Utah Checking Natural Gas Car Pollution Calculations

he number of natural-gas tanks powering Utah vehicles has exploded this year.
Now state officials and clean-car advocates want to ensure the tanks don't blow up, too, and that they pollute as little as intended.
The dozens who claimed clean-fuel tax credits by switching from gasoline earlier this decade mushroomed into the hundreds last year, but Questar fuel consumption suggests the real number of compressed-gas vehicles might have grown to 20,000 in the past year alone, according to the nonprofit Utah Clean Cities Coalition. The utility itself estimates the total is at least 6,000. Since January of 2007, Questar's
Gallons of savings:

Utah motorists are flocking to compressed natural gas because it costs just 87 cents to equal the energy in a gallon of gasoline that now runs $4. Last month, Questar sold 495,000 gallon equivalents of natural gas for vehicles.
natural-gas sales for vehicles have shot up 401 percent, spokesman Chad Jones said.
Many of the vehicles - including the nearly 700 that earned one-time tax breaks last year - are professionally equipped, safe and certified by the Environmental Protection Agency.
Others are backyard jobs with worn tanks and faulty exhaust systems, endangering both motorists and the Wasatch Front's air, Clean Cities Director Robin Erickson said. Those who buy old tanks or don't install kits properly are creating car bombs.
"They could cause a serious explosion," Erickson warned.
It's a time of great promise and caution for those who have worked years to bring Utahns around to the cause of clean air. Motorists are flocking to compressed natural gas because in Utah it costs just 87 cents to equal the energy in a gallon of gasoline that now runs $4. Compressed gas is unusually cheap here because Questar owns both the gas and the pipes and is a publicly regulated utility.
Moving thousands of cleaner vehicles onto the roads gratifies advocates like Erickson, but it's also clear that many drivers are taking chances.
Weber County is gearing up to shut down motorists who bring in unclean or unsafe vehicles for registration inspection. The Weber-Morgan Health Department last month announced that it will start rejecting compressed-gas vehicles whose emissions have been altered without proof of EPA certification and the mechanic who altered it.
There is no statewide rule restricting home conversions.
"The word is getting out that we won't even consider anything that's not EPA-certified [for a tax credit]," Utah Division of Air Quality scientist Mat Carlile said. But many switch without certification anyway, to reap the fuel savings.