In this water contamination case, Plaintiff Suffolk County Water Authority (“Suffolk”) brought suit against manufacturers Dow Chemical Company (“Dow”) and Vibrantz Corporation (“Ferro”).
Suffolk contended that dioxane-stabilized TCA is the source of dioxane contamination in the TCA Claim Wells and offered the opinions of its expert witnesses in support. Dow rebuts this proof through the opinions of its own expert, Steve L. McGinnis. Suffolk sought to exclude a narrow subset of McGinnis’ opinions.
Environmental Engineering Expert Witness
Steve Lee McGinnis received a B.S. in Biological and Agricultural Engineering with a secondary major in Natural Resources and Environmental Science from Kansas State University. He received a Masters of Engineering degree in Civil and Environmental Engineering from the Massachusetts Institute of Technology. He is also certified as a Professional Engineer in fifteen states, a Certified Groundwater Professional, a Board-Certified Environmental Engineer, and a Petroleum Release Remediator in South Dakota.
McGinnis has over twenty years of engineering experience “in the fields of environmental engineering, contaminated site investigation and remediation, contaminant fate and transport, and environmental forensics.” Moreover, he has consulted for numerous sites and facilities regarding contaminant releases, including in Suffolk County. In his consulting experience, McGinnis has overseen site investigation and remediation efforts, including specific experience treating 1,4-dioxane and 1,1,1-TCA.
Discussion by the Court
According to McGinnis, Suffolk’s experts “failed to consider fully the implications of Suffolk County’s unique and long-standing reliance on an archaic network of hundreds of thousands of cesspools and septic systems to discharge sanitary wastewater in the subsurface of Suffolk County on the loading of 1,4-dioxane to the SCWA claim wells from the everyday use of common consumer products, which have long contained 1,4-dioxane.”
Suffolk sought to exclude McGinnis’ opinion that the use and discharge of consumer products in residential areas likely constitutes a primary source of 1,4-dioxane, as well as his opinion that 1,4-dioxane trends are more closely linked to consumer products rather than 1,1,1-TCA.
After walking through the historical implications of Long Island’s lack of sewering and longstanding reliance on a dense system of cesspools and septic systems, McGinnis explained that “residentially recharged contribution areas are known to consist of 1,4-dioxane sources due to everyday use of common, everyday consumer products.” He then stated that his “review of historical land use data confirms that the vast majority of claim wells (238 of 286) capture water from predominantly suburban residential areas” and opined that “the abundant suburban residential land uses in the contribution areas for these claim wells likely constitute a primary source of 1,4-dioxane due to the use and discharge of common, everyday consumer products containing 1,4-dioxane.”
McGinnis summarized this opinion as follows: “it is my opinion that 1,4-dioxane trends are more closely linked to the historical and ongoing use of consumer products containing 1,4-dioxane, rather than 1,1,1-TCA use.”
Analysis
The Court agreed with Suffolk that McGinnis’ challenged opinions must be excluded for several reasons. First, it would mislead and confuse the jury to permit McGinnis to simultaneously opine that 1) a well-by-well analysis is required for a true source identification and 2) that consumer products are a “primary source” of dioxane in 238 wells without performing such a well-by-well analysis himself. It is permissible for McGinnis to opine that Suffolk’s experts failed to properly account for the impact of Suffolk County’s lack of sewering and the Claim Wells’ location on predominantly residential land. However, McGinnis cannot take the additional step of opining that consumer products are “likely” to be a “primary source” of dioxane in 238 wells while disavowing that he undertook a well-by-well analysis, which he opined was necessary to determine the source of dioxane in each well.
McGinnis’ land use analysis must also be excluded for another reason: he did not identify in his report what analysis he used to classify each Claim Well’s contribution area or whatever judgment he may have used to reach his conclusions.
Finally, McGinnis’ opinion that “1,4-dioxane trends are more closely linked to the historical and ongoing use of consumer products containing 1,4-dioxane, rather than 1,1,1-TCA use,” must be excluded for yet another, independent reason. Namely, McGinnis never analyzes TCA as a source of the dioxane in the Claim Wells at all.
Held
The Court granted Defendants’ motion to exclude the opinions of Steve McGinnis.
Key Takeaway
Exclusion is required because the link, if any, between the data McGinnis analyzed and his final land use conclusions is written in invisible ink.
Please refer to the blog previously published about this case:
Environmental Engineering Experts’ Source-Identification Conclusion Excluded
Case Details:
| Case Caption: | Suffolk County Water Authority V. The Dow Chemical Company |
| Docket Number: | 2:17cv6980 |
| Court Name: | United States District Court, New York Eastern |
| Order Date: | June 22, 2026 |
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