FOXBORO - A $25 million townwide sewer expansion proposal will reach voters at Monday's special town meeting.

Water and sewer commissioners estimate that it'll cost a household $15,750 to $21,250 in betterment fees. This fee will vary depending on the actual construction cost and how the homeowner finances it.

A typical residential sewer connection would cost $2,500 to $4,500.

The special town meeting will start at 7:30 p.m. Monday at Foxboro High School, 120 South St.

Voters will be asked to bond $25 million for the sewer expansion. If approved, the sewer expansion would address about 65 percent of Foxboro's sewer needs, commissioners say.

The expansion would be done in five phases between 2008 and 2012.

The $25 million proposal is among several sewer requests on Monday night's agenda.

One request is to seek special legislation to allow the town to incur debt for $7.5 million in wastewater treatment infrastructure upgrades at and around Gillette Stadium on Route 1.

The $7.5 million is among more than $14.8 million in Patriot Place mitigation that the Kraft Group agreed to pay Foxboro in exchange for voters supporting making 12 additional liquor licenses available for their project. Voters passed this measure at the May 14 annual town meeting.

Another request would create a sewerage system overlay zoning district to allow uses related to wastewater collection, conveyance, treatment and disposal in certain parts of town.

Two other zoning proposals would apply this new zoning district to certain parcels on Spring Street and Payson Road. The Payson Road sites are part of the former Foxborough State Hospital campus.

Two other proposals deal with wastewater treatment plans for the Chestnut Green mixed-use development at the former state hospital.

The first request would grant the developer an easement to construct sewer system infrastructure within town right-of-ways.

However, those sewer system plans hinge on a last-minute deal between the developer and the town. Negotiations were continuing Wednesday about the developer building this infrastructure for Foxboro instead of building its own treatment plant. Chestnut Green also is talking with the Kraft Group about tying into the new treatment plant at the stadium.

MICHAEL GELBWASSER can be reached at 508-236-0372 or at mgelbwasser@thesunchronicle.com.