January 30, 2004 | General

Source Separated Organics Pilots

Dan Emerson
BioCycle November 2003, Vol. 44, No. 11, p. 22
In any  city or county in North America, organic material comprises a significant share of the municipal solid waste stream. Estimates range from 10 to 50 percent, with consensus around the 20 to 25 percent level. Recently, in the Minnesota Twin Cities of Minneapolis and St. Paul, five pilot projects demonstrated the potential for source separation and composting of the organic fraction.
The five projects were developed under the auspices of the Solid Waste Management Coordinating Board (SWMCB), which works with the six counties in the Twin City metro region to set waste management policies and assist with collaborative projects. In June 2001, the SWMCB sponsored an evaluation of solid waste management in the region through a “Citizen’s Jury.” The jury recommended that 19 percent of the Metro Area’s integrated solid waste management goal be achieved through source separated organics composting. In 2002, the SWMCB approved five projects that were intended to study perceived barriers to source separated composting, primarily focusing on transportation and collection issues, education and other challenges for various classes of generators, including residential, institutional, commercial and special events.
The projects took place in four of the six counties in the SWMCB’s district — Carver, Dakota, Washington and Hennepin counties. The SWMCB provided partial funding for each pilot project; in some cases, counties put additional funds toward projects, which tested several different collection methods. The compostable organic material included food residuals and soiled paper products such as plates and napkins.
While the projects did not cause an overnight transformation in handling organic waste in the Twin Cities, officials from the various governmental units involved consider them a success. “The pilots have been really important in increasing awareness of organics and helping determine the effectiveness of different collection methods,” says Judy Hunter, a senior program manager with the Washington County Public Health and Environmental Department.
The Minneapolis suburb of Wayzata piloted a citywide, curbside residential organics collection and composting program. Weekly collection of source separated organics (SSO) began on April 7, 2003. Prior to the first pick up, all 1,200 households in the city received a 38-gallon cart, kitchen bucket, and three-month supply of biodegradable bags for collecting their SSO. Randy’s Sanitation collects the SSO, and brings it to the Hennepin County Recycling Center and Transfer Station in Brooklyn Park for inspection to ensure that nonbiodegradable contaminants are below threshold levels. After inspection, material is transported by Hennepin County to the NRG Processing Solutions composting facility in Empire Township in Dakota County. This facility is permitted to process SSO. (The company operates a number of yard trimmings only sites in the region as well). SSO are cocomposted with yard trimmings in CTI aerated bags.
To allow one driver to cost effectively pick up both garbage and organics at the same time, Randy’s Sanitation purchased a specially designed split truck. “We wanted to find out if collecting both at the same time would shift the economics and make collection of organics feasible,” according to John Jaimez, a planning analyst for Hennepin County. “However, we ran into barriers with the split-truck concept. There wasn’t enough organic material to fill that side of the truck.”
The truck is designed to be adjusted from a 50-50 to a 60-40 mix of trash to organics. “Nobody knew exactly how much organic material would be collected,” Jaimez adds. “In the first week, we found out the amount of trash to organics was really disproportionate. The trash side of the truck would fill up long before the organics side, so it would not be economically feasible to use a split-body truck. It would be hauling a lot of air when it goes to the dump. It’s possible that the split truck concept might work at some point in the future.”
Since the project began, Randy’s Sanitation has collected about two tons of organic material per week. “It’s been very clean, with very little contamination; we’ve been able to compost everything,” Jaimez reports. The project has been financed with a $52,000 grant from the SWMCB, matching funds from the city of $48,435 and $95,735 from Hennepin County. The pilot is slated to continue until the end of 2004.
During June and July, city and county officials mounted a public awareness campaign to increase both the number of people participating in the organics program and the amount of material collected. The average setout rate among city residents increased from 25 to nearly 35 to 40 percent. “At least once, it was over 60 percent,” notes Jaimez. Every residential user received an informational doorhanger on their garbage cart, and city officials appeared on local cable TV to talk about the program. Data gathered by the city indicated that during the month of July, 35 residential users were able to reduce the amount of garbage by enough to switch to a smaller collection container. “We’re hoping that if enough people decrease their trash service to save money, the city will be able to switch to every other week trash pick up,” he explains. Biodegradable bags are made available for purchase at local markets to residents.
The city of Burnsville, in conjunction with Dakota County, Waste Management and NRG Processing Solutions, identified residential neighborhoods to test the design and implementation of commingled collection of organic materials from residences. Biodegradable bags (Polargruppen) were used to collect organics. The Burnsville project involved about 900 households in the North River Hills housing development. The neighborhood was chosen partly because it has an active, volunteer residents’ organization that has worked on various solid waste issues.
A $31,000 grant from SWMCB financed the pilot. NRG composted a total of 12.5 tons of material during the six-month pilot, which ended in March. The city plans to continue collecting organics through the rest of 2003, according to Susan Bast, an environmental specialist for the cities of Burnsville, Eagan and Apple Valley. “In November, we plan to sit down and make a decision whether to go on,” she says, adding that the city, NRG and Waste Management would like to make it a permanent effort. “We’re continuing to look at it.”
A follow-up phone survey conducted by Decision Resources, Inc. found that 46 percent of Burnsville households participated. Survey respondents favored continuing separation and composting by nearly a 4-to-1 margin. Those numbers were encouraging, although “we would like to have seen more material composted. The tonnage might have been higher, however, there were some broken bags, and some problems identifying the bags because NRG didn’t have its sorting line up and running,” observes Bast.
Residents did not receive a discount on their waste hauling fees, although they were offered up to five yards of free compost from NRG’s Burnsville processing site. “There were a lot of positive comments from residents,” she says. “Many of them were really happy this program started and is continuing. Many commented they feel they are doing their part to help the environment by participating in this program.”
During the 2002-2003 school year, in conjunction with NRG Processing Solutions, BFI and Dakota County, the Independent School District separated and collected organic material in its buildings. The project was based on a May 2002 study of waste generated by 196 schools in the district, which showed that most comes from the lunchroom and has a high organics content. A waste sort done before the project began indicated that 77 percent (by weight) of the nine tons of daily generated waste was compostable. (The district already recycles office paper, cardboard, cans and plastic bottles.) The district received a $27,000 grant from SWMCB and Dakota County to design and implement the program, with the expectation that it could be replicated in other districts. The district-wide project actively engages 28,500 students and 4,000 staff (this is Minnesota’s fourth largest school district). During the school year, 1,050 tons of SSO were diverted to the NRG composting facility, resulting in a ten percent savings in waste hauling fees. Some schools also experienced increases in recycling rates of as much as 500 percent.
The pilot was initially planned for just three schools, but district officials decided to implement it in all 30 schools in a sustainable manner so it could be continued permanently, says Renee Burman, an environmental specialist with Dakota County. Officials hope the project will serve as a model for other schools in the area. That appears to be happening: In October, three additional school districts in Hennepin County (Minnetonka, Hopkins and St. Louis Park) were slated to launch a similar organics collection program, servicing 20 facilities in all. The county provided $65,000 in grant funding to the three districts. Other schools in Dakota County and the Twin Cities area have also expressed interest, Burman says.
Before the project, “many students and administrators didn’t even know the meaning of compost,” according to Burman. Students developed an 11 minute video describing the purpose of the project, created a district wide web site and individual school web sites, toured a compost facility, participated in pre and postwaste sorts, and made a presentation to a state policy group. “Everyone would define it as very successful,” she adds. “Before we started, even though the schools are required by state statute to recycle, it was pretty limited.”
Washington County worked with two local grocery store chains, haulers and NRG to implement a pilot collection and transportation system for organic wastes. In 2002, county officials enlisted the participation of Rainbow Foods in Oakdale and Kowalski’s Markets in Woodbury. (Twelve of 36 Rainbow Food stores and five of Kowalski’s Markets’ nine stores are located in Washington and neighboring Ramsey county). An evaluation of the stores’ solid waste practices indicated that organic waste management strategies offer the greatest opportunities to divert the largest volume of solid waste generated by grocery stores. However, an economic analysis indicated that such a recovery system would be too expensive to implement. In April, 2003 the county environmental charge (CEC) was set up by Washington and Ramsey counties, to be assessed to all businesses that generate solid waste. Washington and Ramsey counties established CECs of 34.2 percent and 56 percent, respectively. Fees are collected from businesses by trash haulers, based on the volume of waste they generate. Businesses also pay an additional 17 percent Minnesota state solid waste management tax. If materials are separated from the solid waste stream and managed separately — such as recyclables and solid waste — these recycling and organic waste management services are exempt from the CEC and the Minnesota state solid waste management tax.
In April, 2003, both Rainbow and Kowalski’s decided to develop organic waste management systems, diverting food residuals to Endres Processing in Rosemount. Endres makes livestock feed out of the residuals. Rainbow decided to include all 36 stores in its new system; Kowalski’s opted to convert all five of its stores in Washington and Ramsey counties, and is evaluating the economics of including its four remaining stores, all located in Hennepin County.
Before the waste handling charge became effective in April, businesses were “certainly interested in exploring and potentially implementing changes in the way they manage waste, but this got their attention in a way we never had before,” says Jodi Taitt, a Minneapolis-based consultant who worked on the project. “Economics will drive this; businesses will choose the least costly solution to manage waste. As long as the least costly solution entails organic waste management strategies, it will happen.” (A final report on the pilot, with collection data, is pending.)
Special event composting was piloted at the PGA Championship, held August 12-18, 2002 at Hazeltine National Golf Course in the Minneapolis suburb of Chaska. Food residuals and nonrecyclable paper were collected at the food tent and kitchen area. BFI transported the materials to NRG’s composting facility in Empire Township. Noncompostables in the load were transported to NRG’s Newport refuse-derived fuel plant for further processing. Carver County was the lead agency on the project. The collection method involved placing food residuals and nonrecyclable paper in separate containers lined with biodegradable bags.
Materials generated on the first two days of the event were not transported to the NRG composting facility due to the Department of Health not allowing uncovered containers within close proximity to areas where food was being prepared and consumed. After that problem was solved by moving the containers farther away from the food tent, BFI was able to collect and transport the materials to NRG on Wednesday through Sunday, where they were processed and composted.
Noncompostables in the loads, mainly plastic soda bottles and aluminum cans, were separated on the picking line. Other noncompostables included plastic cutlery and salad containers, and were removed during the final screening of the finished compost. The seven-day event attracted over 17,000 visitors who generated 750 tons of garbage. More than 12 tons of material were composted, including 70 percent food residuals and 30 percent cardboard and paper.
Although an overall success, the project did not proceed as initially anticipated. In addition to the collection challenge, the food tent staff proved to be too busy to focus on careful separation of materials and use of different bag types in different containers. Rapid turnover of staff was also a factor. Given this situation and after visually evaluating the contents of the waste generated, the PGA Ecology Committee staff decided to modify the plan by using biodegradable bags in all containers (except recyclables) and bring all material generated to the NRG facility.
While not all of the final reports had been completed as of September, 2003, the five SWMCB projects in the Twin Cities and the agencies involved consider them successful, according to Washington County’s Hunter. “They demonstrate that there is a lot of potential, and give us more direction in working with the various constituencies — the public, businesses, area schools, and other institutional waste generators.” Organics-rich businesses such as grocery stores, restaurants, schools, hospitals and nursing homes are targets with particularly high potential to divert large quantities of organics into composting. During 2004, the SWMCB wants to conduct a study of the public cost of providing organics management services, and determine how to encourage organics management without providing program subsidies.
A major issue is determining the most cost-effective methods of collection, Hunter concludes. “One of the areas we still need to look at from a business perspective is, how is this cost-effective? How do businesses save money? How do you create that without the need to continue to find money to subsidize something? And how do we make it financially viable? That’s still a key barrier we have to address.”

Sign up