A Government minister has voiced his opposition to a super sewerage plant proposed for his constituency.
Health Minister James Reilly fears a systems failure could result in large amounts of raw effluent being be pumped into the Irish Sea, impacting on shellfish beds, the environment and thousands of people living in Fingal.
Dr Reilly also warned any sewage should be treated to advanced levels to make waste water as clean as possible for discharge or recycling.
"Whatever solution emerges, it is my opinion that tertiary treatment should be included, in order to treat the waste to a higher level and produce water that might be suitable for certain purposes," he wrote to constituents.
Nine possible sites across Fingal have been earmarked for a plant to treat sewage from across Dublin and parts of Kildare and Meath.
A preferred site is due to be selected by Greater Dublin Drainage and Fingal County Council before the end of the year. The outfall pipe will be off the east coast between Rush and Portmarnock.
Dr Reilly maintained each of the nine sites are unsuitable for a super plant, particularly in Ballyboughal and the towns of Rush and Lusk.
He said he has raised the issue with Environment Minister Phil Hogan and met and backed members of Reclaim Fingal Alliance, who represent the communities of Fingal opposed to the project.
"I am aware the people of Skerries, Loughshinny and Rush are worried about the effects of the outfall pipe in their area," he continued.
"It could have significant impact on shellfish beds in that area, particularly if there was a failure in the treatment plant or pumping stations and large quantum's of raw effluent were emitted into the sea.
"These plants will adversely impact on thousands of people in the Fingal."
Some 10,000 letters of objection have been submitted against the scheme by environmentalists, farmers and residents who fear the plant will have a detrimental effect on farming and horticulture in the heart of Ireland's market garden and destroy the coastline, which has several protected species.
Brian Hosford, chairman of the Reclaim Fingal Alliance which is fighting for smaller, locally-based plants, said he welcomed support of a Cabinet member.
"The campaign has shown great success in attracting support across communities and from all public representatives, including the Minister of Health," he added.
"We look forward to working closely with him in achieving our aim."
A spokeswoman for the Greater Dublin Drainage Project said a new regional plant will be needed by 2020 to secure long-term public health, and the social and economic future of the Greater Dublin area, when the existing regional waste plant at Ringsend will have reached full capacity.
"The decision on the location of the vital new waste infrastructure will be made later this year following further study," she said.
"If tertiary treatment is required it will be included. The EPA will set the terms of the discharge licence requirements."