After finding the bacteria coliform in private water supplies, the Department of Environmental Protection turned off a total of three businesses in the region, including one in Mendon.
Reacting to the previous round of DEP testing from last week that also identified 15 businesses drawing water from unpermitted wells.
The Mendon location that tested positive for coliform is at 49 Uxbridge Road. It houses A1 Affordable Relocation Systems and Sola's Gymnastics Academy. The other affected locations are a Honey Dew Donuts shop in Sutton and R&R Gymnastics in Millbury.
According to Edmund Coletta, the DEP spokesman, the Mendon and Sutton locations were treated with chlorine before they were tested for coliform a second time this week. And until the results from a separate test are available next week, both locations must use bottled water. Even though both locations tested negative for coliform.
"They're still not utilizing the water from the wells," Coletta said.
Testing for coliform does not indicate how much is present in the water. It only reveals the presence of coliform.
Although the presence of coliform does not violate safe drinking water standards, a second water sample containing coliform "tells you that there may be other bacterial problems there," Coletta said.
The three locations where coliform was found are among 15 in Central Massachusetts operating with unpermitted private wells.
When the state issues a permit to a private well, the well is subject to regular testing and must have a licensed well operator, Coletta said. These measures help protect the water's safety, he said.
Possible penalties for the 15 businesses have not been announced. The DEP is awaiting the results of tests for gasoline additives in the water supplies, Coletta said.
Drake Petroleum Co. Inc., the owner of a Sunco station and convenience store on Milford Street in Mendon, was fined $32,000. When testing this spring found traces of the gasoline additive MtBE in the water at his station. According to the DEP, the station stopped serving food and beverages prepared on site as of March 1.
This spring's tests also found MtBE at a Rutland gas station and convenience store and an unpermitted water supply at an Uxbridge gas station.
"That's one of the main reasons we were out there testing these types of sites," Coletta said.