Problem: A biological filter bed and two final tanks were found to be drying out during long spells of dry weather, killing off the biological process that is fundamental to treatment at Welsh Water’s Llanrhidian WwTW, a remotely located wastewater plant on the Gower Peninsular. In addition there was a problem of no power supply at the site.

Solution: NOV Mono, a framework supplier for Welsh Water, recommended installing one of its solar panels and recirculating pumps. The Mono pump uses renewable energy from the PV solar panel to pump the effluent back to the filter bed and keep the biological process from drying out.

The installation consisted of a Mono SunSub submersible pump, solar array, controller cable and safety wire together with a GRP Kiosk to house all control components, back up batteries, pump starter for the solar unit and day/night/summer/ winter timer controls.

Mike Gillard, capital engineer at Welsh Water, said: “We chose to go with Mono’s system as it offered the most cost-effective solution for the site’s remote location.