Le plan d'eau

Château Ladignac

 l'église (12e siécle) de Ladignac 

Water and Waste


Waste water Purification Plant: Ladignac le Long

dégrilleur red

This plant came into service in 2013 and treats all waste water in the village. Waste water is mixed with rain water since the drains are interconnected. Pumps enable the plant to deal with the waste from the campsite, village hall and the village housing estate.

It provides waste treatment for the equivalent of 700 inhabitants.

Should there be very heavy rain, an overflow beside the church allows excess surface water to flow directly into the black stream without passing through the treatment plant.

Waste water passes through an automated grill system which separates out solid matter (mainly paper) in the waste water.


The waste water then runs through a narrow channel where a meter measures the rate of outflow.

canal mesure débit 2 red

Afterwards the effluent collects in a tank (7m3)called the flush, covered by a grill. When this body of water is full, a syphon starts which sends the water down into a basin planted with reeds on a bed of sand, the waste water being filtered by the sand. There are three receptors like this side by side and the operator decides into which basin the water should flow


Translation : Brigit and David Armes




 arrivée deau dans le bassin N1 red

The water filtered by this first basin eventually arrives at a second tank (7m3 as well) which once full diverts the excess water into a second basin also planted with reeds on a bed of sand. There are two identical spaces and once again the operator decides into which one the water should be directed.

arrosage du bassin N2 1red

In the two levels of the planted basins, the reeds feed on the matter contained in the waste water, after they have been attacked by the baceria present in the sand bed.
Finallly, the water exiting from these reed beds passes under the road and is discharged into the black stream.


arrivée dans la rivière red




Near this outlet point is a small building from which to track the operations and control the functioning of the system. In particular, the concentrations of nitrate, ammonia and phosphate are checked.
The whole installation is maintained by the municipal technical services. The most important parts of the maintenance of the plant are the cleaning of the automated grill system, reed cutting and weeding the planted filter beds.

M. Christophe DUPONT is in charge of the waste water Purification Plant.