IN MINNESOTA, the land of 12,000 lakes, we are experiencing new challenges in protecting those lakes as well as our rivers from growing population and development. According to a recent Minnesota Solid Waste Policy Report, waste generation rates rose four percent over the previous year, and over 50 percent more solid waste is now being landfilled than incinerated in resource recovery facilities. Waste generation has been growing faster than population. And if present disposal trends continue, 41 million tons of waste from 2003 to 2015 will be landfilled. About 14 million tons of this amount will be organic materials (which are 36 percent of the waste stream).
The state solid waste hierarchy goals minimize landfilling as a management option and support reduction, reuse, recycling, source separated composting and resource recovery as preferred options in that order before landfilling. Clearly, we are moving in the wrong direction.
ORGANICS RECYCLING PROJECTS AND FACILITIES
Numerous Minnesota communities have instituted organic waste recovery projects and/or facilities. They include:
City of Burnsville - received a grant to collect organics in one neighborhood involving 900 citizens - pilot project was successful with citizens liking it and with less than five percent contamination in the biodegradable bags.
City of Wayzata - collecting residential organics since 2003 with over 189 tons of food residuals/soiled paper being collected and composted at a nearby compost facility, NRG-Processing Solutions (NRG-PS). Residents have opportunity to lower their level (e.g. from a 90 gallon cart down to a 60 gallon cart) and frequency (every other week) of garbage service to offset the added cost of collecting organics.
School children in Dakota and Hennepin Counties source separate their food lunch residuals.
Commercial organics collection of 950 gallons/day from Kowalski and Rainbow Foods to deliver to Endres Processing where it is made into animal feed.
City of Hutchinson - Creekside Organic Material Processing - composts 2,000 tons of source separated organics/year. Sold 180,000 bags of compost to date.
City of Duluth/Western Lake Superior Sanitary District - Since 2001, focus on commercial and institutional food waste recovery pickup and residential drop off at new compost facility near the shores of Lake Superior.
NRG-PS - Rosemount - permitted for 150 tons/day organics and 300 tons/day mixed solid waste. NRG composts commercial and residential organics in aerated bags from Versa Corporation.
There are, in addition, three solid waste compost facilities operating in Minnesota: Prairieland (near the Iowa border); A newer facility in Dodge County; and a source separated compost/recycling facility in Swift County. In 1992 at the St. Louis, Missouri BioCycle Conference, I gave a presentation on the then eight solid waste compost facilities in Minnesota. For various reasons, six of those are no longer operating.
Yard trimmings is, for the most part, composted separately and is a success story. A ban on landfilling or incinerating leaves and grass clippings has been in effect since 1992 throughout the state. The number of permit by rule community yard trimmings sites have since fluctuated slightly with 78 to 89 facilities and 540,000 cubic yards - 940,000 cubic yards of material being received annually during any given year. Markets are strong and one facility in Olmsted County reported that they had to turn away people who wanted the compost long after it ran out. A recent waste composition study by R.W. Beck, Inc. in the metro area did not find any substantial amounts of yard trimmings when they did a waste sort, pointing to the success of the decade old yard trimmings disposal ban.
In Minnesota, seven landfill owners have sought and received permission from the Minnesota Pollution Control Agency (MPCA) to recirculate leachate under the recent amendments to the MPCA Solid Waste Management Rules that reflect the EPA Research, Development and Demonstration project (RD&D) rule. Landfills that recirculate leachate are still in a pilot mode and data is still being collected. In addition, there are four landfills in Minnesota that utilize gas-to-energy systems, providing 24 megawatts of energy. It is too soon to determine if the post-closure care time will be greatly reduced by recirculating the leachate and speeding up the decomposition of the organic fraction. It is also too soon to determine if more methane gas, a serious greenhouse gas, will escape into the atmosphere.
Another concern is that by landfilling the organic fraction of the waste stream, the nutrients in the organic wastes will be contaminated from mingling with household hazardous waste, heavy metals and other contaminants. Even if the residual organic fraction could be recovered from a landfill, it may not be suitable for farming or landscaping purposes.
WAYZATA CASE STUDY
One impediment to curbside collection of organic wastes in the Metro area is the increased transportation costs of hauling separate loads of organics to transfer stations or compost facilities. One way to ensure cost-effective, adequate volumes is to offer organized collection. The Metro located NRG-PS compost facility is under capacity and has the pad space to double its food residuals composting. However, due to increased costs from hauling just organics, few generators are able to provide them with more feedstock. Most of its food residuals currently come from Hennepin County, which includes materials from the City of Wayzata (a city near Minneapolis), school districts and a correctional facility.
The City of Wayzata is an excellent case to emulate as they have demonstrated how to operate a cost-effective curbside food residuals recycling program (See p. 28, August 2005 BioCycle). Although it costs $40,000/year more to collect food residuals and nonrecyclable paper each week, the Wayzata residents can choose a smaller trash container and every other week collection of their trash. The bill then can actually go down, from $12.50 to $9.75/month. One company, Randy's Sanitation, hauls all of the city's trash and organics and is very supportive of organics recycling.
The organics that Wayzata residents place out on the curb each Monday comes back to their community gardens as compost from NRG-PS. Since the two-year organics recycling pilot program began, there has been a 12 percent decrease in trash and a 23 percent increase in recycling as residents became more thoughtful about separating their waste. The city's director of finance, David Frischmon, convinced the city council that organics recycling made economic sense and the council has voted to continue the program. “It was a win-win situation where diverse members of the community found they had more common ground than differences,” said Frischmon. The success of the program is also due to the talents and skills of the neighborhood recycling coordinators who do everything from putting signs up in their front yards to answering questions from their neighbors.
In summary, food residuals, if thrown in landfills, create leachate and greenhouse gases. They also don't burn well in solid waste incinerators. The MPCA encourages resource conservation and considers food residuals an important resource because of their nutrients and well established benefits as a soil amendment. As population and waste generation increase in Minnesota, waste generators, the compost community and government need to continue to work cooperatively together to protect our natural resources.
Roberta Wirth is a biologist with the Minnesota Pollution Control Agency (MPCA) who has worked on compost and feedlot rule writing and implementation, solid waste training and stormwater issues. The opinions reflected here are those of the author.