November 24, 2008 | General

West Yellowstone Tackles Composting Challenges

BioCycle November 2008, Vol. 49, No. 11, p. 26
With financial security assured, composting facility will invest in additional processing equipment resulting in a better product to further the success of its operation.
Kathleen O’Hern, Beth Pratt and Robert Spencer

JULY 2008 marked the fifth anniversary of the West Yellowstone Compost Facility (WYCF) in Montana, and the year in which the National Park Service assumed the facility’s debt – further solidifying its long-term relationship with Yellowstone National Park. This article updates the July 2005 article, “Composting Finds its Niche in Yellowstone National Park,” and sets the stage for a one day tour of the plant and the recycling programs at Old Faithful Inn scheduled for July 22, 2009 (see sidebar).
From New Mexico, north to Alberta, the remote location of smaller communities and associated distance to recycling markets is one of the largest challenges for successful programs, a fact illustrated by the relatively low rates of recycling throughout the Rocky Mountain region. Lower cost landfills made it more difficult to justify the higher costs of recycling and composting programs.
However, recent closure of many of these landfills is setting the stage for diversion. Available landfills can be 100 to 200 miles away. With rising fuel prices, many more communities are implementing recycling and composting programs. For some resort communities in the region, seasonal swings in quantities of both trash and recyclables can make it more difficult to finance the facilities and equipment, a situation WYCF had to address in order to make payments on the debt for its state-of-the-art solid waste management facility.
In the late 1970s, discussions in West Yellowstone began to surface about closing the local landfill. Several factors contributed to the pending closure. First, the small landfill was nearing capacity, and the special use permit with the National Forest, in which the landfill was located, made expansion difficult. Second, the landfill was located very close to the pristine Madison River, and concentrations of leachate from the landfill began to threaten the water table. Finally, several generations of black and grizzly bears had become habituated to feeding on the garbage at the landfill. The newly formed Interagency Grizzly Bear Study Team voiced concerns about the bears’ habit.
In 1983, the landfill was capped and the West Yellowstone Transfer Station was built. The Transfer Station was sized to handle waste generated in the region and the western portion of Yellowstone National Park. However, like in most western states, the region’s population increased dramatically during the 1980s and 1990s. At the same time, more and more vacationers were visiting the National Park, which increased its waste stream substantially. The transfer station was suddenly undersized.
Another factor during this time period was Yellowstone National Park’s ‘Greening of Yellowstone’ movement. This initiative motivated Park administrators to discuss waste management options with the Solid Waste District, which managed the transfer station. Sending the Park’s waste to the landfill via the transfer station was, of course, determined to be the least favorable option.
A waste characterization study determined that 60 to 75 percent of the transfer station’s incoming waste stream was organic material. Plans were developed to compost the region’s organic waste. The plan called for an in-vessel composting system housed in a building for product curing and refining. It would accept up to 6,000 tons/year (tpy) of MSW, with the majority hauled to the facility from June to September (vacation months). With $4.2 million in financing from Montana’s Revolving Fund Program, the facility was designed and built by Engineered Compost Systems (ECS) and Dick Anderson Construction. It opened on July 1, 2003.
The composting facility accepts an average of 40 tons/day from March to October. This amount dwindles to approximately 20 tons/week during winter months. During peak season, there are five full-time employees – plant manager, scale house operator and three equipment operators. During the winter months, the staff is reduced to the plant manager and two operators who use the time to screen compost in preparation for the following spring growing season, and to perform maintenance on the equipment.
The composting facility is integrated with a transfer station in an adjacent building. An 8-foot high electric fence, plus three feet of fence under ground, prevent bears and other wildlife from getting into the 13 acre site. Approximately 3,000 tons of MSW per year is transferred to the Logan landfill in Three Forks, Montana at a cost of about $100/ton. Operations and maintenance costs for the composting facility are approximately $130/ton.
Most of the MSW processed in the composting facility comes from Yellowstone National Park’s concessionaire-operated restaurants and hotels, as well as from the campgrounds, roadside bins, a few residences and the Park’s trade shops. In order to serve the host community, a small amount of source separated food waste is also processed from a few restaurants outside the Park in West Yellowstone, where the compost plant is located. A dual bag MSW collection system is used by hotel kitchens and restaurants such as Old Faithful Inn, the largest hotel in the Park. Clear bags contain food waste and other organics destined for composting; blue bags are for inorganic material. No construction and demolition material is permitted at the plant.
Packer trucks tip the mix of blue and clear bags onto the tipping floor. An excavator operator removes the blue bags from the tip floor, and pushes the clear bags onto the pit conveyor, destined for the composting process. If the operator notices significant amounts of inorganic material in the clear bags, those bags are treated as the blue bags and removed for transfer to the landfill.
From the pit conveyor, clear bags move to a lifting conveyor and into a Seerdrum Waste Processing Drum where water is added to facilitate the pulping function. Turning at 11 rpm, material is fed into the mixing drum so it spends about one hour tumbling and breaking open the plastic garbage bags. At the same time, dry material – particularly paper and cardboard – is absorbing moisture and starts to break apart, joining other material that is 5-inch minus in dimension. For paper and cardboard, this pulping action is an important function of the mixing drum so that it too will fall through the screen plate to be conveyed to the compost mixer. Since cardboard can take longer to break down, it is sometimes kept separate and fed in at a slower rate than other MSW.
Although the purpose of the clear bags is to separate organic materials, there is a significant amount of inorganic contamination in them, as well as an occasional entrained blue bag. Therefore, plastic, metal, glass and other inorganics also fall through the 5-inch screen plate to be screened out later. The inorganic and larger organic fraction not dropping through the screen becomes residue for landfill disposal.
The 5-inch minus fraction is conveyed to a Luck/Now Mixer manufactured by Helm Welding and mixed with horse manure and wood chips. The typical ratio is 6,400 lbs of MSW, 1,200 lbs of wood chips and 900 lbs of horse manure. In an effort to remove film plastic, a typical household window fan has been installed where the trommeled material falls into the mixer. It is diverting a fair amount of film plastic.
An inclined coreless auger conveyor moves the material from the mixer to an overhead coreless auger conveyor, which feeds a vessel-loading conveyor that can be moved to each of the seven ECS aerated concrete compost vessels (60-feet long by 10-feet wide by 10-feet high). The interior walls of each vessel are concrete, with a stainless steel-lined door, and stainless steel floor drains.
Depending on the volume of material delivered to the facility, it takes four days to load 175 cubic yards into one vessel, which is then closed and composted for a minimum of 14 days. The ECS Comptroller™ process control system records temperature at the top and bottom of the vessel in four different regimes in each vessel, delivering air based on set-point temperatures for each zone. The data is recorded by start date of each batch, and documents pathogen (PFRP) and vector attraction reduction (VAR) temperatures and number of days at those temperatures for each regime. Exhaust air is treated in an adjacent, covered biofilter.
After the 14 day (minimum) period, a front-end-loader removes the compost from a tunnel and constructs a 60 cubic yard windrow on the adjacent, negatively aerated curing floor where the material spends at least six more weeks. Windrows are turned weekly with the loader in a progression down the floor. If required, piles can be irrigated. Exhaust air is treated in a separate biofilter than the exhaust air from the ECS vessels.
From the curing floor, material is moved by loader to a hopper that feeds a bivi-Tec screen with 3/8-inch screen panels on the entire deck. Unders go through a Forsberg air-classifying destoner to separate small pieces of glass, rock and metal. In an effort to remove even more glass, screened material is cured for an additional week, and then run through the final screen a second time. Approximately 1,000 pounds of glass and other heavy materials is screened out of 60 cubic yards of compost.
It took a few years to develop a regional market for the compost. Yellowstone National Park – which uses compost for seeding its developed areas – local gardeners, landscapers and building contractors are now regular customers. A mine reclamation project in Dillon, Montana purchased approximately 1,500 cubic yards. Compost from WYCF sold out in 2008 at $15/cubic yard.
It is possible that the NPS will purchase most of the material in the next few years for use in revegetating an area where an old road is being removed. The compost facility manager also is looking at manufacturing an even higher quality compost made from manure, wood chips and source separated organics that has minimal glass or plastic contaminants, since it would command an even higher price.
As one of the partners in Gallatin County, Montana’s decision to build the WYCF, the National Park Service (NPS) has a direct interest in a financially secure composting facility that serves the Park and its concessions well into the future. Recognizing that operating costs were higher than anticipated, and revenues were insufficient to establish a reserve fund for future repairs and upgrades, the NPS worked with Gallatin County, the state and the Montana Congressional delegation to seek funding to pay off $3.7 million of remaining debt. The loan was repaid in full this year.
“With 17 more years of loan payments, which contributed to 20 percent of the NPS’s tipping fee, it was a good financial decision for both the County and the NPS, and our tip fee dropped from $207/ton to $166/ton, a savings of about $2 million over the next 17 years,” explains Steve Iobst, Chief of Maintenance for Yellowstone National Park. “This will allow the composting facility to make investments in additional processing equipment, such as an upfront system to better sort the organic material, which inevitably contains inorganic contaminants. We want to make an even better compost product, and plastic contamination is an issue.”
Iobst also anticipates the composting facility will serve other organic waste generators in Gallatin County (only a few restaurants currently take advantage of the reduced tip fee for organics), as well as adding some type of material recovery processing for recyclables. He adds that the $166/ton tipping fee is less than disposal costs, considering the nearest landfill is in Logan, Montana, 170 miles from Old Faithful Inn, and 100 miles from Mammoth Hot Springs. “Three years ago it was costing $146/ton for landfill disposal using our own trucks and drivers, and with higher fuel costs that number has increased significantly,” he says.
The issue of hauling distance also applies to markets for recyclable materials, and is a major challenge for the Park. Headwaters Recycling Services collects recyclable material in many areas of the Park, but it is still expensive, and there are portions of the Park that do not recycle certain materials due to the high cost of transportation to markets.
Capturing significantly higher percentages of recyclable materials, as well as organics, will require more sophisticated sorting and processing at the composting facility and a future MRF. “People have to recognize that it is a challenge to have millions of visitors from all over the world separate recyclables into different containers,” notes Iobst. “Therefore, a system that can process mixed recyclables may be the best long-term recycling solution.”
Xanterra is a major concessionaire for Yellowstone National Park and operates nine hotels, five campgrounds, 17 restaurants and nine stores. As the concessionaire in Yellowstone and numerous other national parks, the company takes its role of environmental stewardship very seriously. One of the primary areas of focus has been the management of solid waste generated by its activities.
The composting facility has proven invaluable in assisting Xanterra with developing waste reduction measures. Facility staff can easily identify problem spots as they observe all of Yellowstone’s garbage being deposited on the tipping floor. For example, the small plastic bottles from the in-room amenities offered to hotel guests challenged the composting process. To solve this issue, Xanterra switched to compostable bottles made from a corn-based material this year, which will divert approximately 280,000 plastic bottles a year from the landfill.
The company’s largest waste management initiative involves its food and beverage department. With 17 restaurants operating in Yellowstone at peak season, Xanterra generates a significant amount of food waste. All of its food and beverage employees are trained to sort compostable and noncompostable waste. For example, the chef at the Old Faithful Inn did the source separation training. Staff deposits nonfood and nonrecyclable items such as plastic wrappers into colorful blue garbage bags, while clear bags contain biodegradable items. This enables WYCF to easily identify trash suitable for composting.
Although sorting requires extra effort on the part of Xanterra’s kitchen staff, most employees embrace the idea of helping to transform waste into a useable product. Some have even taken field trips to the facility to observe the process. Xanterra has expanded the program into some of its office operations, and plans to broaden the reach into all departments in 2009.
Xanterra also has a comprehensive recycling program for all its Yellowstone operations, which diverted over 250 tons of material in 2007. It also recycles about 10,000 gallons of cooking oil and grease annually, and manure from stable operations is given to local agricultural businesses, or composted at the WYCF. Xanterra has converted to bulk dispensers in all fast-food operations instead of (or in addition to) individually packaged condiments, and recycles all used automotive batteries, tires, Freon, antifreeze and paint solvents in vehicle and building maintenance operations.
Delaware North Companies Parks & Resorts at Yellowstone (DNC P&R), a subsidiary of hospitality provider Delaware North Companies, assumed the retail contract to operate the 12 General Stores in Yellowstone National Park in 2003. In 2007, DNC P&R at Yellowstone diverted approximately 138 tons of materials from 21 different categories from the solid waste stream; in the past five years, 733 tons have been recycled or diverted. The highly successful program incorporates recycling, reuse and purchasing practices, and involves guests, residents and employees of the park. Over 400 recycling containers are located throughout Delaware North’s Yellowstone operation including the warehouse, food and beverage, and dormitory areas. Three new recyclable materials were added in 2007 – plastic film (shopping bags, shrink wrap and bubble wrap), Styrofoam packing peanuts and electronics.
“The warehouse trucks that deliver products to our stores pick up the recycling and then backhaul these materials to the warehouse in West Yellowstone, where they are then collected and sent off to recycling,” says Deb Holmstrom-Friedel, Environmental, Interpretive, and Risk/Safety Manager for DNC P&R at Yellowstone. “This backhaul method saves additional resources such as energy, time, staff and equipment.” Remaining trash is transferred to the West Yellowstone Composting Facility. In 2008, the concessionaire converted nearly all of its dishware and cutlery (e.g. forks, knives, spoons, straws, stir sticks, plates, bowls, to-go containers, and cups) used in its food and beverage operations to 100 percent compostable material.
All in all, between the composting facility, recycling and concessionaire landfill diversion initiatives, Yellowstone National Park expects to achieve a park-wide landfill diversion rate of 75 percent this year.
Kathleen O’Hern is Manager of the West Yellowstone Compost Facility. Beth Pratt is Director, Environmental Affairs, with Xanterra Parks & Resorts, Yellowstone National Park. Robert Spencer is a Contributing Editor to BioCycle.
Sidebar p. 30
THE Teton Conservation District in Jackson, Wyoming, in collaboration with BioCycle, is organizing a conference – July 19-22, 2009 – at the Snow King Resort in Jackson to address the unique issues of recycling and organic waste management in the Rocky Mountain region. Local landfill closures present opportunities for diversion, as hauling distances for disposal have increased dramatically, along with the cost. That same remoteness, however, presents challenges to economically accessing recycling markets. Conference sessions on July 20 and July 21 will highlight solutions along with opportunities to maximize waste diversion, and generate jobs and revenues for remote communities. Tours will be available of several commercial establishments that source separate organics for composting, along with the local recycling center. On Wednesday, July 22, there will be an excursion to Yellowstone National Park that includes a tour of the West Yellowstone Composting Facility and organics diversion at the Old Faithful Inn. For more information, email; updates will be provided at and on the Teton Conservation District’s website,

Sign up