The day green ooze leaked onto I-696 in Madison Heights

On December 20, 2019, drivers on eastbound I-696 in Madison Heights passed something that looked fake: a mound of bright yellow-green ice oozing out of the wall, just west of the Couzens Avenue exit. It was not antifreeze, and it was not a prank. State chemists named it fast — hexavalent chromium, the same poison made famous by the Erin Brockovich case. For a few days the freeway shoulder was one of the scarier spots in Michigan.

The source sat uphill: a shut-down building on East Ten Mile that had housed Electro-Plating Services. The shop had been condemned and cleaned out once. But tainted groundwater kept seeping down through the soil to the freeway wall, and the December cold froze it into that glowing crust. The U.S. EPA and Michigan’s environmental agency, EGLE, took over. In time they pumped tens of thousands of gallons of bad water out of the basement pits the owner had dug to hold waste.

That owner, Gary Sayers, did not walk away clean. He was convicted of running an unlicensed hazardous-waste site, sent to federal prison for a year, and ordered to repay the government well over a million dollars. The state took lasting control of the site, put in a treatment system, and the building behind the whole mess was finally torn down.

Most spills happen out of sight — a buried tank, a quiet plume, a river you don’t drink from. This one glowed neon and crawled onto a rush-hour freeway in front of thousands of commuters. That is probably the only reason so many people ever learned the words “hexavalent chromium” at all.