A water treatment plant which supplies 150,000 homes in Dublin and Wicklow needs to have a new four and a half kilometre long tunnel to secure supplies in the region, the Environmental Protection Agency (EPA) has said.
The Vartry reservoir in Roundwood, Co Wicklow, is one of three large treatment plants put on the remedial action list by the EPA in their annual report on drinking water quality.
The Vartry reservoir was built in the 1860s when a tunnel was bored through granite rock from Roundwood to Newtownmountkennedy.
Last year Dublin City Council warned that the existing tunnel could “suffer a partial or total collapse at any point in time”.
The EPA’s office of environmental enforcement programme manager Gerard O’Leary said the cost of a new tunnel could be in the region of between €20 and €30 million.
He said the inclusion of the Vartry Reservoir on the list of plants needing remedial action was a precautionary one and there was no present threat to the quality of the water supplies there.
The other two major plants needing remedial action are the Lee Road in Cork which is built on a flood plain and Staleen which supplies East Meath and Drogheda.
Between them the three plants supply water to approximately 500,000 people.
The EPA says the number of E. coli incidents has reduced year-on-year because of better monitoring of supplies which were introduced in 2007. The number of reported incidents has reduced from 52 to 20 in that timeframe.
Mr O’Leary said the reduction in incidences brought Ireland in line with countries such as the UK and the Netherlands who are widely regarded as having excellent standards of water quality.
Mr O’Leary admitted that local authorities were very good at monitoring water supplies but poor at making the information available to the public.
A ministerial directive, published by the former Minister for the Environment John Gormley, allows for the public to have access to information about the quality of the water supply.
To date 19 local authorities have published some or all of their drinking water quality data, but only Mayo and Kerry county councils were found to be providing adqeuaate quality information.
“We’re keen to put a drive out because it is a big public health issue,” said Mr O’Leary. “Only two out of 34 local authorities have produced information that we are happy with.
“We intend in the future to have further monitoring of local authority websites. We want to drive an improvement on up-to-date information that the public can access easily.”
