Advice for farmers on water quality
Article by the Local Authority Waters Programme
We are fortunate in Ireland that many of our lakes are suitable for swimming and other water sports. In 2020, a report by the Environmental Protection Agency identified 148 locations in the country with suitable bathing waters.
Identified Bathing Water is the term used for those beaches and lakes managed under the Bathing Water Regulations. County Westmeath has three bathing water lakes, Portnashangan on Lough Owel, The Cut on Lough Lene and Lilliput on Lough Ennell.
Westmeath County Council manages and monitors these locations during the bathing season which runs from the June 1 to September 15. Council staff test water quality in bathing spots for two common types of bacteria: E.coli and intestinal enterococci. These bacteria live in the gut of both humans and animals and are present in faeces.
They are harmful to humans and are also indicators of other more harmful organisms. Harmful bacteria enter bathing waters via wastewater treatment plants, slurry spreading, and animals accessing streams and lakes.
Over the last three years (2018–2020), Lough Owel and Lough Lene have had excellent bathing water with low levels of these bacteria. Unfortunately, Lilliput at Lough Ennell has been classed as having poor bathing water status over the same period.
Investigations by Westmeath County Council have found that the primary source of pollution affecting the bathing waters at Lilliput is most likely from agricultural slurry run-off. Septic tank discharges are potentially a lesser source of pollution.
The Agricultural Sustainability Support and Advisory Programme (ASSAP) provides water quality advice to farmers. It includes farm advisors from both Teagasc and the dairy co-ops. ASSAP works with the Local Authority Waters Programme (LAWPRO) to identify water quality issues and solutions.
David Webster is a of Teagasc farm advisor working in the catchments of the Dysart and Adeel streams, and the Yellow, Gaine and Gageborough rivers in County Westmeath.
A key part of David’s work is advising and guidance to farmers on how best to protect these rivers and lakes from pathogen and nutrient losses from agriculture. A key focus is on the activities that can affect water quality, including the spreading of slurry during the summer months and cattle access to streams and lakes.
David states: “We know that slurry spreading is an essential part of our agricultural system – however, with better management of slurry, farmers can increase profit by maximising the nutrient value of slurries. If managed incorrectly, slurry spreading can cause nutrient loss, and pollution entering our rivers and lakes.
!Climate change is leading to more frequent and heavy rainfall events, and if slurry is spread before or during heavy rainfall, there is a significant risk of slurry run-off from land entering our waters.”
The advice to farmers is to maintain the required buffer zones or setback for slurry spreading, i.e. to keep back five metres from drains and streams and 20 metres from the lakeshore. It is recommended that the distances are increased in fields that have many drains.
In some cases, it is recommended that slurry is not applied at all. Those include sensitive or waterlogged land or land with steep slopes to a river or a lake.
David says: “Cattle slurry is a source of pathogens and so it needs to be managed carefully during summer months, as that is when it has the greatest impact on bathing waters.
“The big issue is when you have a wet summer. Farmers need to empty the slurry tanks after the silage is cut and even though slurry may be spread in dry weather, when there is a lot of rainfall after land spreading, that can lead to the surface runoff of slurry into the drainage network.
“Applying sufficiently wide buffer zones and setback areas when spreading will help break the pathway and reduce pathogen losses.
“An alternative to spreading slurry in the more sensitive locations, for example in the vicinity of bathing waters, is the use of chemical fertiliser, as it does not contain pathogens.
“It is also advisable that during the silage making season farmers check the diversion valves, underground drains and streams around the farmyard to ensure that all effluent is collected, and always check the weather forecast to ensure that heavy rain is not forecast in the days after spreading.
“A seven-day rainfall forecast is available on the Met Éireann website, met.ie, and the forecast can be tailored for accuracy by adding in your location. The app can be downloaded to your phone so you can check the forecast easily.
“Allowing cattle access to streams can also lead to an increase in pathogens due to excretion of faeces while drinking. Preventing access and looking at ways to provide alternative water supplies to livestock can greatly reduce the impacts of drinking points on water quality.”
By being aware of the potential effects on bathing waters, farmers can adapt their farming practices to minimise losses and play their part in protecting an important resource for their communities.
The national bathing water website, beaches.ie, is maintained by the Environmental Protection Agency and shares the latest information on more than 200 bathing waters sampled during the bathing water season, including which bathing waters have safe water quality or have known pollution events.
Having access to this information allows you to make an informed decision about which bathing water you will go to for a swim or to spend the day with your family and friends.