A sewer plant renovation expected to cost tens of millions of dollars will be outlined next week for townspeople \u2014 who will eventually have to vote on it, probably in fall of 2018. The project includes upgrading the village area\u2019s District I sewage treatment plant on South Street, and also closing the District II plant that serves the area around the intersection of Route 7 and 35, then piping that sewage to the South Street plant for treatment. The last time the town\u2019s District I sewer plant was renovated, more than 20 years ago, the cost was about $13 million \u2014 and the new renovation is expected to cost more. \u201cThis could be three times that amount. It\u2019s premature to say in detail,\u201d First Selectman Rudy Marconi said. \u201cWe have a preliminary design concept,\u201d said Water Pollution Control Authority chairwoman Amy Siebert. \u201cWe haven\u2019t gotten into any detailed design at this point. The detailed design is what really lets you firm up the your costs.\u201d The public hearing on the Phase I and Phase 2 Wastewater Facilities Plan is scheduled for Wednesday, May 3, at 7 p.m. in the conference room of the Town Hall Annex, by the Yanity gym off Prospect Street. The project, which already been under study for a couple of years, is targeted for construction in 2019. The project will have several aspects: \u00a0To upgrade treatment capability at the District I sewer plant, serving the village and town center, to meet higher state environmental standards for the treatment of both nitrogen and phosphorous; To close the District II sewer plant, near the intersection of Routes 7 and 35, and pipe the effluent currently handled by there to the upgraded District I plant off South Street for treatment; To modernize treatment facilities that are old, and have been relentlessly used. The plant will continue to be used for treatment of septic system waste from Ridgefield properties, delivered by commercial septic pumping services after they pump tanks in town. The renovation must meet standards set by the state Department of Energy and Environmental Protection (DEEP), which issues the discharge permit for the plant. \u201cWe have stricter nitrogen and phosphorus limits,\u201d Siebert said. \u201cThose drive the technology that you use, the treatment process that you use to achieve those limits, and those treatment technologies become more complex \u2014 and they\u2019re also not what we have in place right now, so we have to get them in place so we can meet our permit limits.\u201d Getting older Sewer plants are supposed to be upgraded every 20 years, and it\u2019s been 24 or 25 years for District I; but the town has been working with the DEEP. Another problem the project will address is aging facilities. \u201cYou\u2019ve got two treatment plants. It\u2019s kind of the end of their useful life,\u201d said Siebert. \u201cWe\u2019ve been keeping them going. But when you think Route 7 was 1985 approximately, and when I was looking over the plant at South Street, some of the facilities are from 1968, original equipment ... \u201cWhen you have equipment from a 24-7, 365-days-a-year tough environment, it comes time to replace it. Some of our big drivers for this are certainly condition \u2026\u201d \u201cMotors, pipes, general infrastructure,\u201d said Marconi. \u201cInstrumentation,\u201d added Siebert. \u201cYou even have to look at the building,\u201d she said. \u201cWhen you do a facilities plan you have to do everything from soup to nuts \u2014 your building, HVAC, roof structures. You want to look at the integrity of your tankage. \u201cYou really give everything a good hard look because, clearly, that the kind of infrastructure you don\u2019t want to fail,\u201d Siebert said. \u201cYou want to keep that stuff working.\u201d Plant capacity The South Street plant\u2019s current capacity is 1 million gallons a day, and it\u2019s running at about 850,000 gallons per day \u2014 when the weather is dry. \u201cIt\u2019s quite variable when it rains,\u201d Siebert said. \u201cIt depends on how wet it\u2019s been and how big the storm is.\u201d \u201cIt could be up into the millions of gallons per day,\u201d Marconi said the volume that goes through the plant. \u201cWe could go from 850,000 up to 3.5 million. We\u2019ve hit 3.4 million.\u201d With the addition of the District II plant\u2019s 120,000 gallons per day capacity, the renovated plant will have a capacity of 1,120,000 gallons per day \u2014 just what the two plants handle today. \u201cWe\u2019re not expanding capacity,\u201d said Siebert. \u201cNot beyond what we currently have, for in-town, and Route 7,\u201d Marconi added. Efficient treatment The project is being designed to improve the quality of treatment, not add capacity in order to handle more development \u2014 a possibility that was hotly debated when the Planning and Zoning Commission was barraged by 8-30g affordable housing applications. Those were halted by a moratorium granted by the state, but that four-year moratorium ends in the fall of 2018. \u201cWe\u2019re building it to handle current build-out assumptions,\u201d Marconi said. \u201cThat doesn\u2019t include any 8-30g assumptions.\u201d To keep the needed capacity \u2014 and project cost \u2014 down, the town has had a continuing initiative to reduce \u201cinfiltration and inflow\u201d into the village area sewer system, which dates back to the early 1900s. That meant replacing cracked pipes and the like, but also searching out illegal connections where properties pump storm drainage and water from basement sump pumps into the sanitary sewer system \u2014 pushing up the needed treatment capacity with what is essentially rainwater. \u201cWe\u2019ve also done a lot of work over the last several years to the wastewater collection system,\u201d Siebert said. \u201cIf you have a pipe that is older and you have a crack, that allows groundwater to get in. We\u2019ve made a number of improvements to the system: We\u2019ve address pipes, manholes, we\u2019re addressing the illegal sump pumps. \u201cIt was important work to be done before designing a treatment plant upgrade, because it\u2019s work that removed the extraneous flow,\u201d Siebert said. \u201cWe wanted to make the plant more efficient, first,\u201d Marconi added. Efficiency was also part of the decision to close the District II plant at 7 and 35, and pump that waste down Route 35 to the center of town for treatment at South Street. \u201cLong-term cost benefits,\u201d said Marconi. \u201cWe did try to look at it on the 20-year basis, to look at both the capital costs and operating costs over that period \u2014 and in that case the analysis showed it certainly is cost-effective to bring Route 7 over,\u201d Siebert said. The approach will push up the initial design and construction costs, however. \u201cThe cost estimates include the pipelines, the pump station and decommissioning of the Route 7 plant,\u201d Marconi said. Paying for it With the cost potentially is the $30-million vicinity, another issue that will eventually have to be tackled is how to share paying for it. In the previous upgrade of the village sewer system, all town property owners shared in a portion of the cost through general taxes \u2014 although properties on the sewer system, which clearly get more benefit, carried another portion of the cost by themselves, through increased hook-up and use fees. When the Route 7 plant was done, the vast bulk of the cost was put on the users. One argument for having all taxpayers share some of the cost is that the plant treats the waste generated when properties off the sewer lines have their septic tanks pumped. Another is that sewer system benefits the entire town by allowing there to be a more densely developed area, with commercial and multifamily buildings that create a town center \u2014 and pay a lot of taxes. \u201cThose discussion haven\u2019t taken place yet,\u201d Marconi said. The preliminary facilities plan for the sewer plant project is available in the town\u2019 clerk\u2019s office of town hall, the Water Pollution Control Authority office in the town hall annex, at the library, and the plans will be posted on the town website under the Water Pollution Control Authority (WPCA).