From: Lisa Thompson
Sent: Mon Apr 14 16:13:45 2025
To: PUGH Mark * DEQ
Cc: Andie Fitzgerald; Suzy Stumpf
Subject: Former Five Star Cleaners (2305 SW 6th Avenue) – Q1 2025 Quarterly Progress Report
Importance: Normal
Attachments: image001.png; Figure 2_SitePlan.pdf; Q1 2025 Tables.pdf; Q1 2025 O& M Inspection Forms and Field Notes.pdf; Pace_L1831270-Report.pdf; ALS_2505126-Report.pdf;
Microsoft Exchange Server;converted from html;
Mark,
This email provides a quarterly progress report for the former Five Star Cleaners property at 2305 Southwest 6th Avenue (DEQ ECSI Site ID No. 6276) (herein referred to as the Site). This progress report is being submitted for the first quarter of 2025, on behalf of Pacific Skyline Holdings II, LLC.
Actions taken during the previous 3 months:
- Farallon conducted monthly operation and maintenance (O&M) visits to document the Site’s Vapor Collection System performance on January 28, February 27, and March 20, 2025. Monthly O&M activities included monitoring the following parameters:
- Concentrations of volatile organic compounds (VOCs) were measured using a hand-held photoionization detector (PID) at select monitoring points, including at the vapor collection system, subslab vapor points, and vapor recovery wells. PID readings are summarized in Table 1 (attached).
- Differential pressures were measured at the subslab vapor points (VP-5 through VP-8) using a hand-held vacuum gauge (Figure 2). Differential pressure readings are summarized in Table 2 (attached).
- Semiannual air samples were collected from the influent (pre-carbon) and effluent (post-carbon) lines of the vapor granular activated carbon treatment vessels using Summa canisters on February 27, 2025. The samples were submitted to Pace Analytical laboratories for analysis using U.S. Environmental Protection Agency (EPA) Method TO-15 for VOCs, including but not limited to tetrachloroethene (PCE) and trichloroethene (TCE). Analytical results for PCE, TCE, cis- and trans-1,2-dichloroethene, and select petroleum hydrocarbons collected pre- and post-carbon are shown in Table 3 (attached). The analytical report is also attached.
- Indoor and outdoor ambient air samples were collected using Radiello badges between February 6 and 15, 2025. The samples were submitted to ALS Environmental laboratories for analysis for PCE and TCE by EPA Method TO-17. None of the indoor air samples exceeded the State of Oregon Department of Environmental Quality Risk-Based Concentrations Table, revised May 2018, for Occupational for PCE or TCE. Ambient air analytical results are shown in Table 4 (attached). The analytical report is also attached.
Summary of monitoring data and sample analytical results for the previous 3 months:
Monthly O&M field reports are attached. PID readings are tabulated in Table 1, and vacuum and pressure readings are tabulated in Table 2 (attached).
- PID readings from vapor collection system exhaust were as follows:
- VOCs were not detected in the Pits Exhaust from the vapor collection pits in January, February, or March 2025.
- VOCs were detected in the Pre-Carbon Effluent from the vapor recovery wells at concentrations of 26 parts per million (ppm) in January, 15 ppm in February, and 4.0 ppm in March 2025.
- VOCs were not detected in the Post-Carbon Effluent from the vapor recovery wells in January, February, or March 2025.
- Positive pressure was measured at the exhaust stack for the vapor pits collection system in January, February, and March 2025, confirming air flow and that the fan is operational.
- A vacuum was observed at the carbon inlet for the recovery wells in January, February, and March 2025, confirming air flow and that the fan is operational.
- A vacuum ranging from 0.003 to 0.011 inches of water column was measured at vapor points VP-5 through VP-7 during January through March 2025 monitoring. Vacuum was not measurable at vapor point VP-8 during the January and February 2025 monitoring, but vacuum was measured at 0.004 inches of water column during the March 2025 monitoring. Vacuum measurements confirm a negative pressure field beneath the foundation slab.
A description of any problems experienced during the previous 3 months and actions taken to resolve them:
- The subslab vapor collection pit piping was checked for the accumulation of water during the January, February, and March 2025 O&M events. Accumulated water removed from the subsurface piping system ranged from approximately 1/4 to 2 cups. Water removed from the subsurface piping system is collected and stored on-Site in a lidded 5-gallon bucket pending appropriate analytical testing and disposal.
Actions scheduled in the next 3 months:
- Conduct monthly O&M visits in April, May, and June 2025.
- In the event rainfall occurs in the upcoming months, check the piping system for water accumulation.
If you have any questions about the information provided in this progress report, please do not hesitate to contact us.
Project Manager: Lisa Thompson, P.E., Associate Engineer
Farallon Consulting, L.L.C.
Phone: (425) 395-4636
Email: lthompson@farallonconsulting.com
Technical Contacts: Lisa Thompson, P.E., Associate Engineer
Farallon Consulting, L.L.C.
Phone: (425) 395-4636
Email: lthompson@farallonconsulting.com
Suzy Stumpf, P.E., Principal Engineer
Farallon Consulting, L.L.C.
Phone: (303) 489-1032
Email: sstumpf@farallonconsulting.com
Regards,
This correspondence contains confidential or privileged information from Farallon Consulting and may be "Attorney-Client Privileged" and protected as "Work Product." The information contained herein is intended for the use of the individual or party named above. If you are not the intended recipient, note that any copying, distribution, disclosure, or use of the text and/or attached document(s) is strictly prohibited. If you have received this correspondence in error, please notify us immediately. Thank you.
