The prefecture of Finistère announced Sunday August 23 a " return to normal " after pollution of the Aulne, a coastal river, pollution which has impacted thousands of homes since the beginning of the week.
This pollution followed the overflow of a digestate tank from a methanizer in Châteaulin, the prefecture and the operator had confirmed. " The sanitary safety of the water distributed throughout the affected territory is guaranteed and the prefectural order restricting the use of water has therefore been lifted today by the Prefect ", according to a press release from the representative of the State.
“ Veolia, operator on behalf of the Syndicat Mixte de l'Aulne (SMA), also confirms a return to normal at the Coatigrac'h plant. The quality of the water pumped from the Alder no longer varies and shows that the pollution has passed ”. The prefecture adds that "the communities will gradually return to normal in terms of the functioning of their drinking water production and distribution system ".
“ Locally, a particular organoleptic quality (taste and smell) could be observed by the consumer. This phenomenon can be explained by the measures to strengthen the disinfection of water which were implemented over the period. This does not involve any health risk and the distributed water is quite drinkable, ”specifies the text according to which“ the network served being complex and extensive, particular vigilance is necessary and the ARS (Regional Health Agency) will continue in over the next few days, samples and analyzes to verify the sustainable return to normal ”.
50 municipalities without drinking water
Last Wednesday, the prefecture recommended not to drink tap water in 50 municipalities in the department because of this pollution.
This had generated “ ammonia concentrations ” which had led to shutting down the Coatigrac'h drinking water plant overnight from Tuesday to Wednesday.
The pollution was due to the overflow of a digestate tank from the Kastellin biogas plant. Inaugurated in 2018, this methaniser is located about one kilometer from the Aulne, and upstream of a drinking water plant.
Environmental associations have particularly reacted strongly to this pollution. The association Eau et Rivières de Bretagne, which has been fighting for 50 years to protect the quality of water in the region, has thus called for a moratorium " on the pursuit of the creation of industrial methanization units in Brittany " and announced the filing a complaint against the author of this pollution.
Among the municipalities concerned were Châteaulin (5,774 inhabitants), a large part of Quimper (63,000 inhabitants) and the very touristy peninsula of Crozon.