Customers of the Vader and Enchanted Valley Water Systems are advised to boil their drinking water until further notice, the state Department of Health announced Thursday.

The city of Vader’s water treatment plant is not working properly, and the system has had several water line breaks. Both situations could allow bacteria and other contaminants to enter the water system. The problems don’t appear to be weather-related, health officials said.

The advisory affects about 350 homes and businesses in Vader and Enchanted Valley. The Lewis County Health Department has ordered food service operations to shut down and has alerted day-care centers.

State health officials advise customers to use boiled or purchased bottled water for drinking, brushing teeth, dishwashing, preparing food and making ice. Tap water should be boiled for one minute and allowed to cool before use.

The boil-water advisory is likely to last a while. One of the city’s two public works employees is on extended leave, so only one person remains to run the water system and to handle repairs. The Department of Health is helping the city, but it will require that the advisory remain in effect until the agency is satisfied the water meets safe drinking water standards.