Remedial Action Plan Amendment for Caterpillar Site to Replace Groundwater Extraction with In Situ Treatment and Enhanced Natural Attention

Summary

SCH Number
2005128237
Public Agency
California Department of Toxic Substances Control (DTSC)
Document Title
Remedial Action Plan Amendment for Caterpillar Site to Replace Groundwater Extraction with In Situ Treatment and Enhanced Natural Attention
Document Type
NOE - Notice of Exemption
Received
Posted
12/20/2005
Document Description
The project is the approval of a Remedial Action Plan Amendment (RAP Amendment) for the shallow groundwater that is impacted with volatile organic compounds (VOCs) above state Maximum Contaminant Levels (MCLs). The 1994 RAP set the groundwater cleanup goal at MCLs and recommended groundwater extraction and treatment using granular activated carbon (GAC) as the approved remedial action. Caterpillar operated and maintained three groundwater extraction and treatment systems until 1999. Two of the groundwater extraction and treatment systems (Systems 1 and 3) were shut down in 1999 according to the recommendation in the Five-Year Remedial Action Plan Review Report. Groundwater treatment System 2 continues to operate. The extraction rate at System 2 has decreased dramatically since 2000 due to siltation of the sand pack around the extraction wells. TCE concentrations have decreased from 1,100 ug/L in 1989 to 100 ug/L in 2000 to 83 ug/L in 2005. The groundwater extraction and treatment system has not effectively reduced TCE concentrations since 2000. The proposed RAP Amendment consists of demolition of all three groundwater extraction and treatment systems, injection of hydrogen release compound (HRC) with bio-dechlor inoculum (BDI) bacteria to create enhanced monitored natural attenuation.

Contact Information

Name
Jayantha Randeni
Agency Name
Department of Toxic Substances Control
Contact Types
Lead/Public Agency

Location

Cities
San Leandro
Counties
Alameda

Notice of Exemption

Exempt Status
Other
Type, Section or Code
Section 15061(b)(3)
Reasons for Exemption
General Rule 1. Although the site is on the Hazardous Waste and Substances Sites List, the project is exempt because the activities will have no potential for significant impacts and the activities are designed to support the site's remediation. 2. The project will consist of an in-situ treatment of groundwater involving the injection of HRC, a polyactate ester, an environmentally safe material and BDI bacteria that produce rapid and complete degradation chlorinated VOCs. Once HRC and BDI are injected to the groundwater, the VOCs will breakdown through reductive dechlorination to less hazardous substances. 3. HRC and BDI bacteria will be injected once into the groundwater by direct-push technology. Direct-push technology uses hydraulic pressure which does not entail the removal of soil and only a small hole is generated compared to a conventional drilling rig. 4. HRC and BDI will be injected along Hutchings Drive. Once the material has been injected, an appropriate seal, such as hydrated bentonite, will be installed above the materials up to the top of the borehole which will be finished to match the surrounding surface. 5. Groundwater will be monitored to determine the effectiveness of the treatment. An operation and maintenance agreement is already in place to require groundwater monitoring and to ensure that cleanup goals have been achieved. 6. All fieldwork will be conducted according to site-specific Health and Safety Plan and only properly trained personnel will be employed. The Health and Safety Plan incorporates Department, Cal OSHA and Federal worker health and safety regulations requirements. Workers will be trained for hazardous waste handling and will be properly equipped for the material to be handled. 7. Groundwater monitoring will be conducted periodically. Nineteen existing monitoring wells, two extraction wells, and one new monitoring well will be used in the monitoring program. 8. Contamination exceeding drinking water standards in shallow groundwater appears stable and is limited to shallow groundwater zone. Potential migration of VOCs in groundwater from the site into down-gradient areas will be monitored.

Disclaimer: The document was originally posted before CEQAnet had the capability to host attachments for the public. To obtain the original attachments for this document, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at state.clearinghouse@opr.ca.gov or via phone at (916) 445-0613.

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