ORLEANS — The site plan review committee is on board with the final design for the town’s proposed wastewater treatment facility at Overland Way. Plans were approved last week subject to information in the final submittal.
Tom Parece, senior program director for town consultant AECOM, said the site plan’s OK was one of “a myriad of permits” needed before the project is submitted for SRF (state revolving fund) loan approval. He said the conservation commission gave its nod Sept. 17, and the Old King’s Highway Historic District Commission will weigh in Oct. 3.
Now at the 100 percent design stage, the facility at the site of the demolished Tri-Town Septage Facility will have a capacity of 350,000 gallons per day. There are three major structures: a processing building, one for equipment storage, and the big SBR (sequencing batch reactor) tanks.
“The project was funded at town meeting last May and is on schedule for zero percent SRF funding,” Parece said. The plant will handle sewage from the new downtown collection system as well as future flow from the Meetinghouse Pond area when that collection system is constructed. Sewage will flow into the plant, receive treatment, and be pumped out as effluent to wick wells on Lots Hollow Road for dispersion.
The Overland Road site “is laid out so that we can mirror-image it,” Parece said. “If the town needs to expand, we can just mirror that building and build two more SBRs on the back side.”
Parece said the plant will use the roadway that serviced the Tri-Town facility and will add two more hydrants to the site. Fencing will be repaired and new sections added, with chain link replacing collapsed stockade fencing. The existing gate will be moved closer to the new plant to avoid wetland areas.
There will be three locked means of access to the site: the main gate, a location on Oak Ridge Lane, and along the Cape Cod Rail Trail. All will have lock boxes for emergency access.
Parece said septage haulers will use a key pad at the main entry, and town personnel will have garage clickers. Security cameras will be mounted at the gate and inside and outside the building.
The main building’s facade “mimics a little bit what the old treatment plant looked like,” Parece said. “We tried to enhance the construction materials so it’s longer-lasting.” Integrity of the metal roof will be maintained by having chimneys for exhaust.
Speaking of exhaust, Parece said the facility will have an odor control system using activated carbon. A fan will pull air from the septage receiving area and the sludge holding tanks.
The two sequencing batch reactor tanks are open inside a building, but Parece said “the more stinkier air is all in enclosed tanks below grade.” Walls, floors and the ceiling will get a high-protection painted epoxy treatment.
Health Agent Bob Canning wanted to know about odors from the reactor tanks. “There’s no odor control off of those,” Parece said. “It’s a tried and true system. It’s more of a musty type smell, not that rancid odor with raw wastewater or septage.”
“The composting that was there before caused a musty odor,” Canning recalled.
“The compost was much worse than what you’ll (smell) here,” Parece replied.
Septage haulers will be directed to a garage bay area opened by a keypad. Another keypad inside will close the door; without that step, the system for pumping will not start. When they’re done, the haulers will punch in a code, the doors will open, and they’ll be on their way. In a set time, the doors will close again, all in the service of controlling odors on the site.
Water Superintendent Todd Bunzick left the dais to lean over Parece’s set of plans and point out areas where water lines and those for influent and effluent might come together. “We need to pay attention to wherever we’re crisscrossing,” he said. “We want to make sure there’s some separation.”
In response to a question from Canning, Parece said wastewater generated at the facility will pass through floor drains and be treated there. He confirmed to the health agent that there would be no composting and that separated sludge would be taken away by pumper truck.
Canning moved for site plan approval subject to submittal of a final record plan, which is likely to be sizable. “We’ll find a nice table to put it on,” Planning and Community Development Director George Meservey said. “It would be useful to have an electronic version and one in town hall.”