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NSW DEPARTMENT OF PRIMARYINDUSTRIES

JULY 2018

SITE SUMMARYSTAT US

REPORT

BLOODTREE ROAD, MANGROVE

MOUNTAIN, NSW

Site Summary Status Report Bloodtree Road, Mangrove Mountain, NSW

NSW Department of Primary Industries

WSPLevel 27, 680 George Street Sydney NSW 2000GPO Box 5394Sydney NSW 2001

Tel: +61 2 9272 5100 Fax: +61 2 9272 5101

wsp.com

REV DATE DETAILS A 26/07/2018 Draft

NAME DATE SIGNATURE

Prepared by: Davide Menozzi 26/07/2018

Reviewed by: Colin McKay 26/07/2018

Approved by: Colin McKay 26/07/2018

TABLE OF CONTENTS

ABBREVIATIONS............................................................................ III 1 INTRODUCTION .................................................................. 1

1.1 BACKGROUND .......................................................................... 1

1.2 PURPOSE OF THIS REPORT.................................................... 1

1.3 OBJECTIVES .............................................................................. 2

1.4 LIMITATIONS AND INTELLECTUAL PROPERTY.................... 2

2 SITE BACKGROUND.......................................................... 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 ANDGROUNDWATER FLOW DIRECTION.............................. 9

4.1 GROUNDWATER LEVELS ........................................................ 9

4.2 GROUNDWATER FLOW DIRECTION ..................................... 10

5 GROUNDWATER QUALITY ............................................11

5.1 TOTAL DISSOLVED SOLIDS .................................................. 11

5.1.1 TRENDS .............................................................................................. 11 5.1.2 EXCEEDANCES .................................................................................. 12

5.2 PH .............................................................................................. 12


5.3 NUTRIENTS .............................................................................. 13

5.3.1 PHOSPHOROUS................................................................................. 14 5.3.2 NITRATE.............................................................................................. 15 5.3.3 AMMONIA............................................................................................ 16

Project No 2189227D Site Summary Status Report WSP

July 2018 Bloodtree Road, Mangrove Mountain, NSW Page i NSW Department of Primary Industries

5.3.4 TOTAL KJELDAHL NITROGEN (TKN) ................................................ 17

5.4 METALS .................................................................................... 18


6 SITE MAINTENANCE WORK SUMMARY.....................25

7 CONCLUSIONS .................................................................26

REFERENCES................................................................................27


July 2018 Bloodtree Road, Mangrove Mountain, NSW Page ii NSW Department of Primary Industries

ABBREVIATIONS ANZECC 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

LOR Limit of reporting (of chemical concentration) 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

QA/QC Quality assurance & quality control RPD Relative percentage difference

SAQP Sampling analysis and quality plan

SWL Standing water level TDS Total dissolved solids

TKN Total Kjeldahl Nitrogen

TOC Total organic carbon


July 2018 Bloodtree Road, Mangrove Mountain, NSW Page iii NSW Department of Primary Industries

1 INTRODUCTION 1.1 BACKGROUND An outbreak of a poultry disease, known as Newcastle Disease, occurred at Mangrove Mountain on the Central Coast Plateau in 1999. Approximately two million carcasses of slaughtered poultry and associated shed litter and wastes were buried to contain the potential spread of the disease. The poultry carcasses were placed inside tar-lined shipping containers, which were placed into engineered burial pits at George Downes Drive (on the former Hymix Kulnura Quarry site) and Bloodtree Road (on Gosford City Council’s Mangrove Mountain Works Depot site). Shed litter, manure and other potentially virus-contaminated materials were buried at a third site located at Waratah Road, Mangrove Mountain. Subsequently, NSW Department of Primary Industries (DPI, Agriculture), working in collaboration with DPI Water, NSW Environment Protection Authority, the Central Coast Public Health Unit of the Central Coast Area Health Service, and contracted environmental consultants (Robert Carr & Associates Pty Ltd.) developed a groundwater monitoring program to monitor any potential environmental impacts resulting from the 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) were conducted by various consultants between 2001 and 2018. Presently, there are 19 groundwater monitoring wells located across the three sites. DPI Agriculture commissioned WSP Australia Pty Limited (formerly WSP | Parsons Brinckerhoff Australia Pty Ltd) to undertake the bi-annual groundwater monitoring program at the three sites for three years (2015 to 2018). This report presents a summary of results for key groundwater indicators from all GMEs undertaken at the Bloodtree Road site by WSP Australia Pty Limited (WSP) since 2015, which comprise: — WSP | Parsons Brinckerhoff (2017a) Groundwater monitoring event 18, Mangrove Mountain poultry burial sites,

dated 4 January 2017 – November 2015 GME – Rev. C. — WSP | Parsons Brinckerhoff (2017b) Groundwater monitoring event 19, Mangrove Mountain poultry burial sites,

dated 20 February 2017 – June 2016 GME. — WSP | Parsons Brinckerhoff (2017c) Groundwater monitoring event 20, Mangrove Mountain poultry burial sites,

dated 20 February 2017 – October 2016 GME. — WSP (2017 d) Groundwater monitoring event 21, Mangrove Mountain poultry burial sites, dated September 2017 –

March 2017 GME. — WSP (2018a) Groundwater monitoring event 22, Mangrove Mountain poultry burial sites, dated March 2018 –

November 2017 GME. — WSP (2018b) Groundwater monitoring event 23, Mangrove Mountain poultry burial sites, dated July 2018 (draft) –

March 2018 GME. This report presents information and data specifically for the Bloodtree Road site. Separate reports have been produced for the George Downes Drive and Waratah Road landfills.

1.2 PURPOSE OF THIS REPORTThe purpose of this summary report is to document the condition of the groundwater in the vicinity of the containment cell and the physical condition of the cell, particularly with respect to any impacts that may have arisen from possible breaches of the containment of chicken wastes.


July 2018 Bloodtree Road, Mangrove Mountain, NSW Page 1 NSW Department of Primary Industries

1.3 OBJECTIVES The objectives of the regular groundwater monitoring events (GMEs) and visual inspections were to: — Provide data on the quality of groundwater near to and down hydraulic gradient of the containment cell. — Monitor trends in groundwater parameters and contaminants so as to identify possible leakage from containment

cells. — Record the physical conditions of the cell. — Identify groundwater flow direction and potential contaminant exposure pathways.

1.4 LIMITATIONS AND INTELLECTUAL PROPERTY SCOPE OF SERVICES

This site summary report (the report) has been prepared in accordance with the scope of services set out in the contract, or as otherwise agreed, between the client and WSP (scope of services). In some 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, WSP has relied upon data, surveys, analyses, designs, plans and other information provided by the client and other individuals and organisations, most of which are referred to in the report (the data). Except as otherwise stated in the report, WSP has not verified the accuracy 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. WSP will not be liable in relation to incorrect conclusions should any data, information or condition be incorrect or have been concealed, withheld, misrepresented or otherwise not fully disclosed to WSP. ENVIRONMENTAL CONCLUSIONS

In accordance with the scope of services, WSP has relied upon the data and has conducted environmental field monitoring and/or testing in the preparation of the report. The nature and extent of monitoring 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 conditions are encountered. Hence no monitoring, common testing or sampling technique can eliminate the possibility that monitoring or testing results/samples are not totally representative of soil and/or groundwater conditions encountered. The conclusions are based upon the data and the environmental field monitoring and/or testing and are therefore merely

indicative of the environmental condition of the site at the time of preparing the report, 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 of this report have been undertaken and performed in a professional manner, in accordance with generally accepted practices and using a degree of skill and care ordinarily exercised by reputable environmental consultants 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. WSP assumes no responsibility and will not be liable to any other person or organisation for or in relation to any matter dealt with or conclusions expressed in the report, or for any loss or damage suffered by any other person or organisation arising from matters dealt with or Project No 2189227D Site Summary Status Report WSP


conclusions expressed in the report (including without limitation matters arising from any negligent act or omission of WSP or for any loss or damage suffered by any other party relying upon the matters dealt with or conclusions expressed in the report). Other parties should not rely upon the report or the accuracy or completeness of any conclusions and should make their own enquiries and obtain independent advice in relation to such matters. OTHER LIMITATIONS

WSP will not be liable to update or revise the report to take into account any events or emergent 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, buildings and

structures referred to in the report nor the application or interpretation of laws in the jurisdiction in which those properties, buildings and structures are located.



2 SITE BACKGROUND

2.1 SITE IDENTIFICATION AND DESCRIPTION The 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 burial site at Bloodtree Road site which was a former council depot. The identification details for the site are provided in Table 2.1 and the location is indicated in Figure 1 (Appendix A). Table 2.1 Site identification details

IDENTIFICATION BLOODTREE ROAD

Council Gosford

County Northumberland

Parish Popran

Title identification Lot 81 DP 664567

MGA co-ordinates (zone 56) 333398 E, 6315439 N

The area surrounding the site comprises well-developed agricultural and horticultural industries, including intensive poultry farms, the quarry, orchards, vegetable market gardens and more recently groundwater extraction for bottling. The established agricultural areas are surrounded by native bushland areas including the Dharug, Popran and Brisbane Water National Parks, McPherson, Olney and Ourimbah State Forests and other Crown Land. The Bloodtree Road site is located in the southwest corner of the Gosford City Council’s Mangrove Mountain Depot, adjacent to the NSW Rural Fire Service shed. The burial pit was excavated into the sandstone bedrock (maximum depth

of 8 m) and has approximate horizontal dimensions of 13 m x 50 m. The pit was lined with geo-composite clay liner followed by a layer of high density polypropylene and geotextile fabric (BidimTM), and then filled with 48 tar-lined steel shipping containers housing poultry carcasses. The layout of the site is shown in Figure 2 in Appendix A.

2.2 TOPOGRAPHY The site is located near Mangrove Mountain on a sandstone plateau which drains into the Warre Warren Creek, Wyong River, Ourimbah Creek and Brisbane Water catchments. Several small creeks and tributaries of 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 the Gosford-Wyong local government areas. The site topography features undulating sandstone ridge-tops, vegetated by temperate sclerophyll woodland.

2.3 GEOLOGY A review of the Gosford-Lake Macquarie 1:100,000 (1994) geological map indicates that the site is generally underlain by Hawkesbury Sandstone. The Hawkesbury Sandstone consists of inter-bedded layers of sandstone (massive and sheet facies), siltstone and shale. The parent material overlying the sandstone bedrock in the vicinity of the Bloodtree Road burial pit is described as a gravelly lateric colluvium from sandstone according to a more comprehensive map of soils of the central coast plateau (Hawkins and Haddad, 2011). The soils are dominated by material of the Keighley association and characterised by a non-calcareous gradational texture profile, an earthy fabric in the B horizon, much gravel in the upper part of the profile and occasional pisolithic boulders.



Investigations at the Bloodtree Road site, for example, indicate that the sandstone has low strength with deeply weathered profile at depth, where water inflow was observed at around 18 m and 26 m depth. The available borehole logs indicated subsurface profiles at the sites generally correspond with the regional geology identified above.

2.4 HYDROGEOLOGY The aquifer in the Hawkesbury Sandstone has both porous and fractured flow. It is recharged by rainfall and discharges 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 is potentially a hydraulic connection between the perched and upper sandstone aquifer, however the degree of connection is not well known.

2.5 REGISTERED GROUNDWATER BORES A search of the Bureau of Meteorology (BOM) Australian Groundwater Explorer database (http://www.bom.gov.au/water/groundwater/explorer/map.shtml) indicated that several groundwater bores are registered

within 540 m of the sites. A review of the database (on 3 July 2018) identified no additional bores in the vicinity of the sites. A summary of the registered bores and their distance from the Bloodtree Road site is provided in Table 2.2 and shown in Figure 3 in Appendix A. Table 2.2 Summary of registered bores with 540 m radius of the site

SITE BORE ID PURPOSE APPROXIMATE DISTANCE AND DIRECTION FROM SITE(1)

SCREENDEPTH

INTERVAL(m)

STANDINGWATERLEVEL

(mBTOC)

TOTALDEPTH

(m)

BloodtreeRoad

GW069013 Domestic/stock 253 m north 6 – 46 17.0 46.0

GW026458 Domestic 279 m north 3 – 30.4 15.2 30.4

GW103210 Monitoring 200 m north 0 – 36 Unknown 36.0

GW064667 Domestic/stock 265 m west 7.7 – 46 14.0 46.0

GW049010 Domestic/stock 430 m east-south-east 12 – 45.8 15.0 45.8

BLR(3) Domestic/stock 204 m north Unknown Unknown Unknown

GW102429(4) Domestic/stock 502 m south-east Unknown Unknown Unknown

GW101491 Water Supply 360 m north Unknown Unknown 73.0

GW103212 Monitoring 299 m north-east Unknown Unknown 34.0

GW103211 Monitoring 299 m north-east Unknown Unknown 35.0

GW051465 Unknown 540 m north Unknown Unknown 45.0

(1) Distances are approximate only – calculated based on best judgement. (2) Information provided by NSW DPI. These bores are not shown on the public database. “V113642”, “BLR” and “20WA203515”

refer to the bore license numbers, rather than the bore IDs. (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. (4) The location of this bore has not been confirmed. (5) Information provided by NSW DPI indicated this bore (GW101979) is inactive at the time of investigation. The bore may be re-

activated, if required.



http://www.bom.gov.au/water/groundwater/explorer/map.shtml

3 CONTAMINANTS OF CONCERN

ANDAPPLICABLE

CRITERIA

3.1 CONTAMINANTS OF CONCERN The contaminants of concern for the GMEs at Bloodtree Road, as identified in the SAQP (Parsons Brinckerhoff, 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 matter placed within the burial pits and maturing of the waste material over time.

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

Assessment of potential corrosion of the metal containers containing the carcasses and waste.

3.2 GROUNDWATER INVESTIGATION LEVELS With 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 Bloodtree Road site are summarised in Table 3.2. These investigation levels were selected to assess the potential risks to human and ecological species. The environmental and human receptors identified on-site and off-site include: — Workers conducting monitoring or maintenance works at the sites. — Users of the groundwater in the vicinity of the site. Groundwater quality at the site indicated possible the beneficial

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.

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

— Surface water users, including Gosford-Wyong Councils Water Supply Authority, on the catchment streams 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 (Parsons Brinckerhoff, 2013). When the guidance values are not provided in the NEPM 2013, the parent guidelines were

referenced.



Table 3.2 Groundwater investigation levels

ANALYTE UNIT DRINKINGWATERGUIDELINES

(1),(2)

PROTECTION OFFRESHWATERECOSYSTEMS

(1),(3)

LIVESTOCKDRINKINGWATER(4)

IRRIGATIONUSE(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 - - - -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 - 0.35 - 5

Phosphorus mg/L - 0.025 - 0.05

Metals

Aluminium µg/L 200(11) 55(10) 5,000 -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 - - -Boron µg/L 4,000 370 5,000 500

Cadmium µg/L 2 0.2 10 10

Chromium (CrVI) µg/L 50 1.0 1,000 100



ANALYTE UNIT DRINKING PROTECTION WATER OF

GUIDELINES FRESHWATER(1),(2) ECOSYSTEMS

(1),(3)

LIVESTOCKDRINKING

(4) WATERIRRIGATION

(5) USE

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 0.06 2 2

Nickel µg/L 20 11 1,000 200

Zinc µg/L 3,000 8 20,000 2,000

(1) NEPM (2013) Schedule B1 – Investigation levels for soil and groundwater(2)

NHMR

C/NRM

MC (2011

) A

us

tralian Drinki

ng W ate

r Gu

ideli

nes. (Note: H

uman health values are provided as priority, aesthetic values are only prov

ided in

the absenc

e of a hum

an he

alth value)

(3) ANZECC/ARMCANZ ( 200

0)

– trigger

va

l

( ZEC ues

4) AN C/ARMCANZ (2000) – recomm

ended

for the protection of 95% of freshwater ecosystem water

quality trigge

r valu

es

for livestoc

k drinking

water

(5) ANZECC/ARMCANZ (2000) – Agricultural ir rigation

water

long te

r trigg

m er

values

(6) 1 mg/L of NH -N = 1.21 mg/L of NH ; 1 mg/L of NO -N = 4.43 mg/L of NO ; and 1

3 3 3 3 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 N

O

2).(8) Ammonia/ammonium equilibrium concentration is high

ly depen

den

t on pH

a

nd

guidelines, the trigger values for ammonia were der ived fo

r pH 6 to 9

; ex

tra

pola

temperature. In the ANZECC/ARMCANZ (2000) tion outside t

his

ran

ge is not advisable. On

account

that the groundwater at the thr

ee burial site

s is g

enerally

of

a

cidic conditions, mm n

ia conc

a o entr

ation

for pH 6 is adopte

d h

ere.

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

(10) ANZECC (2000)

only

p ov

r ide criter

ia

f

or Al

uminium

where the pH of the groundwater is >6.5 (11) NHMRC/NRMMC (2011) values for Aluminium are aesthetic criteria in the absence of health-based criteria.



4 REVIEW OF STANDING WATER LEVELS AND GROUNDWATER

FLOW

DIRECTION

4.1 GROUNDWATER LEVELS The standing water level (SWL) in the groundwater monitoring bores is used to calculate the direction of groundwater flow. Table 4.1 presents the location, elevation and last recorded SWL (March 2018) of the groundwater monitoring bores on the site. Table 4.1 Gauging results for March 2018 – Bloodtree Road site

BOREHOLE ID EASTING NORTHING T.O.C. SWL (mBTOC) GROUNDWATERELEVATION ELEVATION

(mAHD) (mAHD) BH1 319471 1315425 307.115 18.585 288.530

BH2 319495 1315360 305.100 15.960 289.140

BH3 319594 1315389 311.310 18.700 292.610

BH1B 333215 6315245 306.165 17.475 288.690

(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 BH3 is considered to be the up gradient well and BH1B is considered to be the down gradient well.



(1) The monthly rainfall data was obtained from the Mangrove Mountain AWS (Bureau of Meteorology Automated Weather Station 061375).

Chart 1 shows groundwater elevations from November 2015 to March 2018 in the four groundwater monitoring wells located at Bloodtree Road. Groundwater elevations in the up gradient monitoring well (BH3) are consistently higher in elevation than groundwater levels in the three down gradient monitoring wells (BH1, BH1B and BH2). Groundwater elevations in the down gradient monitoring wells are similar to each other. Groundwater elevation in each monitoring well followed a similar trend of fluctuation over time and was influenced by rain fall as recharge occurred, particularly after heavy rainfall in March 2017. Long-term trends in groundwater elevation and rainfall are presented in Appendix A (Figure 4).

4.2 GROUNDWATER FLOW DIRECTIONGroundwater is inferred to flow towards the west. The groundwater flow direction is presented on Figure 2 (in Appendix A) and has consistently been to the west.



5 GROUNDWATER QUALITY Trends in groundwater quality changes and exceedances of adopted assessment criteria (where applicable) are presented below. This report focuses upon the trends in down gradient well BH1B, because monitoring the quality of groundwater moving away from the pit is a major focus of the program. Data for key contaminants is presented for all groundwater monitoring wells and groundwater assessment levels (see Table 3.2) are also presented, where relevant. Note that in the charts reported through the report, concentrations lower than the LOR were represented as 0 mg/L for nutrients and as 0

µg/L for metals and metalloids.

5.1 TOTAL DISSOLVED SOLIDS 5.1.1 TRENDSThe total dissolved solids (TDS) concentration in groundwater is a measure of all dissolved substances in groundwater, including inorganic and organic substances dissolved in either a molecular, ionised or fine colloidal form. TDS is not a contaminant of concern but it is an indicator of aesthetic characteristics of drinking water, and an indicator of the potential presence of contaminants of concern. TDS data provides a broad indication of fluctuations in the chemical composition of groundwater. Chart 2 presents the TDS measured in groundwater samples collected form the four monitoring wells at the Bloodtree Road site between November 2015 (GME 18) and March 2018 (GME 23).

As shown on Chart 2, concentrations of TDS were generally consistent throughout the monitoring period, fluctuating between 38 mg/L and 58 mg/L. Of note is that the highest TDS was generally encountered up gradient of the pit.



5.1.2 EXCEEDANCES

TDS concentrations were consistently reported well below the adopted assessment criterion of 600 mg/L for drinking water use between November 2015 and March 2018.

5.2 pH 5.2.1 TRENDS

Groundwater at Bloodtree Road and in the vicinity of Mangrove Mountain is generally considered to be moderately acidic, which is common in groundwater associated with the Hawkesbury Sandstone formation. Chart 3 presents pH values measured in the field in each well on the site from November 2015 to March 2018.

It is noted that lower pH values were measured in October 2016 and October 2017 following dry weather, and then increased again in following months during periods of heavier rainfall. It is considered that rainwater mixed with the groundwater raises the pH through a dilution effect.

5.2.2 EXCEEDANCES

The pH values detected in groundwater from all monitoring wells at Bloodtree Road were consistently reported outside of the adopted assessment criteria for drinking water and irrigation use (6.5 to 8.5 pH value) and for protection of freshwater ecosystems (6.5 to 8.0 pH value) between November 2015 to March 2018. The bands of acceptance (between the lower threshold and upper threshold for acceptable pH) and the groundwater pH values are presented on Chart 4.



5.3 NUTRIENTS Nitrogen and phosphorus are released during the decomposition of organic material, including animal carcasses, they are also agricultural fertilisers. Their presence in groundwater downgradient of the burial pit could potentially indicate migration of leachate. Chart 5 presents the trends in key nutrients in down gradient well, BH1B.



5.3.1 PHOSPHOROUS

An excess of phosphorus in surface water can contribute to favourable conditions for algal blooms and eutrophication. Phosphorus binds strongly to iron compounds in soil and is not generally 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 soluble reactive phosphorus. Total phosphorus has been analysed during this monitoring program. Chart 6 presents the trends in total phosphorous concentration in groundwater samples collected from the Bloodtree Road site between November 2015 and March 2018.

5.3.1.1 TRENDS

Concentrations of total phosphorus were detected above the laboratory limit of reporting (LOR) in three occasions between November 2015 and March 2018: in March 2017 in groundwater monitoring wells BH1B and BH3 (up gradient); and in November 2017 in well BH1. In the remaining occasions, total phosphorous concentrations were lower than the LOR.

5.3.1.2 EXCEEDANCES

In the three occasions in which total phosphorus was detected (November 2017 and March 2017), concentrations were above the assessment criterion for the protection of freshwater aquatic ecosystems of 0.025 mg/L. Exceedances were detected in up gradient well BH3 as well as in down gradient wells BH1 and BH1B. Based on the lack of increasing trend downgradient of the pit, and the presence on occasion of elevated phosphate up gradient, it is considered unlikely that the concentrations of total phosphorus detected in November 2017 and March 2017 are related to leakage from the burial pit.



The source of phosphorus could be fertilisers potentially used in the agricultural field located up gradient (to the east) of the Bloodtree Road site.

5.3.2 NITRATE

5.3.2.1 TRENDS

Common sources of nitrate in the environment include fertilisers, animal wastes, septic tanks, municipal sewage treatment systems and decaying plant debris. Excess nitrogen within the environment can contribute to eutrophication

and algal blooms, leading to oxygen depletion in water. Nitrate can also be an important contaminant in drinking water. Concentrations of nitrate (as nitrogen-N) in groundwater in down gradient well BH1B have fluctuated very little (between 0.68 and 0.78 mg/L), as presented on Chart 5. Overall, concentrations of nitrate (as N) in all monitoring wells at the Bloodtree Road showed little variation over time. Concentrations varied between monitoring wells, with minimum concentrations consistently reported in down gradient well BH1B, and maximum concentrations consistently reported in up gradient well, BH3. The elevated concentrations up gradient are considered to be indicative of regional sources, likely due to the agricultural land use around Mangrove Mountain. If nitrogen was being released by leakage from the pit, nitrate (as N) concentrations are expected to be higher in those monitoring wells down gradient of the pit (BH1 and BH1B), given the high nitrogen content of material in the pit



5.3.2.2 EXCEEDANCES

Concentrations of nitrate (as N) in groundwater remained above the adopted assessment criterion of 0.16 mg/L for the protection of freshwater ecosystems in all monitoring wells on the site as presented on Chart 7. Although concentrations of nitrate (as N) are consistently reported above the adopted assessment criteria for protection of freshwater ecosystems, the concentrations are considered to be indicative of background levels and are not considered to be an issue at the site. Nevertheless, nitrate (as N) concentrations continue to be assessed because a significant change in concentrations may suggest leakage from the poultry burial pit.

5.3.3 AMMONIA

Ammonia is produced during the decay processes of animal and vegetable matter and by anthropogenic sources such as livestock farming practices and sewage (including septic systems). Ammonia can be toxic to aquatic organisms at varying concentrations, depending on pH conditions. Ammonia is a nutrient and oxidises to nitrate in surface water which, at concentrations significantly above natural, local levels, can contribute to cause algal blooms. 5.3.3.1 TRENDSAmmonia (as N) concentrations in all monitoring wells on the site fluctuated very little and ranged from below the laboratory LOR to 0.06 mg/L from November 2015 to March 2018. Concentration trends in down gradient well BH1B are presented on Chart 5.

5.3.3.2 EXCEEDANCES

Concentration of ammonia (as N) was not reported above the adopted assessment criterion for drinking water use (0.41 mg/L) in any of the wells on the site, as presented on Chart 8. Project No 2189227D Site Summary Status Report WSP


5.3.4 TOTAL KJELDAHL NITROGEN (TKN)

TKN is the sum of all organic nitrogen and ammonia in a given groundwater sample. 5.3.4.1 TRENDS

TKN concentrations were low and fluctuated around the laboratory limit of reporting (LOR) of 0.05 mg/L. TKN concentrations measured from November 2015 to March 2018 are presented in Chart 9.



5.3.4.2 EXCEEDANCES

There are no applicable adopted assessment criteria for TKN.

5.4 METALS Analysis of heavy metals and metalloids (aluminium, arsenic, barium, boron, cadmium, chromium, copper, iron, lead, manganese, mercury, nickel and zinc) was undertaken to assess the potential degradation and solubilisation of the metal containers containing the chicken carcasses. Leakage of high nutrient liquid may also potentially interact with sub-surface geology and the geochemistry of the groundwater potentially resulting in changes to soluble metal concentrations. The trends for the metals and metalloids reported above the laboratory limit of reporting (LOR) are presented below. 5.4.1 TRENDSChart 10 presents the trends in metals and metalloids concentrations detected during the six groundwater monitoring events (GMEs) undertaken at the site in down gradient well BH1B. Concentrations of arsenic, mercury, chromium and cadmium are not presented in Chart 10 as they were below the laboratory LOR. Between November 2015 and March 2018, concentrations of barium, boron, copper, lead, manganese and nickel were relatively stable, remaining below 25 µg/L. Aluminium concentrations varied from 38 µg/L and 86 µg/L, with the highest concentration recorded in March 2018. Zinc concentrations fluctuated between 2 µg/L and 33 µg/L, except for November 2017 when the concentration increased to 200 µg/L and then dropped to 13 µg/L in the following March 2018 GME. This sudden increase – in all wells, returning in to typical levels at the next monitoring round was considered likely to be



a laboratory error. Iron concentrations were lower than 14 µg/L between November 2015 and November 2017, and then increased to 240 µg/L in March 2018.



5.4.2 EXCEEDANCES

Concentrations of aluminium, which are represented graphically in Chart 11, were reported above the adopted assessment criterion of 55 µg/L in all GMEs undertaken from November 2015 to March 2018 in up gradient well BH3 and cross

gradient well BH2. In contrast, down gradient wells BH1 and BH1B showed aluminium concentrations generally below

the assessment criterion, with the exception of March 2018 when well BH1B presented a concentration of 86 µg/L. These

high aluminium concentrations are likely to be due to the low pH of the local aquifer, as aluminium solubility increases

with decreasing pH, particularly below pH 4 (Hem, 1989). Because the highest aluminium concentrations were systematically measured in up gradient and cross gradient wells, it is unlikely that dissolved aluminium relates to the burial pits.



Concentrations of copper, presented in Chart 12, have generally remained above the adopted assessment criterion for freshwater aquatic ecosystems (1.4 µg/L) in all monitoring wells between November 2015 and March 2018. The only

exceptions were the groundwater samples collected from down and cross gradient wells BH1, BH2 and BH1B in November 2017, which, unusually, presented concentrations lower than the LOR. No up or down gradient monitoring well consistently reported the highest or lowest concentrations of copper during each GME, indicating that it is unlikely that copper detected in groundwater is related to the burial pit.



Lead concentrations measured at the Bloodtree Road site between November 2015 and March 2018 are graphically

presented in Chart 13. Lead concentrations were overall lower than the adopted assessment criterion of 3.4 µg/L. The

only exceedance of the assessment criterion was found in down gradient well BH1B (9 µg/L) in March 2018. As

comparable lead concentrations were generally detected both up gradient and down gradient of the burial pit, they were considered to be indicative of background concentrations. The unusually elevated results from March 2018 will be monitored closely in future rounds to assess if the result indicates a rising trend or is a one off fluctuation in concentration.

Nickel concentrations, presented in Chart 14, fluctuated from values lower than the LOR (1 µg/L) to 45 µg/L between

November 2015 and March 2018. Concentrations of nickel above the adopted assessment criterion of 11 µg/L were

detected in groundwater monitoring wells located up and down gradient of the burial pit between June 2016 and March 2017, as well as in up gradient well BH3 in March 2018. The greatest fluctuation in nickel concentration of all the wells

on the site was displayed in the up gradient well BH3, where the highest concentrations was measured in November 2016

(45 µg/L). This is indicative of relatively high background concentrations of nickel in the groundwater at the site, which

are not directly linked to degradation and solubilisation of the metal containers in the burial pit.



Zinc concentrations measured in groundwater samples collected from the Bloodtree Road site between November 2015

and March 2018 generally remained above the adopted assessment criterion for freshwater aquatic ecosystems (8 µg/L) in both up and down gradient monitoring wells (Chart 15). In three of the six GMEs undertaken in the November 2015 -March 2018 period, concentrations in up gradient well BH3 were higher than in down gradient wells. This is indicative of relatively high background concentrations of zinc in the groundwater at the site. The unusually elevated zinc results in all bores in October 2017 were thought to be a laboratory error. Results in March 2018 have returned to more typical levels.

The remaining metals and metalloids analysed in groundwater showed concentrations lower than the adopted assessment criteria.



6 SITE MAINTENANCE

WORKSUMMARY

At the Bloodtree Road poultry burial pit site, an environmental/geotechnical consulting service provider installed the in-pit leachate monitoring/contingency extraction well in November 2016 (Stage 2 of pit renovation and re-capping). They also completed hydraulic testing, and further chemical and microbiological analysis of pit liquid in January 2017 to characterise/classify for future extraction, treatment and recycling, if required. Local Land Services (Soil Conservation Service) is currently planning Stage 3 re-capping of the Bloodtree Road pit proposed for 2018/19 (strip the vegetation

and surface top-soil layers of the burial pit and install dual High Density Polyethylene (HDPL)/Geocomposite Clay Layer (GCL) upper liner with sub-surface methane drainage/venting), having completed preliminary site investigation and survey in April/May 2018.



7 CONCLUSIONS Groundwater at the Bloodtree Road site is inferred to flow towards the west. Overall, groundwater monitoring from events 18 to 23 were consistent with some fluctuation within expected bounds. Monitoring of key contaminants of concern and indicator parameters in groundwater showed no evidence of any significant leakage from the burial pit. The concentrations of metals and nutrients detected are considered likely to be representative of background levels.



REFERENCES — ANZECC (2000)/ARMCANZ (2000) Australian and New Zealand Guidelines for Fresh and Marine Water Quality. — Australian Government – National Health and Medical Research Council (2011; revised March 2015) Australian

Drinking Water Guidelines.

— Hawkins, C. A. and Haddad, N. I. (2011) Soils of the Plateau of the Central Coast, NSW. — Hem J.D. (1989), Study and interpretation of the chemical characteristics of natural water, 3rd edition, Unites States

Geological Sur y Washington.

ve ,

— National Environment Protection Council (NEPC) (2013) National Environmental Protection Measure (NEPM) Amendm

ent Measure

2013

Schedule B1:

Guideline

on inv

estigatio

n levels for l

and

soi groundwater.

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

).

— Parsons Brinckerhoff (2013) Sampling and Analysis Quality Plan, Mangrove Mountain Groundwater ng Pr ect

Monitorioj

2012 – 2015.

— WSP (2017 d) Groundwater monitoring event 21, Mangrove Mountain poultry burial sites, dated September 2017 – March 2017 GME.

— WSP (2018a) Groundwater monitoring event 22, Mangrove Mountain poultry burial sites, dated March 2018 – November 2017 GME.

— WSP (2018b) Groundwater monitoring event 23, Mangrove Mountain poultry burial sites, dated July 2018 (draft) – March 2018

GME.

— WSP | Parsons Brinckerhoff (2017a) Groundwater monitoring event 18, Mangrove Mountain poultry burial sites, dated 4 January 2017 – November 2015 G

ME .

–

Rev

C.

— WSP | Parsons Brinckerhoff (2017b) Groundwater monitoring event 19, Mangrove Mountain poultry burial sites, dated 20 February 2017 – June 2016 GME.

— WSP | Parsons Brinckerhoff (2017c) Groundwater monitoring event 20, Mangrove Mountain poultry burial sites, dated 20 February 2017 – October

2016 GME.



FIGURES

Image Source: Google Earth

George Downes

Drive poultry burial

site

Waratah Road

poultry burial site

Bloodtree Road

poultry litter

containment site

Approximate site location

km 1

Figure 1 Mangrove Mountain Groundwater Monitoring Locations

Mangrove Mountain Groundwater Monitoring Project

Groundwater Monitoring Event 23 (March 2018)

0

Figure 2


29

0.5

29

0.0

BH1

288.530 BH1B

288.690

29

1.0

29

2.0

BH3

292.610

BH2

289.140

29

1.5

28

8.5

28

9.0

28

9.5

m Groundwater Monitoring Site layout and groundwater elevation contours 0 20 Well

Bloodtree Road, Mangrove Mountain




Figure 3 Registered Groundwater Bores-Bloodtree Road, Mangrove

Mountain



Poultry burial site

GW66748

GW048032

Registered groundwater bore

GW069013

GW103211 GW62458

GW064667

GW49010

GW103210

500 m buffer

PROJECT: MANGROVE MOUNTAIN GROUNDWATER MONITORING PROJECT CLIENT: NSW DEPARTMENT OF PRIMARY INDUSTRIES SITE: BLOODTREE ROAD

Figure 4

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.

Rainfall residual mass vs Standing Water Level Bloodtree Road, Mangrove Mountain, NSW

Project No PS109347Caltex Hamilton (Site ID: 28851)59-63 Tudor Street, Hamilton, NSWEnvironmental Site AssessmentCaltex Australia Petroleum Pty Ltd

WSPJune 2018Page G-1

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