Continuous monitoring of the salinity of water in the Seine at Norville

In Seine-Maritime, the mouth of the Seine has no locks. As a result, depending on the flow of the river and the strength of the tides, chloride rises and reaches the Norville industrial water treatment plant, operated by Saur. The water then became too salty for its intended use and required treatment.

In December 2021, Saur asked us to introduce continuous monitoring of the river’s salinity, to facilitate management of the industrial water plant.

Our patented SMD Intrusion monitoring tool was originally used to monitor saline intrusions into groundwater. We diverted it from its original function and adapted it in 2016 to monitor rising chloride levels in the Vilaine river.

So we reproduced the same scheme here and installed our systems between the mouth of the river and near the Norville plant, to detect the arrival of brackish water. The monitoring is carried out about 5 km downstream of the station, in order to detect in advance any chloride arrivals at the operating station.

The Port of Le Havre allowed us to use their barge located 500 metres downstream of the plant to install our equipment. At the same time, we positioned sensors on the anchor buoys in the port of Le Havre. This allows us to take spot measurements a long way downstream. And when these sensors detect chloride, we use the SMD tool to examine the advance at different depths.

Thanks to the installation of imaGeau and the continuous monitoring of data, Saur can adapt the management of the Norville drinking water plant in real time.
The plant operator can be immediately alerted to the presence of chloride at various points in the Seine, enabling it to anticipate and take the necessary measures to avoid pumping salt water and treating it.