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NATURAL COVERS FOR BURIED WASTES

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