From: HOOD Robert * DEQ
Sent: Wed May 05 10:14:09 2021
To: Bob Dailey; Acaster, Marty
Cc: Men, Terri; Tim Davis; Redlin, Jenny; SCHATZ Jeff * DEQ
Subject: 6451 Central Self Storage Comment to GW Evaluation Report and Other Submittals
Importance: Normal
Bob and Marty:
DEQ reviewed the above mentioned items. Please see our comments below:
Groundwater Report:
· For heavy oil in soil, Partner compared results to diesel risk-based concentrations. There are no generic RBCs for heavy oil. You will need create site-specific RBCs or indicate RBCs are “not established” and rely on a CMMP to address risks.
· As discussed with DEQ, please complete a beneficial water use determination.
o Regarding beneficial use, there was no discussion of the nearby Willamette River and potential for groundwater contaminants to reach the river.
· There were no field sampling logs in the report, nor discussion of whether any sheen or product observed in well points, as might be expected with concentrations of total petroleum hydrocarbons detected. Please provide.
· The report is not stamped or signed by RG. Please provide.
· There are a few errors in Table 6 presenting PFAS data (and text):
o EPA Health Advisory Levels are confined to PFOA and PFOS only. The 70 ng/L HAL presented for non-PFOA and PFOS compounds is correct.
o The 70 ng/L value is for combined PFOA and PFOS. Individually, the screening values for both are 40 ng/L.
o The meaning of the “Other PFAS” row at the bottom of the table is unclear. An explanation in the notes would be helpful. Please explain what other PFAS compounds you are referring to. Perhaps of most interest in the “Other” category is the “fluorotelemers”. Fluorotelemers such as 4:2 FTS, 6:2 FTS, and 8:2 FTS are newer fluorinated compounds, created through the more modern telemerization process, and shorter-chain as opposed to the longer-chain C-F molecules such as PFOA and PFOS presented in historical formulations. They were analyzed for here, and the lack of detection of fluorotelemers in the Central Self Storage samples is consistent with an older release.
· Due to the high concentrations of TPH detected in the downgradient borings, DEQ requests that you conduct additional investigation to the west, northwest, and northeast. Please provide a work plan.
Methane Vapor Migitation:
· The vent riser should be at least 3 feet above building.
· Please provide a scaled map.
· DEQ expects that at least two rounds of sampling be conducted and the samples be analyzed for methane from the soil vapor points and one riser.
Items missing from 2/22 email reply to them:
· Please refer to the email and provide any items you have not yet provided.
If you have any questions, please contact me. Thank you. -Rob
Robert A. Hood, Jr.
Natural Resources Specialist 4
Oregon DEQ
700 NE Multnomah Street, Ste. 600
Portland, OR 97232
(503) 229-5617