Irish Water has reported that exceedances for pesticides continue to be detected in drinking water supplies around Ireland – the water company said they are being picked up in drinking water because the water courses it abstracts from have been contaminated.

The presence of the pesticides may be as a result of spraying activities in land close to water courses, inappropriate storage / handling of pesticide product, or even illegal dumping of pesticide containers.

The legal limit for pesticides in drinking water is so low that even the foil cap from a pesticide container is enough to cause an exceedance in a 30km stretch of stream.

While the pesticide levels being detected do not pose a health risk, Irish Water said they are nevertheless undesirable and ideally should be as close to zero as possible.

Irish Water is working in partnership with a range of organisations involved in the National Pesticides and Drinking Water Action Group (NPDWAG) to provide advice and guidance to all users of pesticides.

Efforts to reduce the incidence of the detections are being coordinated by the NPDWAG. This group is chaired by the Department of Agriculture, Food and the Marine. All of the key stakeholders are represented in this group and include other Government departments and agencies; local authorities; industry representative bodies; farming organisations; water sector organisations; and amenity sector organisations.

MCPA is main pesticide being detected

Recent drinking water monitoring results for Ireland show that a number of pesticides commonly used such as Bentazone, MCPP, MCPA, Clopyralid and Fluroxypyr, are being detected more frequently.

One of the main pesticides being detecting is MCPA - the product is mostly used to control growth of rushes which typically grow in wet, poorly drained land. The Department of Agriculture, Food and the Marine (DAFM) has developed new guidance on the sustainable management of rushes.

Exceedances for the pesticide MCPA have been detected in the public drinking water supplies in two different areas of Monaghan. Following routine sampling of drinking water supplies the exceedances were recorded in the Emyvale and Glaslough public water schemes that are supplied from the Glaslough Tyholland Group Water Scheme.

Dr Pat O’Sullivan, Irish Water’s Regional Drinking Water Compliance Specialist said:

“In Co Monaghan, the exceedances of the drinking water regulations for MCPA were noted in these supplies following routine sampling in August. While the HSE has advised that the levels seen do not represent a threat to public health, it is however undesirable and it is therefore imperative that users of pesticides are mindful of best practice when spraying their lands. These are the first exceedances recorded in 2020 for the schemes with three recorded exceedances in 2019.”

Dr Aidan Moody, DAFM and Chair of NPDWAG commented:

“The continued engagement of all stakeholders, working in partnership, is needed to tackle this issue. Users of pesticides should make sure that they are aware of the best practice measures that should be followed to protect water quality.”