Philip Fauble and Gunnar Svavarsson

               Wisconsin Department of Natural Resources
            Bureau of Solid and Hazardous Waste Management


Yard waste composting facilities have steadily expanded in the state
of Wisconsin. There is some concern regarding these types of
facilities because, under certain circumstances, water percolating
through yard wastes can generate a leachate that could potentially
impact surface water and/or ground water quality. To quantify these
potential impacts, the WDNR began a detailed study of two selected
yard waste compost sites in Wisconsin.

Groundwater monitoring wells were installed at two operating compost
facilities and sampled over the course of the study. Leachate
samples were collected at the two study sites and at two other yard
waste compost facilities.

The ground water sampling results indicate that downgradient wells at
both sites contain elevated levels of nitrate and several other
indicator parameters. Results of the leachate sampling yielded
relatively high concentrations of many compounds, including ammonia
and heavy metals such as lead and chromium.


As in many other states throughout the U.S., the number of yard waste
composting facilities being sited in the State of Wisconsin has
rapidly increased in the past few years. Currently there are
approximately 135 approved yard waste composting sites with
capacities of between 50 and 20,000 cubic yards (yds3) in Wisconsin,
and new sites are continually being licensed. The continued siting
of new composting facilities has been driven in most part by the 1989
recycling and waste reduction law, Wisconsin Act 296. As of January
3, 1993 yard wastes have been banned from disposal at municipal solid
waste landfills and incinerators unless the materials are burned for
energy recovery. With this ban in place, communities and businesses
were forced to come up with new ways to manage their yard wastes.

Presented at the Seventeenth International Madison Waste Conference, September 21-22, 1994,
Department of Engineering Professional Development, University of Wisconsin-Madison.