Gelman Newsletter

No significant updates from the EPA which is still considering public comments on their proposal to include the Gelman site on the Superfund National Priorities List (NPL). The EPA will spend the next few months reviewing and responding to each comment. If, after the formal comment period, the site still qualifies for cleanup under Superfund, it is officially listed on the NPL. After listing, further studies will ensue to determine the nature and extent of the contamination and to help identify potential treatment options.

General EPA updates regarding the Gelman site can now be found on the EPA’s website.

Coalition for Action on Remediation of Dioxane (CARD)

CARD meetings were held virtually on January 7, February 4, and March 4, 2025.  

• Michigan Department of Environment, Great Lakes, and Energy (EGLE) Update
• EGLE completed their 2024 annual surface water quality sampling, and results were shared with CARD. Results are currently available on CARD’s public drive.
• EGLE received the Marshy Area Feasibility Study on January 14, 2025. The document was shared with the CARD chair and is available on EGLE’s public Remedial Information Data Exchange website for download. CARD provided comments on the feasibility study for EGLE’s consideration. EGLE’s comments on the study were due to Gelman by March 13, 2025.
• EGLE met with Gelman representatives on Wednesday, January 22, 2025, to discuss EGLE’s response to the Groundwater to Surface Water Interface (GSI) Work Plan for Allen Creek Drain System. During this meeting, EGLE and Gelman agreed to postpone data collection for the EGLE-approved Eastern Area GSI Work Plan until summer 2025. This agreement was on the technical basis that July-September (drier months) will provide more representative data on the contribution of groundwater to the Allen Creek than data collected in January-March (months likely to be impacted by snow melting and rain events).

EGLE outlined data gaps in the delineation of shallow groundwater that could potentially impact the drain system, specifically around the Slauson School and upgradient of West Park. EGLE’s position is that these data gaps should be addressed as part of a forthcoming Downgradient Work Plan. EGLE and Gelman agreed that this work plan would consider data collected as part of the approved Eastern Area GSI work plan.

Furthermore, EGLE reiterated their position that the Downgradient Work Plan should also address other routes 1,4-dioxane may exploit as the plume migrates towards the Huron River as allowed by the Consent Judgment. These routes include the fill material enclosing the Allen Creek, groundwater directly venting to the Huron River, and groundwater that may intrude into the main branch of the Allen Creek. Adequate monitoring & accounting of all 1,4-dioxane migrating to the river will ensure that cumulative discharges do not exceed GSI criteria.

The next scheduled meeting will be held on Tuesday May 6, 2025, at 6 p.m. via Zoom (the April meeting was canceled). 

No significant MS4 updates.

Concentrations of 1,4-dioxane have been entering the Allen Creek Drain (ACD) stormwater system. The ACD system is part of Washtenaw County’s Municipal Separate Storm Sewer System (MS4). On December 15, 2022, the Washtenaw County Water Resources Commission Office sent a letter to Gelman indicating that action was required to remain in compliance with the County’s MS4 permit requirements regarding outstanding issues previously noted. The letter stated that the migration of 1,4-dioxane into ACD must cease or be in compliance with applicable State and County statutes and requirements.

EGLE Water Resources Division has drafted a framework for a possible permit and is in the process of scheduling a meeting with Gelman representatives to review permit conditions. The permit is intended to address the illicit discharge by requiring an eventual elimination of the discharge into the drain.

Total volume of groundwater treated December 2024 through March 2025: 

• 97,241,340 gallons

Mass of 1,4 Dioxane Removed:

• December: 80.91 lbs
• January: 78.85 lbs
• February: 74.06 lbs
• March: 78.04 lbs
• Total: 311.86 lbs

The mass calculations were determined from the NPDES monthly discharge reports using the maximum daily influent concentration and maximum daily effluent concentrations.

The volume was calculated from the average monthly flows in the monthly discharge report.