A mandatory order directing four Traveller families to immediately leave the site of waterworks in Kells, Co Meath, was made by Mr Justice Michael Peart yesterday.
Tom Clarke, counsel for Meath County Council, told the court there were genuine fears the town's water supply could be chemically contaminated.
He said that last Saturday the outer gate and an inner gate at the town's unmanned water treatment plant had been broken down by Travellers who had entered the site. Mr Clarke said a shed containing chemicals had also been broken into.
He told the judge that the treatment plant contained tanks and small reservoirs which allowed the addition of chemicals to make the water safe.
If the water supply was tampered with excess chemicals could get into the water and there would be a risk to the water supply to 6,000 people. The matter was made returnable for Thursday.