Residents of Shoemakersville, Berks County, are being advised to boil their water until further notice.
Equipment failure in one of the system's wells has increased the chance that the water may contain disease-causing organisms, officials announced late Monday afternoon.
Officials advise all residents to boil their water for one minute and then let it cool before drinking, making ice, brushing teeth, washing dishes and preparing food.
The advisory will remain in effect for at least two consecutive days while samples are taken to ensure the drinking water does not contain disease-causing organisms.
The equipment has been repaired and disinfectant is being added to the water system, officials said.