Like most of its New England neighbors, Maine requires that all new cars meet strict emissions standards.

But Maine is alone in allowing consumers to legally register new cars that produce more pollution than the state policy allows.

In the New Year, state legislators will likely consider closing this loophole, as they weigh a Maine Department of Environmental Protection measure that appeared on the list of bill titles finalized Friday for consideration by the 122nd Legislature.

The measure, titled “An Act to Require Enforcement of the Low Emissions Vehicle Program,” would allow the Bureau of Motor Vehicles to refuse to register a vehicle if the owner cannot prove that it meets state emissions standards, explained Ron Severance of the DEP Air Bureau, who has been advocating for the change.

Gov. John Baldacci, too, is interested in the bill, spokesman Lee Umphrey said, calling registration denial “important to Maine auto dealers and equally important to Maine air quality.”

It’s a matter of fairness, according to Tom Brown, spokesman for the Augusta-based Maine Auto Dealers Association. Cars and trucks bought in New Hampshire or in Canada need not meet Maine’s emissions standards, yet the state allows them to be registered here.

“There are people who have gone out and bought vehicles [Maine dealers] cannot sell,” Brown said.

Brown doesn’t have numbers on how many sales go out of state because of Maine’s stricter standard, but individual dealers tell him that they’ve lost income.

For example, auto dealers last year unsuccessfully challenged the DEP, complaining that automakers could not sell Volkswagen diesel cars in Maine because they had failed an emissions test for a single pollutant. Diesel fans, who cite the cleanliness and efficiency of the cars when they are run on plant-based biodisesel, testified that they would cross the state line to buy the cars if necessary.

Under a registration denial policy, it would be illegal to drive a car that doesn’t meet environmental standards, just like it is currently illegal to drive a car without insurance. Penalties for violating the law requiring cars to be registered – which can range from a warning to serious fines or even impoundment – would not likely change.

Environmental scientists don’t believe that Maine’s air quality is suffering because of the relatively few noncompliant vehicles on the roads, but Maine is suffering consequences nonetheless, said Severance.

Under federal air quality law, each state may either choose to follow the Environmental Protection Agency’s national emissions standards or the more stringent California standards. Maine, New York, Massachusetts and Vermont have all joined California in the stricter rule. New Jersey, Connecticut and Rhode Island each adopted the California standard in 2004 and will begin enforcing the rules in 2008. And New Hampshire, the lone New England hold-out, is currently considering a legislative proposal to join the low-emissions vehicle program.

Of the eight states with the stricter regulations, Maine, which adopted the California program in 1993, is the only state to have opted out of registration denial as an enforcement measure. While it’s up to each state to determine how it will enforce the low-emissions vehicle law, states are given credit for their attempts to clean up emissions. And that credit can be important as EPA determines whether states are complying with the Clean Air Act. States that fail to comply can face fines or lose federal funds.

Maine is getting only 80 percent of the possible credits now because of its lack of a registration denial policy, Severance explained.

Presently, the emissions standard is enforced by DEP inspectors who visit approximately 80 dealerships each year. Compliance with the rule is never less than “excellent,” but it’s impossible for inspectors to visit every lot and check every car, so Maine lacks sufficient proof to convince the EPA to fully recognize the state’s efforts, Severance said.

“You need to do everything you can to bring your emissions under control,” he said. “[And] you want to get credit for the things you’re doing.”

As Maine struggles to meet federal standards for ozone (a component of smog) in southern parts of the state, every policy change that can be made to improve air quality is crucial. It’s not at all guaranteed that Maine will be in compliance when the EPA reviews air quality data in 2005. The state is likely out of compliance right now, Severance said.

“We know the shoe is going to fall. We just don’t know when,” he said.