INAUGURATION OF THE WASTE WATER TREATMENT OF LOROUX BOTTEREAU

The inauguration of the new waste water treatment plant of Le Loroux
Bottereau was held on December 12th, 2009. Mrs Françoise Verchère,
department of Loire Atlantique General Council Vice-president in charge of
sanitation, and Mr Paul Corbet, mayor of the town, were present.
The former plant could no longer ensure a correct treatment of effluents. In
its concern to respect the strictest discharge standards (carbon, nitrogen,
phosphorus), the town council chose to have a new plant built;
thus, fitting in with general policy for surface water quality recovery.
The new plant is sized for treatment of 7520 I.E. effluents.
A 100 m3 storm water tank has been installed on the new site for
upstream flow control.
Then, the water line is traditionally composed of a fine screening, an
aeration tank and a clarifier.
Sludge centrifugation is achieved by a 2 speed centrifuge: with a 7% dryness
sludge will be stored in a silo (liquid sludge for land disposal); dryness may
reach 20%, sludge would then be removed in a skip for composting in case
of land disposal plan failure.
A biological treatment of phosphorus will reduce operating costs
(consumption of chemical reagent reduced by half).
A lifting station of treated water is supplied for direct discharge in the river
La Loire through a discharge pipe.
The structures have all been purposedly located 20 cm above the level of
the 1910's flood, when the village of Le Tertre was flooded.
A night soil treatment unit has been integrated to the plant.
In the end, NDEI is very proud of this new plant of which the integration is a
real success, as underlined by the mayor during this inauguration.