Getting rid of a pollutant before it has contaminated anything has the virtue of simplicity. That was one motive for the 2006 coalition that backed the nationwide vehicle mercury switch removal program, now endangered from reduced funding.

"When we were negotiating for a bill (in Illinois), we took a hammer to a mercury switch in a metal capsule on the table. We could not get it to break," Joey Devereaux, vice president at Available Auto Parts, Decatur, Ill., said. "Our point was that only when it goes to a shredder does it finally break open. That's where it's a problem. And then when it hits the electric-arc furnace it gets released in parts per million into the atmosphere."

Quite simply, mercury kept from shredders doesn't become a mill pollutant.

But there have been two financial setbacks for the mercury switch removal program. The unpredictable one involves General Motors Co., which emerged from bankruptcy in two pieces. Exact numbers haven't been disclosed, but End-of-Life Vehicle Solutions Corp. (ELVS), which coordinates the switch removal program, has an annual budget of slightly more than $2 million; GM supplied roughly $1 million of that.

The piece of GM that owns the assembly plants (post-bankruptcy) argues that it has never put mercury switches into vehicles and has no obligation to ELVS, while the piece of GM that remains in bankruptcy says it is analyzing its obligations and will eventually come up with a plan for settling with creditors—a one-time check, likely just cents on the dollar and probably years away.

The other funding issue is that steel and auto trade associations put up $4 million in mid-2006 to support bounty payments to dismantlers—$4 per mercury switch from mid-2008 to mid-2009—from an allied program, the National Vehicle Mercury Switch Recovery...