Keeping pesticides out of our drinking water
With the good weather we're currently enjoying, the 2025 spraying season is about to get underway. As we begin, it's important to remember to follow safe and responsible practices when applying pesticides to crops — including grassland.
To put things into perspective: a spillage of just one gram of active ingredient would require dilution with 10 million litres of water to meet the European maximum limit for pesticides in drinking water (i.e. 0.1 µg/l).
Despite the great work being done by farmers, there were still 36 exceedances recorded in our drinking water supplies last year. Notably, some of these exceedances occurred in both Cavan and Monaghan during the winter months. This raises an important question: why are such issues arising during a period when spraying is typically limited (October to February)?
A number of active ingredients frequently appear in water monitoring reports. These include MCPA, 2,4-D, Glyphosate, Clopyralid, and Triclopyr. Of these, MCPA is the most common and is found in over 50 products currently on the market.
Key observations
Based on my own visits to farms, I’ve noticed three critical factors that influence the safe use of pesticides:
1. Spraying Equipment
Since November 26, 2016, it has been a legal requirement that sprayers are licensed under the Pesticide Application Equipment Test.
o Boom sprayers (with boom widths of 3 metres or more) must have a valid certificate, renewed every three years from the date of purchase.
o Boom sprayers under 3 metres and ATV-mounted sprayers will require certification every three years from 31st December 2024.
2. The Person Applying the Pesticide
A professional user is defined as anyone applying professional-use plant protection products. Since November 26, 2015, only individuals registered as 'professional users' with the Department of Agriculture, Food and the Marine are legally permitted to apply these products. You must register via the Department's website. This applies to everyone involved in spraying.
3. Buffer Margins
The buffer zone required along all watercourses for grassland herbicides is 5 metres. Adhering strictly to this margin is essential when spraying.
Upcoming Event – Farm Walk
We will be holding a Farm Walk at the out-farm of Andrew and Peter Tully on Thursday, April 24 in Artonagh, Co. Cavan. This event will focus on best practices for applying pesticides to grassland, with an emphasis on protecting water quality.
Who should attend? If pesticides are applied on your farm, this event is for you.
Final Word
By applying pesticides correctly and safely, we can work together to achieve our shared goal: zero exceedances in drinking water supplies in 2025.