A picturesque Massachusetts town is facing a sewage crisis residents have dubbed a “ doomsday scenario,” with experts warning that contaminated drinking water could eventually make its historic village center uninhabitable.

Carlisle, located about 20 miles northwest of Boston , has no public water supply or municipal sewer system. Instead, residents rely on private wells and backyard septic systems, many of which are aging. The problem is particularly concerning in the historic village center, where homes and businesses sit close together on small lots, some about the size of three basketball courts.

Conventional septic systems filter wastewater through surrounding soil, but limited space and the town's fractured bedrock can make it easier for contaminated wastewater to reach nearby drinking wells.

The contamination has already raised concerns across the community. Wells at Ferns Country Store, a general store that served Carlisle for more than 180 years, and Town Hall tested positive for E.…