The remedy selection process involves the evaluation of alternative
remedial actions using the following:
- Be protective of human health and the environment
- Attain applicable or relevant and appropriate requirements (or
provide grounds for invoking a waiver)
- Be cost-effective
- Utilize permanent solutions and alternative treatment technologies
to the maximum extent practicable
- Satisfy the preference for treatment that reduces contaminant
mobility, toxicity, or volume as principal elements (or provide
Remediation measures can range from simply monitoring a site to
the generally far more costly task of removing the contaminants,
or they may involve a combination of both techniques.
- Monitoring the contaminated site: If studies show that
a site poses no threat to human health or if removing the contaminants
would be more hazardous than leaving it in place, monitoring of
a site may be a sufficient step. Monitoring is designed to ensure
that contamination is not migrating to where it would cause exposures.
- Removing the contaminants: In areas where contaminated
sites could pose a threat to human health, contaminants may be
removed by excavation or pumping.
- A combination of removal and monitoring: In some cases,
partial removal of contaminants reduces the threat to human health
to an acceptable level. Monitoring of the site ensures that the
health threat remains at an acceptably low level.
Many remedies can control contamination at hazardous waste sites,
yet deciding which appropriate technology to choose can be a challenge.
For least impact on the environment, less disruption to the community,
and lower costs, the least invasive and least costly remedies should
be considered first. The following general categories of remedies
are listed in order from least invasive to most invasive, disruptive
- Do nothing - If the environmental assessment shows that
the site is safe, then no furtheraction is required.
- Institutional Controls - Prohibit access to the contaminated
site. Examples of institutional controls include fencing off a
contaminated site or prohibiting the construction of wells near
- Monitored Natural Attenuation - In many cases nature
facilitates cleanup. Many contaminants are broken down into safe
elements via sunlight (photolysis), natural bioremediation, and
- Containment of contaminants - Limiting the access of
contaminants to the environment at large can reduce their risk.
Methods include: capping, creating barriers, and stabilization/solidification.
- Destruction of contaminant - Eliminating the contaminants
removes the risk. Treatments can be in situ (in place) or ex situ
(after removal). Technologies include phytoremediation,
- Removal - Physically removing contaminants from a site
moves the problem. Removal involves transport and disposal of
When remediating a contaminated site, two basic approaches are
considered acceptable: a criteria or numerical based approach and
a comprehensive, site-specific risk based approach. In cases where
a risk-based approach is proposed, the specific methodology to be
used (e.g., RBCA - Risk Based Corrective Action) should be specified.
For the criteria based approach, subsequent sections of this policy
set maximum allowable contaminant concentrations in soil and water
for the restoration of affected areas. Information on classes and
concentrations of chemical contaminants, how they are distributed
through out the site, and in what media they appear is essential
to begin the preselection of treatment technologies. The maximum
allowable contaminant concentrations are based on the environmental
sensitivity of the site.
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