COMPLIANCE INFO_EW-5 INSTALL PERMIT PACKAGE 2/14/25

Home Browse Search

www.arcadis.com 1/6 SUBJECT TO CDCR Site Investigation Mr. Brendan Kenny and Remedial Design Work Plan Second Addendum Engineering Geologist Central Valley Regional Water Quality Control Board DATE OUR REFERENCE February 1, 2023 30158195 DEPARTMENT Environment On behalf of Forward Inc., Arcadis U.S., Inc. (Arcadis) has prepared this California Department of Corrections and Rehabilitation (CDCR) Site Investigation and Remedial Design Work Plan Second Addendum (Second Work Plan Addendum) to further describe the expanded interim remedial design scope of work proposed following a virtual technical meeting held with the Regional Water Quality Control Board (RWQCB) on September 26, 2022 (meeting slides provided as Attachment 1). The expanded interim remedial design was presented to the RWQCB in a weekly update email dated October 14, 2022, and in a subsequent Technical Memorandum submitted to the RWQCB in November 2022 (Arcadis 2022a, Attachment 2). In an email dated January 25, 2023, the RWQCB requested that previously submitted technical information be complied into a work plan addendum to facilitate review of the revised remedial design scope of work, including proposed well construction details an d schedule. The CDCR property (site) is located on Newcastle Road approximately 1,500 ft to the north of the Forward Landfill located at 9999 South Austin Road in Manteca, California (the Landfill). The CDCR Site Investigation and Remedial Design Work Plan Addendum (Work Plan Addendum) submitted to the RWQCB in October 2021 (Arcadis 2021) provided an update to the Background and Proposed Scope of Work sections presented in the CDCR Site Investigation and Remedial Design Work Plan (Work Plan) which was submitted to the RWQCB in October 2019 (Arcadis 2019). The Work Plan (Arcadis 2019) and Work Plan Addendum (Arcadis 2021) proposed a multi-phased site investigation (SI) on the CDCR property to delineate the nature and extent of potential release(s) and volatile organic compound (VOC) source masses beneath the CDCR property, leading to an interim remedial design and implementation. Following discussions with the RWQCB in a virtual meeting held on February 7, 2022, the Revised CDCR Site Investigation and Remedial Design Work Plan Addendum (Revised Work Plan Addendum) was submitted in March 2022 (Arcadis 2022b) based on direction from the RWQCB to prioritize installation of the interim remedial action on the CDCR property prior to the completion of the proposed SI activities. In accordance with the Revised Work Plan Addendum (Arcadis 2022b), t he first phase of the interim remedial design and testing was completed in May 2022, and the first phase of SI activities were conducted in June and July 2022. The results of these field efforts were communicated to the RWQCB in the September 26, 2022, virtual meeting noted above and are included as Attachment 1. The additional hydraulic and water quality data collected during the shallow zone groundwater extraction well installation and testing effort have expanded the interim remedial efforts to the intermediate groundwater zone beneath the CDCR property to enable capture of the VOC plume mass. This Second Work Plan Addendum presents an expanded scope of work for the interim remedial action presented in the Revised Work Plan Addendum (Arcadis 2022b).