The Department of Toxics Substances Control (DTSC) has reviewed the Third Quarter 2024 Groundwater Monitoring and Sampling Report (Report) (TRC Solutions, Inc., December 2024). The report was prepared on behalf of Pitney Bowes Inc. and Novitex Enterprises Solutions Inc. for the Former Chicago Musical Instruments (CMI) site (referred to as the Site). The report documents the methods and activities performed and presents the sampling results during the third quarter of 2024 for gauging and sampling 26 monitoring wells and four air sparge wells at the Site.

The Site is approximately 7.5 acres and was owned and occupied by CMI from 1964 through 1979 when CMI constructed several concrete sumps within the manufacturing building. A three-stage clarifier was also located on-site and adjacent to the southeast corner of the building. United Duralume Products, Inc. (UDP) purchased the property in November 1979. UDP operates machinery that bends aluminum sheeting. Some of their products include siding for buildings and patio covers. In February 2010, DTSC issued an Imminent and/or Substantial Endangerment Determination and Remedial Action Order (Docket No. I/SED RAO 09/10-002) to UDP. DTSC conducted environmental investigation, pilot studies, and soil and groundwater remediation from 2010 to 2017 under the State Orphan Site Program, which identified volatile organic compounds (VOCs) in soil, soil vapor, and groundwater.

On May 11, 2015, DTSC approved the Feasibility Study and Remedial Action Plan (FS/RAP) (Amec Foster Wheeler, May 6, 2015). The selected remedy in the FS/RAP includes soil vapor extraction (SVE) to address VOCs in soil vapor, in-situ treatment with potential air sparging for groundwater, and institutional and engineering controls.

In March 2016, DTSC entered into an Agreement to Perform Response Actions & Settlement (Agreement) with Novitex (successor of CMI) and Pitney Bowes (Parent company of Novitex). Since March 2017, Pitney Bowes Inc. has continued the implementation of the FS/RAP under the Agreement. An interim SVE system was then operated at the Site from April 19, 2017, to April 19, 2018, followed by an expanded SVE system since April 20, 2018. The expanded SVE system includes more vapor extraction wells and a treatment system with a larger capacity than the interim system.

Based on its proven effectiveness through a pilot study in 2018 and 2019, in-situ air sparging was conducted as an interim measure to reduce groundwater VOC concentrations from April to September 2020. Subsequently, it was expanded to a full-scale treatment system with the construction of additional wells in August 2020 and started operation in March 2021. The air sparging system was turned off in April 2023 for rebound testing.

The report concludes that groundwater elevations increased in the third quarter of 2024 compared to the first and second quarters and is a continuation of an increasing trend (approximately 25 feet) since the fourth quarter of 2022. The increasing water levels at the Site are likely due in part to the unusually high rainfall totals in California during the winter and spring of 2023 and 2024. VOCs, primarily tetrachloroethene (PCE), perchlorate, and 1,4-dioxane, are contaminants of concern at the Site. The main sump area continues to indicate decreased PCE concentrations in groundwater, with a maximum of 250 micrograms per liter in MW-6. The report recommends the continuation of the groundwater monitoring program and the evaluation and report of trends in dissolved-phase concentrations above the maximum contaminant levels for the upgradient wells. DTSC concurs with these conclusions and recommendations and hereby approves the report.