Wastewater is spotlight at Old Post Road development hearing

By JEFF MORRIS 

The Planning Board on Monday continued a public hearing for the proposed mixed-use development at 633-647 Old Post Road in Bedford Village, next to the Bedford Playhouse, and it was focussed mainly on wastewater issues.

As part of their stated goal of conducting an extended series of meetings on the proposal, the board has limited discussion to particular aspects of the project at each one of these sessions.

This resumption of the public hearing was focused on issues that needed further discussion in Part III of the State Environmental Quality Review, said chair Deirdre Courtney-Batson — specifically, wastewater treatment.

Courtney-Batson said there had not previously been any public discussion of the wastewater treatment plant, and that gap was met by Bill Bright, senior project consultant with Delaware Engineering D.P.C.

The existing Bedford Playhouse building has its own wastewater treatment plant, and the plan is to utilize and upgrade that plant for the new building as well. 

Presently, Bright said, there are two subsurface sand filters or bioreactors. Wastewater comes out of the building, goes through a grease trap and goes into a 10,000 gallon septic; from there it goes into a 4,000 gallon septic, then into a pumping station with two pumps, one pumping to the upper sand filter and one to the lower sand filter.

The effluent flows through the sand, explained Bright; bacteria and micro-organisms grow on the sand, and they break down and oxidize the wastewater. It goes from there into a chlorine contact tank, where it is disinfected; the chlorine is removed, and it is discharged into a tributary of the Mianus River.

The current State Pollutant Discharge Elimination System permit flow, said Bright, is for about 6,700 gallons a day; it receives about 4,000 gallons, so “there is quite a bit of excess capacity in the existing system,” said Bright.

The planned treatment plant is called a “moving bed bioreactor,” said Bright, and it is actually the same technology as the existing plant. He said bacteria grows on buoyant media that floats in an aeration tank, and that is what breaks down the wastewater. From that it goes into a clarifier, then a filter, and then disinfection.

Bright said they have conceptual ideas on the design and do not have a SPDES permit as yet; they are working with the state DEC to get a draft SPDES permit for this project. He said the new facility will be designed to meet what the permit will be.

Board member Diane Lewis asked what becomes of the chlorine that is removed. Bright said there is a chemical reaction involving sodium sulfite that breaks down the chlorine, so there is no chlorine in the discharge.

Courtney-Batson asked if the new system would operate the same as the existing one. Bright said the future system will have some different aspects to it, being larger and using more modern technology; both Courtney-Batson and Lewis fixated on the fact that the discharge will continue to flow into the tributary of the Mianus River. Bright noted he has been working with this property for 15 to 18 years; he said there was a permit renewal in 2014, which upgraded the requirements.

“The plant works fairly well,” he said. “It puts out pretty good effluent right now, for a very, very simple system.” 

He said he likes it because it is simple and it works.

Bright said, based on what he’s seen in other draft SPDES permits, the new permit will probably have more stringent limits, probably on ammonia and maybe on phosphorus. He said he knows DEC in this region is going through a process of upgrading smaller facilities and upgrading their permits. 

“Whatever it is, we’ll be able to design something to meet it,” he said.

Bright noted the new facility would have a much higher flow rating, probably in the range of 20,000 to 30,000 gallons, and he described the discharge as “exceptional” and “crystal clear.”

An extended exchange between Lewis and Bright focused on the biology of phosphorus and the possibility of trace amounts remaining in the discharge, depending on the limits set in the permit. Bright said in all the upgrades they’ve been doing in the NYC watershed, they have brought phosphorus levels down to near zero. 

Courtney-Batson asked if there is any reason why even if the permit were not to have a phosphorus limit, the town of Bedford couldn’t impose its own limit. “I’ve never, in my 50 years in this business, seen a local community become a regulator for the quality of the effluent,” answered Bright. “It’s usually a DEP or DEC thing.” Courtney-Batson wondered if that was actually a matter of law; she mused that perhaps they could make history and become the first local community to do it.

Bright summed up with what the purpose of the treatment plant is.

“I will guarantee you that the effluent coming out of the plant will be significantly better than what the quality of water is in the stream right now,” he said. “That’s the whole 1972 Clean Water Act, that’s what it’s about: to take treatment plants and clean up the effluent so they’re better quality than the receiving stream.”

There was some subsequent discussion regarding the possibility of relocating the treatment plant away from the wetlands buffer, including a question from board member Michael Tierney about the possibility of putting it in the basement of the new building. Project representatives indicated they had not considered that, and noted many treatment plants are in wetlands buffers, but acknowledged they could consider alternatives. They asked if the board might move on to consider any other topics at this meeting, but Courtney-Batson made it clear that the hour was getting late and everyone was tired, so the public hearing was adjourned until May 11.