Fall 2004
Back to the soil
by Amber Potter
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Red worms writhe in a bed of banana peels and coffee grounds. To escape the light, they retreat farther into their dark haven of food scraps. These worms are not the typical garden variety, not the type to sprawl on sidewalks after rain. These worms are urban worms, living three stories above ground in an 8-gallon Tupperware container under Nancy Bonnickson’s desk.
Bonnickson, the scientific lab technician for Western Washington University’s Huxley College of the Environment, smiles as she replaces the lid. Bonnickson employs the worms as her office composters.
“It’s convenient,” she said. “And the worms are my pets.
You can play with them; they take care of themselves, and they’re always there.”
Composting, the process of turning unwanted organic materials into useful soil, takes on a range of forms. Composting can be simple and low-tech, fitting nicely under a desk or kitchen sink, or it can be a career undertaking, involving extensive capital and devotion.
Unwanted food has several fates: into garbage cans, down garbage disposals or into compost piles.
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Green Earth Technology in Lynden uses Gore technology to compost green waste. |
Food waste from Bellingham garbage disposals travels to the Post Point Wastewater Treatment Facility. Waste stays in the secondary treatment plant an average of two days, which is long enough to fully break down all matter in the wastewater except food particles, said Peg Wendling, the lab supervisor of the facility. Any material not broken down is either incinerated or discharged into Bellingham Bay.
Though incoming waste flows have remained stable during the past 10 years, Wendling said the facility has seen an increase in the organic proportion of the flow.
“It is safe to assume this increase is a reflection of the increases in population using our system,” Wendling said. “We know food grinders are a large contributor to organic input.”
Organic matter increases stress on treatment facilities, so many treatment plants in the United States ban commercial and institutional use of food grinders, Wendling said. Bellingham, however, has no regulations prohibiting food grinders.
“I’m not in a position to recommend what folks do in their own kitchen,” she said. “But would we extend the life of the treatment plant and save the taxpayers money for expansion costs if we could reduce our organic loading to the plant? Sure we would.”
Food waste tossed into the trash enters a landfill or an incinerator, according to the Washington State Department of Ecology. In landfills, organic waste decomposes slowly because it is mixed with synthetic materials. Decomposition releases the greenhouse gas methane. Also, decomposing food can lead to the formation of leachate — water that can pick up contaminants and cause hazardous runoff, according to the Environmental Protection Agency.
While composting household waste is simple, large-scale composting is more complex. There are benefits to large-scale composting, as the breakdown of substantial quantities of waste produces beneficial soil amendment. Composting itself, however, is not without potential drawbacks.
The breakdown of plant material by bacteria releases nitrogen, creating the possibility of runoff contaminated with nitrogen or bacteria. Odor also can be an issue. For home composters, these are not great concerns, but commercial composters must carefully monitor their operations, said Joyce Jimerson, the program manager for Master Composter/Recycler, a cooperative extension of Washington State University that educates and trains people about home composting.
Whatcom County has had concerns about large-scale composting operations in the past. Recomp of Washington was a local incineration company that in the mid-1980s began operating a high-tech facility that composted garbage.
The Recomp site later became a mushroom substrate production site. The soil from its composted waste provided an ideal medium for growing mushrooms. But problems with health concerns and smell continued until its eventual shutdown, said Dave Bader, the environmental consultant for Ostrom Mushroom Farm in Whatcom County.
The biggest issue with Recomp was the smell, said Whatcom County Councilwoman Barbara Brenner, who was closely involved with the neighbors and workers of Recomp.
“The stench, the stench, the stench,” she said. “You know, they try to make it sound like it’s just another agricultural operation. That’s a bunch of baloney. It’s not like any farm, it’s not like any farm smell. There’s nothing like it — it’s a horrific smell.”
Brenner flipped through affidavits from community members, pointing to words circled on the complaints: “Gagging sensation,” “Absolutely nauseating,” “Really hard to breathe,” “Headache,” “Odor clings to back of throat,” “Tired of being sick.”
Public outcry resulted in the county adopting new composting regulations.
At Ostrom, mushroom substrate production is done outdoors, a practice prohibited in Canada. While outdoor production creates a better substrate, Bader said that indoor production allows composters to control odor and leachate emissions.
“I’d like to see them have to adhere to the same regulations as up in Canada,” Brenner said. “I’d like to see Ostrom’s have to (compost) indoors and stop causing such a horrific stench in the neighborhood. People hear of composting, and they think of motherhood and apple pie. But really, there are all sorts of aspects to it. I’m an avid composter. I’m a fanatic. But I feel like there are certain things, like you don’t cause pollution and public-health threats to people in the name of composting.”
With proper composting, Bader said, groundwater contamination is a remote possibility.
In April 2004, Andrew Craig, a water quality inspector for Ecology, investigated Ostrom. Craig determined the facility was degrading water quality because Ostrom’s wastewater- containment system overflows during periods of high precipitation. But Craig said water contamination is not an immediate health threat because Ostrom is located in a relatively isolated area.
Bader questions whether the water tested at Ostrom’s site indicated a safety concern.
“It just wasn’t accurate,” Bader said of the testing. “They never tested the groundwater itself. They tested the water at the surface and saw it had bacteria in it, and said that’s a threat to groundwater below. But bacteria filter out through the soil, and there’s no indication that composting actually creates groundwater contamination.”
The composting regulations implemented because of the Recomp experience have made it more difficult for new composting operations to establish in Whatcom County. But the county is home to two progressive composting facilities: Green Earth Technology and Living Soil Earthworm Castings.
Stephanie Harvey, a co-partner of Green Earth Technology, said it took a year and a half to obtain permits to open the composting facility. Having met with county regulations, Harvey said she feels secure in her relationship with the surrounding community.
Green Earth Technology is one of only two companies in the United States — both in Washington — that use Gore technology. Developed in Germany, Gore technology integrates composting with Gore-Tex fabric, a waterproof, breathable membrane sandwiched
between two polyester layers.
Gore technology allows Green Earth to control the undesirable effects of outdoor composting. The Gore-Tex fabric covering the compost heaps lets atmospheric oxygen diffuse into the pile but limits the escape of methane gas and odors, Harvey said. Leachate is collected and recycled back into the pile.
Green Earth composts only green waste: tree scraps, yard clippings and preprocessed foods. The company is testing a partnership between Sanitary Service Co. and Haggen Food and Pharmacy in which SSC transports old Haggen produce to Green Earth for composting.
Gore technology is expensive to implement, requiring the purchase of Gore-Tex membranes and an automated maintenance system. But operation and maintenance costs are low, and the
company can process up to 2,000 cubic yards of material a week.
“We had just two guys working out there, both part-time,” Harvey said. “It’s a high-tech low-tech operation.”
Living Soil, another large-scale composting operation in Whatcom County, composts not green waste but manure. The company uses worms to break down the manure, a process known as vermicomposting. Regulations require vermicomposting facilities to heat manure for three days prior to exposure to worms to kill E. coli and other fecal coliforms. Tests on non-pre-treated waste, however, have shown that passage through a worm eliminates fecal coliforms, making the heating process an unnecessary step, Jimerson said.
“There are a lot of things that happen when it goes through the gut of a worm that even soil scientists don’t really understand,” Jimerson said.
In a decrepit barn amid miles of lazy hills and drooping clouds, Curt Hawley, the site manager for Living Soil, squats next to a mound of dirt. Using his hands as a bowl, Hawley scoops some dirt and lifts it toward the gray light, revealing a few of the thousands of worms pulsing through the dirt.
Hawley is a retired potato farmer. He answered an advertisement five years ago, knowing nothing about worm composting.
“Seeing the material work, I thought, ‘This is great stuff,’ ” Hawley said. “I mean, it’s a great product; let’s do something with it.”
What comes out of the worms, called worm castings, is a biologically active soil amendment. Studies have shown that worm castings, unlike other compost, contain growth hormones beneficial to plants, Jimerson said. Worm castings are what Living Soil is seeking to make money on, marketing worm-casting tea bags for liquid fertilizer and worm-casting soil amendment in gold-foil packaging.
Back at the barn, Hawley’s worms occupy a deep trough. An automated system mediates the worms’ breakdown by loosening and mixing the material. The framework for the system must be replaced every five years, but normal maintenance is minimal.
“It’s really too easy, when you think about it,” Hawley said.
Hawley said he initially had no idea how beneficial worm castings could be as a soil amendment.
“I was really surprised,” Hawley said. “A friend of mine’s house burned, and the family Christmas cactus that had been around for four generations just kind of got fried. I said: ‘Here, take a couple of these tea bag. They’ll brighten it right up,’ and I had not a clue it was really going to work. It’s the greatest testimonial I’ve had. He said, ‘You’ve got to see that cactus!’ and I said, ‘No kidding?!’ ”