Those who visit Fairfax County’s new “Compost Outpost” program at the I-66 Transfer Station in Fairfax should head straight for the pair of green metal shipping containers and stick their heads inside.
The nutrient-rich compost in the making is the best thing they’ll smell at the solid-waste-disposal site.
Fairfax County Department of Public Works and Environmental Services (DPWES) officials and contractor Compost Crew cut the ceremonial ribbon April 5 on a two-year, $100,000 pilot program that converts food waste and other organic materials into a soil amendment that’s ideal for agriculture.
“What’s the difference between dirt and soil?” DPWES Director Chris Herrington asked rhetorically. “Dirt’s what’s under our fingernails. Dirt’s what we sweep off the porch at the end of the day. Soil is life. Soil is alive. We humans are literally alive because we have soil.”
But soil is finite and fragile, requiring 20 years just to produce 1 millimeter of it, Herrington said. Programs like the composting initiative help return carbon to the soil, thus sustaining life, he said.
The Virginia Department of Environmental Quality approved the initiative, which is financed by the county’s Zero Waste Team and hosted by the Solid Waste Management Program and Compost Crew. The company won the contract for the project last fall and began composting this spring.
“Fairfax County has been awesome to work with,” said Compost Crew CEO Ben Parry. “They are a breath of fresh air in terms of being open to ideas, looking down the road. They have a great vision.”
The pilot program represents a closed loop where food waste and organic materials are processed to something beneficial on the same site, he said.
“That doesn’t happen with any of the other materials,” Parry said. “None of this stuff gets tossed in the ocean somewhere [or] put into a landfill. We are making healthy soil.”
The Fairfax County project is the fourth undertaken by Compost Crew in the Washington region. The company also has three operations on farms in Maryland, one in Montgomery County and two in Prince George’s County.
A Maryland farmer who received some of the resulting product said its quality was “amazing” and had allowed him to increase crop yields and reduce fertilizer costs, Perry said.
The program’s compost-fodder comes from 60 nearby households and a residential drop-off area at the I-66 Transfer Station, said Julie Williamson, Compost Crew’s supervisor of composting operations.
The company processes about 1 ton of food scraps per week at the Fairfax County site and sorts them by hand to reduce contamination from non-compostable items such as plastic bags and those little stickers grocery stores often apply to produce.
Recycling food scraps is “extremely easy,” said Kristie Blumer, Compost Crew’s senior composting director. Homeowners can keep food scraps in paper bags in the freezer, then transfer the bags to 5-gallon buckets and take them to the I-66 Transfer Station.
Residents should not place pet feces in the compost materials, because of pathogens, nor add aluminum foil, which will not break down. Paper not stained by food may be composted, but recycling is the preferred option. Food containers should not be composted unless they’re marked “Compostable, BPI-certified.”
A bit of residual grease from cooking is fine for composting, but residents with massive amounts – say from deep-frying a turkey – should recycle it instead, Blumer said.
Residents may bring meat, bones, shells and dairy products for composting at the site, but should avoid composting them at home because those items are difficult to break down or produce unpleasant odors and attract rodents, Blumer said.
After sorting the dropped-off materials, Compost Crew performs aerated, static-pile composting, which requires the addition of more wood chips than would be required if workers were turning the mixture frequently, Williamson said.
The company blends one part of nitrogen-based composting material with three parts carbon-based wood chips and leaf mulch, which also are produced at the county facility. Workers then add water, blend the materials and place the resulting homogeneous mix in the sea-shipping containers.
The containers have open fronts that are covered about halfway up, like horse stables, with blow-torch-charred boards. The resulting carbon layer is not merely a decorative way of highlighting the boards’ grain, but makes them resistant to the elements and not in need of paint, stain or another finish, Blumer said.
The corrugated-metal containers, which are locally sourced, have a rodent- and waterproof aeration chamber below. Blowers behind the containers send air through the chamber and up through holes in the floor for 20 minutes at a time, with equal intervals off in between.
Wood chips in the compost mixture ensure that air permeates it sufficiently and helps break down the material, Blumer said.
The compost mixture heats up quickly and stays at roughly 135 degrees Fahrenheit for three days in order to kill seeds and pathogens.
The composting process takes about three months. After four weeks in the containers, workers remove the material, which by that point should have no discernible food scraps – except for onions.
“Those things are bulletproof, I swear,” Blumer said.
The compost then will spend another four weeks in a secondary wind-fed system, then cured for an additional four weeks before being offered to residents at the site for free.
The composting initiative is but one example of DPWES employees’ myriad duties, Herrington said.
“It is difficult to keep this county running, so anytime we do something new or we take initiatives to be innovative, we’re doing that on top of everything else that we do for this county every single day of the year,” he said.
