To ask the Minister of Agriculture, Environment and Rural Affairs for his assessment of the impact of leaks, from slurry tanks into water courses, on environmental quality and biodiversity.

There is no doubt that if slurry is incorrectly managed and stored within tanks then there is an increased risk of leakage leading to significant environmental impacts.

Slurry leakage into water courses can give rise to higher levels of ammonia, increased eutrophication and lower levels of dissolved oxygen which can contribute to an overall increase in nutrient loading. This will have a negative impact on water quality and in more serious cases it can kill fish and other freshwater or marine life.

Leaking slurry tanks can also have wider biodiversity impacts on sensitive habitats such as fens and bogs, adversely altering the plant community composition in those specialised habitats due to nutrient enrichment. This favours more generalist plants and animals at the expense of specialised, range-restricted species.

My Department carry out intensive routine biological and chemical monitoring in rivers across Northern Ireland. Where water quality is assessed as being at less

than good status they will investigate the pressures impacting on that water course.

In response to specific pollution events further investigative monitoring may also be carried out to assess oxygen levels in the river, to ascertain if there is any impact on invertebrate life in the river and to help identify the source of the pollution.

My Department, through CAFRE and the Knowledge Advisory Service, provides advice, guidance and training on slurry tank maintenance to reduce the risk of leakage, while checks for leakage from tanks form part of the routine cross-compliance inspections undertaken on farms by NIEA. In cases where a leaking slurry tank causes pollution to a water way enforcement action may also be taken under the Water (Northern Ireland) Order 1999.