Update on the Quality of Sediment from Port Curtis - Western Basin ...

Department of Environmentand Heritage Protection<strong>Update</strong> on the Quality of Sedimentfrom Port Curtis and TributariesMay 2012

Prepared by: Environment and Resource Science, former Department of Environment and Resource Management© The State of Queensland (Department of Environment and Heritage Protection) 2012Copyright inquiries should be addressed to or the Department of Environment and HeritageProtection, 41 George Street, Brisbane QLD 4000AcknowledgementsThank you to the following people for their contributions to this report: Nicole Blackett, Mark Davidson, John Ferris, JacobGruythuysen, Michael Holmes, Brad Mayger, Munro Mortimer, Julia Playford, Darren Renouf, Jason Shen, Suzanne Vardy,Michael Warne, Charmaine Wickings, Christine Williams and Ray Williams.DisclaimerThis document has been prepared with all due diligence and care, based on the best available information at the time ofpublication. The department holds no responsibility for any errors or omissions within this document. Any decisions made byother parties based on this document are solely the responsibility of those parties. Information contained in this document isfrom a number of sources and, as such, does not necessarily represent government or departmental policy.If you need to access this document in a language other than English, please call the Translating and Interpreting Service (TISNational) on 131 450 and ask them to telephone Library Services on +61 7 3224 8412.This publication can be made available in an alternative format (e.g. large print oraudiotape) on request for people with vision impairment; phone +61 7 3224 8412 or email.May 2012#29912-v2

ContentsExecutive summaryIntroduction 1Methods 2Sample sites 2Sampling 2Analyses 3Comparison of sediment contaminant concentrations to the Australian Interim SedimentQuality Guidelines, historical Gladstone data and national dioxin data 4Comparison to guidelines 4Comparison to literature data 4Dioxin and dioxin-like chemicals 5Results and discussion 8Metals and metalloids 8Sulfur, sulfide, and sulfates 8Fluoride 9Pesticides 9Dioxins and dioxin-like chemicals 12Organotins 14Petroleum hydrocarbons 14Comparison of sediment contaminant concentrations with previous studies 17Sources of sediment contamination 20Assessing the potential of dredging to release contaminants from Port Curtis sediment 21Conclusions 23References 24iviii

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesExecutive summaryDuring the latter half of 2011, concerns over the health of fish in Gladstone waterways wereraised with the Queensland Government. As part of their integrated response to the situation, theQueensland Government began investigating whether there have been changes in water quality inGladstone waterways during 2011 and 2012. Following recommendations from the GladstoneFish Health Scientific Advisory Panel (2012) this investigation was expanded to analyse sedimentfor persistent organic pollutants (POPs). In addition, the sediments were analysed for metals.Similar to the expanded sampling conducted for the February water sampling round, this programassesses whether any spatial pattern exists in sediment quality which could be explained bydredging or industrial discharges and whether sediment quality could be the cause or contribute tothe cause of the fish ill-health.Sediment sampling was conducted during February–March 2012 at 31 sites throughout PortCurtis. Testing covered a wide range of metals and metalloids, pesticides, and petroleumhydrocarbons, including polycyclic aromatic hydrocarbons (PAHs) and BTEX (the aromatichydrocarbons benzene, toluene, ethylbenzene and xylene), as well as polychlorinated biphenyls(PCBs), dioxins and dioxin-like chemicals. Almost all measured concentrations were less thanguideline trigger values, and the very few exceedances of one metalloid (arsenic) were notsignificantly over the guideline. The sole exceedance for mercury was shown in subsequentresampling to be atypical. For dioxins and dioxin-like chemicals, the levels in Port Curtissediments were consistent with the range in urban/industrial locations elsewhere in Australia.Overall, Port Curtis sediments contained low, negligible or undetectable concentrations of theanalysed chemicals. There was no spatial pattern of contamination suggesting the existence ofpoint sources of sediment contaminants.These results are consistent with previous studies conducted on sediment in Port Curtis andsurrounding areas. The concentrations of elements and compounds found in sediments at all sitessampled are not consistent with levels likely to result in poor fish health. Port Curtis has beenextensively sampled for sediment quality. The total number of sites sampled for sediment qualityin Port Curtis, including this study, is 462 sites. These samples have ranged in depth from thesediment surface down to 22.4 m deep into the sediments. These studies have examined a rangeof potential contaminants including up to 25 metals and metalloids, cyanides, potential acidsulfate soils (PASS), organotins, PAHs, BTEX, total petroleum hydrocarbons (TPH),iv

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributariesorganophosphate pesticides (OPs), organochlorine pesticides (OCs), triazines, carbamates,pronamide, phenoxyacetic acids, PCBs), semi-volatiles, hexachlorobenzene (HCB) and otherhalogenated hydrocarbons, radionuclides and explosives. Collectively, these extensive studieshave found only irregular exceedances of guidelines for silver, arsenic and antimony.v

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesIntroductionAs part of their response to fish health issues occurring in Gladstone waterways, theQueensland Government has been investigating water quality in Gladstone waterways during2011 and 2012. This was undertaken to determine if changes in water quality had occurred inGladstone waterways and if so, whether they were likely to cause or contribute to the observedfish health issues. Initial reports focussed on dredging as a potential source of contaminationbecause of community concerns over this issue but the scope has since been expanded.The Queensland Government released its first report on 5 October 2011 (DERM, 2011a) whichsummarised existing water quality data for Gladstone waterways. This indicated that, overall,the water quality in the Gladstone waterways since the 2011 flooding was consistent with prefloodwater quality data.In September 2011, the Queensland Government commenced monthly water quality samplingat Gladstone in addition to its long-term monitoring of the estuaries of Central Queensland thatcommenced in 1994. The monthly monitoring consisted of measuring dissolved and totalconcentrations of 28 metals and metalloids as well as physical-chemical properties (e.g.turbidity, dissolved oxygen, temperature and pH) and chlorophyll-a. Since October 2011, sevenreports on the water quality in Gladstone waterways have been published and are available onthe website .Sediment samples were collected and analysed for 21 metals and metalloids in the Septembersampling (DERM, 2011b). The concentrations of these chemicals were compared toappropriate sediment guidelines. Only arsenic (at two sites) and barium (at one site) exceededthese guidelines.In September 2011, the Gladstone Fish Health Scientific Advisory Panel (the panel) wasestablished to review the Queensland Government’s initial response to the fish health issue andprovide independent scientific advice to the government. In its final report, released on 6January 2012, the panel concluded that it was not able to provide a conclusive view on thecause of the fish conditions observed around Gladstone and recommended that further1

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributariesmonitoring and research be undertaken to aid in identifying the cause of the fish health issuesbeing experienced in Gladstone, including expanded sediment quality investigations.This report provides the results from the expanded sediment monitoring undertaken in February2012 and some follow-up sampling undertaken in March 2012.MethodsSample sitesAs part of the expanded investigation program that occurred during February 2012, sedimentsamples were collected from 31 sites within Gladstone Harbour 1 and related waterways inproximity to existing industries, including additional sites to provide improved background andreference information (Figure 1).SamplingOver the period 6 to 10 February 2012, sediment samples were collected by Queensland Governmentstaff using a stainless steel van Veen grab manually operated from an aluminium boat. The locations ofsampling sites are indicated in Figure 1.At each site, a single grab sample of bottom sediment was collected and mixed in a stainless steelbucket using a stainless steel spoon to form a well-mixed site sample. Due to compacted and/or stonysubstrate at a few sites, additional grab samples of bottom sediment were taken to provide sufficientmaterial from which to prepare a mixed site sample. From each mixed site sample, subsamples wereplaced into appropriately pre-washed and labelled glass jars for subsequent laboratory analysis. Forsome sites, duplicate or triplicate subsamples were also taken from the mixed site sample for separateanalysis as a QA/QC check 2 . Sample handling and preservation was in accord with the Queensland1 Gladstone Harbour is defined as all coastal waters from The Narrows to South Trees Inlet and east toCurtis Island.2 Triplicates were taken at QE3 (labelled QE3, QE31 and QE32) and MM2 (labelled MM2, MM21 andMM22). Duplicates were taken at FRE0.0 (labelled FRE0.0 and FRE100). Results from QE3, MM2 andFRE0.0 were used in this report. Results for duplicate and triplicate QA/QC samples are presented inAppendix 1.2

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesGovernment water quality Monitoring and Sampling Manual (DERM, 2009). Equipment used forcollecting and mixing samples was decontaminated between sites by washing with de-con (alaboratory-grade detergent), distilled water and hexane, followed by a final rinse with distilled water.A preliminary assessment of the laboratory results showed a reported concentration for mercury insediment from one site (site B0.0 at the mouth of the Boyne River, Figure 1) to be almost an order ofmagnitude greater than at any other site, including other sites nearby. Accordingly, to check thisapparent anomaly, this site was resampled on 21 March 2012. Five further sediment samples eachtaken as a separate grab from different locations a short distance from B0.0 were collected.AnalysesSediments were analysed for a range of elements (including metals and metalloids 3 common inmarine sediments), as well as for sulfur, sulfide, sulfate, fluoride and a range of organicchemicals commonly present in near-shore marine sediments (including pesticides, dioxins anddioxin-like chemicals, organotins, total petroleum hydrocarbons, BTEX, and PAHs). The list ofchemicals analysed for in sediments is provided in Appendix 1 4 . Other properties measured inall sediment samples were: moisture content, particle size distribution, and total organic carbon.All analyses were conducted at a commercial laboratory with National Association of TestingAuthorities (NATA) accreditation for all of the relevant analyses. Copies of the Certificates ofAnalysis and Quality Control Reports for the analyses are provided in Appendix 1. TheCertificates of Analysis also include the levels of reporting (LOR), which are the lowestconcentration that a laboratory will confidently state has been measured. Concentrations ofchemicals below the LOR are usually referred to as being ‘not detected’.3 Metalloids are elements that have physical and chemical properties similar to both metals and non-metals.4 To facilitate rapid downloading of the report, the appendices are provided in a separate file.3

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesComparison of sediment contaminant concentrations to theAustralian Interim Sediment Quality Guidelines, historicalGladstone data and national dioxin dataResults from the analyses in the sediment samples were compared to appropriate Australianguidelines where available, to previous studies of contaminants in Gladstone sediments or tothe National Dioxin Program Report on Aquatic Ecosystems (Müeller et al., 2004).Comparison to guidelinesThe relevant guidelines for metals, metalloids and a range of organic chemicals, includingpolycyclic aromatic hydrocarbons (PAHs) and some organochlorine (OC) pesticides, were theAustralian Interim Sediment Quality Guidelines (ISQGs) (Appendix 2). There are two sets ofISQGs for each chemical included by the sediment guidelines. These are the ISQG-low and theISQG-high. The ISQG-low is the concentration below which adverse impacts on aquatic lifeliving in close association with the sediments is unlikely. The ISQG-high is the concentrationabove which there is a high probability of adverse impacts on aquatic life living in closeassociation with the sediments. However, it is important to note that an exceedance of anISQG-low value does not imply that the sediments are necessarily ‘toxic’ but only that furtherinvestigation is necessary to determine if they are in fact toxic. Such investigations couldinclude sediment chemistry and bioavailability of the above-threshold material.This report examines sediment quality to determine whether chemicals in sediments whichcould be resuspended during dredging could somehow affect fish and other aquatic life. Thereport compares the sediments to ISQG values. These guidelines were developed for assessingpotential impacts on sediment dwelling organisms, living in direct contact with the sediments,not for mobile aquatic animals living in the waterways. However, they also provide anindication of the extent of possible contamination when the sediment is disturbed.Comparison to literature dataThe results of the current study were compared with sediment results from the followingstudies:(a)(b)the sediment sampling and assessment conducted by the Queensland Government inSeptember 2011 (DERM, 2011)material prepared by WorleyParsons (WorleyParsons, 2009a,b, 2010a,b)4

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributaries(c) material prepared by Connell Hatch (Connell Hatch, 2006)(d) material prepared by Aurecon Australia (Aurecon, 2011)(e)(f)material prepared by Douglas Partners (Douglas Partners, 2005a,b)material prepared by URS (URS, 2009a,b)(g) material cited in the Coordinator General’s Report (Coordinator General, 2010)(h)(i)material prepared by GHD (GHD, 2009); andthe Coastal Zone, Estuary and Waterway Management CRC Report (Apte et al.,2006).Mostly these other studies have compared sediment contaminant concentrations to the NationalOcean Disposal Guidelines for Dredged Material (NODGDM) (Environment Australia, 2002)and the National Assessment Guidelines for Dredging (NAGD) (Commonwealth of Australia,2009), which replaced the NODGDM.Dioxin and dioxin-like chemicalsDioxin-like chemicals consist of PCBs/aroclors and furans. There are no ISQG values fordioxins or dioxin-like chemicals in sediments (ANZECC and ARMCANZ, 2000). However,measured concentrations of these chemicals can be compared to the results from the NationalDioxin Program. This program included a number of baseline studies to measure dioxin anddioxin-like chemical emissions from sources such as bushfires, as well as concentrations ofthese chemicals in the Australian environment, food and population. One of those studies(Müeller et al., 2004) collected and summarised the level of dioxin and dioxin-like chemicals inthe Australian aquatic environment, including sediments. That study provides a nationalbenchmark against which the dioxin and dioxin-like chemicals measured in Port Curtissediments can be assessed. The National Dioxin Program (Müeller et al., 2004) reported theconcentrations of dioxins and dioxin-like chemicals as the sum of TCDD equivalentconcentrations (called ΣTEQ) (see Appendix 3 for an explanation of the ΣTEQ). Theconcentrations of dioxin and dioxin-like chemicals were expressed as ΣTEQ units in order tocompare the results with the National Dioxin Program.5

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesFigure 1. Sediment quality monitoring sites from in and around Gladstone waterways sampled in February 2012. The bottom left inset shows the relative position of allsampling sites. Most sites are shown on the main figure, the site at the mouth of Fitzroy River is shown in the top right inset (1) and the Rodds Bay reference sites andthe Hummock Hill Island site are shown in the bottom right inset (2).6

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesTable 1. Summary of sites sampled for sediments in February 2012 (presented from north to south) with a site description.Samples from all sites were analysed for metals, metalloids and organic chemicals.Locality Site ID Site description New or existing site 1Fitzroy River FRE0.0 Mud Island control site, mouth of the Fitzroy River newGladstone HarbourQE3 Potential impact from dredging plume existingQE4 Potential impact from dredging plume newE1a Near current dredging 2 . newE3a Near current dredging 2 . newBW1 Western Bund Basin spoil disposal area existingBW2 Western Bund Basin spoil disposal area existingFL Near the Orica discharge diffuser newCurtis Island SCI South of Curtis Island newGladstone HarbourBG10 Background Gladstone Harbour newST1 Potential impact from dredging plume existingBoat Creek BC Background water quality input to Gladstone Harbour existingGladstone Harbour NGPDP2 Near NGPDP2 outfall newCalliope RiverAuckland CreekC1.6 Calliope River Mouth – general industry existingC6.4 Calliope River 6.4 km upstream from river mouth existingAUK0.0 Auckland Creek, general industry newMM2 Gladstone marina, shipping existingGladstone Harbour NGPSW3 North of GPCSW3 discharge point newSTINM Northern mouth of South Trees Inlet newSTISM Southern mouth of South Trees Inlet newSTI4.8 STI STP 3 newSTI10.9 STI 10.9 km upstream of river mouth 4 newSouth Trees Inlet STI20.0 South Tree Inlet 20.0 km from river mouth 5 newSpoil Grounds SGW4 Spoil grounds existingFacing Island SFI South of Facing Island newB0.0 Boyne River Mouth newBoyne River B5.1 Boyne River 5.1 km upstream of river mouth existingCOI Colosseum Inlet newNorth of Rodds Bay HHI South of Hummock Hill Island newRB1 Reference site in Rodds Bay existingRodds Bay RB3 Reference site in Rodds Bay existing1Classified based on comparison to the previous round of sediment sampling conducted in September 2011 (DERM, 2011b). 2 These siteswere also part of harbour dredged about time of fish illness started. 3 STP = sewage treatment plant. 4 Sample collected against the red muddam wall. 5 Sample collected downstream of red mud dam.7

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesResults and discussionMetals and metalloidsNo metal exceeded the ISQG-low except for mercury (compare Table 2 and Appendix 2) in the sampletaken at the mouth of the Boyne River (site B0.0, Figure 1). This sample contained a mercuryconcentration of 1.36 mg kg -1 on a dry weight basis that was approximately one order of magnitudelarger than the ISQG-low value for mercury of 0.15 mg kg -1 on a dry weight basis. The follow-upsampling of seven samples, conducted to verify this atypical value, all returned a laboratory analysisresult of

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributariesthey be present at concentrations exceeding trigger values, since the presence of sulfide in sediments isan important factor in rendering many contained metals insoluble and thus not bioavailable (ANZECCand ARMCANZ, 2000). The concentrations of these three elements and compounds are presented inTable 3 and Appendix 1 and are within the expected range, suggesting they are not of concern.FluorideThere is no ISQG trigger value threshold for fluoride in sediments. Fluoride is a common constituent ofrock and marine sediment. The fluoride concentrations in oceanic sediments can be as high as1000 mg kg -1 (Carpenter, 1969). Consequently the measured concentrations in the Port Curtis area(which range from 50 to 280 mg kg -1 , Table 3 and Appendix 1) are relatively low.PesticidesNo pesticides were detected in the Port Curtis sediments (Table 4 and Appendix 1). For theorganochlorine pesticides dieldrin, endrin and lindane, the LOR were greater than the ISQG-low values(Appendix 2). Therefore it can not be determined whether or not the ISQG-low values have beenexceeded. However, none of these chemicals has been available for use for agricultural or domesticpest control purposes in Australia for over a decade (APVMA n.d.), and so it is unlikely that theywould be present at concentrations above the ISQG-low values in Port Curtis sediments.9

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesTable 2. Concentrations of metals and metalloids in sediments from Port Curtis during February and March 2012. The certificates of analysis that correspond to these results arepresented in Appendix 1.SiteBW1 BW2 SGW4 E1a E3a FL QE3 QE4 ST1 RB1 RB3 STINM STISM STI4.8 STI10.9 STI20.0 B0.0 B5.1 BG10 NGPCDP2 NGPCSW3 SCI BC C1.6 C6.4 MM2 AUK0.0 SFI COI HHI FRE0.0Analyte Units LORAluminium mg kg -1 50 16200 19600 3690 4520 15800 16600 9290 6470 2880 4390 3750 6670 2040 16400 10900 5010 2270 8560 4350 11600 5140 9020 19300 16100 3640 20200 16800 1920 4150 5010 2880Antimony mg kg -1 0.5

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesTable 4. Concentrations of pesticides in sediments from Port Curtis collected during February 2012. The certificates of analysis that correspond to these results are presented in Appendix 1.SiteBW1 BW2 SGW4 E1a E3a FL QE3 QE4 ST1 RB1 RB3 STINM STISM STI4.8 STI10.9 STI20.0 B0.0 B5.1 BG10 NGPCDP2 NGPCSW3 SCI BC C1.6 C6.4 MM2 AUK0.0 SFI COI HHI FRE0.0Analyte Units LOROrganotin CompoundsTributyltin µg Sn kg -1 0.5

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesDioxins and dioxin-like chemicalsAroclors are commercial mixtures of polychlorinated biphenyls (PCBs) manufactured from the 1960sfor a multitude of uses including transformer oils. Aroclors and PCBs in general are beingprogressively withdrawn from use in Australia and most developed countries under the StockholmTreaty on Persistent Organic Pollutants 2004.Dioxins and furans are ubiquitous products of combustion (both natural, for example in bushfires, andfrom the use of fuels including coal and petroleum). They also occur naturally in rocks and soils aswell as being generated by some industrial processes such as pesticide manufacture, as a result ofwhich they may be contaminants of those products and accumulate in soils, vegetation and animals.No Aroclor PCBs were detected in the Port Curtis sediments (Appendix 1), and the laboratory LORvalues were sufficient to demonstrate that there were no exceedances of ISQG values (Appendix 2).Many other dioxins were detected in Port Curtis sediments. However, there are no ISQG values for theother dioxins in sediments. They have, therefore, been compared with dioxin concentrations fromthroughout Australia using toxic equivalence (ΣTEQ) values.The ΣTEQ values for Port Curtis were compared to corresponding values for sediments adjacent toremote, agricultural and urban/industrial land-uses from the National Dioxin Program (Müeller et al.,2004) (Figure 2). The ΣTEQ values for Port Curtis are typical of those recorded throughout Australiafor aquatic sediments adjacent to urban/industrial environments. Even the maximum ΣTEQ which wasin the marina is within the typical range for Australian sediments adjacent to urban/industrialenvironments.12

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesPort Curtis (n=31)5.80.70.01Figure 2. Comparison using box plots (refer to Appendix 4 for an explanation of interpreting box plots) of thesum of dioxin equivalent (ΣTEQ) concentrations on a dry weight basis in Port Curtis sediments against sedimentsadjacent to remote, agricultural and urban/industrial land-uses published in the National Dioxin Program (Müelleret al., 2004). The most relevant comparison is the concentration for urban/industrial sediments and the Port Curtissediments. The ΣTEQ values were calculated using the World Health Organisation (WHO) toxic equivalencefactor method.The National Dioxin Program (Müeller et al., 2004) also provides background concentrations ofdioxins and dioxin-like chemicals in sediments in freshwater, estuarine and marine aquaticenvironments. All of the Port Curtis sediment sites have been considered ‘estuarine’ for the purpose ofcomparison with Müeller et al. (2004). As shown in Figure 3, Port Curtis sediments are typical ofestuaries in Australia.13

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesPort Curtis5270128043Figure 3. Comparison using box plots (refer to Appendix 4 for an explanation of interpreting box plots) of thesum of dioxin and furan concentrations on a dry weight basis in Port Curtis sediments against sediments fromfreshwater, estuarine and marine environments published in the National Dioxin Program (Müeller et al., 2004).The most relevant comparison is the concentration for estuarine sediments and the Port Curtis sediments.OrganotinsThe organotin compound tributyltin (TBT) was widely used as the active ingredient in antifoulantpaints applied to the hulls of commercial shipping and other craft until the adverse effects of thiscompound on marine life were realised in the 1970s. TBT use in vessel antifoulant paints has beenbanned by international treaty, but the persistence of TBT and its preliminary breakdown products(other organotins) in the environment has resulted in the ongoing detection of these compounds inmarine sediments. Although detected in a small number of Port Curtis sediment samples (Appendix 1),there were no exceedances of ISQG values (Appendix 2).Petroleum hydrocarbonsPetroleum hydrocarbons are a complex mixture of many compounds and the toxicity of petroleumhydrocarbons to aquatic life in any particular situation varies according to the type of hydrocarbonpresent. There are no ISQG values for total petroleum hydrocarbons, nor for individual hydrocarboncompounds (Appendix 2). However, the concentrations measured in the Port Curtis sediments (Table 514

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributariesand Appendix 1) are low relative to levels usually considered as significant contamination, for examplethey are substantially less than the Australian National Environment Protection (Assessment of SiteContamination) Measure and recommended ecological investigation levels in soils (Warne, 2010).The group of petroleum hydrocarbons known by the acronym ‘BTEX’ (the compounds benzene,toluene, ethylbenzene, and xylene) comprise a group of the more toxic components commonly found inpetroleum hydrocarbon mixtures. While there are no ISQG values for BTEX, no BTEX was detected inthe Port Curtis sediments at a LOR of 0.2 mg kg -1 (Table 5 and Appendix 1).Polycyclic aromatic hydrocarbons (PAHs) are another group of the more toxic components ofpetroleum hydrocarbons. There are ISQG values for some of the individual PAHs, and also for the totalof low molecular weight PAHs, total of high molecular weight PAHs, and total PAHs (see Appendix2). There were no exceedances of the ISQG values for PAHs measured in the Port Curtis sediments,and in most cases they were less than the LOR (Table 5 and Appendix 1).15

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesTable 5. Concentrations of petroleum hydrocarbons in sediments from Port Curtis collected during February 2012. The certificates of analysis that correspond to these results arepresented in Appendix 1.NGPCD NGPCSSITEBW1 BW2 SGW4 E1a E3a FL QE3 QE4 ST1 RB1 RB3 STINM STISM STI4.8 STI10.9 STI20.0 B0.0 B5.1 BG10 P2 W3 SCI BC C1.6 C6.4 MM2 AUK0.0 SFI COI HHI FRE0.0Analyte Units LORTotal Petroleum HydrocarbonsC10 - C14 Fraction mg kg -1 3

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesComparison of sediment contaminant concentrations withprevious studiesOverall, the analytical results from Port Curtis sediment sampling conducted by the QueenslandGovernment in February–March 2012 show low to negligible or undetectable levels of elements andcompounds of potential concern in sediments consistent with those reported by other studies conductedin the same area over preceding years (Douglas Partners, 2005a,b; Apte et al., 2006; Connell Hatch,2006; GHD, 2009; URS, 2009a,b; Coordinator General, 2010; WorleyParsons 2009a, b, 2010;Aurecon, 2011; and DERM, 2011).There is an essential difference between Port Curtis sediments assessed by the various consultants andthose sampled by the Queensland Government in September 2011 and February–March 2012. For themost part, the consultants were assessing material to be dredged as to its suitability for disposal onland, for reclamation fill adjacent to the aquatic environment (for example on mudflats adjacent toFishermans Landing), or for disposal to designated oceanic spoil grounds near Port Curtis. Thus, theirassessments of the suitability of sediments for marine disposal were guided by the requirements of theAustralian guidelines for assessment of dredge material for disposal. The assessment of their suitabilityfor disposal as reclamation fill was guided by the Queensland environmental investigation levels(EILs) for soil (DEH, 1998). Only the guidelines for marine disposal are relevant to the issue ofpotential impacts of dredge spoil disposal on aquatic life. Depending on the date when the assessmentswere made, these marine disposal guidelines were either the NODGDM (Environment Australia, 2002)or the NAGD (Commonwealth of Australia, 2009). (The latter is an update of the former, but thesediment quality criteria for elements and compounds are essentially the same in both guidelines, andbased on the ISQG (ANZECC and ARMCANZ, 2000)).Whether the sediment guideline is exceeded for a sediment component (e.g. a metal) is determined bycomparing the appropriate guideline with the upper 95 per cent confidence interval of the mean metalconcentration in sediments in the area to be dredged, or in a distinct site within the area(Commonwealth of Australia, 2009). Typically, these comparisons are made using data from corestaken through the full thickness of the sediments that are intended to be dredged. Such cores usuallypenetrate to several metres depth into the sediment. For example, the GHD study (GHD, 2009) hadcores that were 6 m deep, while in others they have been as deep as 12 m (Douglas Partners, 2005a). Incontrast, the Queensland Government sampling comprised near surface samples taken with a van Veengrab, which has an effective penetration of 10–20 cm in soft sediments, or less where sediments arecompacted or stoney. As explained below, the Queensland Government samples taken from the surface17

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributarieslayers are a better indicator than deep core samples of any recent impact on sediment quality fromanthropogenic activities such as industry or sewage discharges.Apte et al. (2005) estimated that the top 28 cm of sediment in Port Curtis was deposited since 1958,and Vincente Beckett et al. (2006) subsequently stated that this layer of sediment corresponded to theperiod of increased industrialisation at Gladstone and that it was this layer that would contain mostanthropogenic contamination. Since sediments contaminated by anthropogenic activities tend to settleout on top of older pre-existing sediments, the Queensland Government samples (DERM, 2011b andthe present study) are more likely to detect evidence of recent deposition of contaminants than samplestaken for dredge spoil disposal assessment since in the latter, the concentrations of elements andcompounds are averaged over the depth of the core. On this basis, it can be argued that the QueenslandGovernment sampling is more likely than the deep core assessments associated with capital dredgingworks to detect a problem of sediment contamination. Notably, as indicated in the previous sections ofthis report, sediment sampling in this program detected no evidence of significant sedimentcontamination.Worley Parsons have completed four studies of sediment quality in the Gladstone Harbour (WorleyParsons 2009a, b, 2010a, b). The reports were very detailed and sampled 104 sites for many contaminanttypes. Worley Parsons 2009 (a) sampled 42 locations at up to 14.3 m. These cores were sampled for 16metals, organotins, PAHs, BTEX, TPH, OPs, OCs, and PCBs. Thirty-four sites were sampled for potentialacid sulfate soils (PASS). Worley Parsons 2009(b) studied 27 locations at up to 10.5 m. Cores weresampled for 15 metals, organotins, PAHs, BTEX, TPH, OPs, OCs, PCBs and 21 cores were assessed forPASS. Worley Parsons 2010(a) sampled 20 locations at up to 2.6 m for 16 metals, organotins, PAHs,BTEX, TPH, OPs, OCs, and PCBs. Worley Parsons 2010(b) sampled 15 locations at up to 2.3 m for 16metals, organotins, PAHs, BTEX, TPH, OPs, OCs, PCBs and PASS.These studies all found that the 95 per cent upper confidence limits for the mean concentrations ofelements and compounds assessed were less than their NAGD (Commonwealth of Australia, 2009)trigger values, which are essentially those in the ISQG (ANZECC and ARMCANZ, 2000).After reviewing the available literature, Connell Hatch (2006) reported that sediment concentrations ofelements and compounds were almost entirely less than the NODGDM (Environment Australia, 2002)trigger values, other than minor and rare exceedances for five metals and the metalloid arsenic, but thatthe upper 95 per cent confidence intervals of the mean concentrations were less than the trigger values18

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributariesfor all except silver. Due to the depth at which the exceedance of the silver NODGDM (EnvironmentAustralia, 2002) occurred, it was concluded that the silver originated from a natural source.The Aurecon (2011) assessment noted that in the area of Port Curtis assessed, the depth of sedimentdeposited since the 1950s (effectively the start of heavy industrial development in Gladstone (Apte et.al., 2006)) only involves the upper 0.3 m. This observation suggests that capital dredging of sedimentsthicker than this is unlikely to encounter sediment contaminated as a result of anthropogenic activity.However, while elements and compounds at depths greater than this are unlikely to be due to humanactivities, it is possible that dredging activities could resuspend such sediments and lead to their releaseinto the water column. Concentrations of elements and compounds in sediment at depth shouldtherefore be considered. Accordingly, the Aurecon report considered all exceedances, including thosefound in deep sediments. The only exceedence of ISQG values found by Aurecon was arsenic at fourlocations.The sediment assessments by Douglas Partners (2005a, b) sampled 15 sites in 2005a and 16 sites in 2005b.Cores were up to 12 m deep. In both reports cores were analysed for 10 metals, organotins, PAHs, sevenpesticide suites, PCBs and PASS. The assessments found that all elements and compounds assessed in thePort Curtis sediment samples were at concentrations less than the trigger values in the NODGDM(Environment Australia, 2002) when compared to the upper 95 per cent confidence intervals of the meanconcentrations.The URS (2009a) study assessed 26 locations at up to 15 m deep for 13 metals, organotins, cyanides,PAHs, BTEX, TPH, OPs, OCs, triazines, carbamates, phenoxyacetic acids, PCBs, porewater ammonia, andradionuclides. Most Port Curtis sediment samples were found to be at concentrations less than the triggervalues in the NODGDM (Environment Australia, 2002) when compared to the upper 95 per centconfidence intervals of the mean concentrations. In the case of antimony, the upper 95 per cent confidenceinterval of the mean concentration was 2.69 mg kg -1 on a dry weight basis while the trigger value is 2 mgkg -1 on a dry weight basis. However this is a minor exceedance since the ISQG-high for antimony is 25 mgkg -1 on a dry weight basis. The second URS (2009b) study assessed 22 locations at up to 4.5 m depth for25 metals and PASS. The sediment assessment found no exceedances of the NAGD (Commonwealth ofAustralia, 2009) trigger values.The study by GHD (2009) assessed 189 sites to a maximum depth of 22.4 m for 14 metals, organotins,PAHs, BTEX, TPH, OPs, OCs, triazines, carbamates, pronamide, phenoxyacetic acids, PCBs, semi-19

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributariesvolatiles, HCB and other halogenated hydrocarbons, radionuclides and explosives. The assessmentfound exceedances of the NAGD (Commonwealth of Australia, 2009) trigger values for arsenic andnickel in a few individual sediment samples, as well as single samples only for cadmium and copper.However, the 95 per cent upper confidence limits for the mean concentrations of each of these fourelements was less than their NAGD (Commonwealth of Australia, 2009) trigger values. GHD (2009)also reported some exceedances of environmental investigation levels (EILs) for soils (as per DEH,1998). This finding is only relevant to the disposal of dredge spoil to bunded land reclamation and doesnot translate to a risk to aquatic life from exposure to the dredge spoil.The Apte et al. (2006) study collected 59 samples which ranged from surface samples to cores 45 cmdeep. The study examined nine metals, stable lead isotopes and PAHs in sediments. Apte et al. (2006)compared suspended particulate contaminant concentrations in Port Curtis with those in SydneyHarbour, noting that the mean benthic sediment concentrations in Port Curtis for copper and zinc are18 ± 12 and 32 ± 29 µg/g respectively (Apte et al. 2005). The corresponding concentrations in SydneyHarbour that has numerous contaminant inputs are typically 100 and 700 µg g -1 , respectively (Hatje etal. 2001). This indicates that particulate sediment concentrations for these contaminants at Port Curtisare not high in comparison.Sources of sediment contaminationThe CRC study (Apte et al., 2006) was particularly focused on the sources of metals in Port Curtiswaters and sediments, noting that although there were ‘elevated metal concentrations within theharbour’ … ‘The Narrows region was found to have the highest concentrations of dissolved copper andnickel and this could be attributed to natural geological sources.’ In addition, the CRC study found thatthat there were ‘no conspicuous sources of trace metals within Port Curtis’, that ‘there was littleevidence of pulsed inputs of metals, for example, from industrial sources or release from sediments’and that the dissolved metals encountered were ‘most likely to be delivered in solution form and not byrelease of metals from particulates’ (such as suspended sediments). Regarding sources of dissolvedmetals, the CRC report concluded that ‘the Fitzroy River is a source of dissolved metals to the localcoastal region. In particular, the Fitzroy River contains elevated dissolved nickel concentrations. Undersome flow conditions, the Fitzroy River plume may enter The Narrows region and supply dissolvedmetals to Port Curtis’. In terms of sediment quality in Port Curtis, the CRC study concluded ‘usingmultiple lines of evidence, it was shown that the concentrations of particulate arsenic, chromium andnickel in the benthic sediments of Port Curtis are elevated because of the local geology and not becauseof metal contamination from anthropogenic sources. This important factor needs to be taken into20

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributariesaccount when applying the ANZECC/ARMCANZ (2000) sediment quality assessment framework tothis region. Polycyclic aromatic hydrocarbon (PAH) contaminants in sediments were highest aroundthe industrial area of Gladstone; however concentrations at all locations were below ANZECC triggervalues’.The results from the sediments sampled by the Queensland Government in September 2011 (DERM,2011a) and the present study are consistent with the previous studies by other organisations in thatthere are no conspicuous above guideline concentrations of elements and compounds suggestive ofpoint sources of sediment contaminants.Assessing the potential of dredging to release contaminantsfrom Port Curtis sedimentThere has been speculation in the media that sediment-bound toxicants are released during dredgingand this is related to the fish health issues at Port Curtis. The concentrations of many of the organiccompounds analysed in the sediments were not detectable or were at very low concentrations relativeto guidelines. Therefore, it is not reasonable to conclude that dissolved concentrations of organicchemicals, released following dredging, are sufficient to cause the fish health issues observed atGladstone.While it is possible for metals to be released from sediments under circumstances such as acidificationwhen potential acid sulfate sediments are disturbed and allowed to oxidise, studies of acid sulfatepotential in areas to be dredged in Port Curtis have shown that release of acid will not occur becausethe acid generating potential is less than published threshold values (for example Douglas Partners2005b). Consequently, spoil disposal to sub-tidal locations is low-risk. If disposal is to areas whereoxidation is possible, such as the use of dredged sediments as fill for land reclamation, the potential foracid generation is managed. In regard to the risks of acid generation from the oxidation of PASS indredge spoil the Coordinator General’s report (2010) states ‘placement of dredge spoil will be carriedout, as follows to address risks:• PASS spoil will then be deposited until a maximum level of RL 0.67 m (MLW) so that atall times the untreated PASS will be below mean low water mark and remain wet• neutralised PASS spoil will be added until the fill height reached the maximum designheight (less capping); and21

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributaries• for material to be considered self-neutralising, the quantity of calcium salts will be 300 percent of the minimum neutralising requirement for the PASS.’As noted in previous Queensland Government reports (DERM 2011c; 2012a, b, c) the pH of all waterssampled have been alkaline, with pH values all above 7.5 even at sites (e.g. E1a and E3a) in very closeproximity to current dredging activity. As such, there is no evidence for acidification of sedimentsfollowing dredging.Where acidification is not an issue, it is still possible for metals to be released as dissolved metals fromsediments disturbed by dredging. Such metals can come from two sources within the sediments.Firstly, from the release of metals previously attached to the surface of sediment particles, andsecondly, from the release of dissolved metals trapped in the porewater (the water that occupies thespaces between individual particles of sediment).In respect of the release of metals attached to the surface of sediment particles, numerous studies(reviewed in Murray and Norton 1979) have shown that in sea water, any dissolved metals released asa result of disturbance and suspension (e.g. by dredging) are rapidly removed and returned toparticulate forms. This occurs by way of re-adsorption on to suspended clay particles (as shown in theTables in Appendix 1 Port Curtis sediments contain a high percentage of clay), by precipitation, and byscavenging by iron released from the sediments (as shown in the tables in Appendix 1, the natural ironcomponent is substantial in Port Curtis sediments).The quantity of dissolved metals available for release from pore waters in the sediments is minor. Asnoted by Van den Berg et. al. (2001) ‘most trace metals in sediments are present in the particulatephase; in contrast to the water column, only a relatively small amount of trace metals (

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributaries2012c). Only three metals were detectable at E1a and E3a in February 2012. Of these, molybdenumwas present at similar concentrations to sites close by and all Port Curtis sites. Boron was present atconcentrations lower than most Port Curtis sites. Arsenic was present at concentrations higher thannearby sites but well within the ranges found in all Port Curtis sites. Thus, overall there is no evidenceto support the concept that dredging is causing elevated contaminant concentrations.ConclusionsThe sediment quality results from the February 2012 sediment sampling are similar to thosediscussed in previous reports analysing Port Curtis sediments. There is some evidence ofanthropogenic contributions to the levels of some elements and compounds in near-surfacesediments at some inshore locations, for example at the marina, but even these do not exceedguideline thresholds for biological effects.The general lack of exceedances of the Australian Sediment Quality Guidelines and the smallspatial scale of any exceedances does not support the suggestion that contaminants in sediment,either directly or indirectly through the resuspension and dissolution following dredging, causethe fish ill health observed at Gladstone.23

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesTo obtain copies of data used in this reportSend an email to ReferencesANZECC and ARMCANZ. (2000). National Water Quality Management Strategy. Water Quality andMonitoring Guidelines. Section 3.5 – Sediment Quality Guidelines. Australian and New Zealand Environmentand Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand.Canberra.Apte, SC, Andersen, LE, Andrewartha, JR, Angel, BM, Shearer, D, Simpson, SL, Stauber, JL and Vicente-Beckett, V. (2006). Contaminant Pathways in Port Curtis: Final Report. CRC for Coastal Zone, Estuary andWaterway Management, Brisbane.APVMA. The History of ‘organochlorine’ pesticides in Australia. Available from:Aurecon. (2011). Western Basin Dredging and Disposal (Onshore and Offshore) Project dredge ManagementPlan. Gladstone Ports Corporation. Report 216012-001-01 Revision 5 29 June 2011. Aurecon Australia Pty Ltd,Brisbane.Carpenter, R. (1969). Factors controlling the marine geochemistry of fluorine. Geochim Cosmochim Acta33:1153–1167.Commonwealth of Australia. (2009). National Assessment Guidelines for Dredging. Commonwealth ofAustralia., Canberra. 92p. Available from:Connell Hatch. (2006). Wiggins Island Coal Terminal Environmental Impact Statement. Prepared for CentralQueensland Ports Authority and Queensland Rail. November 2006. Connell Hatch, Brisbane.Coordinator General. (2010). Western Basin Dredging and Disposal Project. Coordinator-General’s report for anenvironmental impact statement, July 2010. Dept of Infrastructure & Planning, Brisbane.DEH. (1998). Draft Guidelines for the Assessment and Management of Contaminated Land in Queensland.Department of Environment and Heritage, Brisbane. May 1998. Available fromhttp://www.derm.qld.gov.au/register/p00090aa.pdfDERM (Department of Environment and Resource Management). (2009). Monitoring and samplingmanual 2009. Version 2. DERM, Brisbane. 237p. Available from:DERM (Department of Environment and Resource Management). (2011a). Water Quality of Port Curtis andTributaries. Supplementary Report Based on Data Collected in the Week of 26th September 2011. Environmentand Resource Science, Department of Environment and Resource Management, Brisbane 2011.DERM (Department of Environment and Resource Management). (2011b). Water Quality of Port Curtisand Tributaries. Supplementary Report Based on Data Collected in the Week of 26 th September.Environment and Resource Science, Department of Environment and Resource Management, Brisbane,Qld, 38p. Available from;24

<strong>Update</strong> on the Quality of Sediment from Port Curtis and Tributaries.Downloaded on 18/11/2011.DERM (Department of Environment and Resource Management). (2011c). Second <strong>Update</strong> on the WaterQuality of Port Curtis and Tributaries Including Data Collected in the Week of 24 October 2011.Environment and Resource Science, Department of Environment and Resource Management, Brisbane,Qld, 47p. Available from: .Downloaded on 19/1/2012.DERM (Department of Environment and Resource Management). (2012a). Third <strong>Update</strong> on the WaterQuality of Port Curtis and Tributaries Including Data Collected in the Weeks of 12 November and 21December 2011. Environment and Resource Science, Department of Environment and ResourceManagement, Brisbane, Qld, 52p. Available from: .Downloaded on 27/1/2012.DERM (Department of Environment and Resource Management). (2012b). Fourth <strong>Update</strong> on the WaterQuality of Port Curtis and Tributaries Including Data Collected in the Week of 9 January 2012.Environment and Resource Science, Department of Environment and Resource Management, Brisbane,Qld, 52p. Available from: .Downloaded on 15/3/2012.DERM (Department of Environment and Resource Management). (2012c). Fifth <strong>Update</strong> on the WaterQuality of Port Curtis and Tributaries Including Data Collected in the Week of 6 February 2012.Environment and Resource Science, Department of Environment and Resource Management, Brisbane,Qld, 73p. To be released onto the DERM website: Douglas Partners. (2005a). Report on Geotechnical, Environmental and Acid Sulfate Soils Investigation.Proposed Berth 4 Outloading Conveyor and Dredging Clinton Coal Wharf RG Tanna Coal Terminal, Gladstone.Project 33597/7 Prepared for Central Queensland Ports Authority 18 May 2005. Douglas Partners Pty Ltd,Brisbane.Douglas Partners. (2005b). Proposed Dredging Works Existing Shipping Channels Gladstone. Project 33597/APrepared for Central Queensland Ports Authority 26 September 2005. Douglas Partners Pty Ltd, Brisbane.Environment Australia.(2002). National Ocean Disposal Guidelines for Dredged Material. Commonwealth ofAustralia, Canberra. 182p. Available from:GHD. (2009). Consultants Report for Gladstone Ports Corporation: Report for Western Basin Dredgingand Disposal Project. Sediment Quality Assessment.Gladstone Fish Health Scientific Advisory Panel. Final Report. 5 January 2012. (2012). Report to theQuuensland Government. Brisbane. 47p. Available from:Hatje V, Apte SC, Hales LT and Birch GF. (2003). Dissolved trace metals distributions in Port Jacksonestuary (Sydney Harbour), Australia. Marine Pollution Bulletin, 46, 719–730.Müeller J, Muller R, Goudkamp K, Shaw M, Mortimer M, Haynes D, Paxman C, Hyne R, McTaggart A,Burniston D, Symons R and Moore M. (2004). Dioxins in Aquatic Environments in Australia, National DioxinsProgram Technical Report No. 6, Australian Government Department of the Environment and Heritage,Canberra.25

<strong>Update</strong> on the Quality of Sediment from Port Curtis and TributariesMurray, LA and Norton, MG. (1979). The Composition of Dredged Spoils Dumped at Sea from England andWales. Fisheries Technical Report No. 52. Ministry of Agriculture, Fisheries and Food. Directorate of FisheriesResearch, U.K. ISSN 0308-5589.URS. (2009a). Environmental Investigations of Proposed Capital dredging at China Bay and Pipeline Crossing atThe Narrows, Gladstone. Final Report Reference Marine Sediment Report 28 January 2009. Prepared for SantosLtd. URS Australia Pty Ltd, Brisbane.URS (2009b). Report GLNG Dredged Material Placement facility, Acid Sulfate Soils Investigation. Final ReportReference 42626447/1/D November 2009. Prepared for Santos Ltd. URS Australia Pty Ltd, Brisbane.USEPA (United States Environment Protection Agency). (2012). Mercury. Consumer and Commercial Products.Downloaded from www.epa.gov/hg/consumer.htm 29 March 2012.Van den Burg, GA,, Meijers, GGA, Van der Heijdt, LM and Zwolsman, JJG. (2001). Dredging-relatedmobilisation of trace metals: A case study in the Netherlands. Water Research 35(8): 1979–1986.Vicente-Beckett, V, Shearer , D, Morrison, H, Munksgaard, N, Hancock, G. (2006). Metal and polycyclichydrocarbon contaminants in benthic sediments of Port Curtis. Technical report no. 83. Final report to CRC forCoastal Zone, Estuary and Waterway Management, Brisbane. 76p. Available from:Warne, MStJ. (2010). Review of the appropriateness of the Canadian Petroleum Hydrocarbon Country WideStandards in soil for incorporation into the Australian National Environment Protection (Assessment of SiteContamination) Measure and Recommended Ecological Investigation Levels – 3 Nov 2010. Available from:WorleyParsons. (2009a). Australia Pacific LNG – Dredge Area. Option 2A. Sediment Characterisation Study. 8October 2009. 301001-00752-00-EV-REP-0002 – APLN-000-PC-R01-D-00002.WorleyParsons. (2009b). Australia Pacific LNG – Dredge Area. Option 1B. Sediment Characterisation Study. 8October 2009. 301001-00752-00-EV-REP-0001 – APLN-000-PC-R01-D-0001.WorleyParsons. (2010a). Sediment Characterisation Report – Pipeline. Supplemental Information to the EIS.(Australia Pacific LNG Project EIS). Revision 0 August 2010. Prepared for Australia Pacific LNG Pty Ltd.WorleyParsons Services Pty Ltd.WorleyParsons. (2010b). Sediment Characterisation Report – Materials Offloading Facility, Jetty and Jetty Berth.Supplemental Information to the EIS. (Australia Pacific LNG Project EIS). Revision 0 August 2010. Prepared forAustralia Pacific LNG Pty Ltd. WorleyParsons Services Pty Ltd.26