DTSC is proposing to approve a Human Health Risk Assessment/Feasibility Study/Remedial Action Plan (HHRA/FS/RAP or RAP) pursuant to the regulatory authority granted under Chp 6.8, Div 20, California Health and Safety Code (H&SC) for the PG&E former Fresno-2 Manufactured Gas Plant site located at 1042, 1056, 1102, and 1136 F St, Fresno, CA in Fresno County.
The RAP addresses impacts to soil and soil gas from previous operations on the site. The total volume of contaminated soils that are highly impacted by polycyclic aromatic hydrocarbons (TPH) soil to be remediated is estimated to be 15,926 cubic yards. Of this total soil volume, 3,416 cubic yards of soil will be excavated and transported for off-site disposal. However, as an alternative remedial measure, 14,141 cubic yards of impacted soil is proposed to be treated by in-situ thermal desorption (ISTD) and a temporary soil vapor extraction system, significantly reducing the additional volume of impacted soils that need to be excavated and transported from the site. If the ISTD treatment method proves to be ineffective, an additional 3,616 cubic yards of soil (226 truckloads or 452 round trips) from the top 10 feet of the impacted areas will be excavated and hauled off site for a total volume of (3,416 + 3,616) = 7,032 cubic yards (366 truckloads or 732 round trips) of soil to be transported from the Site to an appropriate disposal facility. The remaining soil impacted areas will be capped with asphalt and/or concrete as part of the Site restoration activities.