Over 200 Dublin householders' water supply has been declared clean today, after contamination was resolved.

The Environmental Protection Agency has signed off on the supply from the Stillorgan Reservoir in South County Dublin, after it underwent upgrades to lower the risk of Cryptosporidium.

It comes as Irish Water says 6,000 customers are currently on Boil Water Notices, down from a peak of 23,000 at the end of 2014.

Mark MaCauley from the company says the latest improvements are to some of the country's oldest water facilities:

Since 2008 homes supplied with water from the Sillorgan site have been at risk of contamination because of inadequate disinfection.

Irish water has introduced UV treatment to remove the contamination risk for these customers, and a recent audit showed them to be clean. 

At the start of 2014 close to 1 million customers were dependent on water supplies that were at risk of contamination. This number has now been reduced to 770,000 and the agency says more investment is needed to clear those risks. 

John Tierney Managing Director of Irish Water said the improvements would not have been possible before the utility was set up.