Approval of Modifications to the Final Remedy at the Former Watkins-Johnson Facility Site
- SCH Number
- Lead Agency
- Toxic Substances Control, Department of (Department of Toxic Substances Control)
- Document Title
- Approval of Modifications to the Final Remedy at the Former Watkins-Johnson Facility Site
- Document Type
- NOE - Notice of Exemption
- Document Description
- DTSC is modifying the final remedy for the Former Watkins-Johnson Facility Site to include injection of potassium permanganate (KMNO4) into shallow groundwater at the Building 5 and 6 areas.
- Contact Information
Department of Toxic Substances Control
Northern California Coastal Cleanup Operations Branch 700 Heinz Avenue
Berkeley, CA 94710
Phone : (510) 540-3826
- Palo Alto
- Santa Clara
Notice of Exemption
- Exempt Status
- Type, Section or Code
- Section 15061(b)(3)
- Reasons for Exemption
- The project will not have a significant effect on the environment because: 1. The groundwater extraction and treatment system in the OU1 area of the Site will continue to operate and control the groundwater plume beneath the Site. Based upon implementation of similar treatment technology at the Hewlett-Packard Building 15 and Teledyne MEC Sites, the KMNO4 will be used up before reaching the nearest well within the OU1 area of the Site located just west of the Building 5 and 6 areas. Therefore, it will not interfere with the continued operation of the OU1 extraction system. The existing groundwater extraction and treatment systems in OU2 will be shutdown in such a way to allow that both Building 5 and 6 systems can be restarted within a period of approximately 2 to 4 weeks. 2. The project is completely in-situ and will not pose any threat to the local air quality. The treatment zone underlies asphalted parking lots, building structures and landscaping within a commercial development. Groundwater occurs approximately 20 to 60 feet bgs. No hazardous air releases were detected during implementation at the Hewlett-Packard Building 15 and Teledyne MEC Sites. 3. The site is fully developed. The closest residence is over 0.25 miles away from the Site. There are no endangered species, either plant or animal, on the Site or in the site vicinity. 4. Shallow groundwater is not used for drinking water at the Site or in the site vicinity. Drinking water to this area and the nearby residential community is provided by Hetch Hetchy. Groundwater wells installed in the Barron Park neighborhood approximately 0.25 miles away are used for irrigation. 5. Temporary injection wells will be installed and abandoned under permit from the Santa Clara Valley Water District. 6. The purple KMNO4 solution is a strong oxidizing agent. It is not volatile or flammable. Pre-mixed 4% KMNO4 solution will be delivered to the treatment area and stored secondarily contained 3,100-gallon containers to prevent spillage. Plastic sheeting will be placed around each injection point and all fittings along with absorbent socks to prevent chemical spills during injection. 7. Groundwater monitoring events will be conducted after two weeks, one month, six months and one year following injection. Groundwater will be evaluated for color and oxidation reduction potential. This is sufficient to monitor groundwater conditions within and in the vicinity of the treatment area. Groundwater will be sampled and analyzed for VOCs and chromium +6 when the purple color indicating the presence of KMNO4 dissipates and when the ORP value drops below 400 mV. This is sufficient to monitor the effectiveness of the KMNO4 solution in destroying the VOCs and to monitor the monitoring and reporting requirements for the Hillview-Porter Regional Program. 8. Site workers will comply with the health and safety requirements of Title 8, California Code of Regulations section 5192 during handling of KMNO4. 9. The project does not require a Storm Water Pollution Plan. 10. The drilling and injection work will be conducted Monday through Friday between 8 am and 8 pm or Saturday between 9 am and 6 pm, which is within the hours allowed under the Palo Alto Municipal Code, Title 9, Chapter 9.10, Noise.
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