University of Denver chemistry professor Donald Stedman and his portable pollution-testing device are in the news once again. (See "Going Mobile," Aug./Sept. 1990.) California wants to use his remote sensor, which measures emissions from cars on the road, to supplement periodic tailpipe inspections. But the U.S. Environmental Protection Agency wants to force California to submit the 20 million cars in the Golden State to a much more expensive test.
The Clean Air Act of 1990 required states and regions that violate auto-pollution standards to submit a smog-reduction plan before November 15, 1993. The act doesn't specify what cleanup technologies have to be used, but the EPA is clear about what it will accept. EPA Administrator Carol Browner has demanded that cars be tested and repaired at separate locations. She cites internal EPA research indicating that test-only locations are three times more likely to identify gross polluters than stations that both test and repair cars.
The EPA wants California to replace its 9,600 "smog-check" centers, which are located at neighborhood garages, with about 250 centralized testing sites equipped with dynamometers, a treadmill-like device. The dynamometers would test cars once every two years.
The state wants to upgrade existing smog-check centers with more-accurate tailpipe testing equipment. It would also use remote testing to continuously check cars on the roads. California's Environmental Protection Agency says it would cost less than $150 million to upgrade smog-check centers; it expects to finance remote sensing with fines and registration fees. By contrast, the state says, installing dynamometers would cost $1 billion.
Recent studies by researchers at the Rand Corp. and at the Department of Economics at the University of California, Irvine question the U.S. EPA's contentions. Rand reported that California's current smog checks "perform nearly as well" as dynamometers. The U.C.-Irvine study concluded that dynamometers were slightly more accurate than tailpipe tests but that "the consequences of this difference are not large." Both studies backed California's approach—periodic tailpipe inspections supplemented by ongoing remote tests.
Remote-testing supporters also got a boost from an article published in Science on July 2 that confirmed that about 10 percent of the cars on the road cause at least one-half of the carbon-monoxide and hydrocarbon automotive emissions. The article praised remote testing and questioned the need for dynamometers. "In a sense," it said, "the cost of more sophisticated systems of vehicle emissions control…is a subsidy to the relatively small number of vehicles that are responsible for the majority of emissions."
An amendment to the Clean Air Act lets states include on-road testing as part of their smog-reduction plans. Remote testing supporters say that each car ideally should be tested six times a year.
The EPA's interpretation of the amendment, however, requires states to do on-road tests of only 0.5 percent of all the cars in the region each year. And "on-road" testing can include having troopers randomly pull drivers over for a tailpipe test.
Browner has threatened to cut off at least $600 million in California's federal highway funds if the state doesn't adopt her pollution-reduction plan. The state and the U.S. EPA hope to negotiate a settlement.
Meanwhile, state Sen. Tom Hayden (D-Santa Monica) has sued Browner and Gov. Pete Wilson for failing to implement a pollution-reduction plan on schedule. If state and federal negotiators can't work out a settlement before Hayden gets a hearing, the courts will decide where Californians get their smog checks.
This article originally appeared in print under the headline "The $600-Million Question".