GREELEY, Colo. -- A growing ozone problem along Colorado's Front Range led state lawmakers to pass a bill last year that will expand the automobile emissions testing program to parts of Weld and Larimer Counties.

But two county commissioners and the Sheriff of Weld County told 7NEWS the pollution is Denver's problem not theirs.

They said Weld County has already done its part to clean up its pollution.

"Working in conjunction with our oil and gas industry we took measures that have substantially reduced ozone for the last three years," said County Commissioner Sean Conway. “That work was done at a total cost of more than $30 million.”

Conway said Weld County is now within the allowable limits for ozone pollution.

“We feel we’re being penalized, quite frankly, because Denver needs northern Colorado’s clean air to meet this new national standard.”

Paul Tourangeau, director of the state Health Department’s Air Pollution Control Division said population is growing all along the Front Range and so is pollution.

He said expanding the emissions testing program will help get more high polluting cars off the road.

“We estimate that we get at least 16 tons per day of ozone precursor emission reduction from this program,” Tourangeau said.

He added that not all of Weld and Larimer counties will be included in the program.

“The borders capture 85 percent of the vehicles in about 15 percent of the land mass in Weld County,” Tourangeau said.

But Weld County Commission Chairman Doug Rademacher questions the science behind the decision.

“The fact is, we may not even be contributing to this ozone problem as much as what they’re putting us at, so I don’t think it’s the time or the place to do it,” Rademacher said.

“I’m contemplating telling my deputies not to enforce this law,” said Weld County Sheriff John Cooke. “This law isn’t going to affect me. It’s going to affect the people who can least afford to spend money to fix their cars.”

Cooke said, “Weld County already has one of the highest unemployment rates in Colorado. We have the highest poverty rate in the state. It’s wrong to put that burden on people who can least afford it.”

The Sheriff said there are some motorists who will have to decide whether to pay rent, put food on the table or spend money to fix a car so it can pass inspection.

“I’d rather have them take care of their families,” Cooke said.

When asked if he cared about clean air, Cooke said, “Yes, but our officers should have the discretion on whether to issue someone a ticket.”

“All of us care deeply about our clean air,” Conway said. “I have a step daughter with asthma. But Weld County is in compliance. We shouldn’t have to pay taxes and fees to clean up Denver’s air.”

Conway also questioned the number of testing stations that will be set up in the portions of Larimer and Weld Counties that will be included in the program come Nov. 1.

“The state only plans to open four new testing stations,” he said. “One in Fort Collins, one in Greeley, one in Loveland and one in Del Camino. That’s not anywhere near enough.”

Tourangeau said the average distance to one of the new centers will be just over 5 miles.

When asked how far metro area residents drive, Tourangeau responded, “It’s under 5 miles.”

But Conway said forcing residents to drive those distances just to get their cars tested may end up contributing to the pollution problem.