What’s the “Water Quality” like here?
I have been working in the Agricultural Catchments Programme (ACP) for 13 years now, and probably the most common question I get asked is “What is the water quality like in the catchments?” writes Edward Burgess, Agricultural Catchment Specialist, Teagasc. He answers that question here
Above image: Rathescar Lake wildlife reserve, Dunleer ACP catchment, Co Louth
Usually people are expecting a short answer along the lines of good, okay or bad. If it was that simple we probably wouldn’t be still investigating it, 13 years later.
Water quality can mean many things to different people or in different places. Sometimes it is very obvious, for example, if a septic tank is discharging straight into a stream it will be very clear to see that the quality is not good. In such a case, there will probably be a steady discharge of effluent to be seen every day all year round. This will impact on drinking quality due to E. coli and also damage fish and insect life in the stream and river bed due to added nutrients.
Herbicides in drinking water sources are another commonly discussed aspect of water quality, but it’s not possible to easily see them. Drinking water analysis has become so precise it is now possible to pick up a single drop of pesticide many kilometres downstream from the site where it got into the watercourse.
Most, if not all, farmers have heard of the Nitrates Directive (ND). This is a European regulation that focuses on the impact agriculture has on water quality. It is very much in the news at the moment because the ND rules get reviewed by the European Commission every four years. This process is happening just now and we are going to have changes to these rules announced in March. If water quality in Ireland is improving the rules usually get relaxed, and if water quality is getting worse they get more restrictive. Unfortunately, the EPA have reported a declining trend in water quality over the last few years and it is likely that the new ND regulations will reflect that declining trend.
So, what are the main aspects of “Water Quality” that the EPA are concerned about?
The current trend of falling water quality is mostly attributed to increasing amounts of nutrients getting into our water bodies. Specifically, it is Nitrogen (N) and Phosphorus (P) that are of concern. Too much of these nutrients lead to excessive algae growth, which in turn lowers the amount of dissolved oxygen in the water. This process is called eutrophication and has a direct impact on the life in our river beds - the ecological status. The most significant water quality issues are:
- Nitrogen content
- Phosphorus content
- Ecological Status
N is of more concern to the ecology in our estuaries and the sea (salty water). P on the other hand impacts more in fresh water (streams, rivers and lakes) and it only takes a tiny amount to cause problems. N is more easily lost to water from free draining soils by leaching through the soil and locations contrast with areas where P is the issue, which is mostly lost by run off over the surface (heavy and wet soils).
Good nutrient management
Good nutrient management, however, is applicable to all soil types and farming systems. It is not just about limiting the amount of N, P and K applied. Good nutrient management also needs to take into account the correct time, soil conditions and placement. These are all important, for both water quality and farm profitability. This is often called the 4Rs : Right fertilizer source at the Right rate, at the Right time and in the Right place.
Perhaps after looking at some of this the next time you are wondering what’s the water quality like you might appreciate why the answer is so long!!
Eddie Burgess, Agricultural Catchments Specialist with the Teagasc Agricultural Catchments Programme joins Cathal and Deirdre on the latest Environment Edge podcast to discuss nitrogen loss from agriculture and the programme’s Working Together for Water Quality week.
For more episodes and information from the Environment Edge, visit the show page at: www.teagasc.ie/environmentedge
The Agricultural Catchments Programme (ACP) is running a week of social media releases showcasing some of its activities from Monday 21 February to Friday 25 February. The week’s theme is “Working Together for Water Quality”. More details of what is on can be found at www.teagasc.ie/ACPweek22
Acknowledgement
The Agricultural Catchments Programme (ACP) was established in 2008 and is funded by the Department of Agriculture, Food and the Marine