United States           Solid Waste and           EPA 510-F-93-025
Environmental Protection     Emergency Response        October 1993
Agency              5403W

Soil  Remediation  For

UST Sites

Ex  Situ  Bioremediation:

Land Farming

   Ex situ bioremediation—land farming (or land
   treatment)—is a technique for removing
biodegradable contaminants from excavated soil. The
excavated soil and added nutrients are spread over a
lined treatment area. The area is periodically tilled to
facilitate the natural release of volatile organic
compounds (VOCs) and the biodegradation of

Land farming is effective on many soil types and a variety
of contaminants. It is also easy and inexpensive to design,
operate, and maintain.
   Petroleum Types And Constituents

   * Fresh or weathered gasoline, diesel, jet fael, kero-
    sene, motor oil, heavy fuel oil, lubricating oils, and
    crude otts

   • Volatile organic compounds (VOCs) such as
    benzene, toluene, ethylbenzene, and xylene {81^0;
    residual semivolatile organic compounds (SVOCs)
    such as polynudear aromatic hydrocarbons; and
    nonvolatile constituents                    ;

Ex Situ Bioremediation: Land Farming
Parameters to
Cleanup Levels
and Timing2
• Simple and inexpensive to design, operate, and maintain
• Effective on many soil types with a variety of
• Targets only biodegradable constituents
• -Requires substantial space
• Nutrients (fertilizer)
• Lined treatment cell with berms around the perimeter
• Tilling equipment
• lime (needed for low pH)
• Irrigation equipment (optional)
• Might need to treat or dispose of collected rainwater or
• Soil contaminant concentration
• Microbial population in soil
• Soil pH, moisture, and nutrients
• Leachate analysis (optional)
• Treats £ 9096 of biodegradable constituents
• For an ideal site3, ~90% in 6 months to 2 years
• For an average site4, ~90% in 6 months to 3 years
• Longer time required to degrade heavier hydrocarbons
• For an average site4, $20,000 to $70,000 ($20 to $70/cu yd)
• Costs vary with the amount of soil to be treated and the
design of the containment cell
'"Parameters to monitor* are for performance purposes only; compliance monitoring parameters vary by state.
 An Ideal site1 assumes no delays in corrective action and a relatively homogeneous, permeable subsurface.
4An leverage site" assumes minimal delays in corrective action and a rnoderateryheterogeneois and r»rmeable subsurface.
5Costs include equipment, and operation and maintenance.