Dáil Éireann díospóireacht -
Thursday, 18 May 1995

Vol. 453 No. 2

Written Answers. - Environmental Impact of Dumping of Sewage Sludge.

Ivor Callely

Ceist:

128 Mr. Callely asked the Minister for the Marine the studies, if any, that have been carried out to investigate the pollution and environmental effect that sewage sludge dumping at Kish Lighthouse has had on marine life and the sea water generally; and if he will make a statement on the matter. [9111/95]

Ivor Callely

Ceist:

129 Mr. Callely asked the Minister for the Marine the environmental impact and effect sewage sludge dumping has had on the immediate vicinity of the old sewage dump site two miles off Howth Head; and if he will make a statement on the matter. [9112/95]

Minister for the Marine (Mr. Coveney)

I propose to take Questions Nos. 128 and 129 together.

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 south-east of the Kish Lighthouse about ten to 14 miles offshore. Some localised environmental impact had been identified in the vicinity of the old site.

Monitoring of the status of the new sewage sludge dumpsite and the recovery status of the old dumpsite close to Howth Head was carried out in 1993. At the new dumpsite the monitoring revealed that there was no significant impact on the sediment fauna in the area while at the old dumpsite the monitoring revealed an increase in the number of benthic faunal species in the area, suggesting good recovery. According to international practice, monitoring of such sites is recommended at approximately five year intervals and the sites will be resurveyed in 1998. Under present disposal conditions environmental problems are not anticipated at the new site.

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 1995 with a maximum of 2,000 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.