The air pollution debate in the Treasure Valley for the past decade has always turned on the disagreement between Ada and Canyon counties about mandatory emissions testing.

The fight has obscured the Valley's success in cleaning up carbon monoxide and particulate pollution tied both to cars and wood-burning stoves.

And as they lean on Canyon leaders to adopt more stringent rules and lament how slow that change has been, Boiseans tend to forget that Ada County went to mandatory testing only after the federal government forced it in the 1990s.

In fact, if Ada and Canyon counties do come together with a joint auto testing program, it would be the first in the country put in place before a region violated federal air standards. The effort could land the region among the nation's leaders for addressing pollution.

But even that would just be a start.

Experts from around the country and the Treasure Valley Air Quality Council say the only way to keep the Valley's air healthy and to prevent federal restrictions is to reduce the miles Treasure Valley residents drive.

The U.S. Environmental Protection Agency recently designated Franklin County on the Utah border and Pinehurst near Coeur d'Alene "nonattainment areas" for fine particle pollution, a designation that requires polluters to offset any new pollution and forces communities to demonstrate new roads won't add to pollution.

The Treasure Valley narrowly missed the designation when fine particle pollution dropped in 2007. But the Valley is very close to exceeding federal standards for ozone, a pollutant similar to fine particles.

A NUDGE FROM THE STATE

The Valley is close enough to breaking federal standards that the Legislature and Gov. Butch Otter required Canyon County to join an emissions testing program or find ways to similarly cut pollution. The state law would force Canyon to join Ada County in an emissions testing program that would cost drivers $20 to test their cars every two years, starting five years after the car was purchased new.

In one last attempt to avoid testing, Canyon County leaders are now increasing their efforts to find alternative solutions.

"We, as mayors and commissioners, understand the legislation and recognize our need to comply and will do so within the deadlines established," said Caldwell Mayor Garret Nancolas. "(We) are dedicated to implementing programs in our communities to reduce ozone emissions and lower the risk of going nonattainment next summer."

But they're not ready to voluntarily join Ada County in a joint auto emissions testing program that state air regulators say is the cheapest, most effective tool for reducing ozone pollution.

"We feel very strongly that we need good science and data to support any decision we make so that we not only can go back to our citizens to explain our choices, but also know that we are making an actual difference in our air quality," said Greenleaf Mayor Brad Holton. "What matters in the end is that we are all breathing cleaner air."

In the meantime, several other initiatives to reduce pollution are in the works.

The state is approving a rule requiring gas stations to capture vapors from the filling of underground tanks, the most cost-effective program identified by the 14-member Treasure Valley Air Quality Council.

A group of business and local officials is considering asking lawmakers to approve an aggressive public education program, another recommendation of the council. The campaign has been shown to be as cost-effective as vehicle testing in reducing the chemicals that mix in the sunlight to create ozone.

NOT JUST ADEQUATE, BUT AWARD-WINNING?

Ada officials have expressed frustration with what they have described as foot-dragging by Canyon County and the Idaho Department of Environmental Quality in setting up the joint emissions program. But that frustration ignores a critical bit of history: Ada County's program was established in the 1990s only when Boise exceeded carbon monoxide and particulate pollution standards.

In fact, no community in the nation has instituted mandatory emissions testing when it wasn't forced to by the federal government, said John Thomas of the EPA in Washington, D.C.

Thomas said a handful of communities have voluntarily developed pollution-reduction programs remarkably similar to the Treasure Valley Air Quality Council's plan approved by the Legislature. He pointed to a Kansas City, Mo., plan that won a national EPA award. If Canyon County succeeds in creating alternatives to testing or joins in testing with Ada County, the region would join the ranks of national leaders, he said.

"I think that might be the kind of thing that gets an award," Thomas said. "It might even make you eligible for a seed grant."

Ada officials have waited for years for Canyon County to join them before they cut testing from annually to every two years. And they're now talking about going ahead with the plan before Canyon County acts. But that would leave the private companies that run the testing vans fighting for less business until Canyon County's program started.

And now the Ada-Canyon fight has made it even harder for the leaders in both counties to cut a deal. A "green smugness" from some Ada testing advocates has turned off many Canyon residents, said Boise State University political science professor John Freemuth.

"We should be asking how can we help Canyon County do the right thing," Freemuth said. "We should be creative."

Peter O'Neill, the Boise developer who heads the Treasure Valley Air Quality Council, has one idea. He wants Ada County officials to explore putting emissions testing vans in Canyon County and paying for free tests so residents there can see how they work.

The Canyon County Ozone Reduction Committee, made up of mayors and county commissioners, is looking at 18 different measures it can take before facing mandatory auto emissions tests as early as 2010. Ideas include instructing small businesses that use solvents on how to reduce vapors, incentives for businesses and governments to reduce employee travel, no-idling policies and public awareness campaigns.

The region has shown it can make the changes needed to improve the air when it has to.

In the 1990s, vehicle testing along with wood-burning bans during winter inversions helped reduce carbon monoxide and particle pollution and brought Ada County within acceptable standards of the EPA, which reduced some restrictions on industry and allowed expansion and growth. Those measures along with others like dust control helped keep the Treasure Valley from exceeding fine particle pollution limits as well.

PEOPLE STILL HAVE TO GET OUT OF THEIR CARS

But in the long run, vehicle testing and scattered restrictions on industry won't be enough, Community Planning Association of Southwest Idaho, or COMPASS, models show. Growth will overwhelm the benefits of both testing and cleaner automobiles unless people get out of their cars, said Matt Stoll, COMPASS executive director.

The only way to curb ozone pollution over time is to reduce the number of miles people drive. The Valley may have barely avoided sanctions this summer in part because of involuntary and unplanned events - $4 gasoline and increasing unemployment sent vehicle miles traveled down by 6 percent this year.

The biggest challenge is providing drivers an alternative way to get to work. Idaho is one of four states without a dedicated fund for mass transit, and it will take a constitutional amendment or a local option tax to raise the $50 million needed for an effective mass transit system for the Treasure Valley.

The question left to be answered is when that point will be. When commuters flocked to the Canyon-to-Ada buses in record numbers this year, ValleyRide simply couldn't keep up with the demand.

Star Republican Mike Moyle, the House majority leader, said local officials killed his efforts to pass a constitutional amendment that would have allowed Ada and Canyon voters to establish a local sales tax for transportation with a 66 percent vote at the polls. And he says that beyond the current bus system, a wide variety of alternatives to driving are available - including the Ada County Highway District's Commuteride program.

Still, Moyle is skeptical about expanding public transit that doesn't pay its way.

"When you get enough rooftops, when mass transit makes sense, we'll probably go there," Moyle said.

Rocky Barker: 377-6484