Bioremediation

Compost bioremediation is a set of technologies that use bacteria and fungi in mature, cured compost to sequester or break down contaminants in soil and water.  Compost is effective in degrading or altering many types of contaminants, including chlorinated and non-chlorinated hydrocarbons, wood preservatives, solvents, heavy metals, pesticides, petroleum products, and explosives.  Compost helps return contaminated sites to pre-contamination condition by improving soil properties and providing nutrients that facilitate plant growth.  This page focuses on the use of compost in surficial soil remediation and biological reactive barriers.  Go to Riparian Restoration for a discussion on constructed wetlands, another bioremediation technology that utilizes compost.

Remediation of Surface Soil

It is appropriate and sometimes preferable to excavate and treat contaminated soils in-place under some conditions.  Monitoring may be required to ensure contaminants do not migrate.  Consult applicable regulatory agencies prior to commencing remediation activities.  In the event that contamination is shallow, till soil to a shallow depth and mix compost into the soil.

Biological Reactive Barriers

A biological reactive barrier is a bioremediation zone constructed in a contamination zone to treat contamination.  A trench is constructed and filled with organic materials such as compost, mulch, manure, straw, and other additives such as bentonite binder.  As groundwater flows through the bioremediation zone, organic materials degrade, sequester, or alter contaminants into safer chemicals.

Permeable Biological reactive barrier infographic

Where to Use Treatment

Compost bioremediation treats soil contaminated with the following:

  • Heavy metals
  • Pesticides
  • Petroleum hydrocarbons

Limitations

Not effective on some contaminants

Benefits

  • Sequesters specific contaminants
  • Breaks down specific contaminants in soil or water
  • Provides additional benefits associated with compost use, such as increasing plant establishment and health

Design Considerations/Plans and Details

Design compost to treat specific contaminants at specific sites

Resources

Research

For more information contact: Organic Materials, organics@calrecycle.ca.gov