Well pumps drinking water from spring

The Jacques Avias pumping station at the karst spring of the French river Lez southeast of Les Matelles supplies the entire Montpellier community with fresh drinking water.

Since 1982, tandem submersible motor pumps have been pumping 1700 l of drinking water a second from three well shafts to the surface. A fourth pump discharges 250 l of water a second into the Lez, which is one of Europe's Natura 2000 protected areas and is home to unique animal species such as the Petit Groppe. After 30 years of operation, two of the pumps have now reached the end of their maintenance cycle.

The pumping station at Les Sources du Lez was equipped with two-stage submersible motor pumps by German pump manufacturer Pleuger Industries at the beginning of the 1980s. It is the only source from which the people of the metropolitan region receive their water. After 30 years Pleuger Industries replaced two of the 20 t and 10-m-long twin units in accordance with regulations.

The new 32-inch centrifugal pumps are two-stage special designs of type QN362-1a + VNI22-150-6-6. The 590 kW water-cooled stainless steel motor with a power output is located below the hydraulics and supplies spring water from the underground cavern via a suction-pressure jacket. The drinking water flows through a single-stage grey cast iron pump hydraulic system into the connected pressure boosting system of the same type, which transports 3500 m³/h of drinking water 36 m upwards. The motor is operated by a frequency controller with a rated current of 1 020 A.