EPA Region 7 has flagged two of eight Superfund sites across the Midwest as having cleanup remedies that no longer protect human health and the environment, the U.S. Environmental Protection Agency confirmed in its latest five-year reviews.

How do five-year reviews work?

Under the federal Superfund statute, EPA conducts five-year reviews at sites where hazardous substances remain at levels that prevent unrestricted use and exposure. Region 7 — covering Iowa, Kansas, Missouri and Nebraska — completed the current cycle at eight sites and opened reviews at seven additional sites across Kansas, Missouri and Nebraska.

The reviews examine whether previously selected remedies continue to control contamination pathways, including groundwater migration and vapor intrusion, or whether new data demands a revised approach. Non-protective findings restart the regulatory clock and can pull additional parties into the response.

Which sites failed?

EPA ruled the remedy at Chemical Commodities Inc. in Olathe, Kansas, not protective. The agency is working with potentially responsible parties to map the migration of a contaminated groundwater plume.

Staff are running vapor intrusion testing, inspecting existing mitigation systems and installing additional units where the data warrants. Vapor intrusion results typically determine whether nearby buildings and workplaces need mitigation.

At the Minker/Stout/Romaine Creek site in Imperial, Missouri, EPA reached the same finding. The agency plans a removal action to address potential dioxin exposure and has scheduled community meetings to present the results.

Where did remedies hold up?

EPA found the Railroad Avenue site in West Des Moines, Iowa, protective site-wide. Three other sites cleared short-term or partial benchmarks:

• Former Blaine Naval Ammunition Depot in Hastings, Nebraska — protective across evaluated portions
• Weldon Spring Quarry/Plant/Pits in St. Charles, Missouri — protective short term
• Ralston site in Cedar Rapids, Iowa — protective short term

EPA deferred protectiveness determinations at several other sites pending additional sampling and information.

What does this mean for material-handling operators?

The Olathe decision ties remedy failure to a groundwater plume and vapor intrusion — two pathways that routinely cross into adjacent scrap, recovery and demolition properties. Operators whose parcels sit inside a re-delineated plume footprint face new short-term compliance questions, particularly around handling of stockpile water and building interiors.

Imperial's planned dioxin removal action brings a short-term disposal and tracking question for any processor whose historical receipts or byproducts trace back to the site corridor. Dioxin is among the toughest contaminant classes for downstream sale, transport and final disposition of affected scrap.

What happens next?

The next regulatory milestone: written protectiveness determinations on the seven newly opened reviews, each governed by its site's statutory five-year review window.

For the two failed sites, EPA's near-term calendar now runs on two parallel tracks — the groundwater delineation in Olathe and the community-meeting-then-removal-action sequence at Imperial. Both tracks decide whether the remedies return to a protective footing before the next review cycle closes.