The quality of local authority water supplies is far higher than that of group and private water schemes, with 92 per cent meeting a satisfactory standard. The Environmental Protection Agency nonetheless cited many problems during 1998 throughout the water supply network:
Cavan County Council: numerous breaches of the limits for aluminium, colour and turbidity. Problems likely to persist until deficient/overloaded plants are upgraded/replaced.
Clare County Council: many cases of excessive fluoride; three cases of high lead levels.
Cork County Council: problems with high aluminium levels in some northern areas and in isolated cases elsewhere. High nitrate in Cahermore and Coppeen. Donegal County Council: group supplies "still poor".
Dublin Corporation: excessive coliform bacteria levels confined to Leixlip supply.
Galway County Council: Severe problems with public supplies in Roundstone and Kilconnell. Distinct disimprovement in many group supplies, with a lot showing "very significant faecal contamination".
Kerry County Council: deterioration of public supplies due mainly to coliforms.
Kilkenny County Council: "numerous" cases of excessive fluoride.
Mayo County Council: most supplies of good quality but the remainder "distinctly unsatisfactory" at times, notably Balla, Kilmaine, Kiltimagh and New port.
Monaghan County Council: aluminium levels in Inniskeen and Rockcorry on occasion are "gross".
Sligo County Council: on-going problem with faecal bacterial contamination of group schemes.
Wexford County Council: problems with non-faecal coliforms in some public supplies.
Increased attention is being paid to the occurrence of trihalomethanes, which include a suspect carcinogen, due to problems when chlorinating coloured water. A few cases where guidelines were exceeded were found in some supplies in counties Donegal, Galway, Meath, Laois and Louth.