New wastewater treatment works designed to replace the existing overloaded filter works at Cookstown, Co Tyrone with a new works to treat a population equivalent load of 45,500 from domestic sewage, sludge, leachate and industrial waste.
The new works includes inlet works with storm overflow and band screens, 4 primary settlement tanks, 6 Sequential Batch Reactors (SBRs) with integrated anoxic mix tanks, storm storage tanks, sludge holding and thickening facilities, imported sludge and leachate facilities and odour control. Careful phasing enabled the original plant to continue to treat the incoming sewage throughout construction.
All mechanical and electrical design, installation and commissioning was carried out by WIS personnel.
After screening and grit removal there are 4 off 22m dia primary tanks for the removal of primary sludge. The new 6 basin SBR system by Fluidyne Inc had to be installed in 2 phases due to site constraints involved in the phasing. This involved installing 3 off SBR’s which were brought into service whilst the old plant was demolished, and then the last 3 SBR’s were installed. There was an odour limit of 5 odour units at the boundary, and this was achieved by the installation of a biological odour control unit. On site thickening of the indigenous sludge was achieved with the installation of 3 off Huber drum thickeners to increase the sludge thickness to 6%. Full site lighting was installed to adhere to the local H&S requirements. This is a fully automatic site with on-site PLC control, SCADA system, and telemetry for emergency call outs.
WIS adhered to all CDM regulation in conjunction with HSE requirements. We conducted site inductions, provided safe systems of work including Risk Assessments and Method Statements, subcontractor competency certification, and general Health & Safety guidance to all site personnel. The M&E and Process sections of the Health & Safety file were completed by WIS and handed over the main contractor as required.
- Population Equivalent: 45,500
- Treatment Flow: 22,400 m3/d
- Client: NI Water
- Completion Date: November 2008
- Total contract Value: £13m