Saginaw, Michigan sits at the confluence of the Tittabawassee, Cass, Flint, and Shiawassee rivers, all of which feed into the Saginaw River and eventually Lake Huron’s Saginaw Bay. It’s a city of about 44,000 people — down from a peak of nearly 100,000 in the 1960s — that carries the industrial legacy of Michigan’s manufacturing era.
The most significant water quality issue in Saginaw isn’t what comes out of the tap. It’s what’s in the river that runs through town: dioxin, one of the most toxic synthetic chemicals ever produced, traced directly to Dow Chemical Company’s operations in Midland, 20 miles upstream.
Dow Chemical and the Dioxin Contamination
Dow Chemical’s Midland facility is the company’s global headquarters and one of its oldest manufacturing sites. Operations there have produced chlorinated chemicals since the early 1900s. Dioxins — specifically 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds — are byproducts of chlorine-based chemical manufacturing.
For decades, Dow’s waste and process water discharged into the Tittabawassee River. Dioxin-contaminated sediments accumulated in the river channel, floodplains, and downstream water bodies. The contamination extends from Midland through Saginaw and into the Saginaw River and Saginaw Bay.
The scope is enormous. The EPA’s Superfund investigation covers more than 50 miles of river and thousands of acres of floodplain. Dioxin concentrations in Tittabawassee River sediments and floodplain soils have been measured at levels hundreds of times above the EPA’s cleanup criteria.
The Tittabawassee River/Saginaw River Superfund site is one of the largest dioxin cleanups in U.S. history.
Why Dioxin Matters
Dioxin is exceptionally toxic, even in tiny amounts. TCDD is classified as a known human carcinogen by the EPA, the World Health Organization, and the National Toxicology Program. Health effects associated with dioxin exposure include:
- Cancer — particularly soft tissue sarcoma, non-Hodgkin lymphoma, and liver cancer
- Immune system suppression
- Endocrine disruption — dioxin interferes with hormone signaling
- Reproductive and developmental effects — including birth defects in heavily exposed populations
- Chloracne — a severe skin condition associated with acute dioxin exposure
Dioxin bioaccumulates in the food chain. Fish in the Tittabawassee River and Saginaw Bay accumulate dioxin in their tissue, which is why Michigan has maintained fish consumption advisories for these waters for decades.
The EPA’s reference dose for TCDD is 0.7 picograms per kilogram of body weight per day. To put that in perspective: a picogram is one trillionth of a gram. This is a chemical measured in parts per quadrillion.
Saginaw’s Drinking Water
Saginaw’s municipal water comes from Lake Huron, not from the Tittabawassee or Saginaw rivers. The city is part of the Saginaw-Midland Municipal Water Supply Corporation, which operates an intake on Lake Huron near Whitestone Point.
This is important: the dioxin in the river system does not directly contaminate the city’s drinking water supply. Lake Huron, while it receives water from the Saginaw River watershed, provides enormous dilution. And the municipal water intake is positioned to draw relatively clean water from the open lake.
The treated water meets all federal and state drinking water standards. Saginaw’s water quality reports consistently show compliance with MCLs for regulated contaminants.
That said, Saginaw faces other water quality challenges common to aging Michigan cities:
Lead — Saginaw has an older housing stock and aging water distribution infrastructure. Lead service lines and lead solder in household plumbing can contribute lead to tap water. The city has been working on lead service line identification and replacement as required by the revised Lead and Copper Rule.
Disinfection byproducts — present within regulatory limits, formed when chlorine reacts with organic matter in the treated water.
Infrastructure age — water main breaks and distribution system issues are ongoing challenges for a city with declining population and a shrinking tax base. The infrastructure was built for a much larger population and is deteriorating.
The Floodplain Problem
While the drinking water is sourced from Lake Huron, residents who live near the Tittabawassee or Saginaw rivers face direct exposure risks from dioxin-contaminated floodplain soils.
When the rivers flood — which happens regularly in Michigan’s spring — contaminated sediments can be deposited in yards, parks, and other areas where people have direct contact with the soil. Children playing in contaminated soil, gardeners growing food in it, and residents tracking it into their homes are all exposure pathways.
The EPA has conducted extensive sampling of residential properties along the rivers and has remediated the most contaminated sites. Cleanup involves removing contaminated soil and replacing it with clean fill. But the scale of the affected area means remediation has been ongoing for years and will continue for years more.
Dow Chemical, under a consent decree with the EPA, is funding the cleanup. The company has spent hundreds of millions of dollars on investigation and remediation, with more to come.
Fish Consumption Advisories
The Michigan Department of Health and Human Services maintains fish consumption advisories for the Tittabawassee River, Saginaw River, and Saginaw Bay. These advisories recommend limiting or avoiding consumption of certain fish species due to dioxin and PCB contamination.
For residents who fish these waters — many do, as fishing is an important cultural and economic activity in the region — the advisories are critical information. Dioxin accumulates in fatty tissue, so fatty fish species carry the highest contamination levels.
The advisories have been in effect for decades and are updated periodically as monitoring data evolves. Some species and areas have seen improvements as cleanup progresses, but the advisories remain in effect for most of the system.
What Residents Can Do
For drinking water: Saginaw’s Lake Huron source is clean, but given the city’s infrastructure age:
- Run your tap before drinking, especially in the morning, to flush potential lead from older pipes
- Consider a point-of-use filter certified for lead reduction
- A reverse osmosis system provides the highest level of protection for drinking water
For dioxin exposure:
- If you live in the Tittabawassee or Saginaw River floodplain, find out whether your property has been tested. Contact the EPA or Michigan EGLE for information about sampling and cleanup in your area.
- Don’t eat fish from the Tittabawassee River, Saginaw River, or Saginaw Bay without checking current Michigan fish consumption advisories.
- Avoid direct contact with river sediments, especially during and after flooding events.
- If you garden near the floodplain, consider raised beds with imported clean soil.
For children: Keep children away from exposed floodplain soils, especially in areas that haven’t been remediated. Children are more vulnerable to dioxin exposure due to hand-to-mouth behavior and lower body weight.
If you’re concerned about your water quality, a certified water treatment professional can test your water and recommend solutions appropriate for your home.
Saginaw’s Double Burden
Saginaw carries two burdens: the environmental contamination from upstream industry and the economic decline that followed deindustrialization. The city has lost more than half its population since its peak. The remaining residents — who are predominantly Black and lower-income — live with the contamination that was left behind by industries that no longer employ them.
The cleanup is happening, funded largely by Dow Chemical under federal supervision. But “happening” and “done” are very different things when you’re talking about dioxin in 50 miles of river and thousands of acres of floodplain.
Saginaw’s drinking water is safe. Its environment is not — not yet. And the gap between those two facts defines daily life for people who live along the rivers that built this city.
Sources: EPA Tittabawassee River/Saginaw River Superfund site records, Michigan EGLE, Michigan Department of Health and Human Services fish consumption advisories, Saginaw-Midland Municipal Water Supply Corporation reports, EPA ECHO database.