Effective water treatment breathes new life into a dead river
A significant deterioration in the oxygen balance in stretches of Sweden’s River Vege led the multinational food business Findus to seek immediate help from ÅF to upgrade its wastewater treatment.
In mid-August 2012 reports were received of large numbers of dead fish in the 55-kilometre long River Vege in south-western Sweden. An investigation showed that the Findus wastewater treatment plant upriver in Bjuv was an unwitting contributor to the cause.
Investment in modernisation
High sediment content in water discharged from the plant during processing of the annual pea harvest had led to a critical lack of oxygen in the water of the river. Fragments of oxygen-consuming organic material had passed through the plant without being decomposed, causing hypoxia and killing the fish. Findus responded by investing 1.4 million euros in modernising its treatment plant and donated around 110 000 euros to the River Vege Water Preservation Association for research and fishery conservation projects.
Multiple measures required
Findus discussed different solutions with various experts, including ÅF. It was decided that the necessary improvements could best be achieved by a combination of more reliable measuring methods, new filter processes, a retention basin and a new control system. ÅF was tasked with replacing the old control system and the outdated SCADA system that monitored and controlled certain key processes. The assignment included programming the two new systems and designing an electrical system that could replace the existing set-up and integrate new components into the plant. The SCADA upgrade also incorporates a function for producing reports that facilitate the work of the County Administrative Board’s engineers when they conduct their inspections.