PROJECT SEA DRAGON PTY LTD CORE BREEDING CENTRE …

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APPENDIX 16 -RESPONSE TO REQUEST FOR INFORMATION 4

PROJECT SEA DRAGON PTY LTDCORE BREEDING CENTRE ANDBROODSTOCK MATURATION CENTRE,BYNOE HARBOURENVIRONMENTAL IMPACT STATEMENT

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1‐1

PROJECT SEA DRAGON

POINT CEYLON BMC AND CBC NOI

RESPONSE TO REQUEST FOR FURTHER INFORMATION

JULY 2016

PSD BMC & CBC NOI ‐ Response to Request for Further Information ‐ July 2106

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CONTENTS

1 Introduction ................................................................................................... 1

1.1 An indication of the range of predicted concentrations of nutrients and the

frequency of occurrence of maximum predicted concentrations ................................... 1

1.1.1 An indication of the range of predicted concentration of nutrients .................................. 1

1.1.2 An indication of the frequency of occurrence of maximum predicted concentrations of

nutrients ........................................................................................................................................ 10

1.2 Whether a worst‐case scenario for mixing and dispersion of nutrients was

modelled and, if so, the results of that modelling ......................................................... 12

1.3 Expected nutrient loads in discharge at full scale (based on the Cardwell operation

if required) ..................................................................................................................... 14

1.4 Waste water treatment options available (in addition to settling) that would

improve water quality prior to discharge ...................................................................... 15

1.5 Proposed monitoring program to detect exceedances in licensed discharge

concentrations and impacts on receiving waters .......................................................... 17

1.6 Contingency measures should licence values be consistently exceeded and/or

impacts to receiving waters be detected. ..................................................................... 18

2 References .................................................................................................... 19

LIST OF TABLES

Table 1 Cardwell Operation Discharge Water Quality – Licence Conditions and Actual Performance ........ 2

Table 2 Additional Nutrient Percentiles ..................................................................................................... 10

Table 3 Implied Load Limits for Cardwell and Point Ceylon ....................................................................... 14

LIST OF FIGURES

Figure 1 Cardwell Operation TN Discharge Monitoring Data For Sites W1 and W2 ...................................... 3

Figure 2 Cardwell Operation TP Discharge Monitoring Data ......................................................................... 4

Figure 3 Location of Model Tracer statistics .................................................................................................. 5

Figure 4 Concentration of Model Tracer around Point Ceylon (dry season) ................................................. 5

Figure 5 Model Interpretation Locations ....................................................................................................... 7

Figure 6 Additional (Discharge) TN Interpretations ....................................................................................... 8

Figure 7 Additional (Discharge) TP Interpretations ....................................................................................... 9

Figure 8 Variation of Model Concentration at Point 1 over a Two Month Period During Dry‐season

Conditions ....................................................................................................................................................... 11

Figure 9 Variation of Model Concentration at Point 1 Over a Two Month Period during wet‐season

conditions ....................................................................................................................................................... 11

Figure 10 Time Series Plots of Additional Nitrogen (Daily average shown by red line) ................................. 12

Figure 11 Potential Treatment Systems ........................................................................................................ 16


1

1 INTRODUCTION

This document provides further information to that provided in the Project Sea Dragon (PSD) Notice of Intent,

lodged on 19 February 2016, and the responses to the Request for Further Information (hereafter referred to

as the RFI response), lodged 20 April, 2016.

As discussed between Roderick Johnson (NT EPA) and Kate McBean (CO2 Australia) on 06 July 2016, and via

email on 07 July 2016, the NT EPA is seeking further information to deal with remaining uncertainty they have

regarding the potential significance of the waste water discharge from a full‐scale Point Ceylon project in order

to inform a decision under the Environmental Assessment Act. As such, this document provides our responses

to the following queries:

an indication of the range of predicted concentrations of nutrients and the frequency of occurrence of

maximum predicted concentrations

whether a worst‐case scenario for mixing and dispersion of nutrients was modelled and, if so, the results of

that modelling

expected nutrient loads in discharge at full scale (based on the Cardwell operation if required)

waste water treatment options available (in addition to settling) that would improve water quality prior to

discharge ‐ such treatment options may be required if proposed licence levels are deemed unsuitable for

Bynoe Harbour

proposed monitoring program to detect exceedances in licensed discharge concentrations and impacts on

receiving waters

contingency measures should licence values be consistently exceeded and/or impacts to receiving waters

be detected.

1.1 AN INDICATION OF THE RANGE OF PREDICTED CONCENTRATIONS OF NUTRIENTS AND THE FREQUENCY OF OCCURRENCE OF MAXIMUM PREDICTED CONCENTRATIONS

1.1.1 An indication of the range of predicted concentration of nutrients

We have shown this in the previous material provided in a number of ways. Table 6 of the Notice of Intent

(NOI) (PSD, February 2016) shows the actual performance of Seafarms' Cardwell facility in terms of monthly

median values, the 80th percentile and maximum value1. That table is reproduced here as Table 1. The full data

series available was presented in Attachment 3 of the response to the Request for Further Information (lodged

20 April, 2016) within the report entitled 'Point Ceylon Coastal Environment and Hydrodynamics Assessment'

(Water Technology, April 2016). Figure 3‐1 (p39) of that report is reproduced here as Figure 1, and shows total

nitrogen concentrations in the discharge waters at two monitoring sites at the two points of discharge at the

Seafarms Cardwell facility. Inspection of these data indicate the full range of 0.25‐2.8 mg N /L. For avoidance of

doubt the 2.8 mg/L concentration at Site W1 occurred once.

1As mentioned below in Section 1.2, the Cardwell facility is considered to provide a conservative indication of the potential range of

nutrients


2

Figure 3‐2 (p40) of the aforementioned Water Technology (April 2016) report is reproduced here as Figure 2,

and shows total phosphorus concentrations in the discharge waters at the two monitoring sites at the two

points of discharge at the Seafarms Cardwell facility. Inspection of these data indicate the full range of 0.02‐

0.27 mg P /L. The 0.27 and 0.23 mg/L concentrations shown at site W2 each occurred once only.

TABLE 1 CARDWELL OPERATION DISCHARGE WATER QUALITY – LICENCE CONDITIONS AND ACTUAL PERFORMANCE

Condition Median 80th Percentile Maximum

Total Nitrogen (mg/L)

Licence Conditions 2.0 2.5 5.0

Actual Performance 1.1 1.5 2.8

Total Phosphorus (mg/L)

Licence Conditions 0.4 ‐ 0.6

Actual Performance 0.08 0.11 0.27


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FIGURE 1 CARDWELL OPERATION TN DISCHARGE MONITORING DATA FOR SITES W1 AND W2

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W2 80th %ileMedian Licence Condition

Median Licence Condition


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FIGURE 2 CARDWELL OPERATION TP DISCHARGE MONITORING DATA

We have also shown an indication of the range of predicted (modelled) concentrations at two geographic

scales. The first is the 'far‐field' mixing 'domain' represented as Points 2 ‐ 6 shown on Figure 3‐6 of the

aforementioned Water Technology (April 2016) report, reproduced here as Figure 3. The predicted

concentrations at nominated points are shown in Figure 3‐7 of the Water Technology (April 2016) report, and

are reproduced here as Figure 4. These concentrations are indicated as a 'percentage of the tracer remaining'.


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FIGURE 3 LOCATION OF MODEL TRACER STATISTICS

FIGURE 4 CONCENTRATION OF MODEL TRACER AROUND POINT CEYLON (DRY SEASON)


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To represent the range of these predicted concentrations, we have used the convention of a box and whisper

plot in which the yellow 'whiskers' represent the full range of realisations (i.e. the range of results), the box

represents the 25%‐75% of the range and the purple bar is the median value. Note that we have used a median

value rather than the arithmetic mean which might be thought of as 'typical' because the distribution of results

is clearly 'non‐normal', thus the median is a more appropriate representation. In other words, the box plot

graphically depicts populations of numerical data through their quartiles: the rectangle represents the second

and third quartiles, and a horizontal line inside indicates the median value. The lower and upper quartiles are

shown as horizontal lines (whiskers) on either side of the rectangle. Outliers are plotted as individual points.

Box plots are non‐parametric: they display variation in samples of a statistical population without making any

assumptions of the underlying statistical distribution. The spacings between the different parts of the box

indicate the degree of dispersion (spread) and skewness in the data, and show outliers. Note also that Figure 4

is plotted on a log‐scale. Plotting the data in this way serves to enable clearer inspection of the output from

each modelling point, but it does tend to make less intuitive the significant attenuation of the tracer. It also

tends to make the skewness of the distribution 'appear' less.

As the results from the far‐field mixing clearly show that any nutrient 'impact' beyond Wheatley Creek would

be negligible/undetectable above the background in the dry season (see Figure 4), we provided additional

'near‐field' information that focussed upon Wheatley Ck.

This following discussion focusses specifically on Wheatley Ck.

Figure 5 provides the information previously presented as Figure 1 in the document entitled 'Further

Information to the NOI ‐ Wheatley Creek discharge', lodged 26 May 2016. Figure 5 shows 17 data retrieval

points from the model from which we have drawn detailed model output around the proposed discharge

location in order to determine the fate of any discharge. Note that the mesh of the model allows a detailed

interpretation of potential impact within Wheatley Creek. These locations are placed at approximately

equidistant intervals in the model domain along the Creek extending upstream and downstream from the

proposed outfall. The locations are mostly along the centreline of the creek, however to illustrate maximum

(worst case) model predictions we have oriented these locations closer to the northern/eastern bank of the

creek in those sections of Wheatley Creek closer to the proposed discharge.

Figure 6 and Figure 7 (also previously presented in Attachment 1 [Water Technology, May 2016] to the

'Further Information to the NOI ‐ Wheatley Creek discharge' document) show the associated box and whisker

plots of additional TN and TP concentrations that are predicted (in a highly conservative manner as discussed

under Section 1.2 below) to result from the discharge. Thus these two figures also illustrate the range of

predicted concentrations of additional nutrients that may result from the discharge.

Note that Figures 6 and 7 also show the single maximum outlier from the model realisations (marked as a red

cross), providing further insight into the information requested at Section 1.1. It is important to understand

that these points represent highly transient and rare instances at the point of entry into the environment.


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FIGURE 5 MODEL INTERPRETATION LOCATIONS


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FIGURE 6 ADDITIONAL (DISCHARGE) TN INTERPRETATIONS


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FIGURE 7 ADDITIONAL (DISCHARGE) TP INTERPRETATIONS

To expand on these above figures, and to further explain the range of predicted concentrations, modelled data

from locations 6 and 13 as shown on Figure 5 (some 900 m upstream and downstream, respectively, of the

proposed discharge) have been further interrogated and the TN/TP percentile table below (Table 2) prepared.

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TABLE 2 ADDITIONAL NUTRIENT PERCENTILES

Percentile Additional Total Nitrogen (mg/L) Additional Total Phosphorus (mg/L)

Site 6 Site 13 Site 6 Site 13

25 0.033 0.017 0.007 0.003

50 0.049 0.028 0.010 0.006

75 0.061 0.043 0.012 0.009

90 0.070 0.055 0.014 0.011

95 0.074 0.064 0.015 0.013

99 0.084 0.081 0.017 0.016

1.1.2 An indication of the frequency of occurrence of maximum predicted concentrations of nutrients

In order to investigate frequencies of 'maximum predicted concentrations' one needs to consider the sources

of variation that may lead to any observed variation in concentration. In broad terms these are:

Variations in the concentrations of nutrient from the discharge waters (source variations);

Variations in concentrations of nutrient arising from variations within the receiving environment (e.g.

tides) (sink variations);

Variations in concentrations from the interaction of source and sink variations.

As already described in the previous section an indication of the frequency in maximum predicted

concentrations due to the operation of the facility is best captured by the data from Cardwell (Figure 1 and

Figure 2).

To show variations in concentrations due to variations within the receiving environment (sink variations),

Water Technology (April 2016 ‐ presented as Attachment 3 of the response to the Request for Further

Information [lodged 20 April, 2016]) modelled a case in which discharge concentrations were held constant

(thus eliminating the source variation) and then showed the concentrations at a nominated point (Point 1,

shown at Figure 3). This point was chosen as it is in Wheatley Creek but upstream of the discharge point.

Obviously a point immediately adjacent to the proposed outfall would not show the variances within the

receiving environment. However, being upstream of the discharge point, Point 1 represents a conservative (or

worst case) point for which to do the assessment This is the conservative approach because the point upstream

represents a more constrained (smaller) water body within Wheatley Creek than downstream which opens up

to McKenzie Arm. During the Dry Season (which represents the timing for the simulation in Figure 3‐8) when

downstream flows from the catchment are at their minimum, flushing is likely to be less and recirculation may

be greater, thus a higher consequential risk of less mixing and dispersion. The Water Technology report (April

2016) showed results at Point 1 in Wheatley Creek for a Dry Season case (Figure 3‐8) and a Wet Season Case

(Figure 3‐12), reproduced here as Figure 8 and Figure 9. In terms of 'worst case' analysis: upstream during the

dry season represents the case in which one would expect to observe the largest perturbation to the system if

there were local circulation patterns that resulted in 'trapped' or undispersed nutrient given low flows.


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FIGURE 8 VARIATION OF MODEL CONCENTRATION AT POINT 1 OVER A TWO MONTH PERIOD DURING DRY‐SEASON CONDITIONS

FIGURE 9 VARIATION OF MODEL CONCENTRATION AT POINT 1 OVER A TWO MONTH PERIOD DURING WET‐SEASON CONDITIONS

We now provide additional information to illustrate the frequency of predicted concentrations. Again, model

predictions have been presented in the form of time series plots (Figure 10). These are shown for sites 6 and

13, respectively upstream and downstream of the discharge point. These predictions are at 15 minute intervals,

with the daily average (a 24 hour running mean) shown by a red line. These show the highly transient nature of

the changes in nutrient concentration and also the underlying neap‐spring tidal variation. We note again that

these results are highly conservative for the reasons outlined in Section 1.2 below.

Considering that the model is a tracer model the frequencies and variances for TP are the same as for TN,

hence only TN is shown here.


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Regardless of all of the above, the key water quality performance metric is the change in the long term median

nutrient level, which will not see exceedance of the nominated water quality performance standards for this

location.

FIGURE 10 TIME SERIES PLOTS OF ADDITIONAL NITROGEN (DAILY AVERAGE SHOWN BY RED LINE)

1.2 WHETHER A WORST‐CASE SCENARIO FOR MIXING AND DISPERSION OF NUTRIENTS WAS MODELLED AND, IF SO, THE RESULTS OF THAT MODELLING

It is our opinion that the information provided to the Northern Territory EPA to date already represents a very

conservative, or ‘worst‐case’ scenario in regard to the mixing and dispersion of nutrients in Wheatley Creek.

A justification for this opinion is as follows:

Results presented are predominantly those for the dry season when mixing will be at a minimal level and

hence would be the worst case in regard to water quality impacts (noting in some instances we have

presented cases for the Wet Season).

All modelling has assumed no biological assimilation of nutrients within Wheatley Creek or other local

waterways. This again is a highly conservative (i.e. worst‐case) assumption as there is extensive scientific

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Additional TN (mg/L)

Additional TN Site 6

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Additional TN Site 13


13

literature for comparable mangrove lined/tropical environments which confirm assimilation rates of the

nutrient component of aquaculture wastewater of around 25% per day (Burford et al., 2003). Were we to

include such a rate in our modelling, the predicted concentration increases and the extent of the zone of

potential impact would be significantly reduced.

We have also assumed that the discharge will always occur at the nominated median license conditions,

these being 2 mg/L for TN and 0.4 mg/L for TP. This assumption is so unlikely it is almost implausible, but it

is conservative from the point of view of assessing potential impact. As evidenced by the Cardwell data, we

expect actual discharge (as is usually the case) to be a better quality than the nominated license

conditions. To illustrate this point, we provide plots of the license condition and recent discharge quality

monitoring data for two discharge locations for the Seafarm operations at Cardwell in Figure 1 and Figure

2. Monitoring occurs at the point of discharge so is comparable to the proposed discharge location for

Point Ceylon shown between Points 9 and 10 on Figure 5. Observed nutrient data are provided, together

with the relevant license conditions. These figures provide evidence that actual performance is typically

significantly better than the license condition, especially in the case of TP. For reasons outlined below, we

expect discharge quality at the Point Ceylon facility to be better than that from the Cardwell operations.

We note that we have chosen to model the median as opposed to the maximum value as the discharge will

not occur at the maximum quality level at all times. The quality will fluctuate depending on which

operation phase the facility is in, with the long term behaviour being best represented by the median. It is

also important to recognise that when short term increases in concentration (i.e. the maximum level) do

occasionally occur, they will be rapidly mixed in Wheatley Creek and that long term water quality (the key

performance metric) will be influenced by the median discharge concentration and not the maximum.

We have nominated licence conditions from Cardwell where there is no discharge water treatment. As

shown above, the quality of this untreated water is significantly better than the licence condition.

At Point Ceylon, we will be deploying settlement ponds, however, the benefits of settlement were not

factored into the modelling ‐ settlement ponds will further ensure that the effluent quality is better than

the licence condition.

We have also included in our modelling what is considered to be an upper bound flow rate of 11,000 m³

per day from the full‐scale level of operation. This does not account for any internal optimistion and

operational refinement.

In presenting the results we have consistently shown fractions (percentages) of tracer remaining and as

described below in many cases these results when contextualised against 'background nutrient levels'

result in computed (modelled) changes that are highly unlikely to be detectable as a separate signal.

When all of the above are considered, concurrently, it is evident that the assessments are highly conservative

or ‘worst‐case’.

The above first‐cut assumptions indicate why the assessment we presented extends beyond these assumptions

to a consistent bias in favour of conservatism. This embedded conservatism is present throughout the analysis.


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1.3 EXPECTED NUTRIENT LOADS IN DISCHARGE AT FULL SCALE (BASED ON THE CARDWELL OPERATION IF REQUIRED)

The proposed operation included in our assessments, and all of the previous material presented, is that

associated with the full scale of the project.

As we originally outlined to the EPA, this approach differs from the assessment strategy for the grow‐out

facilities at Legune where we are only initially considering the implementation of Stage 1 of the ultimate

development.

The reason for the difference in approach is that the full‐scale development at Bynoe Harbour enables the EPA

to gain an a priori understanding of the potential total (cumulative) impact of this relatively small‐scale facility

at this location. Scale effects with these facilities can be reasonably expected to be linear whereas this is not

necessarily the case at Legune where efficiencies may be gained and operating factors (such as recirculation)

may change as the project there scales up. Factors such as this may lead to changes in the relationship

between hectares under production and nutrient outputs.

The table below (Table 3) shows the implied loads based on the licence assumptions included in the impact

assessment. For ease of comparison we have also calculated an implied daily load limit for Cardwell. Note that

Cardwell does not utilise a load‐based licence so these loads are implied or calculated based on continuous

operation of the facility with water quality at the median condition. This makes it straightforward to see that

the proposal for the Bynoe Harbour is of order five‐fold less in terms of daily load than the comparator site at

Cardwell.

TABLE 3 IMPLIED LOAD LIMITS FOR CARDWELL AND POINT CEYLON

Limit Volume Median TN

concentration

Implied TN

allowable load

Median TP

concentration

Implied TP

allowable load

m3/day mg/L kg/day mg/L kg/day

Licenced (Cardwell) 60,000 2 120 0.4 24

Assumed (Pt Ceylon

full scale volume)

11,000 2 22 0.4 4.4

Hence, at the nominated flow and licence conditions, the nutrient loads in the full‐scale discharge from the

proposed Bynoe operation are as follows:

TN 22 kg/day (assuming 11,000 m3/day at the median TN licence condition)

TP 4.4 kg/day (assuming 11,000 m3/day at the median TP licence condition)

Furthermore, we stated in the NoI:

The proposed facility at Point Ceylon will have operating conditions and discharge characteristics that

are similar to the existing Seafarms Group prawn operating operations at Cardwell in North

Queensland. As such, Seafarms propose to adopt the licence condition set by the Queensland

Department and Heritage Protection (QlD DEHP) for the Point Ceylon Facility.

Given the additional questions being asked by the NT EPA it is perhaps useful to provide additional context for

the approach.


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The Cardwell operations are on the Hinchinbrook Channel adjacent to the waters of the Great Barrier Reef. This

is acknowledged as an environment sensitive to nutrients given the cumulative impact of all land uses along the

Queensland tropical coast. The facility operated now by Seafarms has been in operation since about 1984,

Since that time there have been no observed detrimental impacts to the environment from that facility.

There have been a number of scientific studies and scientific papers published that explicitly investigate the

impact of nutrients into mangrove creeks from these and similar facilities along the Queensland coast. In the

Response to Request for Further Information lodged on 20 April 2016, Water Technology (Appendix 7)

reviewed this body of work and explicitly commented on its applicability to the Point Ceylon proposal.

Application of the findings of the peer reviewed studies to the Point Ceylon proposal suggests that (outside of

the mixing zone), water quality is unlikely to change such that proposed interim water quality objectives will be

exceeded. This is considered a logical inference as all the studies cited made no mention of any adverse

impacts on either water quality or mangrove ecosystems along the creeks receiving prawn farm waste.

Furthermore, the review investigated the findings of Trott and Alongi (2000) and McKinnon et al. (2002), which

presented flushing metrics. With respect to these studies, Wheatley Creek will receive a far smaller relative

discharge of wastewater than those estuaries studied. Hence, any potential water quality impacts should be

proportionally far less than their cases. Importantly, they also showed no impacts in regard to water quality in

the estuaries that they investigated, even though they received a proportionally far greater discharge.

1.4 WASTE WATER TREATMENT OPTIONS AVAILABLE (IN ADDITION TO SETTLING) THAT WOULD IMPROVE WATER QUALITY PRIOR TO DISCHARGE

Whilst Wheatley Creek flows into Bynoe Harbour, so in that sense can be considered a part of Bynoe Harbour,

is important to note that the impact assessment that Seafarms has presented indicates there will be no

detectable impact in Bynoe Harbour proper. The modelling at Figure 3‐7 of the Water Tech report shows a

residual of 0.02 percent of tracer at point 5 (Figure 3.5) which is the representative Bynoe Harbour point. To

provide this within the context of the discussion 0.02 percent of 2.0 mg/L (the proposed concentration

maxiumim) is 0.0004 mg/L. This is against a background of at best 0.1 mg/L. Given natural variability it would

be a challenge to develop a program which produced an observable and statistically robust signal given this

difference. Beyond being unable to demonstrate a detectable difference in nutrient concentrations in Bynoe

Harbour, for an impact of significance it is also necessary to demonstrate an effect of this undetectable

elevation of nutrient on a biological variable (e.g primary production, species composition) within Bynoe

Harbour.

Our investigations indicate that settling ponds designed with appropriate residence times represent the 'best

practice' water treatment to improve waste water prior to discharge to Wheatley Creek. Despite not allowing

for the benefits of settling within the settlement ponds prior to discharge, the modelling has shown that the

zone in which the nominated Water Quality Objectives may be exceeded is small (i.e. between points 9 and 10

shown on Figure 5) and would occur only for a small amount of time. We have referred to this as a 'mixing

zone' in previous correspondence, but it is worth noting that this area will not behave as a mixing zone in the

conventional sense, as any elevations above the Water Quality Objectives are only predicted to occur

transiently: at and around low water slack, and to a far lesser degree (due to the greater volume) at high water

slack. Furthermore, those discharge concentrations contributing to those elevations above Water Quality

Objectives in the modelling, will certainly be less in reality, given the conservative nature of the modelling

(explained above in Section 1.2).

Seafarms has nonetheless investigated water treatment options in additional to settling.


16

As part of its initial scoping Seafarms undertook a thorough investigation of potential 'additional' water

treatment options. In particular Seafarms commissioned CSIRO to advise on environmental treatment during

the company's concept investigations. CSIRO identified a combination of technologies represented in Figure 11

below. This theoretical system has not been demonstrated at scale and relies on very high intensity

bioflocculation (biofloc) systems. These are not applicable to the relatively low stocking rates applicable to the

facilities proposed for Point Ceylon and we note that at this site we are not proposing large‐scale commercial

grow‐out.

Stocking rates within the facilities at Point Ceylon (about 27 individuals /m2 to a body weight of approx 49g and

then approx 10 individuals/m2 until spawning within the core breeding centre; and about 10 individual /m2 in

the maturation centre) contrast with commercial stocking rates at between 20‐50 post‐larvae /m2 for grow‐out

facilities.

FIGURE 11 POTENTIAL TREATMENT SYSTEMS

Seafarms is also aware of algal‐based 'solutions' to nutrient discharge promoted by some companies (for

example, a project at Pacific Reef Fisheries at Ayr). Our investigations of these technologies not only indicate

that they are not economic, but they also lead to unacceptable accumulations of algae that require either 'use'

as a 'product', or have to be disposed of some other way. The commercial reality is that there are no ready

markets or channels to market for seaweed products likely to be produced as a result of bio‐nutrient stripping

technologies. Considering that the predominant source of nutrient liberated with culture water is associated


17

with unutilised or unconverted feed, there is a very strong commercial imperative to improve feed conversion

ratios within the production process. Thus avoidance over time is the primary strategy to reduce impact. Key

technologies within the pipeline include: (i) recirculation (ii) improved feed formulations (iii) improved feed

regimes (such as through better timed feeding and smart sensor technologies) and (iv) breeding strategies that

improve feed conversion.

1.5 PROPOSED MONITORING PROGRAM TO DETECT EXCEEDANCES IN LICENSED DISCHARGE CONCENTRATIONS AND IMPACTS ON RECEIVING WATERS

Project Sea Dragon commenced observations of key water quality parameters in November 2015 and has

continued to collect monthly samples. Three points were selected as described on p 42 of the original NOI.

Continued monthly sampling at the points until commissioning the facility is intended and will yield a time‐

series of more than one year. This ought to be sufficient to establish an understanding of the prior condition

from which to monitor against. The work presented in the NOI and in response to other requests for

information from the NTEPA and the Federal Department of Environment, clearly outlines that the modelling

we have conducted is sufficient to establish an expected or predicted future water quality state against which

actual performance can be assessed.

A water quality monitoring program will be conducted of key elements of the system:

from intake water,

during the treatment process,

within ponds prior to and during discharge

at the point of discharge, and

in receiving waters.

In terms of discharges, the following program will be adopted:

Flow based monitoring of daily volume of discharge waters, to provide concentration and mass discharge

of various constituents

Monthly monitoring in receiving waters, within the predicted Dry Season mixing zone, at the edge of the

predicted Dry Season mixing zone, and locations outside of the predicted mixing zone, to measure the

concentrations of key constituents, such as TN, TP and TSS against mixing zone and receiving waters

criteria, and compare to background levels.

Prior to construction we propose to undertake an assessment of mangrove condition and tidal vegetation along

Wheatley Creek and an aquatic ecology survey (benthic macroinvertebrates and macroalgae). Requirements

for subsequent ecological monitoring are best guided by the results of monitoring of water quality parameters.

Project Sea Dragon is aware of the key guidance documents:

ANZECC/ARMCANZ (2000) Australian Guidelines for Water Quality Monitoring and Reporting (National

Water Quality Strategy No 7), and


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Department of Environment and Heritage Protection (2009) Monitoring and Sampling Manual 2009,

Version 2, July 2013 format edits. Monitoring and Sampling Manual 2009 Environmental Protection

(Water) Policy 2009

The monitoring program will be designed with regard to these documents.

1.6 CONTINGENCY MEASURES SHOULD LICENCE VALUES BE CONSISTENTLY EXCEEDED AND/OR IMPACTS TO RECEIVING WATERS BE DETECTED.

Nutrients in the discharge water are directly related to the feed used, food conversion ratio, solubility of feed

nutrients and water stability of the feeds.

Actions in the case of non‐compliance with licence values will be enshrined in the Operational EMP for the

facility. On first detecting exceedances of discharge limits, or impacts in receiving waters, a non‐compliance

process will be initiated. This will involve a number of processes, including determining whether the results are

errors or ‘one‐offs’, or indicate a problem with the system. This will typically involve resampling or

remonitoring.

Consistent exceedances for receiving waters impacts are not expected, but nonetheless, can be addressed in a

number of ways, including:

Process changes within the facility, to retain more sediment and provide more efficient use and/or

removal of nutrients prior to discharge, by such things as changes in recirculation, hydraulic retention in

settling ponds, oxygenation, and feed use and conversion, or by increasing seawater input (better dilution

and lower concentration in process waters)

Review of feed formulation and quality

Changing the discharge timing and volumes, to better target high ebb flows, to enhance discharge out of

the system

The option also remains ultimately to downscale operations such that the discharge and mass discharged into

receiving waterways is reduced. However, it should be noted that conservative modelling has shown that

discharge concentrations will meet discharge limits, and so while this remains a viable option, it is not

anticipated to be needed.


19

2 REFERENCES

Burford, M.A., Costanzo, S.D., Dennison, W.C., Jackson, C.J., Jones, A.B., McKinnon, A.D., Preston, N.P. and

Trott, L.A. 2003. 'A synthesis of dominant ecological processes in intensive shrimp ponds and adjacent coastal

environments in NE Australia', Marine Pollution Bulletin, 46 (2003), 1456‐1469

McKinnon, A.D., Trott, L.A., Capo, M., Miller, D.K., Duggan, S., Speare P., and Davidson A., 2002a. ‘The Trophic

Fate of Shrimp Farm Effluent in Mangrove Creeks of North Queensland, Australia’, Estuarine, Coastal and Shelf

Science (2002), 55, 655 – 671

Project Sea Dragon. February 2016. 'Project Sea Dragon ‐ Core Breeding Centre and Broodstock Maturation

Centre. Notice of Intent for Aquaculture Operations'. Lodged 19 February, 2016.

Project Sea Dragon. April 2016. 'Project Sea Dragon ‐ Core Breeding Centre and Broodstock Maturation Centre.

Notice of Intent ‐ Response to Request for Further Information'. Lodged 20 April 2016.

Project Sea Dragon. May 2016. 'Project Sea Dragon ‐ Core Breeding Centre and Broodstock Maturation Centre.

Further Information to the NOI ‐ Wheatley Creek Discharge'. Lodged 26 May, 2016

Trott , L.A. and Alongi, D.M. 2000. ‘The Impact of Shrimp Pond Effluent on Water Quality and Phytoplankton

Biomass in a Tropical Mangrove History’, Marine Pollution Bulletin, Volume 40 (2000), Number 11, pages 947 –

951,

Water Technology. April 2016a. 'Point Ceylon Coastal Environment and Hydrodynamics Assessment'. Lodged

as Attachment 3 of the Response to the Request for Further Information (PSD, April 2016).

Water Technology. April 2016b. 'Memorandum ‐ PSD CBC/BMC Water Quality NOI (15 April 2016)'. Lodged as

Attachment 7 of the Response to the Request for Further Information (PSD, April 2016).

Water Technology. May 2016. 'Memorandum ‐ PSD CBC/BMC Water Quality NOI response'. Lodged as

Attachment 1 of 'Further Information to the NOI ‐ Wheatley Creek Discharge' (PSD, May 2016).

Documents

PROJECT SEA DRAGON PTY LTD CORE BREEDING CENTRE …