THE ‘Torrey Canyon’ quarry is again being cleaned up by Public Services.

Since 1967, the Chouet headland quarry has stored contaminated oil and water washed ashore when the supertanker ran aground off the Isles of Scilly.

Although several feet of oil was removed in the 1990s, more has been released from bottom sediment.

In May last year, the department started to treat the oil using a bio-remediation technique. A mixture of micro-organisms and enzymes break down oil and produce carbon dioxide and water.

By the end of summer 2008, the oil was cleared. However, when the quarry was used as a water store to extinguish the underground hotspot at Mont Cuet, it disturbed more oil from the bottom sediment. The bio-remediation process is being used again and it is expected to rid the quarry of oil if the treatment is extended over the next year.

It is also believed, as with many former quarries in the area, that unexploded ammunition left after the Occupation was dumped there but should not pose any risk while it remains under water.

The GSPCA reported earlier this year that it has regularly to attend the quarry to rescue birds trapped in the oil. The charity has been lobbying the States to remove it for 10 years.