Exceedances of the pesticide MCPA has been detected in public drinking water supplies in Co Cavan.
Following routine sampling this month, exceedances were found in the Arvagh and Belturbet water supplies.
MCPA is an active substance that is present in many commonly used herbicide products that control the growth of thistles, docks and rushes.
The Belturbet water supply abstracts raw water from the River Erne, which is vulnerable to runoff from land.
Meanwhile, the Arvagh water supply is supplied by Erne Valley Group Water Scheme and abstracts raw water from Garty Lough.
While the HSE has concluded that the levels seen do not represent a threat to public health, Irish Water says it's "imperative that users of pesticides are mindful of best practice and seek out alternatives".
