MONTAGUE — The investigation into stormwater infiltration in the sewage pipes underneath Federal Street in Millers Falls will continue as the town tries to eliminate a key factor contributing to a $94,668 overage charge assessed by neighboring Erving.

Department of Public Works Superintendent Tom Bergeron said the main focus is on pipes between 12 and 20 Federal St., which are still flowing “quite badly.” A document shared by Bergeron at this week’s Selectboard meeting said both of those locations are seeing “constant flow.”

The current challenge, though, is the DPW needs equipment to continue to investigate the water infiltration and a nearby smoke machine the department could borrow is not available until April 1, which Bergeron said is leading the department to start looking for one to purchase. A smoke machine will allow the DPW to determine where there are deficiencies in the pipes by allowing smoke to go through holes in the pipes and then up through the ground.

“The main one we want to do is by 20 Federal St. and see where that one goes,” Bergeron told the Selectboard and Sewer Commissioners this week. “Hopefully when we do shut it off or find it, we shut it off from the source and not from inside the pipe, so we don’t flood something else.”

With so much stormwater passing through the pipes, town officials said that is one of the driving forces behind the $94,668 overage bill Erving has assessed on its neighbor. Montague and Erving are entering their last year of a 10-year contract where the village of Millers Falls has its sewage processed by one of Erving’s three publicly owned wastewater facilities.

“Just keep investigating and working with [Montague Clean Water Facility Superintendent Chelsey Little’s] team if you need to, and let’s try to figure out what’s happening there,” Selectboard Chair Rich Kuklewicz told Bergeron. “We definitely need to be aggressive on this because this could be a big chunk of what’s costing us that money.”

“That’s why I’m not going to wait until April to get the smoke machine,” Bergeron said in response.

Kuklewicz added Wednesday that officials have been seeing these increased flows in the area for “maybe even a year or two,” and the source of the water, wherever that may be, has “contributed a fair amount” to the overage charges they’ve seen from Erving.

Montague pays a negotiated amount for the sewage to be processed, and for every 1,000 gallons over that amount, the town pays an overage fee. That fee is currently $17.03 per 1,000 gallons. Montague budgets $55,000 for overage fees every year, so a $94,668 bill leaves the town nearly $40,000 short.

Little said Monday that incorporating the additional $40,000 into the operating budget of the facility might make more sense than bringing a special article in front of voters at Annual Town Meeting, which will keep other financial calculations “clean.”

Selectboard member Matt Lord asked Bergeron if there is any indication of what “corrective action” can be taken, to which the DPW superintendent said it will be up to whoever owns the property to fix it.

“When we find it, wherever that may be,” Bergeron said, “that property owner, whether it’s us, the railroad or an individual, will have to deal with it to correct it.”

Chris Larabee can be reached at clarabee@recorder.com or 413-930-4081.