Investigative Methods


A hollow stem auger was used to install five wells at each of sites A
and B. The wells were located so that one monitoring well was
upgradient to the site and the other three water table monitoring
wells were either down or sidegradient (Figure 1). In addition, a
piezometer screened below the water table was installed adjacent to
one of the downgradient monitoring wells. Well placement was
determined by examining regional ground water flow maps. Split spoon
samples were collected every five feet during drilling of each well
to determine the subsurface geology.

Ground water quality sampling took place over a one year period
beginning with April, 1993 and ending with April, 1994. Each well
and piezometer was sampled on 5 separate occasions and the sampling
events were all at least 2 months apart.

Ground water samples were collected by utilizing a clean, bottom
emptying bailer. After the samples were collected, the metals and
inorganic samples were run through a 0.45 micron filter and all
samples were acidified to preserve them for shipping. Field blanks
and duplicates were taken during all sampling rounds. All analyses
were conducted by the Wisconsin State Laboratory of Hygiene (SLOH).
Tables 1 and 2 contain a detailed list of the parameters analyzed for
the study.

Leachate samples were also collected over the study year period,
usually coincident with ground water sampling events. The number of
leachate samples collected varied considerably because sample
collection was dependant on the availability of ponded leachate at
the facility. At Site A, ponded leachate was present throughout the
year in fairly large quantities, so a total of 11 samples from 4
different sampling events were collected. Only one sample was
collected at Site B, however, due to the fact that the sandy soils
allowed leachate to infiltrate into the soil very rapidly. A total
of 6 samples were obtained at Site C on two different sampling events
and 3 samples were collected at Site D from two different sampling
events.

The leachate collection procedure consisted of dipping a clean sample
jar into the ponded liquid nearest the compost pile and allowing it
to fill with liquid. The liquid was then decanted into sample jars
and shipped to the SLOH for analysis. All analytical results were
reported as totals. The leachate samples were analyzed for the same
parameters as the ground water samples with the addition of
Biological Oxygen Demand (BOD). Table 5 contains a detailed list the
parameters included in the study.
At sites where more than one leachate sample was collected, an
attempt was made to collect leachate sample at consistent locations.
This procedure worked fairly well at the sites with large, static
piles that were seldom disturbed, such as at Sites A and D, but was
more difficult at sites where the compost piles were moved.    The