The treatment of urban waste water - effluent from houses and businesses - before it is discharge to rivers, estuaries or the sea is important to prevent pollution.
Larger and more modern urban waste water treatment plants tend to outperform the more numerous smaller and older plants throughout the country. Poor performance is a concern, as effluent from even smaller plants can have a significant impact on water quality.
The Environmental Protection Agency (EPA) is required to produce a report detailing the performance of urban waste water treatment plants throughout the country every two years.
Urban Waste Water Discharges In Ireland: A Report For The Years 2006 And 2007 presents summary and detailed information on the performance of urban waste water treatment plants throughout the country. It also deals with recent changes in levels of treatment which have had a significant impact.
The most recent estimate is that about 90% of waste water produced now receives secondary treatment.
The construction of secondary treatment facilities at many locations around the country is at an advanced stage due to major investment in recent years. This is expected to deliver significant improvements in the quality of urban waste water discharges, and in turn lead to improved water quality.
Compliance with discharge limits for the very large plants (i.e. >15,000 p.e.) had improved in 2004/2005 but has disproved in the 2006/2007 reporting period. The majority of smaller treatment plants are not complying with the limits. The percentage non-compliance rates based on monitoring results are summarised below.
