FOXBORO - A well facility under construction near the Plainville line holds a key to the quality of Foxboro town water.

When the two Witch Pond wells go on line, the town for the first time will be removing iron and manganese from the water.

Currently, the town treats the water to try to keep the metals in suspension, but the results are erratic, Water and Sewer Superintendent Leo Potter said.

"It's an aesthetic problem rather than a health problem," Potter said, adding that the state does not set a minimum allowed level of iron or manganese in municipal water supplies.

Seventeen years in the planning, the Witch Pond well project is in high gear now. Barbato Construction of Middleboro was to start installing about 1,500 feet of 12-inch water main on Cedar Street (Route 106), Potter said. Laying the water main is expected to take about two weeks.

The main will run from Wilkeson Way to the Witch Pond wells.

"Basically, this is the final stage of the building of the wells," Potter said.

The two wells were drilled last year on a 41-acre town-owned site adjacent to Witch Pond. The pumping facility is scheduled to go on line in the late fall next year, bringing to 13 the number of wells on Foxboro's system, Potter said.

Potter said iron and manganese don't always stay suspended in treated water, and the precipitation stains laundry, dishwashers, sinks and toilets.

The water coming from Witch Pond wells will have those metals removed on site, and that water will be mixed with water from other town wells.

Depending on the time of the year, the two new wells can supply 40 to 50 percent of the town's daily water needs. For example, on a day the town uses 1.8 million gallons, half of that use can come from the new wells, he said.

The two wells combined will have a pumping capacity of 960,000 gallons per day. The new wells provide "redundancy" and backup for the town's other 11 wells, avoiding excessive drawdown of the wells.

"It gives us the flexibility to draw from better quality and better performing wells," Potter added.

The state permits the town to draw up to 3.1 million gallons per day. The total cost of the well project is about $5.3 million, not including the amount the town paid for the land several years ago.

The water department secured a $4.3 million loan at 2 percent interest from a state revolving fund. The loan will be repaid through water receipts.

The planning board on July 31 voted 5-0 to grant the water department a special permit to build a 3,608 square foot water treatment plant, pump stations, water main, loop driveway and parking.

Several abutters have expressed concerns relating to noise, screening and buffering.

Among other conditions imposed by the planning board, a representative of that board is to review and approve any additional tree removal.

A 2- to 3-foot berm is to be constructed and topped by white pines at least 6 feet tall.