This case arises out of the contamination of surface waters and drinking water in Chattooga County, Georgia, with per- and polyfluoroalkyl substances known as “PFAS.”
In essence, Plaintiff Earl Parris, Jr., alleged that the Defendants have contaminated his water with PFAS. Parris is a resident of Summerville, Georgia, who receives running, potable water to his home from the Summerville Public Works and Utilities Department.
The City of Summerville—which has intervened in this case—used Raccoon Creek, a tributary of the Chattooga River, as the main source of its municipal water supply. Parris alleged that Raccoon Creek and—consequently, his household water—have been contaminated with PFAS by the Defendants. At present, Parris and Summerville jointly moved to exclude the opinion testimony of Defendant 3M’s expert, Maureen Reitman.
Polymers Expert Witness
Maureen Theresa Fahey Reitman, Sc.D. has been practicing in the field of polymer science and engineering for more than 30 years.
She has a Doctor of Science in Materials Science and Engineering, with a thesis in the field of polymers, from MIT. She is also a licensed Professional Engineer in the state of Maryland and a Fellow of the Society of Plastics Engineers.
Discussion by the Court
Relevancy and Likelihood of Confusion
Plaintiffs asserted that Reitman failed to identify any PFOS-containing products at the Mount Vernon Mill or the Trion Water Pollution Control Plant (“Trion Plant”) other than 3M’s product.
The Court agreed with 3M that Reitman’s opinions as to other possible sources of PFAS and PFOS in the Raccoon Creek watershed are relevant to the issue of causation. Although it is 3M’s burden to establish the relevance and reliability of their expert’s opinions, it is ultimately the Plaintiffs’ burden at trial to prove the causal connection between their alleged injuries and the Defendants’ alleged actions.
Here, 3M sought to introduce evidence undermining the Plaintiffs’ causation evidence by showing that there were other possible causes of the Plaintiffs’ injuries. Thus, the Plaintiffs’ argument that Reitman cannot determine “to what extent, if any, a participant in the global supply and use network for PFAS released a particular substance into the environment at issue” entirely missed the mark—the fact that Reitman is testifying she cannot make this determination is the whole point of introducing her testimony.
3M intended to rely on this testimony to argue that the Plaintiffs cannot prove its product is the cause of the alleged PFAS contamination in the Raccoon Creek watershed.
The Plaintiffs also sought to exclude Reitman’s opinions under Federal Rule of Evidence 403, arguing that her testimony about PFOS sources manufactured abroad will confuse the jury because such sources are irrelevant to their claims. Because Reitman’s testimony is relevant and will be helpful for the jury, the extraordinary remedy of exclusion under Rule 403 is unwarranted here.
Reliability
Plaintiffs asserted that Reitman admitted she does not have any data indicating PFOS sources besides 3M’s product are present in the Raccoon Creek watershed, yet she seeks to testify that other possible sources exist.
However, Reitman’s report explains the reasons why the identification of PFOS and PFAS “in an environmental sample is not sufficient to identify the original source of production.” Further, she explains why this is true regardless of the characteristics in a sample associated with electrochemical fluorination (ECF), a process that 3M is known to have utilized in processing PFOS.
And she provided testimony critical to 3M’s causation defense that the Plaintiffs have not provided an appropriate scientific basis for excluding other possible suppliers of the specific PFAS at issue due to the potential contributions of products associated with global supply chains.
The fact that Reitman’s opinions may undermine the causation evidence the Plaintiffs intend to present does not make them unreliable; instead, the Plaintiffs’ concern goes to the weight and credibility of the evidence. The Plaintiffs will have the opportunity to cross-examine Reitman at trial, where their concerns will be more appropriately addressed.
Held
The Court denied the Plaintiff and Intervenor-Plaintiff’s joint motion to exclude the opinions of Maureen Reitman.
Key Takeaway
In the Court’s view, the Plaintiffs did not truly challenge the reliability of Reitman’s opinions, but instead challenged the content of her opinions. But the Court’s inquiry at this stage “must be solely on principles and methodology, not on the conclusions that they generate.”
Case Details:
| Case Caption: | Parris V. 3M Company |
| Docket Number: | 4:21cv40 |
| Court Name: | United States District Court, Georgia Northern |
| Order Date: | March 09, 2026 |
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