people presently living in it.

3.2 Monitoring Well Installation and Design

     Although the author was not directly involved with the

installation   of  the  monitoring   wells, the   following   is  a

description of the methods, techniques, and procedures employed in

the  construction,   installation, and    sampling  of  groundwater

monitoring wells. The information for these descriptions is based

on documentation provided in William Van Ryswyek's MS Thesis and

"A Comparative Study of Nitrate-N Loading to Groundwater from

Mound, In Ground Pressure and At Grade Septic Systems", Shaw and

Turyk, 1992.

      At Site 1, originally one up-gradient and one down-gradient

well were installed in the summer of 1988. These monitoring wells

were constructed of 3.18 cm (1 1/4 in) PVC (polyvinyl chloride) and

werd fitted with 91.44 cm (36 in) slotted, 0.0254 cm (.01 in) slot

size, PVC screens.

      The  original   down-gradient  well   showed  no  significant

 difference in water quality from the up-gradient well. Thus, in

 the summer of 1989, two nested wells (REC and REW) were also

 installed down-gradient of the drainfield.    These two wells were

 installed in an east-west transect with the existing down-gradient

 well, 4.9 m (16 ft) away from and parallel to the down-gradient

 edge of the drainfield as shown in figure 3.1.     It was believed
 that these wells would show whether or not preferential percolation

 was occurring out of this system or if strong vertical flow

 components were transporting contamination deeper into the aquifer