Sewerage treatment in an integrated constructed wetland

Abstract

An integrated constructed wetland was constructed in 2006/2007 to treat combined sewage from the village of Glaslough in North Monaghan, Ireland. With a design capacity of 1750 population equivalent, the plant became operational in October 2007 and the current load is around 800 population equivalent. Untreated influent is pumped directly to a receiving sludge pond; the liquid then flows by gravity through five sequential vegetated ponds and the effluent discharges directly to the Mountain Water River. The banks of the ponds feature equestrian riding trails. Monitoring equipment has been installed in each pond and early results are very encouraging. In the first year of operation, effluent quality consistently surpassed the quality of the receiving river. The system can robustly cope with large variations in volumetric and biological oxygen demand loadings of the influent. The construction and maintenance of the wctland show significant cost savings compared with traditional sewage treatment plants in the county. The extensive monitoring work being undertaken at Glaslough wctland will help promote the wctland concept and its application to a range of water quality management issues such as leachate (from landfills), sewage sludges, drinking water source protection and flood amelioration.