General Permit for In Situ Remediation
In situ remediation is the overall term for an accepted suite of technologies that are useful in remediation of polluted sites. In situ remediation treats pollution "in place", below the ground surface and without significant disturbance. Physical extraction, biologic activity, chemical modification, or other processes are employed to remove, degrade or stabilize pollutants in soil and groundwater. In many instances, this result is accomplished through the introduction of substances into the subsurface of a site. This discharge of substances intended to change groundwater quality requires a permit from DEEP. DEEP has developed general permits for the most common in situ remedial activities - enhanced aerobic biodegradation and chemical oxidation.
In situ remedial activities not covered by a general permit may still be authorized through the issuance of an individual groundwater discharge permit or a temporary discharge authorization, as appropriate for the proposed activity. (Note: if applying for an individual groundwater discharge permit to implement remediation of a site, DEEP recommends contacting DEEP Remediation Division staff prior to the application preparation.)
A registration must be submitted to the Department and may need to be approved for activity to be authorized pursuant to these general permits. Qualitative or quantitative evidence of pollution is required for any authorization pursuant to a general permit for in-situ remediation. The general permits allow for DEEP issuance of a certificate of coverage in lieu of an approval of registration for authorization of certain activities, and also in some cases, provides for limited self-implementation upon registration.
Groundwater monitoring is typically required, especially for potentially affected drinking water supply wells. The monitoring objective is to document that groundwater quality outside the delineated zone of influence is not affected. Additional monitoring may be needed to verify that remedial objectives are met. The environmental professional is required to evaluate monitoring data to determine and report any indications of unexpected outcomes, and mitigation is required for adverse conditions caused by the discharge. Reporting and recordkeeping requirements for discharge and monitoring activities are specified, and combined reporting is allowed when reporting is also required under DEEP remedial program requirements.
In Situ Groundwater Remediation: Enhanced Aerobic Biodegradation (DEP-REM-GP-001)
The General Permit for In Situ Groundwater Remediation: Enhanced Aerobic Biodegradation authorizes oxygenation of groundwater at a controlled rate to enhance in situ aerobic degradation of organic pollutants and allows the use of several different sources of oxygen and delivery methods. Supplemental nutrients or cultured bacteria may also be added under the general permit framework. Chemical oxidation of pollution is not authorized under this general permit; and the permit incorporates limits on ozone and hydrogen peroxide to ensure their use solely as an oxygen source for biodegradation.
The General Permit for In Situ Remediation: Chemical Oxidation authorizes introduction of chemical oxidants and necessary associated substances to soil and groundwater to remediate pollution through the chemical destruction of fuels and other organic materials, and in some cases, chemical modification of inorganic chemicals. The oxidizing chemical classes authorized are: Peroxides, Permanganates, Ozone, Persulfates, and Percarbonates.
Additional Information
In Situ Remediation: Design Considerations and Performance Monitoring Technical Guidance Document (NJ DEP) – This guidance may be useful for evaluating the potential to use an in-situ remedy. However, any plan developed for in-situ remediation must also consider the RSRs and other applicable Connecticut laws and standards.
Content Last Updated February 5, 2018