– Filter backwash recycling from a drinking water membrane filtration process


Backwash recycling from filters is a common practice in many drinking water treatment plants in the USA, but it is still not widely applied North of the border. Recirculating backwash water allows reducing the raw water withdrawals from the natural environment and minimizing the wastewater discharges to the sewer and receiving bodies. Filter backwash water will be recirculated in the Lac-à-la-Pêche drinking water treatment plant in Shawinigan by adding a secondary treatment consisting of equalization, chemical addition, lamellar settling and sludge thickening and dewatering. The results from a pilot plant trial conducted during the design of the treatment plant will be presented in this conference, giving a better insight of the technical and regulatory challenges that filter backwash recycling poses in the context of drinking water production.