U.S. EPA Contaminated Site Cleanup Information (CLU-IN)


U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

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Soil Amendments
Soil Health image
This page discusses soil-related issues, including soil health and the use of soil amendments to revitalize soils in order to make them suitable for sustaining plant life or development.

Why is soil health important?

All components of an ecosystem are dependent on viable and healthy soils for the system to function properly. Increased acidity, the presence of heavy metals and other contaminants, and high concentrations of salts can render a soil infertile by inhibiting plant growth, limiting microbial activity, and altering its physical properties. Therefore, it is critical to revitalize soil health in order to restore a degraded ecosystem. In many cases, adding soil amendments such as compost, manure, or lime can revitalize soil by adjusting pH, addressing chemical imbalances, and improving soil texture and structure.

What are soil amendments?

Some treatments involve adding soil amendments to the contaminated media. Soil amendments are materials added to soils in order to revitalize and make them suitable for sustaining plant life or development. Superfund sites and other sites with contaminated or disturbed soils exhibit a variety of problems that often can be addressed effectively and directly through the use of soil amendments. Project managers could evaluate their effects in the subsurface, their potential for eventual transport to surface waters, and their possible subsequent adverse effects on plant and animal communities.

Compost and biosolids are among the most commonly used soil amendments. Other amendments include manure, digestates, sludges, yard waste, and ethanol production by-products. Inorganic amendments include lime, wood ash, coal combustion products, foundry sands, steel slag, dredged materials, and water treatment residuals.

For additional information on soil amendments, please visit the EPA publication The Use of Soil Amendments for Remediation, Revitalization, and Reuse.

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California Gulch Superfund Site in Colorado
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California Gulch Site After
Before and after photographs of the California Gulch Superfund Site in Colorado where site managers used high rates of lime amendment to neutralize the acidity of the mine tailings and applied municipal biosolids directly into the tailings along the Upper Arkansas River.
Photographs courtesy of Michael Holmes, EPA Region 8.
Atlas before
California Gulch Site Before

What is compost?

Compost is organic material produced by aerobic (utilizing oxygen) decomposition of organic materials such as yard trimmings, food scraps, and manures. Mature compost is frequently used as a soil amendment because it is rich in nutrients, stable, and safe to use near water sources.

Composting is used frequently to significantly reduce pathogens in organic waste streams, since the process generates temperatures hot enough to achieve this reduction. Compost availability and composition varies widely, but in general, compost is generated in much smaller volumes nationally than manures or biosolids.

For more information on compost and how to create your own composting pile, please visit the EPA Composting and Organic Materials Management Pages:

What are biosolids?

Biosolids are the nutrient-rich organic materials resulting from the treatment of sewage sludge (the name for the solid, semi-solid or liquid untreated residue generated during the treatment of domestic sewage in a treatment facility). When treated and processed, sewage sludge can be safely recycled and used as a soil amendment. These biosolids can help maintain productive soils and stimulate plant growth in a sustainable fashion. However, only biosolids that meet stringent Federal and state standards can be approved for use as soil amendments. Now, through a Voluntary Environmental Management System developed by the National Biosolids Partnership (NBP), community-friendly practices also will be followed.

EPA provides the public with educational information, based on the best science, about the safe recycling and disposal of biosolids. To access this information, please visit the EPA Office of Wastewater Management Biosolids web page:

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Kansas State University interview with Dr. Sally Brown, Soil Scientist, University of Washington

Dr. Brown discusses the use of biosolids as soil amendments to remediate contaminated land and improve soil at both the large scale and small urban gardens. Watch video on YouTube

Biosolids Recycling: Restore, Reclaim, Remediate

Film by the EPA Environmental Response Team that outlines the use of biosolids as a remediation tool for contaminated lands and former mining sites.

Further Information and Resources:

  • The Use of Soil Amendments for Remediation, Revitalization, and Reuse. U.S. EPA. December 2007. (Download 1.74MB PDF)
    Hundreds of thousands of acres of disturbed and contaminated land scar this country's landscape. This paper provides information on the use of soil amendments, a cost effective in situ process for remediation, revitalization, and reuse of many types of disturbed and contaminated landscapes.
  • Soil Remediation, Revitalization, and Reuse: Technical Performance Measures
    The purpose of this website is to provide a tool to assist site project managers in the selection of appropriate technical performance measures (TPMs) for evaluating the remedial success of soil amendments used for remediation, revitalization, and reuse of contaminated sites.
  • Soil Amendments for Remediation, Revitalization, and Reuse Tools: Fact Sheet (Published 2007)
    (Download 2.26MB PDF)
    This fact sheet describes two tools developed by U.S. EPA in cooperation with 18 federal and local government, academic, and private sector experts. These tools are designed to encourage and assist site cleanup managers to use soil amendments for remediation, revitalization, and reuse of their sites resulted from this collaboration.
  • Soil Amendments for Site Remediation & Reuse: A Cost-Effective In Situ Technology (Published 2011)
    (Download 1.3MB PDF)
    This fact sheet provides information on soil amendments as a tool for remediation and revegetation. It also provides information on technical assistance provided by the EPA Office of Superfund Remediation and Technology Innovation.

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