DEEP: Air Toxics - Mobile Source Programs

Connecticut's Management of Toxic Air Pollutants

Mobile Source Programs

Air pollution from motor vehicles comes from the by-products of the combustion process (exhaust) and from the evaporation of fuel itself. Although the driving force behind these programs was reduction of criteria pollutants, especially ozone, there have been correlated decreases in toxic air pollutants from implementation of these programs. Emissions from both exhaust and evaporation expose the public to toxic air pollutants. These emissions also contribute to Connecticut's ozone levels and result in a loss of fuel. Consequently, mobile source programs have been developed to target both sources of emissions. These programs include the development of tighter tail pipe standards, enhanced vehicle inspection and maintenance programs and the use of reformulated gasoline.

Tighter Tailpipe Standards: Tailpipe, or exhaust, standards for cars built after 1994 were tightened under the 1990 Clean Air Act Amendments. Connecticut took this one step further and adopted a Low Emission Vehicle program beginning with the 1998 model year. On January 27, 1998, the Department joined the EPA in taking the next step to establish a nationwide program for the manufacture of new cars that emit significantly fewer pollutants. This National Low Emission Vehicle program is a voluntary program whereby EPA, several states and all major automobile manufacturers have agreed to implement emission standards for new motor vehicles that are more stringent than the current federal requirements. The National Low Emission Vehicle program began with motor vehicles of the 1999 model year in nine northeast states and the District of Columbia and nationally in the 2001 model year.

National Low Emission Vehicles are cleaner than recent models. The National Low Emission Vehicle program, upon full implementation, will result in substantial reductions in non-methane organic gases and oxides of nitrogen, which contribute to unhealthy levels of smog in many areas across the country. This program will reduce the transport of these pollutants into Connecticut. The National Low Emission Vehicle program will also result in reductions of toxic air pollutants such as benzene, formaldehyde, acetaldehyde and 1,3-butadiene.

Enhanced Vehicle Inspection and Maintenance Program: Connecticut began implementation of a centralized vehicle inspection program in 1983 to check the efficacy of pollution control equipment in reducing emissions of carbon monoxide, volatile organic compounds and hydrocarbons. This program also yielded collateral reductions of air toxics from the hydrocarbon reductions. In January 1998, Connecticut implemented the Enhanced Vehicle Inspection and Maintenance Program. The Enhanced Vehicle Inspection and Maintenance Program uses sophisticated inspection equipment to ensure that pollution control equipment is operating properly under simulated driving conditions, and that fuel tank caps are sealed tightly to prevent emissions from the evaporation of fuel. The Enhanced Vehicle Inspection and Maintenance Program now also requires diesel cars and many trucks to be inspected. The Enhanced Vehicle Inspection and Maintenance Program is designed to reduce emissions of hydrocarbons, carbon monoxide, oxides of nitrogen and particulate matter. It is estimated that each year this program prevents a minimum of 130,000 tons of vehicle pollutants from entering the air. That translates into reductions of 40 tons of volatile organic compounds and 200 to 400 tons of carbon monoxide every day. Of the 1,213,886 vehicles tested in 1998, 94 percent passed the emission test.

Reformulated Gasoline: Reformulated gasoline has been developed to provide similar performance characteristics as conventional gasoline, while reducing emissions of volatile organic compounds and toxic emissions. Under the Clean Air Act Amendments of 1990, the EPA was required to implement regulations to require the sale of reformulated gasoline in areas with the highest ozone concentrations. The federally administered Reformulated Gasoline program began in January 1995. In Connecticut, the sale of reformulated gasoline is required statewide. Reformulated gasoline means that the combined emissions of

  • benzene

  • 1,3-butadiene

  • polycyclic organic matter

  • acetaldehyde

  • formaldehyde

be reduced from a 1990 baseline of conventional gasoline sold. The emissions benefit reductions are based on a 1990 baseline of conventional gasoline sold. Reformulated gasoline has reduced hydrocarbon emissions by a minimum of 15% during the summer months and reduced toxic emissions by a minimum of 15% throughout the year. Further reductions will be achieved with the implementation of Phase 2 in January of 2000, as described later.

Stage I Vapor Recovery Program: Gasoline vapors contain significant amounts of air toxics, including volatile organic compounds. Much of these vapors were released into the air when gasoline tank trucks delivered gasoline to underground storage tanks at each gasoline station. In a concerted and phased approach to control emissions of gasoline vapors, Connecticut implemented the Stage I vapor recovery regulation, which requires gasoline tank trucks to collect gasoline vapors displaced during delivery to underground storage tanks.

Stage II Vapor Recovery Program: In the second phase of control of emissions of gasoline vapors, Connecticut implemented the Stage II vapor recovery regulation. This regulation requires each gasoline station that pumps more than 10,000 gallons per month to install vapor recovery systems on gasoline pumps, which recover vapors when vehicles are refueled. The recovery of gasoline vapors limits emissions of air toxics, ozone-forming compounds, and prevents the waste of fuel. 1600 gas stations in Connecticut have the systems installed and operating, reducing the amount of VOCs emitted into the atmosphere by 12 tons per day. Stations are inspected at least twice per year, with 3665 inspections conducted from October 1, 1997 to September 30, 1998. View additional information on fuels.

Connecticut's Diesel Reduction Initiatives: Diesel emissions are a health concern in Connecticut and across the nation. View more information on Connecticut's Diesel Reduction Initiatives.

CT's Management of Toxic Air Pollutants | Small Business Assistance Programs

Content Last updated November 2005