Excess levels of pesticides found in Co Cork drinking water sources

FARMERS in Cork have been reminded of the importance of adhering to strict guidelines when spraying pesticides on their land following detections of the MCPA herbicide in drinking water sources.

While Irish Water has insisted the excess levels of pesticide, including those found in the Macroom water supply scheme in 2017, posed no threat to public health the, company has said it was “imperative” that farmers and pesticide users were mindful of best practice when spraying their lands.

The company said that it was working closely with the National Pesticides and Drinking Water Action Group (NPDWAG) in an effort to reduce the number of incidences where excess levels of pesticides are discovered.

Irish Water’s regional drinking water compliance specialist, Deirdre O’Loughlin, said the company was continuing to invest extensively across the country to improve water and waste-water services.

“Providing safe clean, drinking water for all is our first priority. In Ireland, the majority (82%) of drinking water supplies come from water sources (rivers, lakes and streams) and such supplies are vulnerable to contamination from land and animal run-off,” said Ms O’Loughlin.

She said that number of supplies across Cork had seen the herbicide MCPA detected over the past two years, “albeit mostly at very low levels.”

“MCPA is used mainly for eradicating rushes, a problem for many years on Irish farms and one that looks like continuing for many years to come. It is also found in other weed killer formulations used by gardeners and growers, so its use is quite widespread.”

Drinking water monitoring results for Ireland have shown that a number of pesticides commonly used on grassland, such as MCPA, are being detected more frequently.

Dr Aidan Moody, chair of the NPDWAG, said it was important that a concerted approach was taken in addressing the issue among all stakeholders and that all pesticide users were aware of the steps that must be taken to protect water quality.

He said just a single drop of pesticide had the potential to breach the drinking water limit in a small stream for a radius of up to 30 kilometres.

“This clearly highlights the potential risk facing many of Ireland’s drinking water sources. In the modern era, the use of pesticides has played a central role but the effects of this can be far reaching and more and more detections of pesticides in drinking water are being found across the country,” said Dr Moody.

“MCPA, which is commonly used to kill rushes on wet land, is the main offender, and careless storage, handling and improper application means it ends up in our drinking water,” he warned.