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From BioCycle Journal of Composting &Organics Recycling November 2001, Page 30 |
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EDUCATION AND MORE
MISSOURI SCHOOL OPERATES AN IN-VESSEL COMPOSTER
“We’re the only high school in the United States that has an
in-vessel composting project on campus,” declares biology teacher Mike Collins of Reeds Spring, Missouri.
ONE TEACHER and an enthusiastic bunch of students are on a mission, winning awards and recognition from environmental agencies in the process. Biology teacher Mike Collins and his students run an in-vessel composting facility at the Reeds Spring High School campus, known as The “R” Project. They also recycle cardboard and aluminum.
“We’re the only high school in the United States that has an in-vessel composting project on campus,” Collins says of the system the school district began using with the ribbon cutting symbolically taking place on Earth Day, April 23, 2001. The composting facility serves the 2,200 student district providing ways to reduce disposal costs, offer educational opportunities, and generate income from end product sales. And the “R” in the name doesn’t stand for just Reduce, Reuse, Recycle, but for Respect Reeds Spring Schools as well.
In the Reeds Spring School District, 74 percent of the waste stream are food and paper — much of it from cafeteria tray food residuals, nonrecyclable paper and food wrapping. This means that 74 percent of the district’s waste stream goes into the in-vessel composter. The district will save about $11,000 in waste disposal annually, Collins estimates. During the nine-month school year, diversion rates should be about 40.5 tons of paper, 9.2 tons of cardboard and 52.2 tons of food residuals and yard trimmings.
HANDLING FEEDSTOCKS
Unloading, raw materials handling, compost processing and curing, and final compost storage all happen in a 40 by 80 foot building on the high school campus about 500 feet from the school. Capital costs of $137,500 includes the Wright Environmental Management equipment, which includes a biofilter, and the building. The composter is under static pressure and a fan forces air through the biofilter — containing mushroom compost and other organics. The odorous particles attach to the organics, filtering out 98 percent of the odor. So far, the district has not had any complaints about odor and there are houses less than 600 feet away from the facility. Leachate and wash water are routed from a floor drain to a sealed underground holding tank. Collins estimates the tank will be pumped once a year and the material will be sent to the Bronson West Water Treatment Facility. The Missouri Department of Natural Resources (DNR) gave the school district a $100,000 grant for the project and the district is paying the balance.
“We did a waste characterization survey a few years ago and determined that 18 percent of our waste stream statewide is food waste,” says Philip Tremblay, public information specialist for the DNR. The state was looking for ways to divert food residuals when the Reeds Spring proposal came across its desk. “Needless to say, we were very supportive of the project,” adds Tremblay.
CAFETERIA SORT
Students at all of the schools, from elementary to high school, sort tray waste at the end of the cafeteria periods. There are designated bins for compostable materials, such as food residuals, paper towels, napkins and most packaging. There are separate bins for uncompostable materials and bins for aluminum cans. The students are educated at the beginning of each school year on what materials are compostable. Colorful posters on the cafeteria walls serve as reminders in the primary, intermediate, middle, and alternative schools. Right now, the students are separating with 90 percent efficiency as far as keeping contaminants out of bins, Collins says, and should be up to 95 percent efficiency by the end of the school year.
The food service director plays a large role in the high success rate, Collins notes. That person has been educated about compostable packaging and buys only from vendors that meet standards set by The “R” Project. Such standards include biodegradable, minimal packaging made from recycled materials. At the high school, members of The “R” Project Public Relations Team, made up of a dedicated group of students, also present educational programs to their peers and to the community on composting in hopes of increasing awareness and compliance. Staff at the schools and in the administration are asked to separate plate waste as well. Together, 2,450 people — 2,200 students and 250 staff — are working hard to divert materials from the landfill.
GETTING THE JOB DONE
The school district hired a part-time operator to aid in the composting process. He is responsible for collecting the separated materials from all of the district’s schools at designated pick up sites, and for processing, evaluating and monitoring the project. School custodians take the separated materials from the cafeteria to those sites. After the daily pick ups are made, the organics are brought to the high school’s recycling center.
Shredded white paper and yard trimmings are combined with the organics in the machine, which has a mixing unit. The machine has the capacity to handle 750 pounds/day; typically, the district uses about 90 percent of that capacity. However, the throughput could be doubled if the retention time was cut from 28 days to 14 days and the curing period was extended.
For now, the district is using the 28-day retention schedule. Collins expects that capacity to be suitable for the next three to five years. With a growing student population, however, he expects to switch to a longer curing period at some point. “That’s one of the reasons we went with this system. It meets the needs of the growing district and we won’t have to change the technology at all,” he says. Temperature in the composter is maintained at 135° F during the initial 14 days, then drops to 125°F for seven days during the second phase, and remains at that level for the third phase. Oxygen levels are maintained at 15 percent to ensure adequate microbial activity while the mixture moves through the phases on a floor tray. After the 28-day cycle, the mixture is moved into another section of the machine where it is fluffed by spinners and then augured through a wall to the 40 by 20 foot curing room next door to the 40 by 60 foot processing room. After one week of curing in aerated static piles, the finished compost is ready to be marketed. Biology students monitor the piles and chemistry students analyze the finished product to ensure state standards are met.
The final compost is sold in 40-pound bags for $3.75 and in bulk. The bulk price needs to be determined for this school year, Collins says. The local Wal-Mart carries the bagged product and students also sell it around Arbor Day and Earth Day. Some of the compost is used on school grounds as a soil amendment and for erosion — and the uses don’t stop there.
“We find ways to work compost into lots of lesson plans,” says Collins, who recently received the state teacher of the year award and is one of three candidates for national teacher of the year. Touted by his students as a great educator with a fun, hands-on approach, the biology and botany teacher educates students on how to use the compost as a soil additive in the school’s greenhouse. The plants grown there also are sold to the public.
Although a lot of the work involved with keeping the project running is done by science students, and The “R” Project is sponsored by the science department, Collins is quick to point out that it is a school-wide effort. “The English classes write newspaper articles about it. The math classes use it for math problems. Communications, printing and art classes all benefit from this.”
Members of The “R” Project estimate compost sales will raise $9,000 annually. Some of that money will help with operating costs and some will go toward a scholarship fund. The Reed Springs project also is helping to inspire local communities and residents to recycle. “In a state where each person produces 1.84 tons of landfilled waste annually, it’s good to see a project like Reeds Spring bring attention to composting and recycling,” says DNR’s Tremblay. — A.S.
For more information about the project, e-mail Mike Collins at mcollins@wolves.k12.mo .us
www.jgpress.com
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