Program One
Thursday, May 22, 1997

Biofilms and Barriers Kansa A



V.L. Hauser, Mitretek Systems, Inc., 13256 George Rd., Ste. 200, SanAntonio,TX 78230, B.L. Weand, Consultant, (formerly Mitretek Systems), 2421RockbridgeSt., Vienna, VA 22180, and N.J. Balkus, Air Force Center for Environmental Excellence, 3207 North Road, Brooks AFB, TX 78235-5363 Rainfall can leach soluble pollutants to ground water from wastes buried in the vadose zone; therefore, covers are required to keep the wastes dry. We currently use covers designed to resist natural forces and to stop the downward flow of liquid water. These covers are expensive, usually leak some precipitation into the waste, and tend to lose their effectiveness over time.

Natural covers have been little used to cover wastes although the underlying principles have been known for at least 70 years; the literature is voluminous and contained in journals that preceded modern environmental remediation efforts. We call our version of a natural cover the Evapotranspiration (ET) Cover.

The ET Cover contains no compacted clay or synthetic barrier layer, but instead uses natural processes which (1) store infiltrating rainfall in the soil profile and (2) remove water from the soil through the growth of native grass on the cover soil. Depending on the design, it can limit or prevent infiltration of precipitation into the covered waste.

The ET Cover is inexpensive, practical, and easily maintained; it is a self-renewing, biological system. It will remain effective over extended periods of time--perhaps centuries--at low cost. A recently designed ET Cover for remediation of a 41-acre landfill in the Great Plains is expected to save about 10 million dollars in construction costs alone. We discuss pertinent literature, scientific principles, and engineering tools that we have assembled to design ET Covers.

Key words: landfill, cover, cap, evapotranspiration, natural

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Tuesday, May 20, 1997

Metals Kansa A

Remediation of Munitions Compounds Kansa B

Analytical Methods Kansa C/D

General Topics Kansa B

Wednesday, May 21, 1997

Metals Kansa A

Zero-Valent Metals Kansa A

Remediation Kansa A

Vegetation-based Remediation Kansa B

Partnerships & Innovative Technologies Kansa C/D

Nonaqueous Phase Liquids Kansa C/D

Thursday, May 22, 1997

Biofilms & Barriers Kansa A

Bioremediation Kansa B

Partnerships & Technology Innovations Kansa C/D

Remediation Kansa C/D


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