Magherafelt WwTW, Co. Londonderry

Magherafelt WwTW was originally commissioned in 1977 to serve a mostly domestic population equivalent of 12,000 from the town of Magherafelt, utilising primary settlement, biological filtration, humus settlement, sludge thickening and storage. In later years, NI Water identified the works as requiring an upgrade to meet the Urban Waste Water Treatment Regulations (NI) 2007 and revised discharge standards set by the Northern Ireland Environment Agency (NIEA).

This project involved a new scheme to improve treatment capability to meet the new standards of 20 BOD5: 30 SS: 5 NH3-N as mg/l and of 1 mg/l Total P and extends the works to treat flows and loads from a population equivalent of 25,400.

The design reused existing assets where practicable and included a new storm overflow screen, storm transfer PS, storm tank, inlet works screens, conversion of 2 existing storm tanks to primary tanks, refurbishment of 4 existing biological filters, 2 new intermediate settlement tanks, 2 new tertiary biological filters, 3 new final settlement tanks, an interstage PS, 2 new concrete sludge holding tanks, duty/ standby sludge thickeners, standby generator, odour control and refurbishment of the existing administration building.