A NSW Office of Environment and Heritage risk assessment of Lake Macquarie pollution levels warned people should not eat mud crabs from the lake on a weekly basis due to high levels of a heavy metal linked to kidney and liver failure, say documents obtained under freedom of information.
The consumption of most seafood from the lake should also be restricted, particularly for children, because of high levels of a second heavy metal, the OEH risk assessment concluded.
The warnings appear in a Hunter Community Environment Centre report released today, Out of the Ashes, which links ongoing heavy metal pollution levels in the lake system to years of coal ash accumulation from the ageing Eraring and Vales Point power stations.
The report calls for regulatory reforms and much tougher regulatory action to address what it described as the state's "mounting toxic waste problem".
"Our water and sediment sampling found levels of arsenic, lead, selenium, copper, nickel and zinc above the recommended concentrations for healthy marine ecosystems," environment centre coordinator Jo Lynch said.
"The water samples also contained levels of aluminium, iron and manganese above those recommended for marine waters used for recreational purposes. The discharge of these heavy metals into Lake Macquarie really can't be reduced without removing the coal ash from the shores of the lake."
The environment centre conducted water sampling at key locations in the lake, commissioned laboratory analyses, researched coal ash management and composition, reviewed environmental licences and used information and documents acquired under freedom of information law from the Environment Protection Authority (EPA) and Office Environment and Heritage (OEH), the centre said in a statement released today.
The OEH risk assessment recommended people should not eat mud crabs from the lake on a weekly basis due to high cadmium concentrations. Cadmium is linked to liver and kidney damage and failure. High selenium concentrations led the OEH to warn that seafood consumption from the lake should be restricted, particularly for children. Selenium is linked to liver, kidney and heart problems.
Report author Paul Winn said aquatic animals and birds would bear most of the impacts of the high heavy metal concentrations because of their sensitivity to heavy metal accumulation, but "people who eat fish and invertebrates from the lake are also at risk".
Mr Winn and Ms Lynch called for urgent regulatory reforms over coal ash - the waste from coal-fired power stations containing heavy metals produced by power generation that is collected in ash "dams" close to Lake Macquarie.
"Coal ash is a hazardous waste and its regulation needs urgent reform," Ms Lynch said.
"This reform needs to consider the whole life cycle of coal burning, ash production, handling, storage, transport, and reuse. As it stands, this hazardous material is allowed to be shipped around the country with no government agency knowing where it is being sent or what it’s being used for.”
Mr Winn said the exclusion of coal ash from a number of hazardous waste and pollution laws, to encourage its re-use in the construction industry, had failed to incentivise its re-use and presented a risk to communities.
Ash from coal-fired power stations makes up 20 per cent of Australia's total waste stream, but less than 20 per cent is being beneficially re-used in mine site rehabilitation or fixed in concrete. Coal ash is instead being used in agricultural soil, fertilisers and potting mixes which pose risks of contaminating groundwater or entering the food chain, the Hunter Environment Centre report said.
"Regulatory amendments are required that put the financial burden for safe disposal of coal ash back onto the power station operators," Mr Winn said.
"Incentives are required that encourage environmentally responsible coal ash re-use to remove a key source of heavy metal contamination from the shores of Lake Macquarie, reduce a key source of greenhouse gas pollution, and encourage new on-site enterprises that will provide new jobs for displaced workers when these aging facilities are finally decommissioned.”
The environment centre report was released less than two months after residents near Vales Point power station learnt asbestos had been found in demolition waste dropped at the power station's huge coal ash dam site.
It also comes after reports in January that coal ash with elevated heavy metal levels could have left AGL’s Bayswater and Liddell power station sites since 2015, breaching environmental orders.
The Office of Environment and Heritage and Environment Protection Authority have been contacted for comment.