The Tittabawassee River Floodplain: What a Buyer Needs to Check

What an "Exposure Unit" actually is

EPA and Michigan EGLE divide the Tittabawassee River, Saginaw River and Bay Superfund site into numbered Exposure Units (EUs) for cleanup and monitoring purposes. Exposure Unit 002 (EU002) falls within Saginaw County, and Exposure Unit 001 (EU001) sits specifically within the city of Saginaw on the river's north shore near where the Tittabawassee meets the Shiawassee and Saginaw Rivers -- an area EPA and Michigan's environmental agency have described as flooding, sometimes more than once a year, which is precisely why contaminated sediment kept redepositing onto residential land there over the decades.

The underlying contamination traces to Dow Chemical's Midland plant (in neighboring Midland County), where more than a century of chlorine-based chemical manufacturing produced dioxins and furans as industrial byproducts, historically discharged into the Tittabawassee River. Off-site contamination extends more than 50 miles downstream through the Tittabawassee and Saginaw Rivers into Saginaw Bay -- but the practical relevance to a Saginaw County land buyer is specific to the floodplain and riverbank areas within the county, not the county as a whole.

Residential soil testing: a real, documented program along the river

This isn't a hypothetical risk -- EPA Region 5 and Michigan's environmental agency have directly screened residential properties along the Tittabawassee for dioxin-contaminated soil, taking small soil plugs (from as deep as 36 inches below the surface) for lab analysis in flood-prone residential areas. EPA subsequently selected a cleanup approach specifically aimed at reducing exposure to contaminated soil in the areas that flood most frequently. A 2010 Administrative Settlement Agreement and Order on Consent between Dow, EGLE, and EPA sets out Dow's ongoing cleanup obligations for the site, and remediation and monitoring work has continued since.

If you're evaluating a parcel directly along the Tittabawassee or Saginaw River within Saginaw County, don't assume the absence of a for-sale-listing disclosure means the soil has been cleared -- ask EPA Region 5 or Michigan EGLE directly whether the specific parcel falls within a mapped Exposure Unit, and whether it has already been sampled or remediated under this program.

A newer wrinkle: the Tittabawassee River Green Corridor Conservation Program

Running alongside the cleanup effort, the Tittabawassee River Green Corridor Conservation Program aims to protect more than 2,000 acres of floodplain property along the river through conservation easements -- a voluntary land-protection tool distinct from the Superfund cleanup itself, but covering much of the same physical corridor. If a parcel you're considering already carries a Green Corridor conservation easement, that changes what you can build or do with the land regardless of the site's contamination status, so check both -- easement status and Superfund/floodplain status are two separate things to confirm, not one.

Floodplain and flood-insurance basics still apply on top of this

Separate from the dioxin-specific issue, ordinary floodplain rules still apply to any parcel near the Tittabawassee or Saginaw Rivers: a documented Tittabawassee River floodplain of roughly 4,500 acres runs along about 21 miles of the river below Dow's Midland plant, and a property within a FEMA-mapped Special Flood Hazard Area will generally require flood insurance if it's financed with a federally backed mortgage, on top of whatever the Superfund-related soil status turns out to be. Check FEMA's flood maps for the specific parcel independently of the contamination question.