Constructed wetlands in Ireland

Abstract

In comparison to other European countries, Ireland has a very large rural population. As of 2006, 42% of Irish people lived in rural areas. In cities and towns, wastewater is generally treated by centralised treatment plants. However in rural areas, wastewater from domestic treatment is typically decentralised, i.e., wastewater is treated on-site. The most common method of on-site wastewater treatment is private septic tanks and associated percolation areas. In all, there are 400,000 septic tanks in use around the country. These septic tanks and percolation areas are in various states of maintenance. Often, septic tanks are leaking or incorrectly constructed. Percolation areas are frequently clogged and do not treat the wastewater adequately. Typical treatment efficiencies of this system are of the order of 40% removal of organic matter, and 15% removal of nitrogen and phosphorus. Faulty septic tanks and percolation areas are viewed as a major environmental concern by the ...