A FORMER limestone quarry in north-east England is described as a 'source of potential hazard' in a consultant's report.
South Tyneside council asked High-Point Rendel to carry out a site investigation at Trow Quarry near South Shields after community concerns caused by, among other things, the occasional appearance of asbestos on a nearby beach.
After its closure the quarry was used as a landfi ll by the Port of Tyne Authority. Waste disposal stopped in the mid-1980s and the area was levelled and landscaped to create a recreation area for the public.
High-Point Rendel's report, produced in January, says the landfill contains arsenic, mercury and cyanide as well as benzo(a)pyrene and methane.
It states: 'The greatest risk to human receptors is posed by concentrations of benzo(a)pyrene, and asbestos within the made ground, which exceeded derived or published UK guidelines. Cyanide also poses a risk.' High-Point Rendel assistant technical director Chris Sakalas said: 'The benzo(a)pyrene is significant as it is one of the more toxic polyaromatic hydrocarbons.' He added: 'The risk of the methane is that it could migrate through the strata and potentially enter structures. This is very unlikely on this site but you can't be too safe with residential properties nearby.' Some were within 250m of the quarry, he said.
The report says the 'quarry landfill appears not to have a lining to prevent leachate from entering the groundwater system, therefore implications of leachate migration require careful consideration'.
Ian Rutherford, leader of the council environmental protection team, said the three main concerns were gas migration, coastline erosion and protection of recreational site users. But he said the report had reassured him there was no immediate risk to people using the site.
Tackling coastline erosion is a priority because the cliffs forming one edge of the quarry are being eroded by the sea. Landfill material is finding its way on to the coastline around nearby Graham Sands.
'We want to get a coastal defence measure to prevent the sea cutting further into the landfill, ' Rutherford said.
A second High-Point Rendel investi ation was due to begin as GE went to press. This will provide an updated risk assessment and may include remediation proposals. It will also assess the impact of contaminants on groundwater.
Daniel Gray, South Tyneside council senior environmental protection offi cer, said: 'We're waiting for the results of the second round of investigations and we need to see if the contaminants pose a risk to people. Quite a lot of them don't, but we're investigating gas migration and benzo(a)pyrene at the surface.' Sakalas said in his opinion the site did not pose a threat. 'The materials are deep enough that they should not come into contact with users of the site. If we thought it was dangerous we would have said close it off to public access'.
The second report should appear towards the end of this month.