Montville — The owner of a shuttered corrugated cardboard packaging plant and several surrounding properties here plans to repair a leaking dam on the southern end of Oxoboxo Lake.

WestRock recently applied for a construction permit and water quality certification through the Department of Energy and Environmental Protection, saying the repair plans could affect watercourses associated with Oxoboxo Lake and Oxoboxo Brook.

WestRock proposes to repair the dam's spillway, which DEEP says does not meet state regulations, and fix the upstream wall and downstream channel walls.

The most recent inspection, from December of 2016, showed two small leaks pose a serious seepage problem: about 50 to 60 gallons per minute leak through one spot on the masonry wall, and about 10 gallons leak through another spot, according to Art Christian, the supervising civil engineer in DEEP's dam safety division.

Christian and Montville Fire Marshal Raymond Occhialini said on Tuesday the lake likely would be drained during the repairs.

Christian said WestRock and DEEP renewed talks about repairs to the dam late last year. He added he expects the permitting process to take two to three months.

Mayor Ron McDaniel noted if approved by DEEP and subject to weather conditions, WestRock planned to draw down the lake beginning in late September or early October, performing the dam repairs from November to March.

"We've been working with (WestRock) for a long time," Christian said. "They're trying to do the right thing and be responsible."

The dam and lake have been the responsibility of the company that owned the cardboard mill for decades.

Continental Can Co., Newark Boxboard Co., Stone Container Corporation, Smurfit-Stone Container Enterprises and RockTenn CP LLC all have claimed ownership of the mill and dam over the years. WestRock closed the facility in February 2016.

The dam has been raised and rebuilt several times. Montville's 2010 conservation and development plan says the impoundment dates to the 1880s, when "the Oxoboxo River provided waterpower for 15 cotton, woolen, and paper mills."

WestRock, which did not immediately respond to messages Tuesday, previously tried patching the upstream dam wall a few years ago, but Christian said that effort was unsuccessful.

Occhialini applauded WestRock for the proposed repairs and for creating a dam safety plan a few months ago. He called the plans positive moves compared to previous rumors of removing the dam, a decision that would have left several lakefront property owners unhappy and firefighters with one less source of water, he said.

"That is a heck of a lot of water for firefighting in that part of town," Occhialini said. "I'm glad they'll put the money into the dam and be done with it."

Christian estimated the repairs to cost more than $1 million.

RockTenn in 2015 merged with another paper company to form WestRock. WestRock acquired almost a dozen Montville properties, including the plant and several parcels around it, in the merger.

Assessor Lucy Beit said Tuesday that the company still owns the properties.

WestRock would have to disclose the dam's condition to any potential buyer, but Christian said the repairs will make the property more attractive.

"There's very few owners that will take on someone else's liability without having a game plan to get it fixed, and having the present owner on the hook for fixing it," he said.

b.kail@theday.com