OSCODA – Exposure assessment plans, sampling results and Do Not Eat (DNE) updates were among the items discussed during a webinar on the per- and polyfluoroalkyl substances (PFAS) contamination in Oscoda.
Hosted by the Michigan PFAS Action Response Team (MPART), the April 20 event featured updates from such MPART representatives as the Michigan Department of Environment, Great Lakes and Energy (EGLE) and the Michigan Department of Health and Human Services (MDHHS).
A particular subject of interest for those who sat in, was the talk of an Oscoda area exposure assessment. This is noteworthy, as the presentation by MDHHS Toxicologist Puneet Vij included a reminder of some of the health effects in humans, associated with higher PFAS exposure. This pertains to two types of PFAS: perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS).
“Most of what we know about the toxicity of PFAS comes from studies of two specific compounds – PFOA and PFOS,” Vij said. “Adverse health effects have been established in epidemiological and laboratory animal model studies for these PFAS chemicals.” Among them are reduced fertility, high blood pressure or pre-eclampsia in pregnant women, small decreases in infant birth weight, higher cholesterol, thyroid disease, liver damage, decreased immune system response to vaccines and increased chances of certain types of cancer.
“Right now, we are in the beginning stages of exposure assessment planning,” said Vij. The project team has been formed and it includes a toxicologist, epidemiologist, community engagement coordinator and a health educator. Their next meeting is May 4, and they are also in the process of forming a community advisory team.
In the exposure assessment, MDHHS will ask for a blood sample, that will be tested for PFAS analytes. Prior to the blood draw, participants will take a short survey about the ways they could possibly be exposed to PFAS.
While there weren’t many details beyond this, Vij advised that MDHHS will keep the community informed as progress is made.
Co-lead of the Need Our Water (NOW) community action group, Cathy Wusterbarth, said that they will be encouraging participation in the exposure assessment. She also remarked that NOW is very blessed to have assistance from Courtney Carignan of Michigan State University, an exposure scientist and epidemiologist who will serve as an advisor for the process.
Ahead of Vij’s presentation, some history was shared about the former Wurtsmith Air Force Base (WAFB) in Oscoda – where PFAS contamination has been spreading for years, due to the Air Force’s (AF) past use of aqueous film forming foam (AFFF) at the site.
The background was provided by Beth Place, of EGLE’s Remediation and Redevelopment Division (RRD), who is the project manager for the former base.
After a 70-year history in Oscoda, WAFB officially closed in 1993. Place noted that the AF is responsible for investigating and, if necessary, addressing any environmental contamination caused by AF actions while operating WAFB.
The cleanup is currently being conducted under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).
Place summarized a time line, starting from when EGLE first became aware of PFAS at WAFB, which is when they collected samples in 2010. From here, EGLE confirmed that PFAS was in groundwater (GW), surface water (SW), soil and biota, as a result of the AFFF used on WAFB.
She went on to describe some of the subsequent steps which were taken, such as the AF beginning basewide sampling; the EGLE investigations, sampling events and GW monitoring well installations outside of the base boundary; the AF’s completion of some of the CERCLA steps thus far; EGLE’s completion of the GW flow study on the east side of Van Etten Lake (VEL); and the various WAFB treatment system installation and enhancements made by the AF.
In more recent action, she said the AF has begun planning the PFAS remedial investigation (RI) and two interim remedial actions (IRAs). As reported, these IRAs entail Clark’s Marsh and VEL.
Place said that EGLE and the AF began their scoping meetings on the RI this past August, from which the AF took EGLE’s preliminary comments and discussions to write a draft RI work plan. EGLE is now reviewing the draft, and intends to provide its comments to the AF in mid-May. Following this, the department will also review the AF’s draft risk assessment work plan.
For both documents, Place said the two parties will have comment resolution, where they will go back and forth with their remarks. The finalized RI and risk assessment work plans are anticipated this spring/summer, with the fieldwork tentatively to begin in the summer also, but Place pointed out that a lot of the time lines will depend on the comment resolution.
She then went over the proposed additions to WAFB’s FT-02 treatment system, at the former fire training area. This IRA, which has been summarized in detail in this publication, seeks to further address the PFOS/PFOA contamination in Clark’s Marsh.
The AF is now going through the public comments received, which will be addressed in the Clark’s Marsh interim record of decision (ROD). This will be followed by several other steps, including a final ROD, and construction is expected to begin on the IRA later this summer. The tentative startup of the actual system is February/March 2022.
While the VEL IRA isn’t as far along in the process, construction of this is also expected to begin in late summer, with startup of the system tentatively to occur in February/March 2022.
Place said the AF has given EGLE its draft interim proposed plan for the VEL IRA which, along the lake near Ken Ratliff Memorial Park, calls for a series of extraction wells that will be routed back to the central treatment system (CTS) already operating at WAFB. “And so currently, we’re negotiating those comments.”
As with the marsh IRA, the AF will hold a public meeting and a 30-day comment period on the VEL plan. While it will depend on the comment resolution time frame, Place says that this could occur as early as next month.
In other updates, she said EGLE has sent a letter requesting the AF to evaluate an additional IRA, between FT-02 and the Mission Street treatment system. “EGLE thinks that we have some sufficient information there on base, in order to address the PFAS contamination in this area.”
EGLE has also requested that the AF sample for PFAS in the influent and effluent of the landfill (LF) 30 and LF-31 engineered wetland treatment system – an existing system at WAFB to address volatiles. According to Place, responses to both letters and discussions are pending and ongoing.
Next to speak was Amanda Armbruster of EGLE’s RRD, a geologist who is the project manager for the Oscoda Area Sites. She explained that these sites, where EGLE has identified PFAS in the GW, are separate from WAFB.
She said that EGLE installed several monitoring wells (MWs) throughout the Oscoda community in 2017 and 2018. For about the last year and a half, roughly 20-30 of these MWs have been sampled on a quarterly basis.
Armbruster gave a synopsis of the most recent sampling event, from this January, which takes into account PFOS, PFOA and five other PFAS types.
For the Colbath Road Area, on the northwest end of VEL, she reported that there were two MWs which had PFAS above EGLE’s drinking water (DW) cleanup criteria. “And the contamination in this area is believed to be from a house fire that was put out using firefighting foam.”
With the two MWs sampled in the Cedar Lake Area, both were below the DW cleanup criteria.
For the Loud Drive Area, along the southeast portion of VEL, three of the MWs showed exceedances of EGLE’s DW standards. Armbruster said that one of these wells is near the lake shore, around Loud Drive, and the other two are near the southern tip of VEL.
Two of the MWs in the River Road/Oscoda Schools Area also exceeded the DW cleanup criteria. Armbruster said that this is another location where the contamination is associated with a past fire that was fought using AFFF. The Oscoda Area Schools complex is on municipal water, she added.
As for the MW samples in AuSable Township, one of three showed exceedances this January. It is located near the intersection of Mill Street and Sunset Road.
Armbruster said there were high concentrations in this MW in October 2020, as well, and EGLE identified several nearby residential DW wells. “We’ve since sampled those wells.” Eight homeowners agreed to let EGLE sample their water, and all of these results were below the DW cleanup criteria.
EGLE’s Bay City District Supervisor for the Water Resources Division (WRD), Charles Bauer, then shared some details about the discharges from the existing treatment systems on WAFB – FT-02, CTS and Mission Street (MPTS).
He said that EGLE receives monthly discharge monitoring data from the AF, for the systems with Substantive Requirements Documents (SRDs) at the sites on which WRD does compliance.
“In general, all three systems are working as expected,” Bauer noted. The effluent results for PFOS, PFOA and the other PFAS compounds with recent maximum contaminant levels (MCLs) developed, are generally below MCLs and/or Water Quality Standards (WQS), with a few exceptions.
When calculating the averages, he said he utilized a conservative approach by omitting the non-detect (ND) samples. “So, it’s only looking at the concentrations that actually break through the treatment system.”
For the FT-02 data from 2018 to present, he said that the average effluent is still well below, or very close to, MCLs and WQSs. “Most of the sampling results are non-detect, and when you do see detections, it’s at a time where they have to change out the carbon – so it’s at a breakthrough time.”
He shared that the data from 2018 to present for the CTS is also working quite well. For example, the maximum effluent of PFOS was 9.2 parts per trillion (ppt). The MCL and WQS for this compound is 16 ppt and 12 ppt, respectively. Further, the PFOA maximum effluent, as well as several other types of PFAS, were ND.
From 2019 to present, PFOA effluent and some other contaminants were also ND at MPTS. While there was a PFOS maximum effluent of 18 ppt as a breakthrough, Bauer said the average overall is well below the MCLs and WQSs. “And again, I’m only averaging the breakthrough numbers. If I actually averaged in all of the non-detect numbers, the averages would be lower.”
He explained that this data is used by EGLE for compliance purposes, as well as to prepare for inspections. It is also utilized in the instances where EGLE may have to take enforcement actions.
Bauer listed several past examples of this, including one from October 2018, requiring the AF to improve the FT-02 capture and treatment – which is the aforementioned marsh IRA.
Another topic discussed was the contaminated foam which has been found on water bodies/beaches and, with summer fast approaching, Vij also gave a reminder to avoid foam due to PFAS.
Although swimming in the water isn’t a concern – since PFAS do not easily absorb through the skin – the amount of PFAS in foam is usually higher than in the SW, and swallowing it could be a health risk. This is especially true when it comes to hand-to-mouth behavior in children, which creates ingestion concerns. Therefore, it is best to rinse off foam after contact and to shower following such outdoor activities as swimming.
Vij also noted that dogs can potentially swallow foam collected in their fur when grooming themselves, so they should be thoroughly rinsed with fresh water after any contact with foam.
“This evaluation is based on a young child playing by the shore for three hours a day, five days a week, for three months a year during the summer,” he said of the repeated, prolonged whole body exposure scenario.
A statewide press release has also been issued by MDHHS, to avoid foam on water bodies known to have high PFAS levels. In one local example, signage promoting the same message can be found at VEL.
EGLE’s Bay City WRD Compliance Manager Matt Siler also touched on this issue, sharing the ways in which people can report foam appearances. One option is to contact the Pollution Emergency Alerting System (PEAS), at 800-292-4706. “If you want to remain anonymous, you can,” Siler said. Reports made to PEAS will end up on his desk, which he will then enter into MiWaters, the WRD’s electronic database.
The public can also access MiWaters to report a foam event, by going to miwaters.deq.state.mi.us. Siler said that an account does not have to be created, and all one has to do to begin is click on the “Report Spills, Pollution, Unauthorized Activities” box. On the next screen, select the “Report Spill/Incident/Pollution” option, then follow the remaining steps.
In addition to the foam reminders, Vij gave several other updates. One is that MDHHS recently finished its first round of re-sampling, which is an effort to understand PFAS fluctuations in DW wells. “And this, along with the source area characterization – or extent of plume contamination – will help support our final public health determination.”
According to Vij, MDHHS collected samples from 277 of the 427 wells in the Oscoda area which were previously tested by EGLE. Of those, there were 136 NDs and 141 detections. The range of PFOA plus PFOS was 2.05-263.62 ppt, and the range of total PFAS was 2.01-2,514.02 ppt.
Out of the 141 detections, 20 exceeded the MDHHS comparison values. As Vij has explained, these values are the lowest of the two, out of the MDHHS screening levels and approved MCLs. For example, the screening level for PFOA is 9 ppt and the MCL is 8 ppt, so the comparison value is 8 ppt. With PFOS, the screening level is 8 ppt and the MCL is 16 ppt; therefore, the comparison value is 8 ppt. “And we use this lower value to guide our public health recommendations.”
He said that the plan is to begin round two of re-sampling in the first week of May, to capture the seasonal homes, and that MDHHS will be reaching out to the necessary residents. “And when you have your recruitment letters, you can schedule an appointment with a sanitarian.”
With Clark’s Marsh being a contamination hot spot, Vij also gave some details on this site. Still in effect, he said, is the emergency DNE Fish public health advisory. This was issued by MDHHS in 2012 for all fish taken from the marsh, due to high levels of PFOS.
In the fall of 2018, MDHHS issued a DNE public health advisory for deer taken within a five-mile radius of Clark’s Marsh, which Vij says is also in effect.
The department also put out a DNE advisory in 2019, for all resident aquatic and semi-aquatic wildlife taken from the marsh. This was issued as a precaution, due to high PFOS levels in the muscle and organs of one deer out of 20 taken from around WAFB.
In 2020, an additional 44 deer were harvested from around the marsh and tested for PFAS. Vij said that the highest PFOS levels were 82.6 parts per billion (ppb), which was detected in muscle, and 2,970 ppb in liver.
Based on the data, the relationship between detections of PFOS in liver samples and the collection location distance from Clark’s Marsh, MDHHS is recommending that the DNE advisory be changed from within five miles of the marsh, to within three miles.
The deer testing results and data report used for this decision are in the final stages of approval, and Vij said it will be available to the public very soon.
MDHHS continues to recommend not eating the organs from any deer, fish or other wild game in the state because many chemicals, including PFAS, can accumulate in the organs.
Consumption of fish or wildlife from Clark’s Marsh is a concern but, in the case of fish, catch and release is fine.
As for the latest fish sampling, Vij said that MDHHS recently received the mercury and PFAS results for yellow perch collected from VEL in 2018 and 2019. Currently, yellow perch from VEL are covered under the statewide advisory of four servings per month, due to mercury. But the new data suggests that this be changed to two servings per month, as a result of PFOS and mercury.
The meeting also featured questions and comments from the public, several of whom had inquiries regarding the SRDs.
To view the presentation slides and/or to watch the webinar in its entirety, visit Michigan.gov/pfasresponse. Type “All Wurtsmith Documents” into the search bar, then click the first option. The meeting can also be viewed at https://www.youtube.com/watch?v=Hs0fphO88LA.