REDUCING FLAMMABLE BRUSH
OREGON COMPOSTING PROJECT SERVES MULTIPLE PURPOSES
Preventing wild fires and improving air quality were some of the motivating forces to get a collaborative program underway in the Deschutes National Forest.
Molly Farrell

ANEW composting operation for a resort community in Sunriver, Oregon is filling several needs: Helping prevent forest fires, improving air quality, reducing disposal costs for the resort’s biosolids and yard trimmings, and enhancing the area’s notoriously poor soil. A mix of year-round homes, summer second homes and vacation rentals, Sunriver is located right in the middle of the Deschutes National Forest, which poses a serious fire danger to its residents. The danger had been mitigated in the past by “ladder fuels reduction,” a forestry term meaning cutting away lower brush and branches that can carry fire up a tree, and thinning overcrowded trees and brush. The brush then was collected by Sunriver’s public works department and taken to a meadow and burned, but some residents complained about irritation from the resulting smoke.

After major wildfires destroyed several million acres of land in the western states in 2000, Congress appropriated funds for fire prevention and burned area restoration through the National Fire Plan. “Oregon was not as badly hit by fires as other states but there were significant fires in Montana, California and New Mexico,” says Jeffrey Rola, operations coordinator for the Deschutes Soil and Water Conservation District. “This prompted emergency management and forestry officials to try and treat wild fires with prevention instead of attack.” Rola successfully applied for an $89,000 grant from the National Fire Plan to compost the brush created by ladder fuels reduction in Sunriver. “There haven’t been fires in the Sunriver area, but there have been some close calls,” Rola explains. “There have been fires in nearby Bend that have taken out homes.”

Sunriver is located 18 miles south of Bend in central Oregon. Although it is part of Deschutes County, Sunriver is largely self-governing, and has its own fire, police, and emergency medical services departments, as well as its own utility company, Sunriver Environmental LLC. Sunriver and a neighboring community, Crosswater, had other organic materials that could be composted along with the ladder fuels, including treated biosolids and golf course trimmings. Sunriver Environmental LLC operates a sewage treatment plant that serves the 4,000 private properties of Sunriver and Crosswater and produces 1,000 cubic yards cy/yr of biosolids.

The two communities have three golf courses, Crosswater, Meadows, and Woodlands, each of which produce 400 to 500 cy of grass clippings and brush annually. Another 400 to 500 cy are collected each year from the local Sunriver Resort. What wasn’t being burned was brought to the Knott Landfill in Bend, the landfill closest to Sunriver. “It was costing us $20,000 each year in hauling and tip fees to get rid of it,” notes Terry Penhollow, vice president of Sunriver Environmental LLC. Rola says composting was a better alternative than burning or landfilling. “Burning degrades air quality and creates the possibility of out-of-control wildfires, and Oregon has limited landfill space,” he notes.

The composting project evolved into a collaborative effort of several organizations. The grant is administered by the Deschutes National Forest. Sunriver Environmental LLC took responsibility for handling the day-to-day operation of the composting site, with oversight from the Oregon Department of Environmental Quality. Participants also include the Sunriver Owner’s Association, the Crosswater Owner’s Association, Sunriver Nature Center, the Deschutes Soil and Water Conservation District, and other agencies.

The Woodlands Golf Course is irrigated with treated effluent from the Sunriver wastewater plant. Excess effluent is stored in a manmade lake and spread on lands located within a 375-acre parcel traded to Sunriver Environmental by the U.S. Forest Service in January 2000. Sunriver Environmental built the lake and installed two miles of pipe from the wastewater treatment plant to the lake site.

START-UP AND ODOR CHALLENGES

Three acres of the 375-acre parcel were set aside for the pilot composting project. Sunriver Environmental decided to use the enclosed aerated static pile system developed by Ag-Bag Environmental, Inc. of Warrenton, Oregon to compost the biosolids, chipped trees, brush and grass clippings. “The composting site is located within a quarter of a mile of Sunriver Resort, and we wanted to avoid odor problems that can happen with outdoor systems,” says Todd Penhollow, chief operator of the wastewater plant (and son of Terry Penhollow). Sunriver Environmental leased six Ag Bags — 200-foot-long cylinders, five feet in diameter — each capable of processing 85 tons of material.

The first bags were filled in June 2001. The utility’s inexperience with composting created some initial odor problems. “We got off on the wrong foot with Sunriver residents,” Penhollow admits. “We wanted to make sure that we had enough biosolids available for composting when the bags arrived, so we wrote an addendum to our biosolids management plan allowing us to store the biosolids. We built a berm and stored them according to Oregon’s DEQ requirements in a static pile. The biosolids went anaerobic and when we tore into the berm to mix the biosolids with the wood chips and grass clippings, it smelled. It was a big mistake on our part and Sunriver homeowners complained.”

To make sure this didn’t happen again, Sunriver Environmental filled the bags with biosolids and the other materials immediately after the belt filter press was run at the wastewater treatment plant, instead of stockpiling the biosolids. “We did that the whole month of June and had no further problems,” notes Penhollow. “The community has been great about letting us step a little further with composting.”

Later in the summer, another problem developed. The bags were set up on a hill above homes in Sunriver. “The Ag Bags have a ventilation system in which blowers force fresh air through them,” explains Penhollow. As temperatures cooled during the evenings, inversions caused winds normally blowing easterly from a higher elevation to draw back to a lower elevation from east to west. This blew odors into some of the homes, causing residents to complain. Sunriver Environmental solved this problem by installing timers and setting them to turn off the blowers from 8:00 to 11:00 p.m.

“It took a little time to work out the bugs in the pilot phase, but Terry and his crew learned fast, jumped on problems quickly and now have a very efficient operation,” says Kelly Walker, environmental manager of the Sunriver Owner’s Association and a member of the Deschutes Soil and Water Conservation District board. Walker, who wrote his master’s thesis on composting, teamed with Rola to help find a way to make composting a viable solution for Sunriver.

THE COMPOSTING PROCESS

The materials are mixed and chipped on one of the three acres at the compost site. During the pilot project, the wood was chipped with a Morbark brush chipper towed behind a pickup truck. In December, a rotary grinder was brought to the site to grind 1,250 cy of trees and branches. “We have the grinder on a contract and pay so much a yard,” says Terry Penhollow. A manure spreader was used to mix the biosolids with grass clippings and chipped brush and wood.

The compost recipe initially was four parts carbon to one part biosolids. Before filling the sixth bag, it was decided to use more biosolids and grass clippings, changing the recipe to three parts carbon to one part nitrogen. “We wanted to see how much biosolids we could mix in, because we want to use as much as we can in composting,” notes Todd Penhollow. Three hundred cy of biosolids were used in the pilot project. “In 2002, we want to use all 1,000 cy in composting,” he adds. The 3:1 recipe will be used when composting resumes in the spring.

The materials were composted in the bags for eight to ten weeks at temperatures reaching 160°F. “They can remain in the bags longer, and the longer the better,” notes Penhollow. For the pilot, the woody materials were ground before composting to a three-inch-minus size, and aftercomposting, reground to one-and-a-half-inch-minus size. “The regrinding really makes a fine product that’s 100 percent usable, so no screening is necessary,” adds Terry Penhollow.

One cycle of composting was completed in September 2001, producing a total of 1,100 cy of Class A quality compost from the six bags. “We’ve applied a little around the resort but most of it is still sitting there,” says Terry Penhollow. “We’re expecting that the biggest share will be used on the golf courses and by the Sunriver Owners Association.” The bags, which are not reusable, will be shipped to Agri-Plas Inc., an agricultural plastics recycler in Keizer, Oregon for recycling.

Rola and Walker will help market the finished compost. “Marketing is one part of the original grant because it’s the only way to make composting sustainable,” notes Rola. He does not anticipate problems selling the compost. “The area has notoriously poor volcanic soil,” he says. “We have two soil types: loamy sand and sandy loam. We have to apply a lot of chemical fertilizer, so from a soil amendment point of view, it’s a great opportunity in central Oregon. Organic gardening is important here, but consumers have a difficult time getting enough compost. Most suppliers are on the west side of the Cascade Mountains, 150 miles away, so freight costs are high.”

Composting is expected to start up again at the Sunriver site in March 2002. Sunriver Environmental is taking steps to transform the pilot project into a permanent composting operation. It applied to get the acreage on which the compost site is located rezoned to include commercial composting. The Deschutes County Board of Commissioners approved the site for composting in December 2000. “Now we have to have a siting plan approved by the Deschutes Planning Commission and Sunriver Resort,” says Todd Penhollow.

Next year, Sunriver Environmental plans to compost through the winter if it has sufficient sources of carbon. “The U.S. Forest Service’s and Sunriver Owner’s Associations ladder fuels reduction would provide us with sources of carbon, as well as wood and leaves brought by the public,” says Terry Penhollow. Sunriver’s public works department will haul owners’ brush and yard trimmings directly to the composting site next year. Sunriver Environmental plans to use ten to 15 Ag Bags a year. “We’ll probably fill two bags at a time,” he predicts. The initial bags will be paid for through the grant, and future orders from tip fees collected from Sunriver and Crosswater residents, the golf courses and others bringing grass, brush and wood to the composting site. Penhollow hopes that 2,000 yards of finished compost can be produced in 2002.

EXPANDING COMPOSTING TO OTHER SITES

Additional funding is available to expand the composting program to other locations. “The problems with composting here in central Oregon are the prohibitive costs of bringing wood and brush out from the woods, and processing and distribution,” he says. “The enclosed system and all the machinery are portable. You just need a few acres and access to power for the blowers to aerate the bags from inside. Because we can develop remote satellite sites with the Ag Bag system, we don’t have to pay prohibitive transportation costs and people won’t have to drive 20 or 30 miles to haul their brush.”

His agency is interested in creating similar composting systems in Deschutes County. This summer, other resort communities and agencies in the county were invited to attend composting demonstrations at the Sunriver site. “We’d like to see six or seven sites composting 50,000 yards annually,” Rola concludes.