Site B

Site B is a medium-sized, privately operated yard waste composting
facility in central Wisconsin (Figure 1) consisting of approximately
2500 yds3 of material collected from several small gardening services
contractors and limited   members of the public. The site is unlined
and nearly level, but the sandy nature of the soils allows any
liquids to infiltrate into the ground fairly rapidly. The sandy
outwash deposit is approximately 20 feet thick and overlies a sandy
clay deposit of weathered Precambrian bedrock. The monitoring wells
are all screened in the outwash deposit and the piezometer is
partially screened in the weathered bedrock. The water table is
within 10 feet of the surface in all wells.

Waste material is placed into a pile, 100-200 feet long and 9-12 feet
high. At the time of the study, there were two piles of this size on
site, one pile being slightly older than the other. The piles are
turned or moved infrequently, once or twice a year on average. The
waste seems to consist mostly of grass and some leaves. Because of
the sandy nature of the soils beneath the site, very little liquid
accumulates at the base of the piles.

Site C

Site C is a large, municipally-run yard waste composting facility
located in central Wisconsin. is unlined and fairly flat.
Surface water drains to a low, marshy area near the site, but pools
*of dark liquid commonly form at the base of the piles. Because no
wells were installed at the site, the subsurface geology is not
known. Generally, the compost is segregated into a series of piles
arranged in a rough circle. As a new load of waste material is
brought in, each existing pile is moved to the next station and the
oldest pile is taken away to be sieved and given away to the public.
Exact timing may vary, but on average the piles are moved every few
months. The piles are composed mostly of grass clippings and leaves.

Site D

Site D is a large, municipally-run yard waste composting facility
located in eastern Wisconsin. The site is unlined, fairly flat and
poorly drained. The surface soils appear to consist of low-
permeability glacial till material, but, again, because only leachate
samples were collected at this location, no detailed geologic
investigation was performed. Waste materials consisting of leaves,
grass and garden debris are arranged in one of two very large piles.
The piles are rarely, if ever, turned and the waste material is
allowed to decompose anaerobically. Significant quantities of black
leachate frequently collect around the base of the large static