S&W Atlas Iron and Metal Company Interim Soil Vapor Extraction Workplan

Project Description: The Interim Soil Vapor Extraction Workplan commits the S&W Atlas Iron and Metal Company (Facility) to install and operate an Soil Vapor Extraction (SVE) system to address volatile organic compounds (VOCs) in soil gas at the south and southwest areas of the Facility located at 10019 South Alameda Street in Los Angeles. The project activities include installing one SVE pilot well, four additional SVE wells connected to a vacuum extraction unit, and treating the extracted vapors before discharge. The SVE system will protect adjacent properties and buildings while the full site investigation continues. Background: The 3.28-acre Facility is located in an area that was historically used for industrial, commercial, school, and residential development. The Facility is currently covered by impervious surfaces consisting of asphalt, concrete, and one existing warehouse. A second warehouse that previously existed in the west-central portion of the Facility was demolished in September 2022. The Facility was formerly used by Atlas for scrap metal recycling operations, which ceased in 2025. As of January 19, 2026, equipment remaining onsite includes excavators, material handlers, shearing equipment, shipping containers, one roll-off bin for retired items, and one roll-off bin for trash. Prior to ceasing operations, DTSC conditionally approved of the Scrap Removal Work Plan on July 1, 2025. Metal scrap removal began on July 8, 2025, and was completed on August 22, 2025. Air monitoring is ongoing at the Facility in accordance with the Revised Phase I Air Monitoring Workplan dated February 1, 2023. On March 10, 2021, the California Department of Toxic Substances Control (DTSC) issued an Enforcement Order for Corrective Action, Docket No. HWCA-FY20/21-008 (Order), which established several required actions to evaluate if the Facility released chromium, copper, lead, nickel, zinc, polychlorinated biphenyls (PCBs), used oil, and/or polycyclic aromatic hydrocarbons (PAHs) to the subsurface. Previous Investigations: A Facility Investigation (FI) and a Supplemental Site Investigation (SSI) were conducted from 2023 to 2025 to assess Areas of Concern (AOCs) and subsurface impacts. Investigations identified releases of VOCs, metals, total petroleum hydrocarbons, and polychlorinated biphenyls in soil and soil gas. Based on the FI and SSI, the AOCs identified by DTSC are as follows: 1- Receiving Area, 2- Roll-Off Bins, 3- Metal Scrap Piles, 4- Warehouse No.1, 5- Container Loader Area, 6- Clarifier and Associated Piping System, 7- Gated Area, 8- Broken Cement Areas and 9- Lead-Impacted Soil North of the Former Warehouse No. 2. Following the review of the Facility Investigation Sampling Results dated December 12, 2025, DTSC requested that Atlas implement an interim measure to address VOCs in the southwest corner of the Facility while the full investigation of the facility is completed. Project Activities: The project activities consist of installing a skid-mounted SVE system with a vapor/liquid separator, an extraction blower with a maximum flow rate of 300 standard cubic feet per minute (SCFM), and an air-to-air heat exchanger. The SVE equipment will be connected to two vessels with granular activated carbon and one vessel with granular activated carbon and an inorganic oxidizing agent in series. The SVE blower inlet will be connected to the new SVE wells using polyvinyl chloride (PVC) piping and high-pressure vacuum hose. Five existing soil vapor probes (SVPs), SG-10, SG-14, SG-16, SG-17, and SG-18will be used for pilot testing. A chain link security fence will be installed around the SVE skid and carbon vessels. Publicly visible signage with a 24-hour emergency contact telephone number will be displayed on the system fencing. The South Coast Air Quality Metropolitan District (SCAQMD) Rule 1166 and Rule 203 will require notification of the SVE operation for sensitive receptors located less than a quarter mile away including residences, schools, or childcare. The pilot test will be conducted in 5 days or less. The pilot test results will be evaluated to estimate an ROI, which will be used as the basis for the number of wells and spacing between the wells in the interim measure. Although not anticipated, 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 makes an assessment of 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.