Significant progress has been made in reducing the impact of pesticides on drinking water sources in recent years, but MCPA continues to be a major contributor to drinking water exceedances in Irish water.
It is often used on wet and heavy land and so is at higher risk of loss to water. Farmers need to make sure they are using the product appropriately and within the rules.
EU legislation sets down legal limits for the maximum concentration of pesticides that can be found in drinking water bodies.
Under the Drinking Water Directive (DWD), a legal maximum concentration of 0.1 parts per billion (ppb) is specified for any individual pesticide found in drinking water supplies.
A standard of 0.5 ppb applies with respect to total pesticide concentration. To put these standards into perspective, 0.1 ppb equates to one drop of an individual pesticide in an Olympic-sized swimming pool.
Essentially, the DWD requires that there should be no pesticide residues detected in water bodies destined for consumption, and any breach is illegal.
What do the limits mean?
Pesticide limits are statutory and do not imply a health risk, eg, the World Health Organisation (WHO) have set two health-based limits for the herbicide active substance MCPA, both of which are considerably higher than the EU legal drinking water limit:
The concentration of MCPA in drinking water that would cause adverse health effects if exposed to that level over a lifetime = 700 ppb (that’s 7,000 times the current EU limit).The concentration of MCPA in drinking water that would cause immediate health effects if there was a massive contamination incident (spilling) = 20,000 ppb (that’s 200,000 times the current EU limit).
The current situation
A particular challenge for Ireland is that surface waters (rivers and lakes) account for approximately 80% of drinking water supplies, making them especially vulnerable to contamination by pesticides.
Complying with the requirements of the DWD can therefore be demanding for users of pesticide products, requiring constant vigilance and reappraisal of practices, both on farms and by amateur users (gardeners, amenity groups, etc).
0.1 ppb equates to one drop of an individual pesticide in an Olympic-sized swimming pool
Many individuals, especially those using herbicides, fail to make the connection between the ditches or drains bordering their field and the small stream that feeds a tributary running into a larger river or lough from which drinking water is abstracted.
Farmers need to be mindful of these pathways and recognise that any lapse in care, with respect to pesticide use, can ultimately be reflected in the quality of the drinking water consumed on the farm by themselves and their families.
On-farm actions to reduce the problem
To check the Department’s guidance on managing rushes and other information on protecting water bodies, visit the Water Protection page on gov.ie.Consider topping in a grassland scenario.Ensure that application equipment is well maintained, properly calibrated and appropriately tested by a registered sprayer tester.
Rushes do not have to be controlled by spraying - they can be cut.
Comply with all product label directions, including rates of use, applicable buffer zones, frequency of application and weather conditions.Have appropriate facilities for storing pesticides.Only apply pesticides if you are a trained professional user.It is illegal to fill sprayers directly from a river or lake or any other water body.Pesticide products should be used with the utmost care. If your sprayer is not properly calibrated, then you are either applying too much product or not enough – either way you are wasting money.
Taking a chance with the weather and finding the product washed off the crop before it has had time to be absorbed is wasting time and money.
MCPA causing water quality issues
MCPA presents a particularly challenging problem. Its predominant use is as a grassland herbicide to control rushes, which can dominate on wet, heavy land.
Previously, there was some pressure to control rushes, as herdowners were concerned about possible penalties under land eligibility criteria if rushes took over in fields.
However, this is no longer the case. Provided there is evidence of management, eg, livestock grazing, no penalties will be incurred by the herdowner.
Indeed, under ACRES, the presence of rushes can be viewed as a positive indicator of biodiversity.
It should also be noted that within the ACRES scheme, herbicides are only permitted for use as spot-sprays or for weed-wiping to control noxious and invasive species.
Thus, there is no role for products based on MCPA, as these cannot be used in knapsack sprayers or weed wipers.
It is also worth pointing out that individuals considering applying for ACRES in the next tranche of applications should refrain from applying products based on MCPA, as MCPA is particularly effective in reducing grassland biodiversity and so will eliminate species which may be needed to reach ACRES targets.
Amateur users of pesticides
Farmers are not alone in their requirement to protect water supplies from pesticides.
Amateur users (gardeners, local tidy towns groups, etc) also need to embrace actions to protect water quality, as the widespread use of herbicide products to tidy up hard surfaces can also generate pesticide exceedances in drinking water supplies.
There is no role for products based on MCPA, as these cannot be used in knapsack sprayers or weed wipers
Overall, the situation is improving, but sustained efforts by all stakeholders are needed to make further progress.
In making the case to reduce pesticide use where possible, it is important to not only focus on better water quality, but to also emphasise co-benefits, such as enhanced biodiversity.
It is encouraging to see increasing awareness of the need to allow biodiversity to flourish, both on farmland and within our towns and villages, which is an important driver to help minimise pesticide use.
Significant progress has been made in reducing the impact of pesticides on drinking water sources in recent years, but MCPA continues to be a major contributor to drinking water exceedances in Irish water.
It is often used on wet and heavy land and so is at higher risk of loss to water. Farmers need to make sure they are using the product appropriately and within the rules.
EU legislation sets down legal limits for the maximum concentration of pesticides that can be found in drinking water bodies.
Under the Drinking Water Directive (DWD), a legal maximum concentration of 0.1 parts per billion (ppb) is specified for any individual pesticide found in drinking water supplies.
A standard of 0.5 ppb applies with respect to total pesticide concentration. To put these standards into perspective, 0.1 ppb equates to one drop of an individual pesticide in an Olympic-sized swimming pool.
Essentially, the DWD requires that there should be no pesticide residues detected in water bodies destined for consumption, and any breach is illegal.
What do the limits mean?
Pesticide limits are statutory and do not imply a health risk, eg, the World Health Organisation (WHO) have set two health-based limits for the herbicide active substance MCPA, both of which are considerably higher than the EU legal drinking water limit:
The concentration of MCPA in drinking water that would cause adverse health effects if exposed to that level over a lifetime = 700 ppb (that’s 7,000 times the current EU limit).The concentration of MCPA in drinking water that would cause immediate health effects if there was a massive contamination incident (spilling) = 20,000 ppb (that’s 200,000 times the current EU limit).
The current situation
A particular challenge for Ireland is that surface waters (rivers and lakes) account for approximately 80% of drinking water supplies, making them especially vulnerable to contamination by pesticides.
Complying with the requirements of the DWD can therefore be demanding for users of pesticide products, requiring constant vigilance and reappraisal of practices, both on farms and by amateur users (gardeners, amenity groups, etc).
0.1 ppb equates to one drop of an individual pesticide in an Olympic-sized swimming pool
Many individuals, especially those using herbicides, fail to make the connection between the ditches or drains bordering their field and the small stream that feeds a tributary running into a larger river or lough from which drinking water is abstracted.
Farmers need to be mindful of these pathways and recognise that any lapse in care, with respect to pesticide use, can ultimately be reflected in the quality of the drinking water consumed on the farm by themselves and their families.
On-farm actions to reduce the problem
To check the Department’s guidance on managing rushes and other information on protecting water bodies, visit the Water Protection page on gov.ie.Consider topping in a grassland scenario.Ensure that application equipment is well maintained, properly calibrated and appropriately tested by a registered sprayer tester.
Rushes do not have to be controlled by spraying - they can be cut.
Comply with all product label directions, including rates of use, applicable buffer zones, frequency of application and weather conditions.Have appropriate facilities for storing pesticides.Only apply pesticides if you are a trained professional user.It is illegal to fill sprayers directly from a river or lake or any other water body.Pesticide products should be used with the utmost care. If your sprayer is not properly calibrated, then you are either applying too much product or not enough – either way you are wasting money.
Taking a chance with the weather and finding the product washed off the crop before it has had time to be absorbed is wasting time and money.
MCPA causing water quality issues
MCPA presents a particularly challenging problem. Its predominant use is as a grassland herbicide to control rushes, which can dominate on wet, heavy land.
Previously, there was some pressure to control rushes, as herdowners were concerned about possible penalties under land eligibility criteria if rushes took over in fields.
However, this is no longer the case. Provided there is evidence of management, eg, livestock grazing, no penalties will be incurred by the herdowner.
Indeed, under ACRES, the presence of rushes can be viewed as a positive indicator of biodiversity.
It should also be noted that within the ACRES scheme, herbicides are only permitted for use as spot-sprays or for weed-wiping to control noxious and invasive species.
Thus, there is no role for products based on MCPA, as these cannot be used in knapsack sprayers or weed wipers.
It is also worth pointing out that individuals considering applying for ACRES in the next tranche of applications should refrain from applying products based on MCPA, as MCPA is particularly effective in reducing grassland biodiversity and so will eliminate species which may be needed to reach ACRES targets.
Amateur users of pesticides
Farmers are not alone in their requirement to protect water supplies from pesticides.
Amateur users (gardeners, local tidy towns groups, etc) also need to embrace actions to protect water quality, as the widespread use of herbicide products to tidy up hard surfaces can also generate pesticide exceedances in drinking water supplies.
There is no role for products based on MCPA, as these cannot be used in knapsack sprayers or weed wipers
Overall, the situation is improving, but sustained efforts by all stakeholders are needed to make further progress.
In making the case to reduce pesticide use where possible, it is important to not only focus on better water quality, but to also emphasise co-benefits, such as enhanced biodiversity.
It is encouraging to see increasing awareness of the need to allow biodiversity to flourish, both on farmland and within our towns and villages, which is an important driver to help minimise pesticide use.
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