The state Department of Environmental Management (DEM) is requiring a North Tiverton neighborhood to be connected to town sewers after discovering pollution in the Mount Hope Bay from failed septic systems, according to Tiverton officials.

Connecting the entire neighborhood will cost Tiverton $17 million.

"Pollution was in the Mt. Hope Bay and discharges from two pipes was severely affecting water quality in the bay," said Stephen Berlucchi, director of public works, describing a DEM water quality study along the East Bay up to Fall River.

After DEM identified the two Tiverton neighborhoods where failed septic systems were releasing pollutants into the Mt. Hope Bay: the Robert Gray Avenue Watershed and the Summerfield Lane Watershed.

Berlucchi said a DEM report told the town to commit to a design and project schedule to commence construction of sewers for these prob areas.

"We talked about ways dispute it, but it's pretty hard to dispute sample residue coming out of our pipes," said Berlucchi.

According to Berlucchi, the large instance of septic failures in North Tiverton caused pollutants to leech into the town's groundwater system, where they were flushed through to the Mt. Hope Bay.

While no action was taken on a schedule, design or timeline for the sewer expansion during Monday night's meeting, town employees are working with DEM to develop a long term - perhaps 20 year - construction.

Currently that town is still conducting a facilities update that will help with designs for the sewer expansion.

Berlucchi identified a three-phase approach to the construction:

• Phase one would initially attach 77 homes along Old Colony Terrace at a cost of $1.1 million
• Phase two would connect another 351 homes north up to Main Street at a pricetag of about $6 million.
• Phase three would tie in another 500 homes on the other side of Main Street for $10 million.

"We can't do it all at once, it would absolutely tear up the entire town," said John Lincourt, sewer superintendent. "What we are planning on doing is manageable sewer contracts so that we finish the project in a reasonable time - which a reasonable time is really 20-year time span to do the whole town."