Palace Cleaners Interim Removal Action Workplan for Soil Vapor Extraction

Project Description: The project consists of installation and operation of a soil vapor extraction (SVE) system to address soil vapor releases from Palace Cleaners located at 201 South Glendale Avenue in the city of Glendale (Site). The project activities consist of constructing nine new extraction wells as part of the overall SVE system. The SVE will be implemented to address elevated volatile organic compounds (VOCs) concentrations in soil vapor at the Site and adjacent properties while a final comprehensive remedial approach is developed to address the VOCs. Background: The Site is located in a mixed commercial and residential area and consists of two adjoining buildings and a parking lot. It consists of two adjoining buildings and a parking lot Palace Cleaners occupies one of the buildings (201 South Glendale Avenue) and Best Liquor Meat and Deli occupies the second building (205 South Glendale Avenue) covers approximately 0.1 acres. The Site is bound to the south by Shiraz Restaurant and Banquet Hall, to the west by an alley and parking lot, to the north by commercial and residential apartment buildings across East Harvard Street, and to the east by commercial buildings across South Glendale Avenue. Dry-cleaning operations began at the Site in approximately 1955 which included Palace Cleaners from 1955 to the present, and Norge Coin Operated Laundry & Dry-Cleaning Village that operated at 205 South Glendale Avenue between approximately 1961 and 1972. The dry-cleaning solvent tetrachloroethene (PCE) was used at Palace Cleaners between 1955 and March 2017, after which the PCE machine was replaced by a dry-cleaning machine using a petroleum hydrocarbon solvent. Previous Investigations: Based on previous investigations the contaminants concern include PCE and trichloroethene (TCE) in soil vapor because these exceeded applicable regulatory screening criteria. Soil vapor releases of VOCs have been identified at and in the vicinity of the Site through multiple environmental investigations conducted since 2016. A total of 33 soil samples have been collected at depths ranging from 5 feet to 130 feet below ground surface (bgs) and PCE was detected at 5 feet bgs in 3 soil samples. A total of 74 soil vapor probes have been installed at depths ranging from 5 feet 130 feet bgs and PCE has been detected in all soil vapor samples. In addition, sub-slab soil vapor probes have been installed and sampled repeatedly since 2015 at 201 South Glendale Avenue, 205 South Glendale Avenue, 211 South Glendale Avenue. Data from a December 2024 sampling event showed the highest PCE concentrations located beneath and directly west of Site. PCE concentrations decrease radially with distance from the Site with the exception of elevated concentrations to the north that may be associated with an off-Site source yet to be identified. Project Activities: The project is intended to address elevated VOCs in soil vapor and to prevent accumulation of residual soil vapor at the Site and adjacent properties thereby reducing the potential for vapor intrusion. An SVE system will be implemented to remove soil vapor at the Site and the vapor stream will be treated to prevent VOC emissions to the atmosphere. The SVE system will consist of: Vapor extraction wells and associated piping connecting the wells to the vapor treatment system; A water knockout tank with transfer pump; A soil vapor extraction and carbon adsorption unit to extract and treat soil gas from the vapor extraction wells; Required valves, gauges, hoses, and sample ports for the SVE systems; On-Site power to the system; and Meters and gauges as required to obtain system operation data. Three new extraction wells (screened from 5 to 30 feet below ground surface (bgs)) will be located at the following locations in the upper 30 feet of the subsurface: EX-2 – immediately to the north of the Site on the south side of East Harvard Street (approximately 20 feet north of the Site) EX-3 – immediately to the south of the Site in the northeast corner of the 211 South Glendale Avenue (approximately 30 feet south of the Site) EX-4 –on the northern boundary of the 217 South Glendale Avenue (approximately 80 feet south of the Site) Six new deep extraction wells (screened from 65 to 85 feet bgs) will be located at the following locations: EX-5 – on the southern corner of the East Harvard Street before the intersection of South Glendale Avenue (approximately 75 feet northeast of the Site) EX-6 – on the western side of South Glendale Avenue (approximately 90 feet south of the Site) EX-7 – in the parking lot immediately east (approximately 5 feet east of the Site) EX-8 – in the parking lot (approximately 170 feet west of the Site) EX-9 – on the western side of South Isabel Street (approximately 150 feet north of the Site) EX-10 – on the in the parking lot (approximately 200 feet southwest of the Site) All extraction wells will be constructed of 2-inch diameter casing and screen. Piping trenches will be installed to connect each vapor extraction well to a manifold in the SVE system enclosure. Each extraction well will have a dedicated pipe connecting the well to the manifold. At the manifold, the dedicated pipe from each well will be fitted with a valve and sampling port so that each well can be individually controlled and sampled. A single 4-inch diameter pipe will convey vapor exiting the manifold into the knockout pot and activated carbon tanks. The vapor treatment system will consist of three, 2,000-pound carbon adsorption canisters plumbed in series. Ports will be installed to sample vapors at the inlet to the first canister, between each canister, and the exhaust stack to the atmosphere. Once installed, the system will operate continuously for 2 years except for as needed for maintenance and brief shutdowns to collect soil vapor samples to evaluate remedial progress. Once SVE operations cease DTSC will evaluate the risk to human health and the SVE’s effectiveness in removing and treating VOCs in the subsurface. This evaluation along with any additional sampling will be used in preparation for the development of a final remedy to address releases in all media. A Permit to Operate the SVE system will be obtained from the South Coast Air Quality Management District (SCAQMD). Requisite permits/releases from the City of Glendale Building, Planning, and Fire Departments will also be obtained as necessary. The Site is in a previously developed area and does not provide habitat value. The project is consistent with applicable state and local environmental permitting requirements including, but not limited to, air quality rules such as those governing VOC emissions and approved by the regulatory body with jurisdiction over the Site (e.g., SCAQMD, City of Glendale). In addition, a Permit to Operate will be obtained from SCAQMD for the SVE system. For these reasons, the project would not have the potential to negatively impact any nearby receptors, which include industrial and commercial land uses. 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.