New requirements from the California Air Resources Board (known as CARB) and a proposed rule from the Environmental Protection Agency (EPA) aim to further reduce lawn and grounds equipment emissions.

Looking at today's lawnmowers, leaf blowers and other equipment, strides already have been made to make them cleaner. Over the last decade, changes in outdoor equipment design have reduced exhaust emissions by more than 70 percent, according to Bill Harley, CEO of the Outdoor Power Equipment Institute (OPEI), representing lawn and garden maintenance products and components manufacturers and suppliers.

Still, no pollution is better than some pollution. Pollution from gasoline-fueled lawn and garden equipment has two sources: the combustion process (exhaust emissions) and fuel evaporation. OPEI reports emissions from outdoor power equipment, such as walk-behind lawn mowers, account for less than 3 percent of all smog-forming emissions nationwide.

The non-profit organization and others continue working with EPA and CARB to further reduce small engine emissions. Historically, California has had a more serious pollution problem than any other state and began addressing air pollution decades before the federal government. When the Clean Air Act was written, California was given the authority to continue writing its own regulations. Other states must follow EPA standards.

"All regulations are developed in cooperation with stakeholders over long periods of time that allow concerns to be vented and addressed," says Dimitri Stanich, CARB public information officer.

While California air is cleaner than it has been in more than 50 years, Stanich says the state's population is large and growing quickly, and with growth typically comes emissions increases.

"We constantly look at our regulations to determine their efficacy and whether technology has developed to the point where we can ask industry to take advantage of those developments and reduce emissions further," Stanich says. "Technology changes quickly and something could be developed tomorrow that completely changes the way we do things."

New regulations
Since the start of this year, engines (including displacement between 80cc and 225cc) sold or used in California for lawn and grounds equipment (and other applications, excluding agriculture and construction), must be built to meet CARB Tier 3 engine requirements.

The changes required are:

• Lower exhaust emissions through an exhaust catalyst for reduced oil consumption and improved combustion efficiency.
• Control evaporated fuel emissions from the fuel system while the engine is not operating. This can be done by using a non-vented fuel tank cap and carbon canister vapor recovery system, and non-permeable fuel tanks and fuel lines.

In April of this year, EPA proposed a new emissions control program similar to CARB's that would reduce hydrocarbon emissions from small spark-ignition engines by about 35 percent.

With the proposed rule, nonroad gasoline-powered engines, such as those in lawn and garden equipment, would see an additional 35-percent reduction in hydrocarbon and nitrogen oxides emissions beyond a 60-percent reduction that finished phasing in last year under an earlier rulemaking, according to EPA. Those engines would also see a 45-percent reduction in fuel evaporative emissions, EPA says.

The entire proposal and information about how to submit comments on the proposal - by August 3 - can be found at www.epa.gov/otaq/equip-ld.htm. New standards would apply as early as 2011 for most lawn and garden equipment (under 25 horsepower).

Until then, CARB Tier III will be the highest standard in the United States for small engines to follow. Most manufacturers will follow CARB's lead because they prefer to make engines that can be sold in any state, says Brad Murphy, vice president of sales and marketing for Subaru Robin.