Almost 100 drinking-water samples had outside the allowable limit of lead, or an environmental pollutant.
According to Irish Water's most recent test results, seven properties had too much lead in their water.
Homes in Donegal, Cavan, Cork, Limerick, Roscommon and Kerry were all outside the allowable limit.
91 properties nationwide, had too many T-H-Ms, which some studies have linked to cancer.
Dr Michelle Minihan, from the Environmental Protection Agency, says long-term exposure to lead can cause serious harm: