Fingal County Council is investigating the suspected contamination of a stream bordering a new housing estate near Swords which has been blamed for the fatal poisoning of a bullock on a neighbouring farm.
The stream is said to have been contaminated by sewage seeping into the water from a septic tank on the site of an illegal tip-head at Killeek, St Margaret's.
The council recently erected a barrier to prevent the water from flowing into the River Ward, or onwards to a local reservoir.
But, according to the local farmer whose bullock has died, this has merely created a new health hazard.
Mr Liam Lumley, whose 30-acre farm borders the stream,said the stagnant water was now "a breeding ground for disease".
Causing particular concern was the fact that a 24-house estate was due to open on neighbouring lands within the coming weeks.
"The first place the kids will head for is where there is water, or a stream. It's a terrible thought, but if it killed a big, 27-month-old bullock, God knows what it would do to a young kid who went down there," said Mr Lumley.
According to his vet, the bullock died of E-coli and salmonella poisoning, believed to have come from sewage in the water. The animal was dead within five days of Mr Lumley finding him ill earlier this month.
"I couldn't believe an animal would die that quickly," he said.
Mr Lumley said he had been campaigning since January 2000 to get the council to do something about the dump. Repeated letters to the council were ignored, he said, and last December when hospital waste was discovered at a different site in north Dublin, the council seemed to suggest it was unaware of the Killeek dump.
"They are afraid of their lives of what is going to be found if they clean it up," said Mr Lumley, who said he picked out syringes from the tip-head several years ago, and informed the council of this fact.
"The dam they built is an insult to any man's integrity. There'll be effluent from the dump running into the ditch until the gods call us," he added.
A spokesman for the council said samples had been taken from the stream indicating it had been contaminated, and that the source was a septic tank. "We will be formally writing to the owner asking him to rectify the problem and clean up the ditch, and if we don't succeed we will carry out the work ourselves and then levy the costs back to the polluter."
As for the barrier which the council installed earlier this year, he said it may have allowed "local pockets" of pollutant matter to build up but, he said, it did offer some drainage from the stream. Tests had shown, he noted, that the River Ward had not been polluted by the effluent.
Of the dump itself, he said since it had come to the council's attention no more illegal tipping had taken place there, and its owner had been co-operating with the local authority. Samples had been taken indicating there was mainly construction and demolition waste on the site, he said. But "the site remains under investigation, and further tests will be carried out."
Mr Lumley criticised the council for allowing the dump to stay. Since it finally acknowledged its presence last December, he said, "absolutely nothing has happened except I've lost a bullock. They've been saying for years they'll prosecute but still nothing's happened."
A Labour Party councillor, Mr Tom Kelleher, said yesterday he was particularly concerned at the prospect of children moving into the area while there was any potential health hazard.
The council spokesman said it expected to open the new housing estate at River Meade before the end of next month. Delays in completing the scheme were unconnected the pollution, he said.
The owner of dump was unavailable for comment yesterday.
