NORTON - About 15 Hill Street homes were hit with their fourth water main break Thursday over the past two weeks.

The breaks are related to the upgrade of about eight miles of water mains throughout town, Water-Sewer Superintendent Duane Knapp said.

Hill Street has been particularly hard hit because of the consistency of the soil beneath the road, Knapp said.

Contractors have dug through soil everywhere but Hill Street, where there are "apparently a lot of ledge and big boulders," he said.

"Every time you turn around, the old (asbestos-concrete) water main keeps breaking" due to the water pressure, Knapp said. The most recent break was about 8 a.m. Thursday and lasted two to three hours, he said.

Knapp said there are about 15 homes on Hill Street, off South Worcester Street near the Norton Commerce Center.