Technical and reference docs

The EPA has established an environmental quality management framework for Cockburn Sound, which has been given effect through the State Environmental (Cockburn Sound) Policy 2015 (Government of Western Australia, 2015). The framework is underpinned by established environmental values and clearly expressed and spatially defined environmental quality objectives to guide decision-making and provide the common goals for management. The objectives have been developed in consultation with the community and are intended to reflect the values held by the community for the marine environment of Cockburn Sound.

The revised and updated version of the Environmental Quality Criteria Reference Document released in March 2015 has been further updated and the new version published in April 2017.

Implementation of the management framework requires a cooperative approach that involves all stakeholders. Environmental quality criteria (EQC) play an important role in the management framework by providing the quantitative benchmarks for measuring success in achieving the environmental quality objectives. The goal of environmental management would therefore be to ensure that direct and indirect sources of contaminants are managed such that the EQC are met and the environmental quality objectives achieved. If the EQC are exceeded, then the regulator, manager and discharger must cooperatively develop and implement management strategies, with timelines, and interim objectives if necessary, to restore environmental quality to the levels defined by the EQC.

All the EQC that support the SEP and the EMP, and the decision schemes which explain how they should be applied, are included in this reference document. They are based on known current and historical contaminant inputs and are relevant to the potential issues/pressures in the Sound (GHD, in draft). The decision schemes are also included in the SEP. If other contaminants are considered to pose a potential threat to the environmental values of the Sound in the future then guidance should be sought from the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC & ARMCANZ, 2000), the Western Australian Shellfish Quality Assurance Program (DoH, 2011) and the Australia New Zealand Food Standards Code to establish additional EQC.

Several water quality surveys were undertaken in the coastal waters of the Kimberley region from September 2007 to August 2008 to measure typical TSS concentrations and determine background total and dissolved concentrations of aluminium, arsenic, cadmium, chromium, cobalt, copper, lead, mercury, nickel, silver and zinc. This work was undertaken to establish a baseline for the Kimberley from which to assess local and regional changes in water quality in years to come and to ascertain whether the guideline trigger values from ANZECC & ARMCANZ (2000) are relevant to the region.

The results of this study indicate that the coastal waters of the Kimberley region are generally of very high quality. The concentrations of metals across the region were relatively low and met the guideline trigger values from ANZECC and ARMCANZ (2000) for a very high level of ecological protection (99% species protection) at the time of sampling.

Following a blowout at the Montara wellhead platform on 21 August 2009, petroleum hydrocarbons flowed effectively unabated into the Timor Sea, approximately 175 kilometres (km) from Western Australian coastal waters, until the leak was contained on 3 November 2009. This report presents findings of a petroleum hydrocarbons survey conducted in July 2010 as part of the response to the Montara incident.

The aim of this survey was to determine the petroleum hydrocarbon content of shoreline sediments and filter feeding organisms some eight months after the flow of hydrocarbons from the Montara wellhead platform was stopped in order to assess the intensity, extent and duration of potential Montara oil-related contamination. To this end, data were collected to allow direct comparisons with baseline data collected during an earlier survey in October 2009 (McAlpine et al. 2010). The July 2010 survey involved sampling shoreline sediments and intertidal rock oysters at seven Kimberley islands and two mainland promontory sites visited by McAlpine et al. (2010). Cultured pearl oyster tissue samples were also collected from the four pearl farms visited in October 2009 (McAlpine et al. 2010). There were no detectable concentrations of petroleum hydrocarbons found in any of the shoreline sediment or oyster tissue samples collected during this survey. This result was consistent with the findings of the baseline survey (McAlpine et al. 2010).

In view of the overall consistency of the results, spatial coverage of the surveys and the lack of evidence of any recent oil impacts at any of the sites, it is likely that if any oil from the Montara spill reached the coastal waters of the Kimberley region, the resulting impact on the coastal environment would have been transitory and at levels that could not be detected by the sampling methods used in these surveys. The values reported in this survey and the previous baseline survey are therefore considered to broadly represent readily-measureable natural background petroleum hydrocarbon conditions in this part of the Kimberley marine bioregion.

The findings of this survey as well as the 2009 baseline survey also suggest that natural petroleum hydrocarbon seeps in the Timor Sea do not appear to have a readily measureable chronic or residual effect on the quality of the Kimberley marine environment at the sites investigated.

These data will be of value to all stakeholders for assessing potential impacts of future development and monitoring the quality of the marine environment in the Kimberley bioregion.

A water quality survey was undertaken in December 2008 at two locations on the Western Australian Kimberley coast that were shortlisted as potential sites for the construction of an LNG processing precinct. Water samples were collected and processed to determine total suspended solids (TSS), chlorophyll a, b and c, ammonia, total phosphorous (P), total nitrogen (N), nitrate plus nitrite (NO3+NO2) and orthophosphate concentrations at selected sites across both study areas. The sampling program was designed to obtain a water quality snapshot of the early wet season.

Results indicate that chlorophyll a and c concentrations and total phosphorus concentrations were consistently higher in bottom waters at both sites, but highest at James Price Point. TSS concentrations in surface waters were found to be higher at James Price Point than at Perpendicular Head and total nitrogen concentrations were similar across all sites and depths.

As a result of this survey it was found that the default guideline trigger values from ANZECC & ARMCANZ (2000) for Australian tropical marine waters may not be relevant to the Kimberley region for chlorophyll a and total nitrogen concentrations, at least during the early wet season. In these situations the approach recommended in ANZECC & ARMCANZ (2000) is to derive site specific guideline trigger values using local reference sites or baseline data. However, fully characterising these waters would require a significant allocation of resources.

A survey was carried out to establish a quantitative baseline for petroleum hydrocarbons in seawater, shoreline sediments, intertidal filter feeders and cultured pearl oysters across the Kimberley bioregion.

This technical report comprises part of Appendix 4 of EPA Report 1359.

The report, on the avifauna, is part of a series of studies which assess the vertebrate fauna values of the Dawesville to Binningup study area. It was prepared for the EPA by John Dell and Bridget Hyder.

This technical report comprises part of Appendix 4 of EPA Report 1359. The report is a summary of the vertebrate fauna values of the Dawesville to Binningup study area for herpetofauna, avifauna, non-volant mammals and bats, together with a consideration of the overall significance of the study area for vertebrate fauna. It was prepared for the EPA by John Dell and Bridget Hyder.

This technical report comprises part of Appendix 4 of EPA Report 1359. The report, on the non-volant mammals, is part of a series of studies which assess the vertebrate fauna values of the Dawesville to Binningup study area. It was prepared for the EPA by John Dell and Bridget Hyder.

A report for the Department of Environment and Conservation as part of the Swan Bioplan Project. Authors:BJ Keighery, GJ Keighery, A Webb, VM Longman and EA Griffin (April 2008)

A survey of the Whicher Scarp was undertaken by the Departments of Environmental Protection and Conservation and Land Management together with the Wildflower Society of Western Australia (Inc.) over a period of more than 10 years. This work was completed as part of the Swan Bioplan Project to provide a more detailed knowledge of the conservation status of species and communities that occur in this area.

This report provides the results of a survey to determine the concentrations of a range of selected metal and organic chemicals in marine sediments under natural background conditions in the Midwest region and to ascertain the applicability the nationally-recommended sediment quality guidelines from the Australian and New Zealand Guidelines for Fresh and Marine Water Quality to the region. A set of sediment quality guidelines that could be applied to the marine environment off the Midwest coast is provided.