With limited grant funds available, Pennsylvania corrections facility and technology provider find a way to build in-vessel composter within budget and in-house.
BioCycle May 2012, Vol. 53, No. 5, p. 25
“We wanted something that was easy to operate and didn’t require a lot of manpower,” says Brown. “We have a jail to run — we just dabble in recycling. The system we built has automated controls and takes up a small space.” The unit includes three 10-foot by 20-foot vessels that can be filled with feedstock up to 9-feet high. It has the capacity to process 3,000 pounds/day of institutional food waste. With an average inmate population of 1,050, jail personnel needed the system to be operational 365 days a year. The in-vessel retention time is 21 days, after which the compost is windrowed for another two weeks before being utilized at the jail farm and for landscaping and other county projects both on and off jail property. The putrescible food waste is stored in a designated walk-in cooler prior to transport (weekly) to the composting facility.
The ECS SV Composter (stationary vessel) system can be built to almost any size up to a maximum size of 700 to 1,000 cubic yards. The arrangement for Berks County Jail (BCJ) to fabricate the vessels came about because by the time the jail had all of its funding, permits and related requirements in place, materials and other costs had grown beyond the institution’s budget to complete the project. ECS and jail administrative staff worked to find a creative way to move the project forward. “We sent architectural drawings of the vessels, along with mechanical and electrical drawings,” recalls Steve Diddy, business development director at ECS. “Then we shipped off our aeration and aeration control system along with technical assistance and a lot of encouragement.” The arrangement included signing nondisclosure agreements that protected ECS intellectual property and granted permission to construct the Berks facility only.
That was early in 2008. Diddy didn’t hear much from Berks County “until about four months ago, when we got a call from the jail and they said the SV Composter was ready for start-up,” he says. “Sure enough, they had been diligently building the vessels and making all the components in their shop and following our drawings. So we sent Chris Hibbard, ECS Senior Project Engineer, out there last month to start up the system and train the staff. It’s now fully functional and running.” Brown says the project came in at about a third of the cost of having it built by an outside contractor. Ultimately, she notes, the jail was able to utilize $100,468 of the grant funds, which also included purchase of a dump truck and other tools necessary for processing compost. Maintenance Officer Kenny Heffner with assistance from Maintenance Officer Marc Speece, navigated the plans, fabricated the equipment and constructed the vessels.
Design And Operation
The SV Composter has 100 percent capture of fugitive emissions; about 80 percent of the process air is recirculated with the balance sent to a biofilter for scrubbing. The vessel walls and ceilings are well insulated as are the doors. All doors exposed to the process air are stainless steel, and all other components in contact with the compost’s corrosive airstream are made with either stainless steel or polymeric material. There is an in-floor aeration system, and condensate/leachate is collected in the aeration floor and drained into a sealed sump. The SV Composter is operated as a batch system.
Currently, the composting vessels sit just inside the chain-link fenced and razor-wired secure perimeter of the jail. Plans are to move the fence line so that the building is just outside that perimeter, providing easier access to county employees bringing in carbon-rich materials. Green waste is ground into chips, and mixed in with the food waste using a skid loader. “All meats that come out of the kitchen are put in the composter, too,” says Pajski, adding that food served but not eaten is diverted to composting as well. “Hot dogs, Salisbury steak, peas, carrots — whatever comes back, I get.” Each vessel is wide enough to accommodate a skid loader, dump truck or backhoe, making it convenient for loading and unloading the material.
Under Warden George A. Wagner’s watch, the Berks County jail has historically composted. “We have windrows on the jail grounds not too far from the composter that we still maintain,” adds Brown. “We utilize equipment [such as skid loaders] to turn the rows. We do not have a turner, and we do not plan to screen.”