New Order Received in Sonzier

The new membrane ultrafiltration plant for the treatment of spring water high above Lake Geneva will operate gravimetrically and thus be energy-efficient.

The WABAG company in Winterthur, Switzerland has established its reputation as a provider of customised and innovative solutions. At present the company is completing a new spring water treatment plant with a capacity of 20.000 m3/d in the district of Sonzier. The ultrafiltration membranes employed would ensure supply of pure drinking water and during the treatment process require minimum amounts of energy is required as the plant is operated on a gravimetric basis. Located 650m above Lake Geneva, the gradient from the spring to the plant will be employed efficiently. Prior to order issue, the process technology was tested together with systems from two other companies for a 12-month period. WABAG’s technology proved to be the best with regard to both performance and process stability, where upon in mid-February 2012 the client, eauservice de Lausanne, awarded the company a contract for the project with a value of CHF 3.7 million (approx. EUR 3 million).

The new drinking water plant will produce 15,000 l/min and in future will provide the city of Lausanne with a continuous supply of clean water. To date, after precipitation and especially following the snowmelt, the spring water was unsuitable as drinking water owing to its excessive turbidity. Surface water from Lake Geneva was employed as a substitute, but this required a large amount of power for preparation and pumping up to 650m. This energy will now be saved twice over, as the new treatment plant operates gravimetrically.

Before the order was issued, the process technology from three suppliers was subjected to testing in an on-site pilot plant over a period of a year. The WABAG Switzerland system proved to be the outstanding solution by far with the best cleaning performance, the highest water yield (98%), low chemical consumption and extremely stable, fault-free operation.

The ultrafiltration membranes employed guarantee sterility, as viruses and bacteria are removed entirely. The high turbidity levels of the spring water caused by the silt and clay particles emanating from so-called glacial polishing in the wake of the spring melt were easily dealt with during filtration without any impact on the treatment technology.

In the initial phase, the plant will have an output of 15,000 l/min, but subsequent expansion to 24,000 l/min has already been provided for. All the pipes are dimensioned for maximum capacity and have been installed accordingly. As a result, future expansion will be perfectly possible.

WABAG is responsible for plant design, engineering, the supply of the electromechanical equipment, installation and start-up. Commissioning is scheduled for completion by the end of 2012 and the work is already in full swing in order to meet this ambitious deadline.