Site summary status report Waratah Road, Mangrove Mountain, … · Parsons Brinckerhoff | 2189227B-CLM-RPT-1061 RevC ii NSW Department of Primary IndustriesSite summary status report

NSW Department of Primary Industries

Site summary status reportWaratah Road, Mangrove Mountain, NSW16 November 2015

Document information

Client: NSW Department of Primary IndustriesTitle: Site summary status reportWaratah Road, Mangrove Mountain, NSWDocument No: 2189227B-CLM-RPT-1061 RevCDate: 16 November 2015

Rev Date Details

A 29/07/2015 Draft

B 22/09/2015 Final

C 16/11/2015 Final

Author, Reviewer and Approver details

Prepared by: Yliane Yvanes-Giuliani Date: 16/11/2015 Signature:

Reviewed by: Imogen Powell Date: 16/11/2015 Signature:

Approved by: Adrian Heggie Date: 16/11/2015 Signature:

Distribution

NSW Department of Primary Industries, Parsons Brinckerhoff file, Parsons Brinckerhoff Library

©Parsons Brinckerhoff Australia Pty Limited 2013

Copyright in the drawings, information and data recorded in this document (the information) is the property of ParsonsBrinckerhoff. This document and the information are solely for the use of the authorised recipient and this documentmay not be used, copied or reproduced in whole or part for any purpose other than that for which it was supplied byParsons Brinckerhoff. Parsons Brinckerhoff makes no representation, undertakes no duty and accepts noresponsibility to any third party who may use or rely upon this document or the information.

Document owner

Parsons Brinckerhoff Australia Pty LimitedABN 80 078 004 798Level 27 Ernst & Young Centre680 George Street, Sydney NSW 2000GPO Box 5394Sydney NSW 2001AustraliaTel: +61 2 9272 5100Fax: +61 2 9272 5101Email: [email protected] to ISO 9001, ISO 14001, AS/NZS 4801A GRI Rating: Sustainability Report 2011

Parsons Brinckerhoff | 2189227B-CLM-RPT-1061 RevC i

NSW Department of Primary Industries Site summary status reportWaratah Road, Mangrove Mountain, NSW

ContentsPage number

Abbreviations iii

1. Introduction 1

1.1 Background 1

1.2 Purpose of this report 2

1.3 Objectives 2

1.4 Limitations and intellectual property 2

2. Site background information 4

2.1 Site identification and description 4

2.2 Topography 4

2.3 Geology 4

2.4 Hydrogeology 5

2.5 Registered groundwater bores 5

3. Contaminants of concern and applicable criteria 6

3.1 Contaminants of concern 6

3.2 Groundwater investigation levels 6

4. Review of standing water levels and groundwater flow direction 10

4.1 Groundwater levels 10

4.2 Groundwater flow direction 11

5. Groundwater quality 12

5.1 Total dissolved solids 12

5.1.1 Trends 125.1.2 Exceedances 13

5.2 pH 13

5.2.1 Trends 135.2.2 Exceedances 14

5.3 Nutrients 15

5.3.1 Nitrate 155.3.2 Ammonia 165.3.3 Total Kjeldahl Nitrogen (TKN) 185.3.4 Phosphorus 18

5.4 Metals 19

Parsons Brinckerhoff | 2189227B-CLM-RPT-1061 RevC ii


5.4.1 Trends 205.4.2 Exceedances 215.4.3 Summary of trends in metal concentrations 28

5.5 Hydrocarbons 28

5.5.1 Exceedances 29

5.6 Summary evaluation of trends in contaminant concentrations 29

6. Site maintenance work summary 31

7. Risk mitigation actions, further monitoring and investigations 32

8. Conclusions 33

9. References 34

List of tablesPage number

Table 2.1 Site identification details 4Table 2.2 Summary of registered bores with 500 m radius of the site 5Table 3.1 Contaminants of potential concern 6Table 4.1 Gauging results for March 2015 – Waratah Road 10Table 5.1 Hydrocarbon results 29Table 7.1 Waste-water volume extracted for transport off-site for treatment and recycling

(December 2010 to 30 June 2015) 32

List of appendicesAppendix A Figures

Parsons Brinckerhoff | 2189227B-CLM-RPT-1061 RevC iii


AbbreviationsANZECC Australian & New Zealand Environment & Conservation Council

BOD Biochemical oxygen demand

BTEX Benzene, toluene, ethyl benzene, xylene

DP Deposited Plan

DPI Department of Primary Industries

DQO Data Quality Objectives

EPA Environment Protection Authority

GCL Geo-composite clay liner

GME Groundwater monitoring event

LEP Local Environmental Plan

mAHD Metres Australian Height Datum

mBTOC Metres below top of casing

NATA National Association of Testing Authorities

NEPC National Environment Protection Council

NHMRC National Health & Medical Research Council

PAH Polycyclic aromatic hydrocarbons

PPM Parts per million

PQL Practical quantitation limit (of chemical concentration)

QA/QC Quality assurance & quality control

RPD Relative percentage difference

SAQP Sampling analysis and quality plan

SWL Standing water level

TOC Total organic carbon

TDS Total dissolved solids

TKN Total Kjeldahl Nitrogen

Parsons Brinckerhoff | 2189227B-CLM-RPT-1061 RevC 1


1. Introduction1.1 BackgroundAn outbreak of a poultry disease, known as Newcastle Disease, occurred at Mangrove Mountain on theCentral Coast Plateau in 1999. Approximately two million carcasses of slaughtered poultry and associatedshed litter and wastes were buried to contain the potential spread of the disease. The poultry carcasses wereplaced inside tar-lined shipping containers, which were placed into engineered burial pits at George DownesDrive (on the former Hymix Kulnura Quarry site) and Bloodtree Road (on Gosford City Council’s MangroveMountain Works Depot site). Shed litter, manure and other potentially virus-contaminated materials wereburied at a third site located at Waratah Road, Mangrove Mountain.

Subsequently, NSW Department of Primary Industries (DPI, Agriculture), working in collaboration with DPIWater, NSW Environment Protection Authority, the Central Coast Public Health Unit of the Central CoastArea Health Service, and contracted environmental consultants (Robert Carr & Associates Pty Ltd.)developed a groundwater monitoring program to monitor any potential environmental impacts resulting fromthe presence of the burial pits. The groundwater monitoring program commenced in January 2001, following“baseline” groundwater monitoring events undertaken in 1999. Groundwater monitoring events (GMEs) wereconducted by various consultants between 2001 and 2012. Presently, there are 17 groundwater monitoringwells located across the three sites.

DPI Agriculture commissioned Parsons Brinckerhoff Australia Pty Ltd (Parsons Brinckerhoff) to undertakethe bi-annual groundwater monitoring program at the three sites for three years (2012 to 2015).

Douglas Partners was engaged to conduct one groundwater monitoring event in June 2012. This reportpresents a summary of results for key groundwater indicators from all GMEs undertaken at the WaratahRoad site by Parsons Brinckerhoff since 2013, which comprise:

n Parsons Brinckerhoff (2013) Groundwater monitoring event 12, Mangrove Mountain, dated 13September 2013 – March 2013 GME

n Parsons Brinckerhoff (2014) Groundwater monitoring event 13, Mangrove Mountain, dated 11 February2014 – June 2013 GME

n Parsons Brinckerhoff (2015a) Groundwater monitoring event 14, Mangrove Mountain, dated 3 June2015 – September 2013 GME

n Parsons Brinckerhoff (2015b) Groundwater monitoring event 15, Mangrove Mountain, dated 4 June2015 – March 2014 GME

n Parsons Brinckerhoff (2015c) Groundwater monitoring event 16, Mangrove Mountain, dated 3 June2015 – September 2014 GME

n Parsons Brinckerhoff (2015d) Groundwater monitoring event 17, Mangrove Mountain (draft), dated 13September 2015 – March 2015 GME.

This report presents information and data specifically for the Waratah Road site. Separate reports have beenproduced for the Bloodtree Road and George Downes Drive landfills.



1.2 Purpose of this reportThe purpose of this summary report is to document the condition of the groundwater in the vicinity of thecontainment cell and the physical condition of the cell, particularly with respect to any impacts that may havearisen from possible breaches of the containment of poultry wastes.

1.3 ObjectivesThe objectives of the regular groundwater monitoring events (GMEs) and visual inspections were to:

n determine the present occurrence, nature and extent of contamination

n determine the existence of or potential for off-site transport of contaminants and the associatedenvironmental risks; and, should contamination and/or associated off-site risks exist

n identify and recommend appropriate mitigation/remedial measures, or otherwise provide a monitoringstrategy.

1.4 Limitations and intellectual propertyScope of services

This site summary report (the report) has been prepared in accordance with the scope of services set out inthe contract, or as otherwise agreed, between the client and Parsons Brinckerhoff (scope of services). Insome circumstances the scope of services may have been limited by a range of factors such as time,budget, access and/or site disturbance constraints.

Reliance on data

In preparing the report, Parsons Brinckerhoff has relied upon data, surveys, analyses, designs, plans andother information provided by the client and other individuals and organisations, most of which are referred toin the report (the data). Except as otherwise stated in the report, Parsons Brinckerhoff has not verified theaccuracy or completeness of the data. To the extent that the statements, opinions, facts, information,conclusions and/or recommendations in the report (conclusions) are based in whole or part on the data,those conclusions are contingent upon the accuracy and completeness of the data. Parsons Brinckerhoff willnot be liable in relation to incorrect conclusions should any data, information or condition be incorrect or havebeen concealed, withheld, misrepresented or otherwise not fully disclosed to Parsons Brinckerhoff.

Environmental conclusions

In accordance with the scope of services, Parsons Brinckerhoff has relied upon the data and has conductedenvironmental field monitoring and/or testing in the preparation of the report. The nature and extent ofmonitoring and/or testing conducted is described in the report.

On all sites, varying degrees of non-uniformity of the vertical and horizontal soil or groundwater conditionsare encountered. Hence no monitoring, common testing or sampling technique can eliminate the possibilitythat monitoring or testing results/samples are not totally representative of soil and/or groundwater conditionsencountered. The conclusions are based upon the data and the environmental field monitoring and/or testingand are therefore merely indicative of the environmental condition of the site at the time of preparing thereport, including the presence or otherwise of contaminants or emissions.

Also, it should be recognised that site conditions, including the extent and concentration of contaminants,can change with time.



Within the limitations imposed by the scope of services, the monitoring, testing, sampling and preparation ofthis report have been undertaken and performed in a professional manner, in accordance with generallyaccepted practices and using a degree of skill and care ordinarily exercised by reputable environmentalconsultants under similar circumstances. No other warranty, expressed or implied, is made.

Report for benefit of client

The report has been prepared for the benefit of the client and no other party. Parsons Brinckerhoff assumesno responsibility and will not be liable to any other person or organisation for or in relation to any matter dealtwith or conclusions expressed in the report, or for any loss or damage suffered by any other person ororganisation arising from matters dealt with or conclusions expressed in the report (including withoutlimitation matters arising from any negligent act or omission of Parsons Brinckerhoff or for any loss ordamage suffered by any other party relying upon the matters dealt with or conclusions expressed in thereport). Other parties should not rely upon the report or the accuracy or completeness of any conclusionsand should make their own enquiries and obtain independent advice in relation to such matters.

Other limitations

Parsons Brinckerhoff will not be liable to update or revise the report to take into account any events oremergent circumstances or facts occurring or becoming apparent after the date of the report.

The scope of services did not include any assessment of the title to or ownership of the properties, buildingsand structures referred to in the report nor the application or interpretation of laws in the jurisdiction in whichthose properties, buildings and structures are located.



2. Site background information2.1 Site identification and descriptionThe Mangrove Mountain region is located in the municipality of Gosford City Council (Council),approximately 85 km north of Sydney. This report presented information and data specifically for the burialsite at the Waratah Road site which was a former piggery effluent dam site. The identification details for thesite are provided in Table 2.1 and the location is indicated in Figure 1 and Figure 2 (Appendix A).

Table 2.1 Site identification details

Identification Waratah Road

Council Gosford

County Northumberland

Parish Kooree

Title identification Lot 12 DP 860200

MGA co-ordinates (zone 56) 329350 E, 6315165 N

The area surrounding the site comprises well-developed agricultural and horticultural industries, includingintensive poultry farms, the quarry, orchards, vegetable market gardens and more recently groundwaterextraction for bottling. The established agricultural areas are surrounded by native bushland areas includingthe Dharug, Popran and Brisbane Water National Parks, McPherson, Olney and Ourimbah State Forests andother Crown Land.

The Waratah Road site is located on a rural lot owned by NSW DPI. The site backs onto McPherson StateForest and is constructed at the site of a former intensive piggery effluent containment dam. The burial pithas horizontal dimensions of 60 m by 70 m, with an average depth of 5 m. Like the other pits, it is excavatedinto sandstone bedrock. It was lined with two layers of geo-composite clay liner (GCL) and capped with onelayer of GCL and 1 metre-deep clay. This burial pit was filled with poultry shed litter and may also contain arelatively small number of incidental carcasses. The layout of the site is shown in Figure 3 in Appendix A.

2.2 TopographyThe site is located near Mangrove Mountain on a sandstone plateau which drains into the Warre WarrenCreek, Wyong River, Ourimbah Creek and Brisbane Water catchments. Several small creeks and tributariesof the Hawkesbury River, including Mangrove, Mooney Mooney and Popran Creeks drain the area.Mangrove Creek has an urban water supply dam in its upper catchment and provides drinking water to theGosford-Wyong local government areas. The site topography features undulating sandstone ridge-tops,vegetated by temperate sclerophyll woodland.

2.3 GeologyA review of the Gosford-Lake Macquarie 1:100,000 (1994) geological map indicates that the sites aregenerally underlain by Hawkesbury Sandstone. The Hawkesbury Sandstone consists of inter-bedded layersof sandstone (massive and sheet facies), siltstone and shale.



The parent material overlying the sandstone bedrock in the vicinity of the Waratah Road burial pit isdescribed as a gravelly lateric colluvium from sandstone according to a more comprehensive map of soils ofthe central coast plateau (Hawkins and Haddad, 2011). The soils are dominated by material of the Eulooassociation and characterised by a non-calcareous gradational texture profile, an earthy fabric in the Bhorizon and a moderate amount of loose gravel in the upper part of the profile.

The available borehole logs indicated subsurface profiles at the sites generally correspond with the regionalgeology identified above.

2.4 HydrogeologyThe aquifer in the Hawkesbury Sandstone has both porous and fractured flow. It is recharged by rainfall anddischarges as springs and to surface water systems that flow from the Mangrove Mountain plateau.

Perched aquifers are common across the area in the weathered material, with the more productive aquifers,commonly used for commercial and domestic purposes, located at depths below 20 metres. There ispotentially a hydraulic connection between the perched and upper sandstone aquifer, however the degree ofconnection at the site is not well known.

2.5 Registered groundwater boresA search of the NSW Office of Water groundwater database (www.nratlas.nsw.gov.au) indicated that severalgroundwater bores are registered within 500 m of the site. The recent review of the database(http://allwaterdata.water.nsw.gov.au/water.stm) (on 22 April 2015) did not identify any new bores in thevicinity of the site. A summary of the registered bores and their distance from the Waratah Road site isprovided in Table 2.2 and shown in Figure 2 in Appendix A.

Table 2.2 Summary of registered bores with 500 m radius of the site

Site Bore ID Purpose Approximatedistance anddirection from site(1)

Screendepthinterval(m)

Standingwaterlevel(mBTOC)

Totaldepth (m)

WaratahRoad

GW101979(1) Domestic/stock DPI - 240m south 5.5 – 48 14.0 48.0

GW104330Domestic/stockFarm/Industrial 427m south-south-east 0 – 33 Unknown 33.0

BLR(3) Domestic 434m south-south-east N/A N/A N/A

GW103472 Farm/Industrial 482m south 0 – 47.0 Unknown 47.0

GW102510 Irrigation 346m west-south-west 20.0 –30.5 6.5 30.5

20WA203515 Irrigation 408m west-south-west N/A N/A N/A(1) Distances are approximate only –calculated based on best judgement.(2) Information provided by NSW DPI indicated this bore (GW101979) is inactive at the time of investigation. The bore may be re-

activated, if required.(3) The term “BLR” refers to Basic Landholder Rights (domestic and stock) bore, where the work has not been allocated a Groundwater

Work number (GW prefix) on the public database.



3. Contaminants of concernand applicable criteria

3.1 Contaminants of concernThe contaminants of concern for the GMEs at Waratah Road, as identified in the SAQP (ParsonsBrinckerhoff, 2013), are presented in Table 3.1.

Table 3.1 Contaminants of potential concern

Contaminant Justification

Total dissolved solids (TDS)

Major anion and cation concentrations (chloride, sulphate,bicarbonate, magnesium, calcium, potassium and sodium)

Biochemical oxygen demand (BOD)

Electrical conductivity (EC)

Dissolved oxygen

Alkalinity (bicarbonate, carbonate, hydroxide and total)

Assessment of general water quality.

Nutrients (ammonia, nitrate and nitrite, total Kjeldahl nitrogen(TKN), total nitrogen and total phosphorus

Assessment of breakdown of organic matterplaced within the burial pits and maturing of thewaste material over time.

Metal concentrations (arsenic, cadmium, chromium, copper,iron, lead, manganese, nickel, and zinc)

Assessment of potential corrosion of the metalcontainers containing the carcasses and waste.

3.2 Groundwater investigation levelsWith reference to the National Environmental Protection Measure Amendment No. 1 2013 (NEPM, 2013),the groundwater investigation levels adopted for assessing the quality of groundwater for the Waratah Roadsite are summarised in Table 3.2. These investigation levels were selected to assess the potential risks tohuman and freshwater aquatic ecosystems. The environmental and human receptors identified on-site andoff-site include:

n Workers conducting monitoring or maintenance works at the sites.

n Users of the groundwater in the vicinity of the site. Groundwater quality at the site indicated possible thebeneficial uses of groundwater at the site include irrigation, stock, domestic and potable use.Groundwater in the surrounding area is also used for bottling and sale as mineral spring water.

n Aquatic ecosystems in the surface waters down gradient of the site (Ourimbah Creek, Warre WarrenCreek, Bull Gully and Broula Gully). In addition, spring-fed streams were previously identified in thearea.

n Surface water users, including Gosford-Wyong Councils Water Supply Authority, on the catchmentstreams of Warre Warren Creek and Mangrove Creek downstream of Warre Warren Creek.

The rationale for selecting the investigation levels presented in Table 3.2 was detailed in the SAQP (ParsonsBrinckerhoff, 2013). When the guidance values are not provided in the NEPM 2013, the parent guidelineswere referenced. Where there is more than one guideline value, the most conservative guidelines is used.



Table 3.2 Groundwater investigation levels

Analyte Unit Drinking waterguidelines(1),(2)

Protection offreshwater

ecosystem(1),(3)

Livestockdrinkingwater(4)

Irrigation use(5)

Indicators

pH - 6.5 – 8.5 6.5 – 8.0 - 6.5 – 8.5

Total dissolved solids mg/L 600 - 2,000 – 10,000 -

Biochemical oxygen demand mg/L - - - -

Chemical oxygen demand mg/L - - - -

Sulfide (S) - - - -

Soluble methane - - - -

Anion

Total alkalinity mg/L - - - -

Hydroxide mg/L - - - -

Carbonate mg/L - - - -

Bicarbonate mg/L - - - -

Chloride mg/L 250 - - -

Sulfate mg/L 500 - 2,000 -

Cations

Calcium mg/L - - 1,000 -

Magnesium mg/L - - - -

Potassium mg/L - - - -

Sodium mg/L 180 - - -

Nutrients

Ammonia (as NH3-N) (6) mg/L 0.41(7) 2.57(8) - -

Nitrate (as N) (6) mg/L 11.3(7) 0.16(9) 338 -

Nitrite (as N) (6) mg/L 0.91(7) - 9.12 -

Nitrate + nitrite (as N) mg/L - 0.04 - -

Total Kjeldahl Nitrogen (TKN) mg/L - - - -

Total nitrogen mg/L - 0.5 - 0.5

Phosphorus mg/L - 0.05 - 0.05

Metals

Arsenic µg/L 10 - 500 – 5,000 100

Arsenic (as AsIII) µg/L - 24 - -

Arsenic (as AsV) µg/L - 13 - -

Barium µg/L 2,000 - - -



Analyte Unit Drinking waterguidelines(1),(2)

Protection offreshwater

ecosystem(1),(3)

Livestockdrinkingwater(4)

Irrigation use(5)

Cadmium µg/L 2 0.2 10 10

Chromium (CrVI) µg/L 50 1.0 1,000 100

Cobalt µg/L - - 1,000 50

Copper µg/L 2,000 1.4 400 – 5,000 200

Iron µg/L 300 - - 200

Lead µg/L 10 3.4 100 2,000

Manganese µg/L 500 1,900 - 200

Mercury µg/L 1 60 2 2

Nickel µg/L 20 11 1,000 200

Zinc µg/L 3,000 8 20,000 2,000

Microbial indicators

Faecal coliform CFU/100 mL - - - -

Escherichia Coli CFU/100 mL non-detect - - -

Sulfite-reducing Clostridia(including C. perfringens)

orgs/100 mL - - - -

Clostridium perfringens orgs/100 mL - - - -

Campylobacter spp. CFU/100 mL non-detect - - -

Pseudomonas spp. CFU/100 mL - - - -

Hydrocarbons

TRH C6 – C10 µg/L - - - -

TRH C6 – C10 –BTEX (F1) µg/L - - - -

TRH C10 – C16 µg/L - - - -

TRH > C10 – C16 –Naphthalene (F2)

µg/L - - - -

TRH C16 – C34 µg/L - - - -

TRH C34 – C40 µg/L - - - -

Hydrocarbons

Benzene µg/L 1 950 - -

Toluene µg/L 800 - - -

Ethylbenzene µg/L 300 - - -

Xylene (m & p) µg/L - - - -

Xylene (o) µg/L - 350 - -

Xylene Total µg/L 600 - - -

Naphthalene µg/L - 16 - -

(1) NEPM (2013) Schedule B1 – Investigation levels for soil and groundwater



(2) NHMRC/NRMMC (2011) Australian Drinking Water Guidelines. (Note: Human health values are provided as priority, aestheticvalues are only provided in the absence of a human health value)

(3) ANZECC/ARMCANZ (2000) – trigger values for the protection of 95% of freshwater ecosystem(4) ANZECC/ARMCANZ (2000) – recommended water quality trigger values for livestock drinking water(5) ANZECC/ARMCANZ (2000) – Agricultural irrigation water long term trigger values(6) 1 mg/L of NH3-N = 1.21 mg/L of NH3; 1 mg/L of NO3-N = 4.43 mg/L of NO3; and 1 mg/L of NO2-N = 3.29 mg/L of NO2.(7) The guideline values for drinking water are: 0.5 mg/L ammonia (as NH3), 50 mg/L nitrate (as NO3) and 3 mg/L (as NO2).(8) Ammonia/ammonium equilibrium concentration is highly dependent on pH and temperature. In the ANZECC/ARMCANZ (2000)

guidelines, the trigger values for ammonia were derived for pH 6 to 9; extrapolation outside this range is not advisable. On accountthat the groundwater at the three burial sites is generally of acidic conditions, ammonia concentration for pH 6 is adopted here.

(9) The guideline value for the protection of 95% of freshwater ecosystem is: 0.7 mg/L nitrate (as NO3).



4. Review of standing waterlevels and groundwater flowdirection

4.1 Groundwater levelsThe relative difference in the standing water level (SWL) in the groundwater monitoring bores is used tocalculate the direction of groundwater flow.

The shed litter burial pit is located in the catchment area of Warren Creek, which flows through theMcPherson state Forest and into Mangrove Creek.

Table 4.1 presents the location, elevation and last recorded SWL (March 2015) of the groundwatermonitoring bores on the site.

Table 4.1 Gauging results for March 2015 – Waratah Road

BoreholeID

Easting Northing T.O.C.elevation(mAHD)

SWL(mBTOC)

Groundwaterelevation(mAHD)

BH5W 329409 6315171 268.865 19.087 249.778

BH6W 329352 6315115 266.910 16.617 250.293

BH7W 329290 6315134 265.560 15.975 249.585

BH9W 329409 6315194 259.545 18.980 250.565

BH10W 329406 6315214 270.565 19.224 251.341

BH11W 329274 6315182 267.845 13.953 253.892

BH12W 329409 6315147 268.165 20.793 247.372

BH13W 329411 6315116 269.025 18.689 249.336(1) Abbreviations: T.O.C. – top of casing; mBTOC – metres below top of casing, mAHD – metres Australian Height Datum, mBGL –

metres below ground level

Monitoring well BH11W is considered to be the up gradient well and BH5W is considered to be the downgradient well.

Chart 1 shows groundwater elevations from June 2012 to March 2015 in the eight groundwater monitoringwells located at Waratah Road. The SWLs at the Waratah Road site ranged from 247.372 mAHD (inBH12W) to 256.504 mAHD (in BH11W) over the three year period. Groundwater elevations in the upgradient monitoring well (BH11W) are consistently higher in elevation than groundwater levels in the sevenother wells. Groundwater elevation in each monitoring well followed a similar trend of fluctuation over timeand was slightly influenced by rain fall as recharge occurred, particularly after heavy rainfall in February2013. Groundwater elevations in down gradient well BH12W are consistently lower than the other wells onthe site, at around 249 mAHD. Long-term trends in groundwater elevation and rainfall are presented inAppendix A (Figure 4).



(1) The monthly rainfall data were obtained from the Mangrove Mountain AWS (Bureau of Meteorology Automated Weather Station061375).

4.2 Groundwater flow directionDespite groundwater level fluctuations over time, the inferred groundwater flow direction was similar in thelast two gauging events. The gauging data presented in Table 4.1 showed that groundwater is anticipated toflow towards the south-east.

The groundwater flow direction is presented on Figure 3 (Appendix A).

0

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242.000

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246.000

248.000

250.000

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258.000

Jun-

12

Aug

-12

Oct

-12

Dec

-12

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-13

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-13

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-13

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-14

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Rain

fall

(mm

)

Grou

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ater

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AHD)

Date

Chart 1 - Groundwater elevation (mAHD) and monthly rainfall(1) at Waratah Road- June 2012 to March 2015

Rainfall

BH7W

BH5W

BH6W

BH10W

BH12W

BH13W

BH9W

BH11W



5. Groundwater qualityTrends in groundwater quality changes and exceedances of adopted assessment criteria (where applicable)are presented below. This report focuses upon the trends and exceedances in the down gradient monitoringwell BH5W, because monitoring the quality of groundwater leaving the pit is a major focus of the program.Data for key contaminants is presented for all groundwater monitoring wells and groundwater assessmentlevels (see Table 3.2) are also presented, where relevant.

5.1 Total dissolved solids5.1.1 Trends

The total dissolved solids (TDS) concentration in groundwater is a measure of all dissolved substances ingroundwater, including inorganic and organic substances dissolved in either a molecular, ionised or finecolloidal form. TDS is not a contaminant of concern but it is an indicator of aesthetic characteristics ofdrinking water, and an indicator of the potential presence of contaminants of concern. TDS data provides abroad indication of fluctuations in the chemical composition of groundwater.

As shown on Chart 2, concentrations of TDS were generally consistent in each well throughout themonitoring period, with the exception of down gradient wells BH5W and BH9W. However, quite a lot ofvariation was observed between the wells on the site, with TDS concentrations around 100 mg/L in wellsBH6W, BH7W, BH10W, BH11W, BH12W and BH13W, and concentrations generally above 300 mg/L indown gradient wells BH5W and BH9W. The observed differences are likely to be a consequence of theparticular characteristics of the geological profile at each well.

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700

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/201

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/201

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/201

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TDS

conc

entr

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n(m

g/L)

Date

Chart 2 - Trends in TDS concentrations at Waratah Road

BH5W

BH6W

BH7W

BH9W

BH10W

BH11W

BH12W

BH13W

TDS assessmentcriteria



5.1.2 Exceedances

TDS concentrations were consistently reported below the adopted assessment criteria of 600 mg/L fordrinking water use from June 2013 to March 2015, with the exception of one exceedance in BH9W in June2013. ADWG (2001) states that TDS concentrations from 600 to 900 mg/L are regarded as having fairpalatability.

5.2 pH5.2.1 Trends

Groundwater at Waratah Road and in the vicinity of Mangrove Mountain is generally considered to be acidic,which is common in groundwater associated with the Hawkesbury Sandstone formation. Chart 3 presents pHvalues measured in the field in each deep well on the site from March 2013 to March 2015.

There was some fluctuation in the pH values in each well over the 3 year period; however variations were ofless than 1 pH unit in each well over that period. It is worthwhile to note that field-measured pH values arenot always accurate and pH variations could be caused by the monitoring equipment.

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/201

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/201

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/201

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Chart 3 - pH in groundwater at Waratah Road, March 2013 to March 2015

BH5W

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BH10W

BH11W

BH12W

BH13W



5.2.2 Exceedances

The pH values detected in groundwater from all monitoring wells at Waratah Road were consistentlyreported outside of the adopted assessment criteria for drinking water and irrigation use (6.5 to 8.5 pH value)and for protection of freshwater aquatic ecosystems (6.5 to 8.0 pH value) between March 2013 to March2015. The bands of acceptance (between the lower threshold and upper threshold for acceptable pH and thegroundwater pH values are presented on Chart 4.

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Chart 4 - pH values in groundwater and guidelines values Waratah Road, March 2013 toMarch 2015

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Lower drinking water andirrigation guidelines

Upper drinking water andirrigation guidelines

Lower freshwaterguidelines

Upper freshwaterguidelines



5.3 NutrientsNitrogen and phosphorus are released during the decomposition of carcasses. Poultry litter and waste alsocontain high concentrations of nitrogen and phosphorous so their presence in groundwater could indicatemigration of leachate. Chart 5 presents the trends in key nutrients in down gradient well, BH5W.

5.3.1 Nitrate

5.3.1.1 Trends

Common sources of nitrate in the environment include fertilisers, animal wastes, septic tanks, municipalsewage treatment systems and decaying plant debris. Excess nitrogen within the environment can contributeto eutrophication and algal blooms, leading to oxygen depletion in water.

Concentrations of nitrate (as nitrogen-N) in groundwater in BH5W have progressively decreased since firstsampled in June 2013, as presented on Charts 5 and 6. Concentrations of nitrate (as N) in all othermonitoring wells at Waratah Road are substantially less, ranging over two orders of magnitude withmaximum concentrations consistently reported in down gradient wells BH5W and BH9W but also BH12W.Some of the lowest nitrate (as N) concentrations reported on the site were encountered in up gradient wellBH11H but also BH6W, BH10W and BH13W.

It is noted that because the Waratah Road site was previously used as an effluent dam for the piggeryoperation, the elevated nitrogen concentrations in BH5W, BH9W and BH12W may be attributed to previousland use.

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Chart 5 - Nutrient concentrations in BH5W Waratah Road

Ammonia as N

Nitrate (as N)

Total KjeldahlNitrogen (as N)

Totalphosphorus (asP)Nitrite +nitrate(as N)



5.3.1.2 Exceedances

Concentrations of nitrate (as N) in groundwater consistently remained above the adopted assessment criteriafor the protection of freshwater aquatic ecosystems in all wells on the site, as presented on Chart 6. It isnoted that concentrations of nitrate (as N) have significantly decreased in down gradient well BH9W;however, they remain high and above the adopted assessment criteria for the site. Nitrate (as N) levels inthese wells have also approached or exceeded the Australian Drinking Water Guideline (2011) level of 11.3mg/L at times, or consistently (BH5W). The 11.3 mg/l guideline is for infants less than 3 months old and aguideline of 22.6 mg/L is applicable to children over 3 months old and adults.

Given the likely high nitrogen content of material in the pit, elevated concentrations observed in downgradient wells BH5W, BH9W and BH12W may be indicative of a leak from the container. Nitrate (as N) levelsin these wells have also approached or exceeded the Australian Drinking Water Guideline (2011) level of11.3 mg/L at times, or consistently (BH5W).

5.3.2 Ammonia

Ammonia is produced during the decay processes of animal and vegetable matter and by anthropogenicsources such as livestock farming practices and sewage (including septic systems). Ammonia can be toxic toaquatic organisms at varying concentrations, depending on pH conditions. Ammonia is a nutrient andoxidises to nitrate in surface water which can contribute to algal blooms.

5.3.2.1 Trends

Concentrations of ammonia (as N) in all monitoring wells on the site did not fluctuate much in each wellbetween September 2013 and 2015 ranging from below the laboratory LOR to 21 mg/L. Ammonia (as N)

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Chart 6 - Nitrate (as N) concentrations and the adopted assessment criteria at WaratahRoad

Nitrate (as N)assessment criteria

BH5W

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BH9W

BH10W

BH12W

BH11W

BH13W



concentrations in wells BH6W, BH7W, BH9W, BH10W, BH11W and BH13W have consistently been close toor below the laboratory limit of reporting (LOR = 0.01 mg/L).

Elevated ammonia (as N) concentrations have consistently been observed in down gradient wells BH5W andBH12W, which may be indicative of nutrient leakage from the containment cell. Concentration trends in downgradient well BH5W are presented on Chart 5.

5.3.2.2 Exceedances

Concentrations of ammonia (as N) in groundwater consistently remained above the adopted assessmentcriteria for drinking water (aesthetic; Australian Drinking Water Guidelines (2011) of 0.41 mg/L, and alsoexceeds the higher level identified for the protection of freshwater aquatic ecosystems in down gradientbores BH5W and BH12W, as presented on Chart 7.

In all other wells, ammonia (as N) concentrations have consistently been reported below the adoptedassessment criteria for drinking water use.

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Chart 7 - Ammonia (as N) concentrations and the adopted assessment criteria at WaratahRoad

Ammonia (as N)assessment criteria

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5.3.3 Total Kjeldahl Nitrogen (TKN)

TKN is the sum of all organic nitrogen and ammonia in a given groundwater sample.

5.3.3.1 Trends

TKN concentrations were similar and relatively low, ranging from the laboratory limit of reporting (i.e. 0.1mg/L) to 1.3 mg/L, in all wells on the site with the exception of down gradient monitoring wells BH5W, BH9Wand BH12W, as presented on Chart 8. Significantly higher TKN concentrations were reported for BH5W,BH9W and BH12W ranging from 1 mg/L to 40 mg/L.

5.3.3.2 Exceedances

There are no applicable adopted assessment criteria for TKN.

5.3.4 Phosphorus

Phosphorus is used in the production of fertilisers. An excess of phosphorus in surface water can contributeto favourable conditions for an algal bloom. Phosphorus binds strongly to iron compounds in soil, and is notgenerally as mobile as nitrogen in groundwater.

Phosphorus is commonly analysed as soluble reactive phosphorus (which is predominantly orthophosphate)or total phosphorus, which includes organic phosphorus and particulate phosphorus, as well as solublereactive phosphorus. Total phosphorus has been analysed during this monitoring program.

5.3.4.1 Trends

The concentration of total phosphorus in all monitoring wells on the site fluctuated slightly throughout themonitoring period with concentrations ranging from below the laboratory LOR to 2.55 mg/L, as presented in

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Chart 8 - TKN concentrations at Waratah Road

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BH11W

BH12W

BH13W



Chart 9. The lowest total phosphorus concentrations are generally reported in up gradient and cross gradientwells BH6W, BH7W, BH9W and BH10W during each GME.

5.3.4.2 Exceedances

Total phosphorus has been reported above the adopted assessment criteria for the protection of freshwateraquatic ecosystems at least once during the 3 year monitoring period in all wells with the exception of BH7Wand BH10W. During the last monitoring event, total phosphorus concentrations exceeded the adoptedassessment criteria for the site in BH5W, BH9W, BH12W and BH13W, which are located to the east of theshed litter burial pit. There are no guidelines established for phosphorus for the protection of human health oraesthetic criteria.

Given the likely high phosphorous content of material in the pit, elevated concentrations observed in downgradient wells BH5W, BH9W and BH12W may be indicative of leakage from the shed litter burial pit.

5.4 MetalsAnalysis of heavy metals and metalloids (iron, arsenic, cadmium, chromium, copper, lead, manganese,nickel and zinc) was undertaken to assess the potential leakage of soluble metals from the poultry shed littercontained in the pit at the Waratah Road site, and from potential mobilisation of metals due to interactionbetween any fluid leakage from the pit and the surrounding geology.

The trends for the metals and metalloids reported above the laboratory limit of reporting (LOR) are presentedbelow.

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Chart 9 - Total phosphorus concentrations and the adopted assessment criteriaat Waratah Road

Phosphorusassessment criteria

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5.4.1 Trends

Concentrations of arsenic, cadmium, copper, nickel and lead have fluctuated slightly between March 2013and March 2015, remaining below 50 µg/L in down gradient well BH5W, as presented on Chart 10 and 11.Concentrations of zinc have fluctuated between 28 and 239 µg/L between March 2013 and March 2015.Very high concentrations of manganese have been reported in BH5W ranging from 3150 to 3880 µg/Lbetween March 2013 and March 2015. Iron concentrations have fluctuated slightly ranging from below thelaboratory LOR (50 µg/L) to 80 µg/L between March 2013 and March 2015 in BH5W.

Across all the groundwater monitoring bores, cadmium, copper, lead, manganese, nickel and zinc weredetected in the majority of the groundwater samples tested. Iron was only detected above the LOR (50 µg/L)in BH5W, BH9W and historically in BH11W. Arsenic was only detected in BH5W and then only at the LOR (1µg/L) and well-below both the ANZECC (2000) trigger value for the protection of freshwater aquaticecosystems and the Australian Drinking Water Guideline (2011) level (10 µg/L). Arsenic is therefore notconsidered likely to be a problem at this site. Chromium was not detected in any of the wells on the site overthe three year monitoring program.

Metal concentrations were generally higher in down gradient monitoring wells BH5W, BH9W and BH12W.

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Chart 10 - Metal concentrations in BH5W at Waratah Road

Iron

Arsenic

Copper

Lead

Manganese

Nickel

Zinc

Cadmium



5.4.2 Exceedances

Iron, copper, cadmium, lead, manganese, nickel and zinc were detected exceeding the site investigationlevels in one or more of the samples. The adopted investigation level (or assessment criteria) for all metalswas the thresholds values for the protection of freshwater aquatic ecosystems with the exception of iron andmanganese for which the drinking water guideline was applied.

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Chart 11 - Metal concentrations in BH5W at Waratah Road with the unusual manganeseconcentrations removed

Iron

Arsenic

Copper

Lead

Nickel

Zinc

Cadmium



Iron exceedances have only been observed once in monitoring well BH11W in June 2013, as presented inChart 12. As BH11W is located up hydraulic gradient of the pit, the detection of iron at an elevatedconcentration is likely due to natural fluctuations and indicative of background levels rather than a potentialleakage from the burial pit as BH11W.

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Chart 12 - Iron concentrations and the adopted assessment criteria at WaratahRoad

Iron assessmentcriteria

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BH12W

BH11W

BH13W



Manganese exceedances have been observed regularly in monitoring well BH5W, BH9W and BH12W, aspresented in Chart 13. The distribution of elevated dissolved manganese concentrations in monitoring wellsis similar to that of nutrients (i.e. nitrogen, ammonia and phosphorous) and other metals (as discussedfurther below). Higher concentrations were evident in the three monitoring wells which are located east of thepoultry shed litter burial pit, and thus may be indicative of material leaking from the shed litter burial pit.

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Chart 13 - Manganese concentrations and the adopted assessment criteria atWaratah Road

Manganese assessmentcriteria

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Concentrations of cadmium were reported above the adopted assessment criteria in all wells on the site atleast once, with the exception of monitoring well BH13W, as presented on Chart 14. Cadmium was,however, not detected at the laboratory LOR (i.e. 0.1 µg/L) in any well during the last monitoring event. Whilelevels have exceeded the ANZECC (2000) trigger value for the protection of freshwater aquatic ecosystemson occasion, reported levels have remained well below Australian Drinking Water Guideline (2011) level forcadmium (2 µg/L), and it is therefore not considered to be a concern at the site.

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Chart 14 - Cadmium concentrations and the adopted assessment criteria atWaratah Road

Cadmium assessmentcriteria

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Concentrations of zinc, presented on Chart 15, have consistently remained above the adopted assessmentcriteria for freshwater aquatic ecosystems in both up and down gradient monitoring wells on the site.Concentrations of zinc peaked in March 2014 following a period of higher rainfall. It is noted that the highestexceedances were reported for down gradient wells BH5W, BH9W and BH12W. There is no establishedhealth guideline level for zinc in the Australian Drinking Water Guidelines (2000).

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Chart 15 - Zinc concentrations and the adopted assessment criteria at WaratahRoad

Zinc assessmentcriteria

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Concentrations of copper, presented on Chart 16, have consistently remained above the adoptedassessment criteria for freshwater aquatic ecosystems in both up and down gradient monitoring wells on thesite. Concentrations peaked in BH13W in March 2014; this observation could not be explained at the time ofsampling. These consistent exceedances are, however, considered to be representative of regionalgroundwater levels and unlikely to be attributable to leachate migrating from the burial pit. The reportedlevels remain well-below the Australian Drinking Water Guideline (2011) level for copper (2,000 µg/L).

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Chart 16 - Copper concentrations and the adopted assessment criteria atWaratah Road

Copper assessmentcriteria

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Concentrations of nickel were generally reported above the adopted assessment criteria in the period sinceMarch 2013, as presented on Chart 17. The concentrations of nickel on the site were therefore considered tobe representative of the background levels. It should be noted that levels reported on occasion in a numberof the bores on the site (up gradient bores BH7W and BH11W, and down gradient bores BH5W, BH9W,BH10W and BH12W) exceeded the Australian Drinking Water Guideline (2011) level for nickel (20 µg/L).

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Chart 17 - Nickel concentrations and the adopted assessment criteria at WaratahRoad

Zinc assessmentcriteria

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Concentrations of lead were consistently below the adopted assessment criteria in most wells on the site,with the exception of down gradient wells BH5W, BH9W and BH12W, as presented in Chart 18. The levelsreported in down gradient bore BH5W also exceed the Australian Drinking Water Guideline (2011) level forlead (10 µg/L). Lead has not been detected in poultry litter samples or in numerous liquid samples from thepit contents submitted for laboratory analysis, the exceedances reported in groundwater on the site east ofthe burial pit may be indicative of a leakage from the burial cell interacting with sub-surface geology, or other(undetermined) source of lead).

5.4.3 Summary of trends in metal concentrations

The monitoring of metals showed considerable variability in concentrations and several exceedances ofwater quality criteria. It should be noted that natural background concentrations of several heavy metals are,not uncommonly, in excess of the ANZECC water quality criteria for fresh water in sandstone aquifers in theSydney and Central Coast regions. Furthermore, the groundwater in the Mangrove Mountain district hasacid pH. With acidity around pH 4 to 4.5, some metals in the profile tend to be dissolved and mobilised, thusincreasing the likelihood of high natural concentrations.

The distribution of dissolved manganese, lead and zinc concentrations in monitoring wells located east of theburial pit is consistent with a leaking containment cell.

The results of the metals monitoring at the Waratah Road site suggested that leachate migration from theburial pit into the groundwater is occurring.

5.5 HydrocarbonsDuring Event 17 (March 2015) additional analysis of TRH was undertaken from historically contaminatedwells (BH5W, BH9W and BH12W) to determine if any hydrocarbons were present in the groundwater.Results of the additional analysis identified “heavy” (or high carbon) range hydrocarbons (TRH C34 - C40

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Chart 18 - Lead concentrations and the adopted assessment criteria at WaratahRoad

Lead assessmentcriteria

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fraction) present in all wells, with the highest reported concentration occurring in down gradient monitoringbore BH12W (1,500 µg/L), as presented in Table 5.1. Hydrocarbons from the TRH C16 – C34 fraction werealso reported in BH12W, marginally above the laboratory LOR (100 µg/L). No BTEX compounds (benzene,toluene, ethylbenzene, xylene) or naphthalene were detected in this analysis.

It is noted that the TRH detected in the samples may be made up of polar compounds (i.e. fatty acids andesters), and not petroleum hydrocarbons as was concluded from a previous investigation of leachatesamples from the in-pit leachate well.

The detection of presumably polar hydrocarbon compounds in down gradient wells BH5W, BH9W andBH12W may be indicative of leachate leaking from the containment cell. It is also likely that the effluent damused in the vicinity of the site for the prior intensive piggery operation, and decommissioned some yearsbefore construction of the containment cell, acts as a secondary contaminant source.

Table 5.1 Hydrocarbon results

Analyte (1) BH5W BH9W BH12W

TRH

TRH C6 – C10 <20 <20 <20

TRH C6 – C10 –BTEX (F1) <20 <20 <20

TRH C10 – C16 <100 <100 <100

TRH > C10 – C16 – Naphthalene (F2) <100 <100 <100

TRH C16 – C34 <100 <100 160

TRH C34 – C40 160 540 1,500

BTEXN

Benzene <1 <1 <1

Toluene <2 <2 <2

Ethylbenzene <2 <2 <2

Xylene (m & p) <2 <2 <2

Xylene (o) <2 <2 <2

Xylene Total <2 <2 <2

Naphthalene <5 <5 <5

(1) Concentrations expressed in µg/L

5.5.1 Exceedances

There are no applicable adopted assessment criteria for TRH. The concentrations of BTEXN compoundswere below the laboratory limit of reporting and therefore below the relevant assessment criteria for the site.

5.6 Summary evaluation of trends in contaminantconcentrations

The distribution of dissolved heavy metals (i.e. manganese, lead and zinc) was similar to that of nutrients(i.e. nitrogen, ammonia and phosphorous) and hydrocarbons (i.e. presumably polar non-petroleumhydrocarbons) in wells located east of the burial pit and is likely to be indicative of leachate leaking from thecontainment cells on the site.



It is noted that an effluent dam was used in the vicinity of the site for the piggery operation prior to thecontainment cell being buried on the site and may be acting as a secondary contaminant source. However,due to the higher contaminant concentrations generally occurring in wells located down gradient of the burialpit, it is likely that leachate is leaking from the burial cells.



6. Site maintenance worksummary

The surface at the Waratah Road site was consistently moderately vegetated during site inspectionsbetween March 2013 and March 2015. There was no sign of surface cracking but a small depression wasobserved in the north-eastern corner of the pit. The subsidence was observed during all site visits and didnot appear to have increased in size or depth throughout the monitoring period.

During the site walkover of event 12, 16 and 17, the site appeared to have been mown recently.

Mesh-panel site fencing was installed and retained around the leachate wells since 2011.

In March 2014, an abandoned stockpile of rubble was identified in the eastern part of the site, betweenmonitoring wells BH5W and BH12W. The stockpile, approximately 1 m3, contained blue metal, bricks, fabricand soil. In September 2014, the stockpiled appeared to have more rubble added to it. A 44 gallon steeldrum was also noted to the east of monitoring wells BH12W and BH13W. The drum appeared to be emptybut given the sediment accumulated around the drum and the extent of surface rusting on the drum, it waslikely that the drum had been there for a considerable period of time. The drum has since been collected anddisposed at an appropriately licensed waste management facility.

Aside from periodic mowing of the vegetation on the pit surface, Parsons Brinckerhoff is not aware of anyother maintenance undertaken at the Waratah Road site between March 2013 and March 2015.



7. Risk mitigation actions,further monitoring andinvestigations

The following information regarding the risk management of the project was provided by DPI Agriculture:

During pit resurfacing a large diameter well was installed in the pit for the purpose of seepage watermonitoring and extraction. DPI has undertaken periodic extraction of liquid waste water from this well fordisposal off site to a licensed waste water treatment and recycling facility. The extraction schedule for theperiod between December 2013 and June 2015 is presented in Table 7.1 below.

Table 7.1 Seepage water volume extracted for transport off-site for treatment and recycling (December2010 to 30 June 2015)

Monitoring PeriodSeepage water volume

(litres) §

December 2010 – December 2011 12,643

January 2012 – December 2012 19,175



January 2015 – 30 June 2015 16,710§ Data from Volman Enterprises Pty Ltd.

DPI Agriculture extract accumulated seepage water from the well for the following reasons:

n to reduce the hydraulic load and the potential for leakage from the pit

n to monitor the concentrations of compounds of interest in the seepage water

n to reduce the volume of contaminants in the pit.

A surface water sample was collected from Broula Gully, which drains into Warre Warren Creekapproximately 800 m east of the site, in September 2014 and submitted for laboratory analysis. Informationprovided by DPI Agriculture stated that concentrations of the key contaminants, which have been reported inthe near-pit down gradient monitoring wells, were not found (or present) at elevated levels in the surfacewater.

DPI Agriculture has identified a potential location for an additional, more distant, down gradient monitoringwell. This location has been selected based on inferred groundwater flow direction and consideration ofhydrogeological features.



8. ConclusionsMonitoring of indicator parameters in groundwater from event 13 to event 17 showed that leachate may beleaking from the containment cell buried on the site. Given nitrogen, sulfate, magnesium, manganese andnickel are common constituents of poultry shed litter; the elevated concentrations of these indicators, whichare limited to wells BH5W and BH12W, located immediately down gradient of the pit, may be consideredindicative of leakage from the cell.

Prior to the use of the Waratah Road site for the containment of biological waste, the site was used as aneffluent dam for an intensive piggery operation. It is therefore possible that the historical activities at the sitemay have contributed to the presence of contaminants of concern at monitoring wells down gradient of theburial pit. The scope of the GMEs is not sufficient to confirm that the presence of contamination is due to theburial of poultry litter on the site or the former intensive piggery operation.

Groundwater at the Waratah Road site is anticipated to flow towards the south-east. Historic assessmentdata provided by DPI indicated that groundwater flow velocity in monitoring wells BH5W, BH7W and BH8Wranged from 7 to 28 m/year. The closest down gradient registered borehole is located 227 m south-south-east of the site. It is considered likely that contaminants of concern would disperse over this distance,however, this cannot be confirmed without undertaking a site specific risk assessment.



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

n AS4482.1 (2005) Guide to the investigation and sampling of sites with potentially contaminated soil –Part 1: Non-volatile and semi-volatile compounds.

n AS4482.1 (1999) Guide to the sampling and investigation of potentially contaminated soil – Part 2:Volatile substances.

n AS/NZS 5667.11 (1998) Water Quality – Sampling – Guidance on Sampling of Groundwater.

n Australian Government – National Health and Medical Research Council (2011; revised March, 2015)Australian Drinking Water Guidelines.

n C. M. Jewell & Associates Pty Ltd (2011) Status report – Waratah Road, Mangrove Mountain

n Hawkins, C. A. and Haddad, N. I. (2011) Soils of the Plateau of the Central Coast, NSW.

n National Environment Protection Council (NEPC) (2013) National Environmental Protection Measure(NEPM) Amendment Measure 2013 Schedule B1: Guideline on investigation levels for soil andgroundwater.

n National Environment Protection Council (NEPC) (2013) National Environmental Protection Measure(NEPM) (Assessment of Site Contamination).

n NSW DECC (2009) Guidelines on the duty to report contamination under the Contaminated LandManagement Act 1997.

n NSW DEC (2007) Guidelines for the assessment and management of groundwater contamination.

n NSW DEC (2006) Guidelines for the NSW Site Auditors Scheme (2nd edition).

n NSW EPA (2000) Guidelines for Consultants Reporting on Contaminated Sites.

n Parsons Brinckerhoff (2013) Sampling and Analysis Quality Plan, Mangrove Mountain GroundwaterMonitoring Project 2012 – 2015

n Parsons Brinckerhoff (2013) Groundwater monitoring event 12, Mangrove Mountain, 13 September2013

n Parsons Brinckerhoff (2014) Groundwater monitoring event 13, Mangrove Mountain, 11 February 2014

n Parsons Brinckerhoff (2015a) Groundwater monitoring event 14, Mangrove Mountain, 3 June 2015

n Parsons Brinckerhoff (2015b) Groundwater monitoring event 15, Mangrove Mountain, 4 June 2015

n Parsons Brinckerhoff (2015c) Groundwater monitoring event 16, Mangrove Mountain, 3 June 2015

n Parsons Brinckerhoff (2015d) Groundwater monitoring event 17, Mangrove Mountain (draft), 13September 2015

Appendix AFigures

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13MANGROVE MOUNTAIN GROUNDWATER MONITORING PROJECT

NSW DEPARTMENT OF PRIMARY INDUSTRIES

Landfill SiteGroundwater Bores500m buffer

0 1 2 3 km

Figure 1Site Location and Setting

[0 100 200 300 m

Figure 2-1Site Locations and Setting

Waratah Road Landfill

MANGROVE MOUNTAIN GROUNDWATER MONITORING PROJECTNSW DEPARTMENT OF PRIMARY INDUSTRIES

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BH5W(249.778)

BH6W(250.565)

BH7W(249.585)

BH9W(250.565)

BH10W(251.341)

BH11W(253.91)

BH12W(247.72)

BH13W(249.336)

250

251

250

249

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253

252


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Figure 3Groundwater flow direction

Waratah Road, Mangrove Mountain, NSW

Groundwater boreGroundwater contourInferred groundwater flow direction (March 2015)Approximate location of landfill area

Figure 4Rainfall residual mass (mm; Jan 1999 - Jun 2015) vs

Standing Water Level (January 2001 - March 2015)Waratah Road, Mangrove Mountain, NSW


NOTE: The rainfall residual mass is the cumulative sum of the residual (the difference) between the actual monthly rainfall, and the long-term mean monthly rainfall.Where the rainfall residual mass curve has a positive slope (trending upwards left-to-right), the period is characterised by rainfall being greater than the long-term mean.Reference:David, K., Liu, T. and David, V. (2014) Use of several different methods for characterising a fractured rock aquifer, case study Kemfield, New South Wales, Australia, pages 307-328,in Fractured Rock Hydrogeology, International Association of Hydrogeologists Selected Papers 20, J.M. Shard (ed.)(2014) CRC Press, Taylor & Francis Group, LLC, Boca Raton,Florida.

Documents

Site summary status report Waratah Road, Mangrove Mountain, … · Parsons Brinckerhoff | 2189227B-CLM-RPT-1061 RevC ii NSW Department of Primary IndustriesSite summary status report