One of the biggest infrastructural projects ever proposed for Warren will soon go before voters, who will likely be asked at Financial Town Meeting in May to approve bonding $20 million to expand and upgrade the aging wastewater treatment plant on Water Street.

Without a doubt, it will be one of the most expensive and complicated projects Warren has ever tackled, and taxpayers will feel its financial hit for years to come. But town officials say they must improve the aging plant now, or face significant fines from the state Department of Environmental Management (DEM). The plant is just too old, they say, and the state environmental requirements too stringent to make do with what they have.

Planning for the project has been in the works for a decade, ever since the DEM commissioned a study of the toll nitrogen was having on the Palmer River and decreed that Warren and other “point source” contributors take steps to reduce their impact. Warren has been working with DEM to reduce nitrogen discharges for five years now, but many Warren residents still don’t know too much about the construction project. One recent afternoon, project manager Jon Himlan of the firm Woodard and Curran, and plant workers Eric Komiega and Dave Pion walked through the facility and answered a few questions about the project:

How much effluent does the plant process a day? “Roughly 1.5 to 2 million gallons a day. In an extreme rain event it goes off the charts. We max out at seven million at our recording capability. If the plant upgrade goes through there’s going to be an increase in the capacity. We are going to be able to handle nine million gallons a day.”

What happens now when it rains? “It backs up. Everyone’s OK with that until it starts going into their basement. But it’s one of those things that nobody thinks about when they flush their toilet. They just kind of walk away. Overall, the plant just has a lot of maintenance issues and you have to call people in when things get wet.

When was the plant built? “In the early 1980s, the majority of the plant was built though there were parts of the older plant (built in the 1940s) that remain.

What about the DEM study? “The (2005) study found that there was a lot of nitrogen entering the Palmer River from point and non-point sources (from runoff and specific areas, essentially) and negatively affecting water quality. In that study, DEM’s solution was to reduce nitrogen discharges from the treatment plant and Blount. But also part of their model was a reduction in the non-point sources. They were looking at Warren to clean up, but they were also putting a similar percentage of reduction in the non-point sources upstream in the Palmer River.

Read more about the project's expected financial impact here, in a letter from Interim Town Manager Jan Reitsma to the Warren Town Council.

It is easy to see how the town and other point source contributors could be held to a quantifiable standard. But what about non-point sources? “That’s the issue. Dealing with those sources and reducing (nitrogen emissions from them) is much more difficult.”

What did the state and town do? “DEM issued a new discharge permit in 2010 with nitrogen limits that the plant could not meet. As a result a consent agreement (between town and DEM) was signed in 2011. Through additional engineering evaluations and a collaborative effort with DEM, Warren was able to get the permit modified in 2013. The modified permit provided more flexibility for the operation of the plant. And the consent agreement required that the town would work toward a plant upgrade.

Has the town ever been in violation of the permit requirements? And what will DEM do if that happens? “There’s never been a situation where the town has not been in compliance with that consent agreement. It specifies $1,000 fines a day if the town doesn’t meet the schedule in the consent agreement.

How does the plant currently work? “This plant was not designed to remove nitrogen. It was designed to remove organic material and pathogens. You have some larger solids that settle easily and are removed in the first part of the process. And then you have the dissolved material that doesn’t settle. So you have a secondary process where you get microorganisms to consume that. They are slightly heavier than water, so by having them consume that organic material you can then settle them and the organics they have consumed out in clarifiers. As those microorganisms grown and consume they use the nitrogen in the wastewater. But they’re not removing it to the levels that DEM requires.

How would the new system differ? “It’s still a biological system. But you’re manipulating the environment to get the microorganisms to do a certain job. By adding more air to one part of the reactor, restricting air in another part, providing longer retention times, things like that , the microorganisms convert ammonia into nitrate, and that is released in the form of nitrogen gas which then goes out into the atmosphere.

Are the upgrades just for nitrogen treatment? “Throughout the entire facility, the mechanical and electrical equipment are at the end of their design life. It still works, which is a credit to Suez (the operation and maintenance firm that runs the plant for the town). This group has done a really good job of maintaining what’s here, and working with what they’ve got. But they’re limited. The reality is that the whole plant works as a system. So to achieve the DEM’s requirements for nitrogen removal, we need to add reactor tanks and expand the biological process. But to just add that tankage and not address the other pieces, if they fail then you’re not going to be able to utilize the new equipment that you’ve put in.

What are the physical changes? “We’re adding more reactor tanks to grow more microorganisms, but the clarifiers will still be the end stage. And there are improvements that are going to make the plant more efficient. Equipment that is old and is currently a maintenance problem prone to breakdowns is going to be replaced with more efficient equipment. Overall, we’re going to increase energy usage because we’re adding blowers and mixers and things that aren’t here. But if you were to look at just the existing systems here, we’re going to reduce their energy usage because we’ll be operating more efficiently.

Will a new plant lead to fewer closures at the Warren Town Beach? “I don’t think it’s this treatment plant that’s causing the closure situations.

Will it reduce the smells in the neighborhood? “We’re adding odor control as part of the plan. It’s a biological process so (reducing odor) is a tricky thing. Part of these updates are designed to enhance odor control at the facility. It should be substantially better.

What is the current staffing level, and will that change? “There are five full time employees, and three operators  that are responsible for maintaing the plant and the collection system in the street, and we have a secretary/lab person and we have the plant manager. We are projecting an additional operator will be needed.

What is the timeline? “We would complete the design in the fall of this year. Then there’s a period for DEM to review and approve it. We would then go out to bid for a construction contract in early 2017. The construction would start thereafter, late winter or early spring of 2017. We project it will be a 15-18 month construction period.

How will the engineers juggle changing over the plant while still dealing with the day to day job of running the existing plant? “The construction sequencing will be developed during the detail design. The plant is a two-train system. There are times of the year when only one train is needed and we will take advantage of that; we can make it work.”

Is there a contingency built into the $20 million cost? “A $2.2 million contingency is included. We’ve included it because we are still at a preliminary stage in design. It is standard industry practice to include a contingency so that as we progress in the design, if we find some things that we didn’t anticipate it allows us to continue to move forward.”