14 October 2019 Go back to News
Pesticides detected in drinking water supplies across Ireland
Farmers and other users urged to use best practice when spraying pesticides
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 2,4-D. These substances and others have been detected in drinking water supplies across Ireland. While there is no threat to public health, the detected levels sometimes exceed the legally permitted limit value for pesticides in drinking water, which is set at an extremely low value (equivalent to one drop in an Olympic-sized swimming pool).
The pesticide MCPA has been detected in the Fanad East Public Water Supply in Co Donegal for the first time since Irish Water began sampling for pesticides in 2016. The Fanad East supply has now been placed on the Environmental Protection Agency’s (EPA’s) watch list for pesticides due to two exceedances for MCPA detected in September and October. The supply will remain on the watch list until one full season (April-Nov inclusive) of at least monthly compliant results is obtained and submitted to the EPA.
There have been eight detections of pesticides in the Nore catchment in the past three weeks. The majority of these detections relate to the pesticide MCPA, but there have also been detections of the pesticide 2,4-D and 2,4-DB. Supplies such as the Kilkenny City/Troyswood Water Supply are vulnerable to contamination from land and animal run-off. Irish Water asks users of pesticide products in the River Nore catchment to consider the vulnerability of the Kilkenny City/Troyswood water supply to pesticide contamination and the importance of this supply to the local community. The Kilkenny City/Troyswood Water supply is on the action list and while the pesticide levels detected in the Kilkenny City/Troyswood Water supply do not pose any immediate risk to health, it is imperative that users of pesticides are mindful of best practice when spraying their lands.
The pesticide MCPA has been detected in the Tully-Tullycross Public Water Supply in Co Galway following a year of clear sampling results. The Tully-Tullycross supply was on the Environmental Protection Agency’s (EPA’s) watch list for pesticides due to persistent exceedances for MCPA. However, following a year of clear sampling results, the file was removed, but the EPA has notified Irish Water that it will be put back on its watch list following this latest exceedance.
There have been 20 detections of pesticides in the Deel catchment in the past three weeks, while the Feale catchment has seen six detections in the same period. The majority of these detections relate to the pesticide MCPA, but there have also been detections of the pesticide 2,4-D and 2,4-DB. The Deel and Feale river catchments are among eight priority catchment areas of particular concern around the country where exceedances of pesticides are persistent. All of these areas are being prioritised for action by members of the NPDWAG.
The Navan/Mid Meath water supply in Co Meath is on the watch list and while the pesticide levels detected in the Navan Mid Meath water supply do not pose any immediate risk to health, it is imperative that users of pesticides are mindful of best practice when spraying their lands. Fluoroxypyr and trichlopyr exceedances were recorded in the supply in June, the first exceedances in 2019 to date. Supplies such as these are vulnerable to contamination from land and animal run-off. Irish Water asks users of pesticide products in the River Blackwater and Boyne catchments to consider the vulnerability of the Navan/Mid Meath drinking water supply to pesticide contamination and the importance of this supply to the local community.”
Ardee, Cavanhill and Tallanstown supplies in Louth are on the watch list and while the pesticide levels detected in these water supplies do not pose any immediate risk to health, it is imperative that users of pesticides are mindful of best practice when spraying their lands.
National Pesticides and Drinking Water Action Group (NPDWAG)
Irish Water, working in partnership with a range of organisations involved in the National Pesticides and Drinking Water Action Group (NPDWAG) is appealing to all users of pesticides including the farming community, sporting organisations and domestic users, to ensure that best practice measures to protect drinking waters are always followed.
There are currently eight priority catchment areas of particular concern where exceedances of pesticides are persistent. These areas cover the Lough Forbes catchment in Co Longford, the River Deel and River Feale catchments in Limerick, the Clonroche Water Supply in Wexford, the River Nore in Kilkenny, Lough Acanon in Cavan, the River Erne in Cavan and Newport in Co Mayo. All of these areas are being prioritised for action by members of the NPDWAG.
Watch list currently comprising over 20 supplies
There is a separate watch list, currently comprising over 20 supplies, which is also a focus for targeted actions, since the pattern of detections in these areas indicates a risk of persistent pesticide exceedances. While pesticide levels detected do not pose any immediate risk to health, it is imperative that users of pesticides are mindful of best practice when spraying their lands.
Efforts to reduce the incidence of detections are being coordinated by the NPDWAG which 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.
Providing safe, clean drinking water for all is our first priority
Commenting, Dr Pat O’Sullivan, Irish Water’s Regional Drinking Water Compliance Specialist, said “While MCPA accounted for the majority (75 per cent) of pesticide exceedances detected nationally in public water supplies during 2018, 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 per cent) of drinking water supplies come from surface water sources such as rivers, lakes and streams. Supplies such as the Tully-Tullycross public water supplies are vulnerable to contamination from land and animal run-off. Irish Water asks users of pesticide products in the local catchment to consider the vulnerability of the water supply to pesticide contamination and the importance of this supply to the local community.”
Dr Aidan Moody, Chair of the NPDWAG commented “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.”
MCPA, which is commonly used to kill rushes on wet land, is the main offender, however, other pesticides such as 2,4-D, fluroxypyr and MCPP (also known as mecoprop) are being detected more frequently than in previous years. Careless storage, handling or improper application of any pesticide product can easily result in traces ending up in drinking water, leading to breaches of the drinking water regulations. Users of pesticides are asked to carefully consider how these products may access water courses via rainwater drains, drainage channels or other means before application.
Regulations for pesticides are very stringent
The regulations are so stringent that a single drop of pesticide is enough to breach the drinking water limit in a small stream for up to 30 kilometres. This clearly highlights the level of care needed to protect drinking water sources.
Irish Water working in partnership with the National Pesticides and Drinking Water Action Group would like to remind farmers and professional users of pesticides of the need to follow best practice in the application of pesticides such as MCPA on land, particularly near lakes and rivers used as drinking water sources.
The basic steps in reducing pesticide risks are:
- 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 or strong wind 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 3 times into the sprayer
- Store and dispose of pesticides and their containers properly
Information leaflets on pesticide use are also available to download from the Teagasc website.