THE pollutant involved in the Dodder River fish kill on Sunday was probably an industrial chemical but laboratory tests have yet to be concluded. A factory is believed to have been the pollutant's source.
Mr Pat Roddy, a water pollution inspector with Dun Laoghaire/Rathdown county council, said "a lot of samples" of the polluted water had been sent for testing, and the pollutant "seemed like an industrial chemical". He described the kill as "a wipe out" which was "very extensive".
The county council is confident that its investigation into the source of the pollution will have "a satisfactory conclusion".
Standing orders at the planning, development and tourism committee meeting of Dun Laoghaire/Rathdown county council yesterday were suspended on a proposal of My Richard Greene (Muintir na hEireann) to allow for a discussion on the kill.
Officials told councillors of their confidence that the polluters would be identified soon and assured them that a prosecution would follow.
The pollutant entered the Little Dargle/Churchtown stream about three quarters of a mile from where it joins the Dodder at the rear of Mount Carmel hospital a spokeswoman for the Eastern Regional Fisheries Board said.
The pollution of the Dodder continued for about another three quarters of a mile, at least as far as Milltown.
The Fisheries Board believes that, though the kill was not reported until 11 a.m. on Sunday, the spillage most probably took place nine to 10 hours earlier. They believe the source of the spillage was most likely a factory.
Thousands of fish were killed, including trout weighing two to three pounds, eels and minnows, according to the board.
From Milltown onwards, however, fish life in the Dodder appeared unaffected.
On the Little Dargle/ Churchtown stream, everything was as normal upwards from the point where it disappears into a culvert towards the Dodder at Nutgrove.
As recently as the June bank holiday weekend there was another industrial discharge into the Dodder system but it was not severe enough to kill the fish life.
The Progressive Democrats spokeswoman on the Environment, Ms Mairin Quill, has called on the Minister, Mr Howlin, to inform the Dail what specific action has been taken in respect of last year's 75 fish kills.
Pointing out that the Dodder fish kill had occurred 10 days after two major kills in Cork, she said it was "logical to conclude that the levels of fines being imposed under the law at present are not acting as a sufficient deterrent".