Water to be sampled on a weekly basis for MCPA

Water supplies will be tested once a week for MCPA as part of a new industry-led product stewardship scheme.

According to the Department of Agriculture, Food and the Marine, the scheme will monitor and sample water in four priority catchments from March to October 2018.

During busy spraying periods (April and May) sampling for MCPA in water supplies will be carried out on a weekly basis. Sampling will be carried out every two weeks outside of this time.

Routine sampling

Sampling will take place as part of the routine sampling programme carried out by the local authorities on behalf of Irish Water. Phenoxy acid based herbicides such as MCPA and 2, 4-D will be tested for.

Sampling will focus on minor rivers and streams before they flow into a “major” water course. If improvements are not seen in water samples then further restrictions may be implemented by the Department of Agriculture on the use of these herbicides.

What has been detected?

Low level detections of grassland herbicides have been found in drinking water supplies in the last number of years. MCPA is the chemical of most concern. Provisional figures for 2017 indicate that there were just over 150 exceedances, of which MCPA accounted for 119 notifications. This is an increase from 2016, when there were 137 notifications.

49 water supplies were affected in 2017, up from 42 in 2016. The Department of Agriculture has stated that, to date, the breaches have not given rise to health concerns.

Monitoring has been more intensive in recent years and some of the higher levels may be because product label guidelines are not being followed.

Surface waters (rivers and lakes) account for 80% of drinking water supplies in Ireland. This makes supplies vulnerable to contamination, particularly from pesticides.

Actions already taken to reduce levels:
  • Rates of all “straight” herbicides based on MCPA were reduced;
  • A 5m buffer strip was made mandatory;
  • It was made illegal to apply a “straight” MCPA-based product between the months of October and February;
  • Use of MCPA in a knapsack sprayer or weed-wiper was also made illegal;
  • Good Plant Protection Practice guidelines were also amended to make it illegal to fill sprayers directly from water courses;
  • The Sustainable Use of pesticides Directive was introduced.

Four priority catchments

Sampling will be carried out in four priority catchments – identified by Irish Water and the EPA – for two years. This may be extended to other areas after the two year period.

The four priority catchments are:
  • Longford Central (Lough Forbes);
  • Troyswood, Co. Kilkenny (River Nore);
  • Abbeyfeale, Co. Limerick (River Feale);
  • Newcastlewest, Co. Limerick (River Deel).

The efforts to reduce the incidence of these detections are being coordinated by the National Pesticides and Drinking Water Action Group. 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.