Farmyards and Water Quality
Farmyards can impact on water quality where wastes & effluents gain access to water directly, as point source pollution or indirectly, by diffuse pollution. With good farmyard management & design these impacts to water, where they occur, can be eliminated as Kevin O’Sullivan ASSAP Advisor outlines
The areas where problems arise include:
- silage storage
- animal housing
- management of soiled water
Silage pits – slabs and walls - need to be structurally sound to ensure ensiling is completed safely and effluent is not lost to the environment. Silage effluent is a highly polluting liquid and can cause fish kills in watercourses/rivers and contaminate wells if not collected, stored and land spread properly. Silage effluent collection channels and tank storage must be capable of managing the volume of effluent generated whether from pit or baled silage. Silage slabs and channels must be leak proof and all silage effluent must be collected and safely stored. If a silage pit is not fit for purpose, cease using and make the necessary repairs. When cutting silage aim to wilt for 24 hours before ensiling in order to reduce the volume of silage effluent produced. For pit silage all effluent should enter the channels under the cover of the silage polythene and the edge of the ensiled grass should not extend onto or over any channel. The open space should be maintained by placing a plastic drainage pipe in the channel. Ensure effluent is diverted to an effluent tank.
Effluent from round bales must be collected and stored in same way. It is recommended not to store bales greater than 3 bales high as this will lead to more effluent being generated due to weight pressure on the bales. Wilting and making silage in dry conditions is important in order to minimise loss of effluent.
Livestock housed over the winter period need facilities that are fit for purpose and have adequate storage capacity for both the numbers housed and the housing period. There should be a significant buffer of additional slurry storage to reduce the need to empty tanks in poor weather and ground conditions. Ensure that all water troughs are not leaking and prevent external water from entering tanks and housing. Loose (straw bedded) sheds should always have sufficient straw (or other bedding) in pens under the animals with appropriate controls in place to collect runoff from pens. Ensure the capacity of farmyard manure stores are sufficient and there are adequate collection and storage facilities for seepage from the farmyard manure (FYM) store. A roofed FYM store greatly reduces the amount of seepage that needs to be collected.
Open yard feeding is not advisable as all rainfall must be collected as it mixes in with the slurry. Sufficient storage is needed for both the slurry and the winter rainfall to prevent leakage to the environment.
Soiled water is water which is contaminated by contact with substances such as livestock faeces/urine, silage effluent, chemical fertilisers, washings (such as vegetable washings, milking parlour washings or washings from mushroom houses etc.) and water used in washing farm equipment. Soiled water is an issue for water quality because of the nutrients, contaminants and sediment it may carry to waters. Soiled water must be stored in tanks that have sufficient capacity to store all soiled water likely to arise on the holding during a 10 day period for tanks built up to 2015, and 15 days for tanks built since 1st Jan 2015.
Soiled water is less concentrated than slurry and is defined as having a biochemical oxygen demand of less than 2500mg/l or a dry matter content of less than 1% (10g/l).
Farmyards, where poorly managed can be a significant source of pollution to waters. This might be a good opportunity to review your facilities and ensure that clean water from roofs and clean yards is separated from soiled water and slurry. Take a look over the farmyard facilities to satisfy yourself that they meet requirements to prevent losses to waters. Farmers can avail of funding under the Targeted Agricultural Modernisation Scheme (TAMS) to assist funding new or improved animal housing and storage.
If you liked this article you might also like to read Managing the Farmyard
ASSAP – Agricultural Sustainability Support and Advisory Programme working with farmers to help improve water quality. More on Farming for Water Quality - ASSAP here
You can contact any of our Teagasc offices using this link Teagasc Advisory Regions here