With their heads in their binoculars, these 5th graders look for birds on the bodies of water.
“Hey sir, are they seagulls?
asks a young man.
“Yes, but they are little gulls.
They are recognizable in particular thanks to a black line located under the wing”, specifies Christophe Boucher, person in charge of the animations of the station of lagooning of Rochefort (Charente-Maritime) on behalf of the League for the protection of birds (LPO).
In the pool next door, swans and cormorants can be observed through telescopes.
On this greyish November morning, 38 college students came to discover this atypical place extending over 70 hectares on the banks of the Charente.
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This unique site in France has the particularity of using both an ecological process to treat wastewater and being a remarkable natural area for waterfowl.
Here, 5 million liters of wastewater arrive every day, corresponding to the consumption of the 25,000 inhabitants of the municipality.
The malodorous liquid will undergo a pre-treatment phase, then a passage in a decanter.
The sludge – in other words, excrement – then goes to a digester.
There, they are transformed into mineral salts and then into compost.
But also in electricity, thanks to the production of methane which feeds a dynamo motor.
“The station is completely self-sufficient in electricity and 100 tons of compost are produced per year, directly reused by the green spaces department of the City of Rochefort”, underlines the facilitator.
“Nature works for us”
Christophe Boucher, LPO manager of activities at the Rochefort lagooning station
Two good points in terms of sustainable development.
However, the originality of the method comes in the next step.
After the decanter, the water passes into the various lagoon basins.
These lagoons, bodies of water dug over 35 hectares, are used to purify the water using the natural mechanisms of the environment.
“Thanks to the sun and the wind, oxygen is created and microscopic algae develop.
Germs are killed by the ultraviolet rays of the sun.
The water is rich in plankton, which is eaten by waterfowl.
Themselves attract predators like harriers.
This forms a food chain and as a bonus, nature works for us!
“, details Christophe Boucher.
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After four months, the water thus depolluted is discharged into the Charente.
And this since 1985, the date of creation of this lagooning station, considered to be the largest in Europe.
The abundance of plankton and the tranquility of the place make it a haven for aquatic birds, with 160 species observed regularly (ducks, waders, grebes, passerines, etc.) The LPO has also set up specific basins on the banks of the river.
Guided tours are offered to the general public, to discover the technique of lagooning, the production of electricity but also the interest of the site for birds, with access to the observatory of the station.
www.station-de-lagunage.fr
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Visits to be booked with the Espace Nature, place Colbert, in Rochefort (Charente-Maritime).
Such.
05 46 82 12 44,
space.nature@lpo.fr