OSCODA – The following is the second of a two-part story on the April 15 Wurtsmith Restoration Advisory Board (RAB) meeting. The first ran in last week’s edition of this publication, and highlighted such items as the expanded site inspection (ESI) completed at the former Wurtsmith Air Force Base (WAFB) in Oscoda this past December.
Also summarized were comments in response to the $13.5 million which was allocated to the Air Force (AF) for per- and polyfluoroalkyl substances (PFAS) remediation at WAFB. Many RAB participants shared their aggravation that the funds will likely be used for more research and studies, and not on direct cleanup – despite there already being more than a decade of investigations, along with the issuance of several public health advisories.
But David Gibson of the AF Civil Engineer Center (AFCEC), who serves as project manager and RAB co-chair, said the money from Congress is for conducting the base-wide remedial investigation (RI) phase at WAFB. He noted, though, that it may be possible to do some interim remedial actions during the RI.
As for the ESI, this concentrated on seven priority areas identified during the site inspection (SI). Gibson says the ESI was a stop-gap measure to look at the drinking water (DW) pathway, which was the most important pathway to determine impacts on the local populous. The purpose of the ESI was to evaluate pathways to DW sources and determine the need for interim actions to protect DW from exceeding the Environmental Protection Agency’s (EPA’s) lifetime health advisory (LHA) of 70 parts per trillion.
The Michigan Department of Environment, Great Lakes and Energy (EGLE) submitted its comments on the ESI findings in January, and Gibson said a response from the AF will be forthcoming shortly.
A synopsis of the ESI was given last week, along with a list of recommendations for what the base-wide RI should include.
There is a second ESI recommendation, as well, which is to evaluate the following response actions for implementation:
• Develop and implement a sentinel well plan to monitor PFOS/PFOA (two types of PFAS) concentrations in groundwater (GW) downgradient of suspected sources and upgradient of DW wells.
• Evaluate expansion of MS TS capture zone.
• Evaluate expansion of the FT-02 (former fire training area) granular activated carbon (GAC) pump-and-treat system (PTS).
As for the final ESI findings, under the Defense Environmental Restoration Program (DERP), there are three possible outcomes from the SI phase. One is that here is no need for action (all contaminants detected lower than screening values set at a Hazard Index of 0.1). Another is that there is a need for immediate action (contamination detected at levels that present an imminent hazard to human health), and third is a need for RI.
According to the AF, the ESI documents exceedances of one or more screening levels for PFOS or PFOA, but not at levels warranting immediate action. The recommendation is to proceed to the RI phase, consistent with DERP, the National Contingency Plan and the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) process.
As previously noted, the AF’s investigation work and response actions are guided by CERCLA, along with applicable state laws and the EPA’s LHA for DW.
The preliminary assessment (PA) and SIs are complete for Wurtsmith, and the AF is now moving into the RI phase. The PA first identified areas with potential releases of aqueous film forming foam (AFFF). This PFAS-laden foam was used at WAFB by the AF, beginning in the 1970s.
Six more CERCLA steps still remain, those being a feasibility study (FS), proposed plan, record of decision (ROD), remedial design, remedial action construction/remedial action operation and long-term management.
Gibson acknowledged that there are areas of contamination at WAFB which exceed the LHA level. “But no one is being exposed at an imminent health concentration. As a matter of fact, I don’t think there’s an actual contaminant level that’s been determined.”
EGLE’s summary of the report can be viewed at https://www.michigan.gov/pfasresponse/, by searching for “Wurtsmith ESI.”
In reference to the second possible outcome under the final ESI findings, RAB Co-Chair Arnie Leriche asked if the AF has done any evaluation with the data provided by EGLE on the various Do Not Eat advisories, in order to determine whether this is an imminent hazard to human health.
“I cannot speak directly to knowledge that the DoD [Department of Defense] or the Air Force is actually examining EGLE’s data, no,” Gibson answered.
He said the DoD does have a PFAS working group of scientists who are collaborating with different organizations to look at this information and the toxicology, and evaluating with them what that might lead to, as far as decision making for the DoD and AF.
Gibson said that, at this point, he doesn’t know of any definitive criteria beyond the LHA that would be in line to be considered by the DoD or a regulatory agency to cause a determination of an imminent health hazard. An example of other sites where this has been determined, though, are those where the public water supply was pulling in PFOS/PFOA above the LHA for people to use daily.
Gibson then moved on to the RI presentation, explaining that this phase will focus on defining the nature and extent of contamination, and assessing risk to human health and the environment.
AF officials say the RI results will provide the necessary information to make decisions on further remedial actions, including possible interim steps, as necessary to limit PFAS migration and address unacceptable risks.
The RI will involve a scoping process that calls for analyzing existing data; identifying likely responses; initial Applicable or Relevant and Appropriate Requirements (ARAR) identification; data quality objectives and updating the conceptual site model (CSM).
Gibson said a work plan will be developed during the scoping, which will be the point of agreement with the AF and EGLE as to where the wells are going to be installed, what kinds of samples are going to be collected and so on.
Another RI step is site characterization, which entails field investigation, the nature and extent of contaminants, ARAR identification and a baseline risk assessment.
Upon completion of the RI – for which Gibson said the contract to start this should be awarded in September – the next step will be the FS, followed by the remaining phases in the CERCLA process. Based on the AF’s projected RI schedule, development of the FS project requirements is expected in August 2022.
Gibson said it will be during the work plan stage when he would want to entertain how to address interim actions but, he’s got to ensure that he meets the overall goal of an RI for WAFB.
He said the AF will be looking at judicious use of resources to complete the RI and answer as much as possible regarding the extent/direction of either soil, surface water (SW) or GW around WAFB, to gain enough information to develop an FS. “We have to do the RI, but maybe we can do it in a way that enables us to get to a decision on going to the feasibility study phase for certain areas of contamination or certain sites.”
Gibson noted that the time frame for installing a remedy will come in at the ROD phase.
When RAB member and AuSable Township Trustee Jeff Moss asked if the $13.5 million from Congress was for interim action at WAFB, Gibson said the money was to conduct the RI.
“Wasn’t there already a budget number for the RI to occur?” Moss questioned. He also asked that, if this money wasn’t provided, would the RI simply not have gotten underway this year?
“In short, yes,” said Gibson, adding that AFCEC doesn’t have its own set of funds for work outside of what Congress allocates.
He said that, at Wurtsmith, there wasn’t a problem with the municipal water supply that required immediate action. So, based on the conditions at WAFB, the next step is the RI. “Unless there’s funding, we cannot contract that work.”
Moss contested Gibson’s statements, saying that he believes the $13.5 million was not for an RI, but for actual remediation.
Secondly, regarding whether or not WAFB meets certain criteria, Moss said the contamination has been going on for decades, there is a DW problem and there continues to be a SW problem.
Based on the time lines presented, Oscoda Township Supervisor Aaron Weed asked if 2024 is the earliest there will be remediation infrastructure installed.
Gibson said this is possible but it will be affected by whatever happens with the interim actions, based upon the data that can be collected in the summer, and when the review is done to see whether the FS can start earlier.
“How is the EGLE data that already exists, and all the data gathered from the Air Force, not enough data?” Weed questioned.
Gibson said the focus of the ESI was DW and protecting the DW sources. There has been a lot of good data gathered, though, for GW and other items, and these will also be incorporated.
RAB member and Need Our Water (NOW) Co-Lead Cathy Wusterbarth then asked if the AF would address the NOW priority statement to have the AF stop the flow of WAFB contamination into all Oscoda area surface waters by no later than 2023, including remediation with the utmost speed and urgency of the PFAS plumes impacting Van Etten Lake (VEL).
Gibson said the work plan will drive what can be done to capture the plumes which are not already captured. Efforts can be made to help stop the migration, but he can’t commit to whether a remedy will be installed to do so by 2023.
Remarks were also shared by RAB alternate Rex Vaughn, who said that CERCLA requires natural resource injury integration and imminent substantial endangerment evaluation, if the AF is only focused on DW vectors. Michigan has identified several other vectors for human and wildlife ingestion of PFAS around WAFB, issuing the Do Not Eat orders.
“These health risks are particularly significant in a community where some parts of the population rely on hunting and fishing to meet their regular nutrition needs. Why has the Air Force ignored the human and wildlife health risks?” Vaughn asked.
Gibson said it was based on the relative risks and the funding available to DoD and AF. With limited funds, they must be focused on the biggest hazard, which is DW. And that has been the case, until now. Since the money was released for the RI, the matter is no longer just about determining if there is an immediate problem with DW. All pathways, including deer, fish, soil and GW/SW interface, are now part of the RI.
“You don’t have to just look at water, and you’ve known that all along,” said VEL property owner Anthony Spaniola. “There’s nothing in CERCLA that ties your hands to do that. This was simply an arbitrary decision made by the Department of Defense, without regard to the public health and safety of people in Oscoda.”
In separate topics, Jeremiah Morse of AECOM went over the EGLE transducer study, which has been ongoing in the community for a couple of years.
He began with a map showing total PFAS detected in the GW, which was the driver for the study. The reason for showing total PFAS and not just the compounds that have criteria – PFOA and PFOS – are because products containing PFAS that impact GW, such as AFFF, are made up of dozens of different PFAS compounds.
Morse said each of the compounds can move through the aquifer differently, so it’s better to look at the sum of all the detected PFAS concentrations, for a more holistic picture of where impacted GW is or could be in the future.
He said that, after PFAS was found widespread across WAFB, EGLE focused on determining if there were impacts outside the base boundary. “As you can see, PFAS is found all throughout the Oscoda area.”
He pointed out that not all of these areas are the result of on-base activities. “For example, PFAS-impacted groundwater in the Colbath area, to the north of the former base, was the result of AFFF being used at a house fire.”
Another example is near Oscoda Area Schools, where PFAS-impacted GW is the result of AFFF being used on a nearby forest fire, and later in a bus garage fire.
According to Morse, one area where the source hadn’t been determined for PFAS-impacted GW, was the east side of VEL. In the spring of 2018, EGLE decided to conduct a study here to better understand GW flow directions and how it changes over time. To do so, pressure transducers were installed in the EGLE monitoring wells (MW). “These instruments measure the [GW] elevation at regular time intervals by sensing a change in water pressure as the water levels move up and down inside a well.” Transducers were installed in 20 MWs, with an additional one installed at the VEL dam to measure lake levels.
Morse said there are two sets of GW elevations, from two separate measuring events. He showed a graph from a 1983 U.S. Geological Survey report, as well as the more recent elevations from 2018, and both data sets showed a similarity in GW conditions over time.
He explained that GW on WAFB flows from the west. “As it moves across the base, it divides in two directions.” East discharges into VEL, and south into Clark’s Marsh and eventually the AuSable River. On the east side of VEL, water is flowing from a high at Cedar Lake, and it divides either west into VEL or east into Lake Huron. “This divide extends all the way south, between Van Etten Lake and Lake Huron.”
Morse said when there is a rise or fall in lake level elevation, there’s a similar response shortly thereafter in the GW elevation. What this indicates is that in this location, when the lake is at its highest level, it is influencing near shore water elevations and potentially discharging lake water into near shore GW.
“Based on the current set of data from this and previous studies, combined with the current hydrogeologic understanding of this area, it is unlikely that PFAS-impacted groundwater from the former base is migrating beneath the lake, impacting groundwater north and east of VEL,” he noted.
However, Morse said there is influence of near shore GW levels around the southeastern end of VEL, due to the seasonal, artificial raising and lowering of the lake level. This lake level influence may have implications for understanding detections of PFAS in GW within a few hundred feet of the VEL shore.
He said there are three possibilities, one being that elevated near shore detections of PFAS may be from the undetermined source of up GW gradient. Another is that PFAS-impacted GW discharges, from WAFB into VEL, could be impacting SW and then SW is infiltrating into near shore GW along the southeastern end of the lake. Or three, it could be a combination of these two processes.
EGLE representative Beth Place advised that the department has completed its portion of the transducer study on the eastern side of VEL. During the RI process, EGLE will ask the AF to determine how far PFAS is moving off WAFB and how it is moving.
In other business, the following items were also highlighted:
• Michigan Department of Health and Human Services (MDHHS) Toxicologist Abiy Mussa said MDHHS has mailed more than 400 letters to Oscoda area residents, to re-sample their well water. The intent is to help determine if PFAS levels change in residents’ drinking water over time.
• Department of Natural Resources representative Tammy Newcomb shared that 18 deer taken from the greater Clark’s Marsh area this fall were donated to be tested for PFAS. This brings the total to 20 deer from within the marsh, and 40 from the greater marsh area. “Today, those folks were notified that all 18 of the samples were non-detect in the muscle tissue.” Testing will continue once the labs no longer have to be closed due to coronavirus restrictions, and the goal is to have all the details together in time for MDHHS to do an analysis of the results. This will help determine any potential changes this fall for the Clark’s Marsh area deer.
• EGLE Remediation and Redevelopment Director Mike Neller gave an update on the dispute resolution status between EGLE and the AF, which has been on the books for more than 2½ years. There were originally seven items and four had been resolved. For the remainders, the resolution was predicated upon the ESI completion. “After reviewing the ESI, we are in agreement that those disputes or questions have been answered, and so I will be signing a letter here as soon as I can get back in the office to issue to the [AF], saying that we feel that all of the disputes have been resolved.”
• “In addition to that, our Bay City office has been conducting some quarterly sampling at select monitoring wells in the area, and they will continue doing that and sharing results on the MPART page as they become available,” Place noted.