LADCO – means Lake Michigan Air Directors Consortium. The main purpose of LADCO is to provide technical assessments for and assistance to its member states on problems of air quality; and to provide a forum for its member states to discuss air quality issues.

LAER – means Lowest Achievable Emissions Rate. Under the Federal Clean Air Act, the most stringent emission limitation derived from either (1) the most stringent emission limitation in the implementation plan of any state for such source or category of source; or (2) the most stringent emission limitation achieved in practice by such class or category of sources.

LDD – mean Light-Duty Diesel.

LDDT – means Light-Duty Diesel Truck.

LDDV – means light-duty diesel vehicle. A diesel-powered motor vehicle, other than a diesel bus, that has a GVWR of 8,500 pounds or less and is designed primarily for transporting persons or property.

LDGT – means light-duty gasoline truck. A gasoline-fueled motor vehicle that has a GVWR of 8,500 pounds or less, a vehicle curb weight of 6,000 pounds or less, and a basic frontal area of 45 square feet or less, and that is designed primarily for the transportation of property or more than 12 passengers; or is available with special features enabling off‑street or off‑highway operation and use.

LDGV – means light-duty gasoline vehicle. A gasoline-fueled motor vehicle that has a GVWR of 8,500 pounds or less, is designed primarily for use as a passenger car or is a passenger car derivative and is capable of seating no more than 12 passengers.

LHDDV – means light heavy-duty Diesel Vehicle.

Lead (Pb) – means elemental lead or any compound containing lead measured as elemental lead. A heavy metal that is hazardous to health if breathed or swallowed. Its use in gasoline, paints, and plumbing compounds has been sharply restricted or eliminated by federal laws and regulations.