Page 568 - Materials Chemistry, Second Edition

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Land Disposal of Hazardous Waste 539

TABLE 17.3
The Major Pathways of Contamination of Underground Sources of Drinking Water

Faulty well Leaks in well casing or fluid escaping between
construction well’s outer casing and well bore
Nearby wells Fluids from pressurized area in injection zone may
escape through wells in injection area.
Faults or fractures in Fluids may leak out of pressurized area through
confining strata faults or fractures in confining beds.
Direct injection Inject fluids into or above USDWs
Diplacement Fluid may be displaced from injection zone into
hydraulically connected USDWs

Source: U.S. EPA, 2002b. With permission.

● The waste generator may be required to perform physical, chemical, biological, or ther-
mal treatment for the removal of various constituents from the waste to modify the phys-
ical and chemical character of the waste and ensure its compatibility.
● High concentrations of suspended solids (typically >2 ppm) can cause plugging of the
injection equipment and injection zone.
● Corrosive media may react with the injection well components, with the injection zone
formation or with confining strata.
● Equipment will last longer if wastes are neutralized prior to injection.
● High Fe concentrations may cause fouling when conditions alter the valence state and
convert soluble into insoluble species.
● The presence of significant amounts of organic carbon may result in rapid microbial pop-
ulation growth and subsequent fouling.
● Waste streams containing organic contaminants above their solubility limits may require
pretreatment before injection into a well.
● Site assessment and aquifer characterization are required to determine the suitability of
the site for wastewater injection.

REFERENCES

American Society for Testing and Materials, Standard Test Method for Determination of External Loading
Characteristics of Plastic Pipe by Parallel-Plate Loading ASTM D2412-02, West Conshohocken, PA,
2002.
American Society for Testing and Materials, Standard Test Method for CBR (California Bearing Ratio) of
Laboratory-Compacted Soils, ASTM D1883-99. West Conshohocken, PA, 1999.
American Society for Testing and Materials, Standard Test Method for Permeability of Granular Soils
(Constant Head)ASTM D2434-68, West Conshohocken, PA, 1968.
Federal Remediation Technologies Roundtable, Deep well injection 2003. See: http://www.frtr.gov/matrix2/
section4/4_57.html
Gallagher, G., Virginia Polytechnic University. See: http://www.cee.vt.edu/program_areas/environmental/teach/
gwprimer/hazmat/hazmat.html, no date.
Haxo, H.E. Jr., Haxo, R.S., Nelson, N.A., Haxo, P.D., White, R.M., Dakessian, S., and Fong, M.A.,. Liner
Materials for Hazardous and Toxic Wastes and Municipal Solid Waste Leachate, Noyes Publications,
Park Ridge, NJ, 1985.
PGI, Comparison of 30 mil PVC and 60 mil HDPE Geomembranes, PGI Technical Bulletin, Urbana, IL,
March 1999.
Tenax, No date, Leachate Collection and Removal System (LCRS), Baltimore, MD. See: http://www.tenaxus.
com/landfills/applications/leachate.html