The inhabitants of the island of Groix are prohibited from drinking tap water, the Morbihan prefecture announced on Thursday evening. This decision was taken following an analysis carried out on the Créhal reservoir on Thursday July 6, which revealed the presence of trihalomethane (THM) above the quality limit defined by the Public Health Code. A distribution of bottles to all inhabitants and residents will be carried out “until the situation is restored” for the 2,200 inhabitants of the island.
These trihalomethanes are residues of water chlorination, “a common process that ensures the effective disinfection of water, formed mainly by a chemical reaction between chlorine and organic matter naturally present in surface waters used to produce tap water”, reports the prefecture of Morbihan. The latter is reassuring about the impact on the health of residents who have consumed drinking water in recent days. According to the Regional Health Agency (ARS), “only long-term exposure to these trihalomethanes would present risks to human health”.
The prefecture specifies that “tap water can always be used for cleaning and cooking food, personal hygiene, household uses (dishes, laundry, etc.), for the entire population”. Lorient Agglomeration, which distributes drinking water on the island, is continuing its analyzes of the Créhal drinking water production plant to restore the situation.