Written Answers. - Dublin Sewage Sludge Dumpsite.

Ivor Callely


52 Mr. Callely asked the Minister for the Marine the effect, if any, the sewage sludge dumpsite in the Dublin bay area has on the marine environment; the quantity of sludge dumped on a daily and weekly basis; and if he will make a statement on the matter.

In March 1991, following extensive scientific studies of the site, the authorised sewage sludge dumpsite was relocated from its previous location two miles off Howth Head to a new site southeast of the Kish Lighthouse about ten to 14 miles offshore. Some localised environmental impact had been identified in the vicinity of the old site.

A comparative survey of marine life on the seabed at both the new site and the disused Howth Head site was carried out in 1993 to assess the impact of the change of dumping location on the marine environment. The range of marine life present at the new site showed that it is not suffering from any pollution. Under present disposal conditions environmental problems are not anticipated at this location which will continue to be monitored. The assemblage of marine life at the former site confirmed that it was recovering well from the earlier localised pollution.
Dublin Corporation currently holds an annual permit under the Dumping at Sea Act, 1981, and is permitted to dispose of up to a maximum of 340,000 tonnes of sewage sludge at sea during 1994 with a maximum of 6,000 tonnes to be dumped per day. Three trips are normally made to the site per week with approximately 2,000 tonnes being disposed of on each trip. The dumping of sewage sludge at sea will be prohibited internationally under the Oslo Convention from 31 December 1998. Alternative land-based methods of treatment and disposal are being developed by Dublin Corporation with that timeframe in mind.