'km'

to'the'east'of'the'Waterbody.''

Drinking'water'is'sourced'from'the'Dawson'River'much'further'downstream'than'the'

receiving'environment'reach'of'the'river.''Drinking'water'is'therefore'considered'

applicable'to'this'reach'of'the'Dawson'River,'although'the'large'distance'to'the'

nearest'water'supply'storage'on'the'Dawson'River'

Not'Applicable' Applicable'–'

moderate'

Industrial'Use' The'Waterbody'is'in'a'remote'location'and'on'private'land,'as'such'it'is'not'accessible'

to'the'public.'The'property'holder'does'not'currently'use'the'Waterbody'for'industrial'

purposes'(e.g.'power'generation,'manufacturing'etc.).'Consequently,'the'industrial'

use'EV'is'not'considered'applicable.'

Similarly,'there'are'no'industrial'uses'of'water'in'the'vicinity'of'the'receiving'

environment'reach'of'the'Dawson'River'


frc environmental




Cultural'and'Spiritual'

Values'

Cultural'and'spiritual'purposes'are'considered'applicable'to'the'Waterbody'and'the'

Dawson'River.''While'there'are'no'mapped/documented'Cultural'Heritage'Exclusion'

Zones'within'the'immediate'vicinity'of'the'Waterbody,'there'are'several'cultural'

heritage'zones'in'the'vicinity'of'the'Dawson'River.'

Applicable'–'

moderate'

Applicable'–'

high'

'

frc environmental


Table'2.2' Comparison'of'Environmental'Values'for'the'Dawson'River'and'Waterbody.'

,

Aquatic,Ecosystems,

Irrigation,

Farm,supply/use,

Stock,water,

Aquaculture,

Human,consumption,

Primary,recreation,

Secondary,recreation,

Visual,appreciation,

Drinking,water,

Industrial,use,

Cultural,and,spiritual,

values,

Environmental,Values,

EPP*Water*Dawson*River*Sub?basin*Environmental*Values*and*Water*Quality*Objectives,*Basin*No.130*(part),*including*all*waters*of*the*Dawson*River*Sub?basin*except*

the*Callide*Creek*Catchment,*September*2011'

Upper'Dawson'(Injune'Area)'main'channel'

(upstream'of'Hutton'Creek'junction)'–'developed'areas'

!' ' ' !' ' !' !' !' !' !' ' !'

Upper'Dawson'(Injune'Area)'main'channel'

(upstream'of'Hutton'Creek'junction)'–'undeveloped'areas'

!' ' ' !' ' !' !' ' !' !' ' !'

Upper'Dawson'(Taroom'Area)'main'channel'downstream'of'

Hutton'Creek'junction)'–'developed'areas,'including'Glebe'

Weir'

!' !' !' !' ' !' !' !' !' !' !' !'

Human,Use,Environmental,Values,as,determined,through,community,consultation,throughout,the,Fitzroy,Basin,(Feb,–,Mar,2010),

Values*for*the*Fitzroy:*Community*Consultation*September*2010*(FBA,*2010)**

Values:*!*–*Present,*X*–*Absent,*H*–*High,*M*–*Medium,*L*–*Low'

40'–'Upper'Dawson'main'channel/immediate'tributaries'

(Injune'Workshop)'

!' X' X' !' X' !L' !L' !L' !L' !L' X' !L'

Santos,Determined/Assessed,Environmental,Values,

Values:*!*–*Present,*X*–*Absent,*H*–*High,*M*–*Medium,*L*–*Low'

Dawson'River'(within'vicinity'of'release'point)' !M' X' X' !L' X' !L' X' !L' !L' !L' X' !'

Waterbody' !L' X' X' !L' X' !L' !L' !L' X' X' X' !L'

frc environmental


Water'quality'Guidelines'(WQGs)'to'protect'the'identified'environmental'values'have'been'

published'in'the'following'documents:''

!' the'Australian* and*New*Zealand*Guidelines* for* Fresh* and*Marine*Water*Quality'

(ANZECC' &' ARMCANZ' 2000a),' which' specifies' national' and' where' possible'

regional'WQGs'for'different'biographic'regions'within'Queensland'

!' the'Queensland* Water* Quality* Guidelines' (EHP' 2013a),' which' encourages' the'

development'of'local'WQGs,'and'

!' the'Dawson*River*Sub–basin*Environmental*Values*and*Water*Quality*Guidelines*

EPP*(Water)*2009'(EHP'2013a),'which'specifies'sub–regional'WQGs'for'different'

areas'of'the'Dawson'River'Sub–basin.'

The'FAPA'EA'(EPPG00928713)'also'specifies'water'quality'guidelines'(i.e.'contaminant'

limits)' for' a' number' of' parameters' at' certain' monitoring' points' for' the' purposes' of'

compliance'monitoring'during'discharge'periods.''

In' accordance' with' the' approach' for' selecting' and' applying' WQGs' as' outlined' in' the'

National* Water* Quality* Guidelines' (ANZECC' &' ARMCANZ' 2000b),' the' default' WQGs'

applicable' to' each' EV' identified' for' the' receiving' waters' were' collated,' based' on'

published' guidelines' (Appendix' A).' ' Where' separate' WQGs' were' available' for' Upper'

Dawson'River'waters'and'lakes'/'reservoirs,'the'value'prescribed'for'Upper'Dawson'River'

waters' has' been' adopted' for' the' Dawson' River,' and' the' value' prescribed' for' lakes' /'

reservoirs'for'the'Waterbody.''If'no'sub]regional'value'was'available,'the'national'default'

values'were'adopted.''Where'two'or'more'WQGs'were'available'for'one'parameter,'then'

the'more'stringent'value'was'adopted'for'the'WQG.'''

There' are' no' WQGs' for' secondary' and' visual' recreation' for' the' relevant' parameters,'

however,'water'should'be'free'of:'

!' floating'debris'

!' oil'and'grease'

!' substances'that'produce'undesirable'colour,'odour,'taste'or'foaming,'and''

!' undesirable'aquatic'life'such'as'algal'blooms'or'dense'growth'of'attached'plants'or'

insects.''

Similarly,' there'are'no'specific'WQGs'to'protect'cultural'heritage,' though'the' indigenous'

and' non–indigenous' cultural' heritage' of' waterways' should' be' protected' or' restored' in'

accordance'with'relevant'policies'and'plans.'

frc environmental


In'the'absence'of'local'WQGs,'the'existing'published'WQGs'presented'in'Appendix'A'are'

the' best' available' for' assessing' water' quality' within' the' receiving' environment' of' the'

DRRS.''

However,' the' National* Water* Quality* Guidelines' (ANZECC' &' ARMCANZ' 2000a)'

recommend'that'local'WQGs'based'on'locally'collected'water'quality'data'are'developed'

and' used' preferentially' over' national' and' state' WQGs,' particularly' with' respect' to' the'

protection' of' aquatic' ecosystems' EV.' Therefore,' the' local'WQGs' developed'within' this'

report'will'replace'some'of'these'existing'WQGs.'

frc environmental


3" The"QWQG"Approach"to"Developing"Local"WQGs"

3.1" Defining"the"Water"Types"in"the"Receiving"Environment"

The'QWQGs'(EHP'2013c)'recognise'a'number'of'different'water'types'within'Queensland'

that' have' considerable' natural' variation' in' water' quality' and' biological' characteristics,'

including' freshwater' lakes' (i.e.' non]flowing' systems)' and' freshwater' watercourses' (i.e.'

flowing' systems).' It' is' recommended' that' local' WQGs' be' developed' for' distinct' water'

types' for' which' natural' water' quality' is' reasonably' consistent.' ' This' allows' setting' of'

guideline'values'for'each'water'quality'parameter,'for'each'water'type.''

3.2" Selection"of"Reference"Sites"

The'QWQGs' indicate' that' local'WQGs' can' be' derived' using' an' ‘acceptable' departure'

from'natural'or'reference'condition’'approach.''

This' requires' an' appropriate' amount' of' water' quality' data' from' ‘reference' sites’,' to'

determine' the' reference' condition' for' each'water' type.' 'Reference' sites' for' each'water'

type'must'satisfy'the'following'criteria:'

!' no'intensive'agriculture'within'20'km'upstream'(dry–land'grazing'is'not'considered'

intensive'agriculture)'

!' no'major'extractive'industries'(current'or'historical)'within'20'km'upstream'

!' no'major'urban'area'(population'greater'than'5,000)'within'20'km'upstream'

!' no'significant'point'source'wastewater'discharge'within'20'km'upstream,'and'

!' seasonal' flow' regime' is' not' greatly' altered' by' abstraction' or' regulation' further'

upstream.'

Reference'sites'can'also'be'planned'receiving'environment'sites,'providing'that:'

!' the'locations'satisfy'the'above'criteria,'and'

!' water'quality'data'used'to'develop' local'WQGs'is'collected'before'any'discharge'

into'the'receiving'environment'commences.'

frc environmental


3.3" Selecting"Appropriate"Water"Quality"Parameters"

The'QWQG' indicates' that' local'WQGs' can' be' set' for' a' range' of' indicators' (e.g.'water'

chemistry,' water' flow,' aquatic' habitat' and' aquatic' biota)' and' that' the' selection' of'

indicators' and' parameters'must' reflect' the' EVs' identified' for' the' receiving' environment'

and'other'management'goals.'

3.4" Selecting"Appropriate"Water"Quality"Data""

The'QWQG'considers' that'water'quality'data'collected'using'either'of' the' following' two'

approaches'is'suitable'for'establishing'local'WQGs:''

!' data' collected' from' two' reference' sites,'with' a'minimum'of' 18' discrete' samples'

collected' at' each' site' (36' samples' in' total)' over' a' period' of' 12' or' preferably' 24'

months,'or'

!' data'collected' from'three'or'more'reference'sites,'with'a'minimum'of'12'discrete'

samples'collected'at'each'site'over'a'period'of'12'to'24'months.'

3.5" Procedure"for"Calculating"the"Local"WQGs"from"Reference"Site"Data"

Local' WQGs' were' calculated' according' to' the' methods' in' the' QWQG' for' slightly' to'

moderately'disturbed'aquatic'ecosystems'(EHP'2013c):'

!' Baseline'water'quality'data'was'pooled'for'each'reference'site'for'each'water'type'

separately'(i.e.'the'Waterbody,'Dawson'River'and'Hutton'Creek),'and'appropriate'

percentiles'calculated'for'each'parameter'for'each'site:'

"' the'75th'percentile'was'calculated'for'electrical'conductivity''

"' the'80th'percentile'was'calculated'for'all'other'parameters,'and'

"' the' 20th' percentile' was' calculated' for' pH' and' dissolved' oxygen' (where' low'

values'can'also'be'problematic)'

!' The' mean' (±' one' standard' error)' of' these' percentiles' was' calculated' for' each'

parameter'for'each'water'type'

!' Where' the'mean' of' the' percentiles'was'within' one' standard' error' of' the' default'

WQG'for'each'water'type,'no'change'was'made'

!' Where' the'mean'of' the'percentiles'was'higher' than' the'upper' limit'or' lower' than'

the'lower'limit'by'more'than'one'standard'error'of'the'default'WQG'for'each'water'

frc environmental


type,' then' the' mean' of' the' percentiles' was' adopted' as' the' local' water' quality'

guideline'for'that'parameter'for'that'water'type,'and''

!' Where' the' mean' of' the' percentiles' was' lower' than' one' standard' error' of' the'

default'WQG'no'change'was'made'(EHP'2013d).''

frc environmental


4" Developing"Local"WQGs"for"the"DRRS""

4.1" Water"Types"in"the"Receiving"Environment"

Based'on'the'definitions'in'the'Dawson*River*Sub–basin*Environmental*Values*and*Water*

Quality* Objectives* EPP* (Water)* 2009' (EHP' 2013a),' there' are' two' water' types' in' the'

receiving'environment'of'the'DRRS:''

!' the'Waterbody'–'freshwater'lake'/'reservoirs'(non]flowing'water),'and'

!' the'Dawson'River'–'freshwaters'within'the'Upper'Dawson'River'(flowing'water).'

Local'WQGs'were'developed'separately'for'the'Waterbody'and'the'Dawson'River.'

Waterbody"

The'Waterbody'is'a'large'semi'permanent'oxbow'with'an'approximate'volume'of'500'ML.''

There'are'several'dry'gullies'upstream'of'the'Waterbody,'including'the'gully'to'which'the'

release'water'will'be'discharged.''An'ephemeral'stream'connects'the'Waterbody'with'the'

Dawson'River'downstream'of'the'Waterbody.''The'Waterbody'is'a'riverine'wetland'and'is'

considered' to' be' a' wetland' of' General' Ecological' Significance' (GES)' under' the'

Environmental*Protection*Regulation'2008'(EHP'2013b).''

Dawson"River"

The'Dawson'River' is' a'major' tributary' of' the'Fitzroy'River.' ' The'Dawson'River' and' its'

tributaries' cover' an' area' of' approximate' 50' 776' km2' (EHP' 2013a).' The' stretch' of' the'

Dawson'River'in'the'receiving'environment'has'a'perennial'flow'regime.''

4.2" Selection"of"Reference"Sites"

Eight'sites'that'satisfy'the'criteria'listed'in'Section'3.2.1'were'selected'for'developing'local'

WQGs'for'the'DRRS'(Table'4.1):'

!' five'sites'were'identified'as'appropriate'reference'sites'for'developing'local'WQGs'

for'the'Waterbody'(all'in'the'Waterbody),'and'

frc environmental


!' three' sites' were' identified' as' appropriate' reference' sites' for' developing' local'

WQGs' for' the'Dawson'River.'One'of' the'sites' (DRR1)' is'upstream'of'where' the'

release'water'will'be'discharged'via'the'tributary'gully'to'the'Dawson'River.'

'

Table'4.1' Location'of'Reference'Sites.'

Site"Name" Description"GDA94"

Latitude" Longitude"

Waterbody"Sites" " " "

WLMP1'(Wetland'

MP'1)'a'

Waterbodyh'200'm'downstream'of'where'the'

tributary'gully'discharges'into'the'Waterbody.'

]25.708' 149.146'

WLMP2'(Wetland'

MP'2'b'

Waterbodyh'450'm'upstream'of'where'the'


]25.706' 149.143'

WLMP3'(Wetland'

MP'3)'c'

Waterbodyh'300'm'downstream'of'where'the'


]25.707' 149.149'

WLMP4'(Wetland'

MP'4)'d'

Waterbodyh'1.5'km'upstream'of'where'the'


]25.698' 149.139'

WLMP5'

(Wetland'MP'5)'e'

Waterbodyh'1.0'km'downstream'of'where'the'


]25.701' 149.153'

Dawson"River"Sites"

DRMP1'

(Dawson'River'

MP1)'

Dawson'Riverh'3.5'km'downstream'of'where'

the'tributary'gully'discharges'into'the'

Waterbody'and'200'm'downstream'of'the'

confluence'of'the'tributary'gully'and'the'

Dawson'River.'

]25.690' 149.163'

S4' Dawson'River'at'Yebna'Crossingh'9.8'km'

downstream'of'where'the'tributary'gully'

discharges'into'the'Waterbody'and'8'km'

downstream'of'the'confluence'of'the'tributary'

gully'and'the'Dawson'River.'Represents'the'

downstream'extent'of'the'receiving'

environment.'

]25.692' 149.215'

DRR1'f' Dawson'Riverh'550'm'upstream'of'the'

confluence'of'the'tributary'gully'and'the'

Dawson'River.'

]25.688' 149.156'

The'site'names'in'parenthesis'represent'the'name'of'the'monitoring'point'as'described'in'the'EA.'

Baseline'site'represented'by:'a'='WMP1,'

b'='WMP2,'

c'='WMP3,'

d'='WMP4,'

e'=WMP5,'

f'='RS1'

' '

Inju

ne

Roa

d

Inju

ne R

oadDawson River

Dawson River

Daw

sonR

iver

DawsonRiv

er

Daws

on

Riv

er

Com

miss ion

erCree

k

Boyd Cre ek

oExpedition (Limited

Depth) National Park

oExpedition

Resources Reserve

oBelington Hut

State Forest

oStephenton

State Forest

Fitzroy

Basin

DRMP1

DRR1

WLMP1

WLMP2 WLMP3

WLMP4

WLMP5

S4

149.2° E

149.2° E

149.15° E

149.15° E25

.66

7°

S

25

.66

7°

S

25

.7°

S

25

.7°

S

25

.73

3°

S

25

.73

3°

S

LEGEND

Dawson River

wetland

Watercourse

Lake/Reservoir

Basin

Road Network

Local Road

Protected Area

National Park

Other Reserve

Coordinate System: GCS GDA 1994

Datum: GDA 1994

Units: Degree

Santos GLNG Local Water Quality Objectives

Fairview Project Area ±0 21

Kilometres

© Copyright Commonwealth of Australia (Geoscience Australia) 2001, 2004, 2006

© The State of Queensland (Department of Natural Resources and Mines) 2015

© The State of Queensland (Department of National Parks, Recreation, Sport and Racing) 2015

SCALED

awson Rive r

Me

riv

ale

Cre

ek

War

re go

Riv

er

Mara

no a

Riv

er

Warrego

Basin

Burnett

Basin

Fitzroy

Basin

Condamine-Balonne

Basin

MilesRoma

Tara

Surat

Mitchell

Wandoan

Yuleba

Injune

Leic

hh

ard

tH

i ghw

ay

Warrego Highway

Roma Con damine Road

Leic

hhard

tH

i ghw

ay

Ca

rnarv

on

Hig

hway

0 25 Km

Scale: 1:40,000 @ A3

SOURCES

Map 4.1:

Reference sites

PROJECTION2015-03-19

CF, JC

VERSION

DATE

DRAWN BY

02

PO Box 2363

Wellington Point

Q 4160 Australia

P 07 3286 3850

E [email protected]

www.frcenv.com.au

Document Path: Y:\P rojects\2015\150106_SAN_DRRS_Technical_Studies\Mapping\Workspaces\150106_si temap_15-03-19_JC.mxd

frc environmental


4.3" Selecting"Appropriate"Water"Quality"Parameters"

While' the'QWQG' indicates' that' local'WQGs' can' be' set' for' a' range' of' indicators' (e.g.'

water'chemistry,'water'flow,'aquatic'habitat'and'aquatic'biota),' this'report'relates'only'to'

water'quality'(i.e.'water'chemistry)'parameters.'

The'FAPA'EA'(EPPG00928713)'outlines'the'water'quality'parameters'to'be'monitored'for'

the' DRRS' (Schedule' B,' Table' 4).' ' The' parameters' associated' with' the' waterbody'

monitoring' sites' are' currently' considered' the' water' quality' parameters' for' which' to'

develop'local'WQGs.''

4.4" Available"Water"Quality"Data""

Water'quality'data'from'January'2013'to'February'2015'for'the'Dawson'River,'and'June'

2013' to' February' 2015' for' the'Waterbody,' was' supplied' by' Santos' GLNG.' ' Over' this'

period,' individual' sites'were'sampled'between'13' (site'S4)'and'39' times' (site'DRMP1),'

except'for'percent'saturation'of'dissolved'oxygen'(Appendix'B).'

This'data'satisfies'the'criteria'for'establishing'LWQGs'as'prescribed'by'the'QWQGs'(EHP'

2013c).''

Data"Quality"

All' water' quality' monitoring' and' sampling' was' by' appropriately' trained' people' in'

accordance'with'EHP’s'Monitoring*and*Sampling*Manual*2009*Version*2'(DEHP'2013).'''

Dissolved'oxygen,'pH,'electrical'conductivity'and'turbidity'were'tested'both'in'the'field'and'

in'samples'that'were'collected'for'laboratory'analysis.''The'following'data'was'used'in'the'

analyses:'

!' Temperature'and'dissolved'oxygen'were'assessed'using'field'data''

!' electrical' conductivity'was'assessed'using' laboratory'data' (specific' conductivity),'

and'

!' pH' and' turbidity' results' from' each' method' were' assessed' individually' and' the'

most'conservative'values'were'used'to'develop'LWQGs.'''

The'total'fraction'of'cation'and'anion'parameters'were'used'in'the'data'analysish'the'total'

and'dissolved'fractions'of'metals'and'metalloids'were'assessed'separately.''

frc environmental


4.5" Calculated"Local"WQGs""

The' results' of' the' calculations' of' the'mean' 5th,' 20th,' 80th' and' 95th' percentiles' for' the'

applicable'water'quality'parameters'for'the'Waterbody'and'the'Dawson'River'are'shown'

in'Appendix'C.''The'baseline'monitoring'data'was'assessed'as'reasonably'consistent'for'

all'water'quality'parameters'within'each'water'type.'

The'mean' 80th' percentile' for' each' parameter' was' then' compared' to' the' existing'water'

quality' guidelines' in' the' EA,' except' for' electrical' conductivity' for' which' the' mean' 75th'

percentile'was'used'(Table'4.2h'Appendix'C).''Where:'

!' the'existing'guideline'was'within'one'standard'error'of'the'mean'of'the'percentiles,'

no'change'to'the'guideline'was'made'

!' the'existing'guideline'was'higher'than'the'upper'limit'or'lower'than'the'lower'limit'

by'more'than'one'standard'error'of'the'mean'of'the'percentiles,'then'the'mean'of'

the'percentiles'was'adopted'as'the'new'water'quality'guideline,'and'where'''

!' the' existing' guideline' was' lower' than' one' standard' error' of' the' mean' of' the'

percentiles,'no'change'was'made'(EHP'2013d).''

The'results'show'(Table'4.3):'

!' one' parameter' (temperature)' had' mean' 20th' and' 80th' percentiles' that' reflect' a'

constant' water' quality' guideline' in' comparision' to' the' EA,' in' which' the' current'

water'quality'guideline'is'relative'to'background'temperature'at'site'WLMP42'

!' four'parameters'for'which'the'mean'of'the'appropriate'percentiles'of'baseline'data'

collected' from' the'Waterbody'was'more' than'one'standard'error'higher' than' the'

current'EA'water'quality'guideline,'and'

!' no'parameters'for'which'the'mean'of'the'appropriate'percentiles'of'baseline'data'

collected' from' the'Dawson'River'was'more' than' one' standard' error' higher' than'

the'current'EA'water'quality'guideline.'

'''''''''''''''''''''''''''''''''''''''' ''''''''2' It' should' be' noted' that'WLMP4'was' dry' for' about' half' of' the' baseline'monitoring' surveys,' and' has'

much'shallower'water'than'sites'WLMP1'and'WLMP5.''These'reasons'mean'that'the'current'EA'water'

quality'guideline'is'not'appropriate.'

frc environmental


Table'4.2' Calculation'of'local'water'quality'guidelines'compared'to'current'EA'water'quality'guidelines.'

Parameter' Units' Current'EA'Guideline'Calculated'Mean'(80

th)'Percentile'

Waterbody' Dawson'River'

Physical'Chemical' ' ' ' '

Temperature' °C' +'/'–'background'

temperature'at'site'

WLMP4'

19.0'–'29.3' 15.8'–'27.1'

Dissolved'Oxygen'a' mg/L' 6.4'–'16.1' 7.8'–'10.5' 6.6'–'9.1'

Electrical'Conductivity'@'25°C'' µS/cm' 500' 627' 303'

pH'a' pH'Unit' 6.5'–'8.5' 7.4'–'8.2' 7.1'–'7.9'

Suspended'Solids' mg/L' 50' 128' 9'

Turbidity'a' NTU' monitor'only' 105' 12'

Nutrients' ' ' ' '

Ammonia'as'N' mg/L' 0.9' 0.16' 0.03'

Total'Nitrogen'as'N' mg/L' 0.620' 3.93' 0.31'

Total'Metals'and'Metalloids' ' ' ' '

Boron' µg/L' 1000'b' 134' 50'

Zinc' µg/L' 8' 12' 5'

Dissolved'Metals'and'Metalloids' ' ' ' '

Boron' µg/L' 1000'b' 116' 350'

Zinc' µg/L' 8' 9' 6'a' based'on'field'data'

frc environmental


b'based'on'direct'toxicity'assessment'of'total'boron'(Halcrow'2012).'

Grey'shading'denotes'where'the'calculated'mean'of'the'percentiles'was'higher'than'the'upper'limit'or'lower'than'the'lower'limit'of'the'current'EA'limit'by'more'than'

one'standard'error'.'

frc environmental


4.6$ Recommendations$for$Modifying$the$Water$Quality$Guidelines$

Recommendations' for' modifying' the' current' EA' water' quality' guideline' were' made' for'

each'water'type'where'the'calculated'mean'of'the'percentiles'was'higher'than'the'upper'

limit'or'lower'than'the'lower'limit'of'current'EA'limit'by'more'than'one'standard'error.''The'

lower'of'the'two'water'quality'guidelines'was'selected'as'the'new'value'for'the'EA'water'

quality'guideline'because'this'value:'

!' is' less'stringent'than'the'current'EA'water'quality'guideline'for'that'parameter'for'

that'water'type,'and'

!' will' achieve' protection' of' the' aquatic' ecosystem' environmental' value' for' both'

water'types.'

The' following' recommendations' are' made' for' modifying' the' water' quality' guidelines'

(Table'4.3):'

!' five' parameters' (temperature,' electrical' conductivity,' suspended' solids,' total'

nitrogen,'total'zinc)'had'calculated'local'water'quality'guidelines'for'the'Waterbody'

water'type'that'could'be'adopted'as'water'quality'guidelines'

!' one'parameter' (temperature)'had'calculated' local'water'quality'guidelines' for' the'

Dawson'River'that'could'be'adopted'as'water'quality'guidelines,'and'

!' the' current' EA' water' quality' guidelines' or' the' published' WQO' (Table' A.1)' are'

recommended'to'be'retained'for'all'other'parameters'.'

frc environmental


Table'4.3' Local'water'quality'guidelines'developed'from'baseline'data'as'per'the'QWQG'

Parameter' Units'

Current'

EA'

Guideline'

Calculated'mean'(80th)'percentile' Recommended'local'water'quality'guideline'

Waterbody' Dawson'River' Waterbody' Dawson'River'

Physical'Chemical' ' ' ' ' ' '

Temperature' °C' –' 19.0'–'29.3' 15.8'–'27.1' 19.0'–'29.3' 15.8'–'27.1'

Dissolved'Oxygen'a' mg/L' 6.4'–'16.1' 7.8'–'10.5' 6.6'–'9.1' 6.4'–'16.1' 6.4'–'16.1'

Electrical'Conductivity'@'25°C'' µS/cm' 500' 627' 303' 627' 370c'

pH'a' pH'Unit' 6.5'–'8.5' 7.4'–'8.2' 7.1'–'7.9' 6.5'–'8.5' 6.5'–'8.5'

Suspended'Solids' mg/L' 50' 128' 9' 128' 30c'

Turbidity'a' NTU' monitor'

only'

105' 12' monitor'only' monitor'only'

Nutrients' ' ' ' ' ' '

Ammonia'as'N' mg/L' 0.9' 0.16' 0.03' 0.9' 0.02c'

Total'Nitrogen'as'N' mg/L' 0.620' 3.93' 0.31' 3.93' 0.620'

Total'Metals'and'Metalloids' ' ' ' ' ' '

Boron' µg/L' 1000'b' 134' 50' 1000

'b' 1000

'b'

Zinc' µg/L' 8' 12' 5' 12' 8'

Dissolved'Metals'and'Metalloids' ' ' ' ' ' '

Boron' µg/L' 1000'b' 116' 350' 1000

'b' 1000

'b'

Zinc' µg/L' 8' 9' 6' 8' 8'a' based'on'field'data'b'

based'on'direct'toxicity'assessment'of'total'boron'(Halcrow'2012).'c' based'on'the'published'WQO'(Table'A.1)'

Blue'shading'indicates'the'origin'of'the'Waterbody'recommended'local'water'quality'guideline]'Grey'shading'indicates'the'origin'of'the'Dawson'River'recommended'local'

water'quality'guideline]'Green'shading'indicates'the'origin'of'the'recommended'local'water'quality'guideline'for'both'water'types'

frc environmental


5" Summary"

There'are'default'published'WQGs'for'a'number'of'water'quality'parameters'in'the'Upper'

Dawson'River.' 'However,' these'may'not'be'representative'of'water'quality'conditions'in'

the'receiving'environment'of' the'DRRS'(i.e.' the'Waterbody'and'the'Dawson'River).'The'

National'and'State'Water'Quality'Guidelines'(ANZECC'&'ARMCANZ'2000aQ'EHP'2013a)'

recommend'that'local'WQGs'based'on'locally'collected'water'quality'data'are'developed'

and'used'preferentially'over'national,'state'and'regional'WQGs.''The'Queensland'Water'

Quality' Guidelines' (QWQG)' (EHP' 2013a)' present' the' procedure' for' developing' local'

WQGs'in'Queensland.''

This'procedure'was'applied' to'baseline'water'quality'data'collected'from'reference'sites'

within'the'Waterbody'and'the'Dawson'River'within'the'DRRS.'''

Where'the'baseline'data'indicated'a'less'stringent'LWQG'than'the'published'WQG,'then'

it'was'adopted'as'the'LWQG.'However,'where'direct' toxicity' testing'studies'show'that'a'

less' stringent' value' for' a' water' quality' parameter' will' protect' the' Protection' of' Aquatic'

Ecosystems' Environmental' Value,' then' this' value' was' adopted' as' the' WQG' for' that'

parameter.'

Five' parameters' have' local' WQGs' that' were' developed' using' baseline' data' for' the'

Waterbody,' and' baseline' data' was' used' to' set' a' local'WQG' for' the' Dawson'River' for'

temperature'(Table'4.2).''One'parameter'(total'boron)'has'a'local'WQG'developed'using'

direct'toxicity'assessment'for'both'the'Waterbody'and'the'Dawson'River'(Table'4.2).'The'

published'WQG'(i.e.'EA'limit'or'published'WQO,'see'Table'A.1)'was'recommended'for'all'

other'parameters'(Table'4.2).'

frc environmental


6" References"

ANZECC' &' ARMCANZ,' 2000a,'Australian* and* New* Zealand* Guidelines* for* Fresh* and*

Marine*Water*Quality,'National'Water'Quality'Management'Strategy,'Australian'

and' New' Zealand' Environment' and' Conservation' Council' &' Agriculture' and'

Resource'Management'Council'of'Australia'and'New'Zealand.'

ANZECC'&' ARMCANZ,' 2000b,'Australian*Guidelines* for*Water* Quality*Monitoring* and*

Reporting,' National' Water' Quality' Management' Strategy,' Australian' and' New'

Zealand' Environment' and' Conservation' Council' &' Agriculture' and' Resource'

Management'Council'of'Australia'and'New'Zealand.'

DEHP,' 2013.'Monitoring* and*Sampling*Manual* 2009,* Environmental* Protection* (Water)*

Policy* 2009,* Version* 2,* July* 2013.' Department' of' Environment' and' Heritage'

Protection,'Canberra.'

EHP,' 2013a.' Environmental* Protection* (Water)* Policy* 2009,* Dawson* River* SubNbasin*

Environmental* Values* and* Water* Quality* Objectives* Basin* No.* 130* (part),*

including* all* waters* of* the* Dawson* River* SubNbasin* except* the* Callide* Creek*

Catchment.'Environmental'Policy'and'Planning,'Department'of'Environment'and'

Heritage'Protection,'State'of'Queensland.'

EHP,'2013b,'Map*of*referable*wetlands,'

http://www.ehp.qld.gov.au/ecosystems/wetlands/referable\wetlands\maps.html,''

accessed'October'2016.'

EHP,'2013c.'Queensland*Water*Quality*Guidelines*2009.'Department'of'Environment'and'

Heritage'Protection,'Queensland'Government,'Brisbane.'

FBA,'2010,'Environmental*Values*for*the*Fitzroy:*Community*Consultation,'Fitzroy'Basin'

Association.'

Halcrow,' 2012.' Dawson* River* Release* Scheme* Direct* Toxicity* Assessment.* Santos*

GLNG*Project.'

'

frc environmental

Santos'GLNG'Dawson'River'Release'Scheme:'Local'Water'Quality'Guidelines' A1'

Appendix"A" Published"WQGs"

frc environmental

Santos'GLNG'Dawson'River'Release'Scheme:'Local'Water'Quality'Guidelines' A2'

Table'A.1' Published'WQGs'for'Water'Chemistry.'

Parameter'' Unit''

Aquatic'Ecosystems'

Stock'Water' Irrigation'and'Farm'Supply' Aquaculture'Human'

Consumption'

Recreation'

(primary,'

secondary'

and'visual)'c'

Adopted'Default'

WQG'Upper'Dawson' Reservoirs' ANZECC'

a'

Compliance'Parameters'

PhysicalKChemical'

pH'' pH'Unit' 6.5'–'8.5' 6.5'–'8.0' 6.5'–'8.0' 6.0'–'9.0' >'6' 5.0'–'9.0' –' 5.0'–'9.0' 6.5'–'8.5'

electrical'

conductivity''

µS/cm' 210'high'flow'370'base'

flow'

250'base'

flow'

125'–'

2200'

3582' refer'to'ANZECC'&'ARMCANZ'guideline' –' –' –' 250'

dissolved'oxygen' mg/L' –' –' –' –' –' >5' –' –' –'

dissolved'oxygen' %'sat' 85'–'110' 90'–'110' 85'–'110' –' –' –' >85' –' 85'–'110'

turbidity'' NTU' 50' 1'–'20' 6'–'50' –' –' –' –' –' 1'–'20'

total'suspended'

solids'

mg/L' 30' –' –' –' –' 40' –' –' 30'

Nutrients'

total'nitrogen' mg/L' 0.62' 0.35' 0.5' –' 5'(long'term)'–'25'(short'term)' –' –' –' 0.35'

ammonia'as'N' mg/L' 0.02' 0.01' –' –' –' 0.03' 0.5' 0.01' 0.01'

Total'Metals'and'Metalloids'

boron' µg/L' –' –' 370'c' 5000' 500'(long]term)' –' –' 1000' 370'

zinc' µg/L' –' –' 8'd' 20000' 2000'(long]term)'–'5000'(short]term)' 5' 3000' 5000' 5'

Dissolved'Metals'and'Metalloids'

boron' µg/L' –' –' 370'c' 5000' 500'(long]term)' –' –' 1000' 370'

zinc' µg/L' –' –' 8'c' –' 2000'(long]term)'–'5000'(short]term)' 5' 3000' 5000' 5'

Grey'shading'denotes'values'that'have'been'adopted'as'the'WQG'from'the'available'published'WQGs.' '

NA' Published'guideline'not'applicable'because'regional'guideline'available.'

a' ANZECC'&'ARMCANZ'guidelines'for'south]east'Australia,'lowland'rivers'

b' In'addition'to'the'WQGs'specified,'to'support'this'EV'water'should'be'free'of:'floating'debrisb'oil'and'greaseb'substances'that'produce'undesirable'colour,'odour,'taste'or'foamingb'and'undesirable'aquatic'life'such'as'algal'blooms'or'dense'growth'of'

attached'plants'or'insects'

c' Figure'may'not'protect'key'test'species'from'chronic'toxicity'(this'refers'to'experimental'chronic'figures'or'geometric'mean'for'species).'

d' Interim'guideline'based'on'current'Canadian'guideline'value'

frc environmental

Santos'GLNG'Dawson'River'Release'Scheme:'Local'Water'Quality'Guidelines' B1'

Appendix(B( Number( of( Data( Points( Used( to( Calculate( Local(

WQGs(

frc environmental

Santos'GLNG'Dawson'River'Release'Scheme:'Local'Water'Quality'Guidelines' B2'

Table'B.1' Number'of'data'points'used'to'calculate'local'WQGs'for'each'parameter.!

Parameter!!

Waterbody! Dawson!River!

WLMP1! WLMP2! WLMP3! WLMP4! WLMP5! DRMP1! DRR1! S4!

Physical!Chemical! ! ! ! ! ! ! ! ! !

Temperature' °C' 27' 31' 34' 15' 31' 37' 46' 17'

Dissolved'Oxygen'–'Field' mg/L' 27' 31' 34' 15' 31' 37' 45' 17'

Electrical'Conductivity'–'Field' µS/cm' 27' 31' 34' 15' 31' 37' 45' 17'

Electrical'Conductivity'@'25°C'' µS/cm' 30' 35' 38' 19' 36' 39' 38' 17'

pH'–'Field' pH'Unit' 27' 31' 34' 15' 31' 37' 46' 15'

pH'–'Lab' pH'Unit' 30' 35' 38' 19' 36' 39' 38' 17'

Suspended'Solids' mg/L' 30' 35' 38' 19' 36' 39' 38' 17'

Turbidity'–'Field' NTU' 23' 23' 24' 15' 24' 27' 36' 13'

Turbidity'–'Lab' NTU' 0' 0' 0' 0' 0' 0' 0' 17'

Nutrients! ! ! ! ! ! ! ! ! !

Ammonia'as'N' mg/L' 30' 35' 38' 19' 36' 39' 38' 17'

Total'Nitrogen'as'N' mg/L' 30' 35' 38' 19' 36' 39' 38' 17'

Total!Metals!and!Metalloids! ! ! ! ! ! ! ! ! !

Boron' mg/L' 30' 35' 38' 19' 36' 39' 38' 17'

Zinc' mg/L' 30' 35' 38' 19' 36' 39' 38' 17'

Dissolved!Metals!and!Metalloids! ! ! ! ! ! ! ! ! !

Boron' mg/L' 30' 35' 38' 19' 36' 39' 38' 17'

Zinc' mg/L' 30' 35' 38' 19' 36' 39' 38' 17'

frc environmental

Santos'GLNG'Dawson'River'Release'Scheme:'Local'Water'Quality'Guidelines' C1'

Appendix(C( Calculations(for(Local(WQGs(for(Water(Chemistry(

frc environmental


Table'C.1' Water'chemistry'parameters'for'Waterbody.''

Parameter' Units' LOR'5th'%ile' 20th'%ile' 80th'%ile' 95th'%ile'

Average' St'Error' Average' St'Error' Average' St'Error' Average' St'Error'

Physical'Chemical' ' ' ' ' ' ' ' ' '

Temperature' °C' –' 16.30' 1.88' 19.04' 0.65' 29.28' 0.21' 32.68' 0.40'

Dissolved'Oxygen'O'Field' mg/L' –' 7.30' 0.70' 7.81' 0.53' 10.49' 0.11' 12.26' 0.80'

Electrical'Conductivity'@'25°C'O'Lab' µS/cm' 1.00' 368.47' 50.79' 431.00' 13.50' 627.45' 56.00' 874.45' 145.36'

pH'O'Field' pH'Unit' –' 7.15' 0.17' 7.42' 0.04' 8.21' 0.06' 8.61' 0.11'

Suspended'Solids' mg/L' 5.00' 31.96' 5.47' 39.16' 4.09' 127.64' 38.02' 213.41' 60.52'

Turbidity'O'Field' NTU' –' 15.74' 9.85' 23.66' 7.31' 105.43' 12.94' 355.41' 98.81'

Nutrients' ' ' ' ' ' ' ' ' ' '

Ammonia'as'N' mg/L' 0.01' 0.01' 0.01' 0.01' 0.00' 0.16' 0.06' 0.62' 0.24'

Total'Nitrogen'as'N' mg/L' 0.10' 1.86' 0.19' 2.44' 0.18' 3.93' 0.46' 5.44' 0.47'

Total'Metals'and'Metalloids' ' ' ' ' ' ' ' '

Boron' µg/L' 50.00' <50' 11.00' 62.00' 1.26' 134.00' 14.57' 175.00' 15.96'

Zinc' µg/L' 5.00' <5' 0.70' <5' 0.56' 11.80' 1.36' 18.87' 2.08'

Dissolved'Metals'and'Metalloids' ' ' ' ' ' ' ' '

Boron' µg/L' 50.00' <50' 11.00' <50' 6.48' 116.40' 14.78' 161.20' 17.40'

Zinc' µg/L' 5.00' <5' 0.00' <5' 0.50' 8.80' 1.23' 14.62' 2.22'

75%'percentile'values'are'presented'in'place'of'80%'percentile'values'for'electrical'conductivity'

' '

frc environmental


Table'C.2' Water'chemistry'parameters'for'Dawson'River.'

Parameter' Units' LOR'5th'%ile' 20th'%ile' 80th'%ile' 95th'%ile'

Average' St'Error' Average' St'Error' Average' St'Error' Average' St'Error'

Physical'Chemical' ' ' ' ' ' ' ' ' '

Temperature' °C' –' 13.06' 1.10' 15.81' 0.91' 27.14' 0.42' 29.32' 0.42'

Dissolved'Oxygen'O'Field' mg/L' –' 5.46' 0.62' 6.62' 0.44' 9.11' 0.45' 10.07' 0.34'

Electrical'Conductivity'@'25°C'O'Lab' µS/cm' 1.00' 249.33' 0.88' 264.33' 4.91' 303.33' 23.85' 339.57' 36.12'

pH'O'Field' pH'Unit' –' 6.79' 0.05' 7.10' 0.09' 7.94' 0.12' 8.09' 0.10'

Suspended'Solids' mg/L' 5.00' <5' 0.00' <5' 0.00' 8.80' 0.61' 35.47' 8.92'

Turbidity'O'Field' NTU' –' 0.00' 0.00' 0.00' 0.00' 12.18' 5.79' 113.61' 22.46'

Nutrients' ' ' ' ' ' ' ' ' ' '

Ammonia'as'N' mg/L' 0.01' <0.01' 0.00' <0.01' 0.00' 0.03' 0.01' 0.06' 0.00'

Total'Nitrogen'as'N' mg/L' 0.10' <0.1' 0.00' <0.1' 0.00' 0.31' 0.01' 0.56' 0.03'

Total'Metals'and'Metalloids' ' ' ' ' ' ' ' '

Boron' µg/L' 50.00' <50' 0.00' <50' 0.00' <50' 0.00' 71.92' 27.86'

Zinc' µg/L' 5.00' <5' 0.00' <5' 0.00' <5' 0.47' 9.12' 0.69'

Dissolved'Metals'and'Metalloids' ' ' ' ' ' ' ' '

Boron' µg/L' 50.00' <50' 0.00' 90.00' 65.00' 350.00' 325.00' 684.83' 657.58'

Zinc' µg/L' 5.00' <5' 0.00' <5' 0.00' 5.63' 0.20' 9.72' 0.83'

75%'percentile'values'are'presented'in'place'of'80%'percentile'values'for'electrical'conductivity''

'