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H N CLEARWATER 11A 0 V 11i PROPOSED APPLICATION OF ISCO Concentrations of TPH-g and benzene are present in soil at levels greater than regionally established acceptable limits (2004 Tri-Regional Guidelines). Remediation of the sorbed-phase source area is necessary to remove and/or reduce these concentrations to levels acceptable by the CVRWQCB for site closure. It is known that oxygen infusion system technology is effective at this site for dramatically reducing TPH-g concentrations in groundwater. PROJECT PLANNING Once this CAP is approved by the SJCPHS-EHD, Clearwater will develop a Bench Test Workplan to perform three chemical oxidation bench tests to verify petroleum hydrocarbon degradation rates and to confirm that heavy metals desorption from the soil into groundwater does not occur as a result of changing redox conditions. After SJCPHS-EHD approves the bench test workplan, Clearwater will perform the bench testing. Once the results are known, the In-Situ Chemical Oxidation (ISCO) Design Specification Workplan will be prepared with a task-specific Health and Safety Plan (HSP), for in-situ chemical oxidation injections, and post-treatment sample collection. BENCH TESTING Bench testing is useful in evaluating the site geochemistry of the proposed treatment. Two important issues will be examined: 1) the level of contaminant reduction and 2) the amount of heavy metals that might be mobilized, because of changing REDOX conditions, when the chemical oxidant is injected. Bench testing will not only record the rate of contaminant degradation over time (0, 1 , 4, 7, 14, and 21 days), but also will evaluate whether desorption of transition metals into the groundwater occurs owing to the changes in REDOX conditions (by adding oxidizers) . For this case, the following bench tests are recommended (a complete bench test workplan will be prepared and included in the RAP): • CASE 1 : Hydrogen Peroxide with iron catalyst (Classic Fenton's Reagent) with pH adjustment • CASE 2: Sodium Persulfate activated by Iron(HI) EDTA and no pH adjustment; and • CASE 3 : Ozone activated with hydrogen peroxide. INJECTION EVENT After the bench test has been performed, the optimal chemistry will be used in developing a Pilot Test at the site. The Pilot Test consists of up to 5 days of injections. Additional injection events may be required for full mineralization of the petroleum hydrocarbons into carbon dioxide and water. HEALTH AND SAFETY Health and safety procedures for the in-situ chemical oxidation is an important part of the project design and field implementation . A detailed, site-speck HSP will be prepared for the project. The HSP will include general information regarding chemicals at the site, organizational structure, emergency response, waste management, labeling, handling, spill response procedures, emergency equipment, notification procedures, and evacuation plan. Floyd Bames 6 Updated CAP ZB178 Update to CAP March 2010