A $48 million cost is projected now for the town’s sewer plant renovation, up about $6 million from earlier estimates, according to First Selectman Rudy Marconi.

“It went from $42 to $48 million,” he told the Board of Selectmen last week.

The money will do more than replace facilities and improve treatment at the town’s District I sewage treatment plant, which cleans wastewater from the village and sewered area of central and southern Ridgefield. The project also involves closing the District II plant, which serves the commercial and multifamily area near the intersection of Route 7 and 35, and building a pipeline so that waste can be pumped to the District I plant, off South Street, for treatment.

In the planning stages for a few years now, the project will replace equipment that is more than 25 years old — past its useful life expectancy — and will upgrade the plant’s operations to meet newer state and federal standards for phosphorus and nitrogen removal.

The largest cost share is expected to fall on sewer users — that’ll be about $30 million, according to Marconi’s June 6 update for the selectmen. Sewer use fees — $440 a year, for a residential user — are likely to double, he said.

Two factors are expected to reduce the local cost from $48 million to about $30 million: a $10 million federal clean water grant the town expects to qualify for; and a plan for the town’s general taxpayers to take on $8 million of the cost, with a bond issue.

“In our debt service schedule is $8 million for the plant,” Marconi told the selectmen. “Instead of $38 million for users, it’ll be down to $30 million.”

This $8-million bond would add to the town’s debt, repaid by all taxpayers.

Some costs might also be covered by increased fees to septic system pumpers bringing trucks to pump out at the plant — increases presumably passed on to homeowners in higher bills for septic tanks cleaning.

The town Water Pollution Control Authority (WPCA) has consultants doing a rate study and recommending how costs could be shared.

The town has used differing approaches in the past.

When the District I sewer plant got a $13-million upgrade in 1990-92, all property owners shared part of the cost through general taxes — although properties on the sewer system carried much of the repayment through increased sewer hook-up and use fees.

When the District II sewer system at Routes 7 and 35 was created — reusing a treatment plant originally built for an industrial facility — the bulk of the cost was on users.

A variety of elements could be factored in.

“Something senior citizens said, ‘Should it be based on the number of people in the house?’” Marconi said to the selectmen.

In sewered areas with water piped in, sewer charges could parallel water bills — “water in equals water out.”

Requirement

While the plans will go to a referendum vote — planned for this fall — the sewer renovation isn’t something the town can put off forever.

“It’s basically required by the DEEP,” Marconi said, meaning the state Department of Energy and Environmental Protection.

Plant renovations are required every 20 years, and Ridgefield is overdue.

The District I plant was upgraded in 1990-92, but some of the facilities date back to 1968. Village sewer lines were originally put down in the early 1900s — with treatment left to Great Swamp.

Equipment in the District II plant dates to about 1985, when the town took over and renovated what was a private treatment facility for a factory — now the Pond’s Edge professional and medical offices on Route 7.

The DEEP understands the need for engineering and cost studies, and a referendum. But if the town is perceived as foot-dragging, the state could impose fines.

Timelines show the contract award in July 2019 — a deadline Marconi says is key to the $10 million grant town officials hope will reduce local costs. Construction would follow shortly.

Capacity

The District I plant has a one million gallons-per-day capacity, and treats about 800,000 gallons a day.

“Do we want to increase capacity?” Selectman Steve Zemo asked.

“No. The public hearing was overwhelming,” Marconi said. “We’re not looking to increase capacity — only the amount we have now, plus Route 7.”

With the District II plant’s 120,000 gallons per day capacity added in, the renovated District I plant will have a capacity of 1,120,000 gallons per day.

While about 800,000 gallons a day are treated in dry weather, the numbers are much higher when it rains — storm flows of several million gallons a day have been reduced but not eliminated.

Extensive, but only partially successful, efforts have been made to reduce infiltration and inflow — groundwater entering the system from leaky pipes and and storm runoff through illegally connected drains and sump pumps.  

Sleeves have been inserted into underground pipes to reduce the groundwater leaking in. And property owners have been badgered to disconnect storm drains and sump pumps.

Further efforts are needed.

“We’re still getting a tremendous amount of water right at that rain event,” Marconi said. “We have to look at the manholes. Do you seal manholes?”

Winds and odors

Other questions affected the project’s cost.

“Do we do odor control?” Marconi said.

The WPCA decided yes, do it, he told the selectmen.

“As long as the wind’s out of the west, we haven’t had an issue.” he said. “But when the wind’s out of the east…”

While odor control isn’t required, Marconi said, if an odor complaint is filed, the town must address the problem right away — it seemed best just to make it part of the project.

“That added, probably, a couple of million.”