Martin Metal Finishing Removal Action Workplan

Martin Metal Finishing Removal Action Workplan

Project Description: The Department of Toxic Substances (DTSC) approved the Martin Metal Finishing (MMF Project Site) Removal Action Workplan (RAW) (CDIM Engineering, November 2024). The Cleanup Decision Document, referred to as a RAW, summarized the environmental conditions for the MMF Building and the Mormon Slough and identified the remediation activities to address the constituents of potential concern (COPC). The RAW concluded that the recordation of a LUC for the MMF Building would be required to prevent receptor exposure above acceptable exposure limits for tetrachloroethylene (PCE) in the subsurface vapor and excavation and off-site disposal of approximately 750 cubic yards of soil impacted by lead and hexavalent chromium for a portion of the Mormon Slough. Background: The MMF Building is located within the Fairgrounds Industrial Park (FIP) and occupied the Site between 1981 and 1990 performing metal plating and painting onsite; the operations included chemical dip tanks, rinse tanks, and wastewater pretreatment. The MMF Project Site is surrounded by industrial businesses within FIP, which is bounded to the south by East Charter Way (also known as East Doctor Martin Luther King Jr. Boulevard) and the San Joaquin Fairgrounds, to the north by Mormon Slough, to the west by South Wilson Way, and to the east by other industrial properties. The MMF Site is an approximately 8,500 square foot unit (Building B-12 of the FIP) within an approximately 120,000 square foot warehouse structure of stucco and wood frame construction, and paved parking area. The MMF operations occurred in the easternmost 150 feet of the warehouse and the associated outdoor area immediately north of the building. A structural steel supplier most recently occupies the Site. The Mormon Slough is an undeveloped and unpaved area which receives runoff and stormwater discharge from nearby commercial and industrial properties including the FIP Property and its onsite storm drainage system. Minimal to moderate amounts of biota, primarily non-domesticated terrestrial plants and rodents, are present in the slough dependent upon rainfall. An ecological risk screening was performed as part of the Preliminary Environmental Assessment (PEA) to evaluate risk to the ecosystem. This screening concluded that the Mormon Slough is a small, industrialized habitat with degraded conditions, and that no special status plants or animals are known to inhabit the Slough. As such, it is not considered a sensitive ecosystem. PEA investigation activities were performed in 2022 and 2023 to further evaluate the presence and extent of contamination at the Site and surrounding areas, and associated risks to Site users and the environment. Based on the soil vapor results of the initial investigation under the PEA Work Plan, CDIM prepared and submitted an Addendum to the PEA Work Plan for additional soil vapor and indoor air investigation at the Site, which was approved with comments by DTSC on April 12, 2023. Subsequently, another PEA Report was approved by DTSC on March 4, 2024. A Supplemental Site Investigation (SSI) was requested for a portion of the Mormon Slough to further refine the delineated extent of elevated lead and hexavalent chromium and implementation of a deed restriction to require additional evaluation. A Standard Voluntary Agreement Docket Number HSA-FY21/22-146 was signed May 30, 2022, between DTSC and Fairgrounds Industrial Park. State of California – California Environmental Protection Agency Department of Toxic Substances Control Project Activities: The remedy activities consist of the following: • MMF Building - Administrative Controls. The recordation of a Land Use Covenant (LUC) to prevent receptor exposure above acceptable exposure limits. The LUC will prohibit the MMF Building to be utilized for residential, hospital, school or daycare facility developments. • Mormon Slough - Administrative Controls, Excavation and Offsite Disposal, and Capping. This combined remedy includes the excavation of approximately 750 cubic yards of impacted soil to a uniform depth of two feet below existing grade. The depth of the excavation area is based on the depths at which samples were found to contain concentrations below DTSC-SLs, and which will enable placement of a capping soil layer without disrupting site drainage patterns. A cap compliant with the PT&R Guidance soil cap guideline will be placed in the excavation void consisting of a single layer of clean imported soil two feet thick. The soil cap will promote positive drainage and vegetation growth. A LUC will also be recorded to prohibit soil-disturbing activities without pre-notification to DTSC, and the preparation and DTSC’s approval of a soil management plan The excavation would take place over approximately four to six weeks requiring approximately 80 truck trips for transport and disposal. A Health and Safety Plan (HSP) will be prepared to address Site activities. In addition, on-site dust monitoring will be performed concurrently with the excavation activities to ensure that unsafe concentrations of dust are not migrating outside the active work area. The Contractor will perform Visible Dust Emissions opacity testing in accordance with SJVAPCD Rule 8011. In addition, the Contractor will document air monitoring requirements in the Project HSP to ensure the health and safety of workers. In the event biological, cultural or historical resources are discovered in the course of project activities, work will be suspended while a qualified biologist, cultural or historical specialist assesses the area, and arrangements are made to protect or preserve any resources that are discovered. If human remains are discovered, no further disturbance will occur in the location where the remains are found, and the County Coroner will be notified pursuant to the Health and Safety Code Chapter 2, Section 7050.5.

Stockton

San Joaquin

Northern California

San Joaquin