A mercury contamination expert has urged the NSW Government to crack down on the chemical company Orica, saying there are dangerous levels of mercury around its Port Botany site in Sydney.
The plant is almost 60 years old and Orica says its testing for mercury always returns results below the levels set by the Environment Protection Authority (EPA).
However, mercury expert Andrew Helps says there "is a very serious problem" with sediment that is contaminated with mercury in an estuary near the plant.
Mr Helps, who runs a company that specialises in clearing sites of mercury contamination, says the tests run by Orica barely touch the surface of the problem.
"They have not and never have addressed the issues of what mercury left the site, either gaseously or as a metallic form in the waterways," he said.
"There's a very serious problem with mercury and incidentally chromium in the sediment in Port Botany - 184 parts per million down in the estuary below in the Orica plant.
"What concerns me about Port Botany is very clearly the sediments are highly contaminated with mercury and there's a large population of people there who fish recreationally and eat them." People living nearby are say the tests run by Orica may not be comprehensive enough because they do not look at off-site contamination.
Chantal Snell lives a kilometre away from the Orica plant and says she feels "quite scared" that she may be unwittingly exposing her children to chemicals.
"I'm frightened as to whether I'm putting my children's health at risk," she said.
Orica spokesman Simon Westaway has defended the company's efforts but has not ruled out further tests.
"If there's a desire by the EPA for us to look at more testing, we'll look at that," he said.
"We're also assessing, based on the latest commentary coming out of the community, that they want to see some further testing.
We've taken that on board and we'll be making some decisions in the near future as to, if more testing occurs, where it will occur, and how we'll go about it." The NSW Land and Environment Court began hearing a case against Orica in December over incidents at its Kooragang Island site in Newcastle and at its site at Port Botany.
The most high-profile incident came in 2011 when a plume of the carcinogenic chemical hexavalent chromium was sent over the Newcastle suburb of Stockton.