EPSE complete Phase 2 of the Bonawe WwTW project

Phase 2 of the Bonawe WwTW for Scottish Water Solutions has been completed ensuring that the continuous and intermittent discharges at the works meet the SEPA requirements for the receiving water. This design and construction contract was carried out after SEPA identified the need for first time sewerage provision in line with ministerial objectives. The project required appropriate treatment to provide protection to meet the drivers identified. Bonawe is a settlement of 24 houses with a PE of 51. Found on the north shore of Loch Etive on the B845, the network discharges untreated sewage into the shellfish waters of Loch Etive.

Improvement works included installation of a new Submerged Aeration Filter (SAF), blowers and humus tanks for secondary treatment. The new SAF unit receives effluent from 3 No. septic tanks via existing Copasac screens. The treated effluent gravitates to 2 No. new up flow conical bottomed humus tanks. The clarified secondary effluent l subsequently undergoes UV disinfection & discharge to an adjacent watercourse. Settled sludge from each humus tank will be discharged to the existing septic tank flow splitter chamber to allow co-settlement within the septic tanks. A new works power supply was required together with a new Control Kiosk to house the MCC and telemetry outstation.