such as chromium is an analyte of interest, the well casing or screen should not

increase or decrease the amount of chromium in the ground water. Any

material leaching from the casing or screen should not be an analyte of interest,

or interfere in the analysis of an analyte of interest.

In addition, monitoring well casing and screen materials should be relatively easy to install

into the borehole during construction of the monitoring well.

Owners and operators also should consider the purpose of the well when determining

the well's design. Will the well be used solely as a piezometer? Will the well be placed in

an area where there is currently no contamination and where natural water quality is not

likely to interact with it? Will the well be used to delineate the extent of a plume, but not

used to determine compliance with cleanup levels? Will the well be used to extract

contaminated ground water as part of corrective action activities? Will the well be used as a

point of compliance well for which accurate information is crucial?

The following discussion of casing and screen materials comes from several sources,

but the majority of it is directly from the EPA/EMSL Las Vegas Handbook of Suggested

Practices for the Design and Installation of Ground Water Monitoring Wells (Aller et al.,

1989), with additional information from various references, as cited. EPA believes that the

use of this up to date technical guidance, along with the technical criteria provided below, aid

in the selection of appropriate well materials. In addition to references cited by Aller et al.

(1989) the following references also are available for consideration when choosing well

casing and screen materials:

Cowgill, U.M. 1988. The Chemical Composition of Leachate from a Two 

Week Dwell Time Study of PVC Well Casing and Three Week Dwell Time

Study of Fiberglass Reinforced Epoxy Well Casing, in A.G. Collins and A.I.

Johnson, eds., Ground Water Contamination: Field Methods, ASTM STP 963,

American Society for Testing and Materials, Philadelphia, PA, pp. 172 184.

Gillham, R.W. and S.F. O'Hannesin. 1990. Sorption of Aromatic

Hydrocarbons by Materials Used in Construction of Ground Water Sampling

Wells, in D.M. Nielsen and A.I. Johnson, eds., Ground Water and Vadose Zone

Monitoring, ASTM STP 1053, American Society for Testing and Materials,

Philadelphia, PA, pp. 108 122.

Hewitt, A.D. 1989. Leaching of Metal Pollutants from Four Well Casings

Used for Ground Water Monitoring. CRREL Special Report 89 32, U.S. Army

Cold Regions Research and Engineering Laboratory, Hanover, NH 03755 1290.

November 1992

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