Spraying grass? Adhere to good practice

MCPA accounted for 63% of all pesticide exceedances in Irish water supplies in 2019. Fluroxypyr and 2-4D were among the other common exceedances.

In a statement Irish water commented: “Great care must always be taken to protect drinking water supplies wherever pesticide use is considered necessary, particularly if using products for grassland weed control containing substances such as MCPA, fluroxypyr and 2-4D.”

MCPA, fluroxypyr and 2-4D have all been detected in drinking water supplies across Ireland and the detected levels exceed the legally permitted limit for pesticides in drinking water, which is set at an extremely low value (equivalent to one drop in an Olympic-sized swimming pool).

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 to all users of pesticides, including the farming community, greens keepers, grounds keepers and domestic users.

This is to ensure that best practice measures to protect drinking waters are always followed.

6 regions persistently affected

Six regions across the country have had persistent exceedances of pesticides. According to the group, “there are currently six priority catchment areas of particular concern where exceedances of pesticides are persistent”.

These catchments include:
  • Longford Central (MCPA);
  • Newcastlewest (MCPA), Belturbet (MCPA);
  • Cavan RWSS (MCPA);
  • Clonroche (Bentazone);
  • Newport (Glyphosate/MCPA).

There are also 20 separate water supplies, which are also a focus for targeted actions, as there is a pattern of detections in these areas which indicate a risk of persistent pesticide exceedances.

Best practice

Professional pesticide users should be the only people applying these products and should carefully consider how these products may access water courses via rainwater drains, drainage channels or other means before application.

One single drop of pesticide is enough to breach the drinking water limit in a small stream for up to 30km. This clearly highlights the level of care needed to protect drinking water sources.

Best practice should always be followed, but particularly near watercourses, lakes and rivers used as drinking water sources.

If pesticides have to be used, the basic steps in reducing risks are (provided by the NPDWAG):
  • Choose the right pesticide product (note that products containing MCPA are not approved for use in weed-wipers);
  • Read and follow the product label;
  • Determine the right amount to purchase and use;
  • Don’t spray if rain is forecast in the next 48 hours;
  • Make sure you are aware of the location of all nearby water courses;
  • Comply with any buffer zone specified on the product label to protect the aquatic environment. Mark out the specified buffer zone from the edge of the river or lake or other water course;
  • Never fill a sprayer directly from a water course or carry out mixing, loading or other handling operations beside a water course;
  • Avoid spills, stay well back from open drains and rinse empty containers three times into the sprayer;
  • Store and dispose of pesticides and their containers properly.

The video below might provide some useful information on the application of MCPA.

Rush control guidance

The Department of Agriculture, Food and the Marine (DAFM) has developed new guidance on the sustainable management of rushes based on containment or suppression to minimise the use of pesticides.

More information is available here

‘MCPA accounted for the majority of pesticide exceedances detected’

Andrew Boylan, Irish Water’s regional drinking water compliance specialist, stated: “At a time of significant challenges for farmers and other essential workers managing land, we are asking everyone to continue to be mindful to protect the water bodies.

While MCPA accounted for the majority (63%) of pesticide exceedances detected nationally in public water supplies during 2019, Irish Water routinely tests for a wide range of pesticides and is closely monitoring the situation for pesticides other than MCPA.

“Irish Water is continuing its extensive investment programme to safeguard the water supply for homes, farms and businesses in Ireland.

Providing safe, clean drinking water for all is our first priority. In Ireland, the majority (82%) of drinking water supplies come from surface water sources such as rivers, lakes and streams.

“Such supplies are vulnerable to contamination from land and animal run-off. Irish Water asks users of pesticide products to consider the vulnerability of the drinking water supply to pesticide contamination and the importance of this supply to the local community.”

Dr. Aidan Moody, chair of the NPDWAG, added: “A lot of good work has been done and progress has been made. The continued engagement of all stakeholders, working in partnership, is needed to make further progress.

“Users of pesticides should always consider in the first instance if there are alternative non-chemical weed/pest control methods that would be feasible. If pesticides have to be applied users must make sure that they are aware of and follow best practice measures to protect water quality.”