Gasoline Systems

Gasoline Systems Permit ProgramAs part of the agency’s strategy to achieve compliance with the federal standard for ozone, the APCD Board has adopted regulations that control emissions from the operation of gasoline distribution facilities and mechanisms.

The focus of this function is primarily at the point of wholesale and retail distribution of gasoline and focuses on those processes where the vapors from gasoline can most readily be emitted into the ambient air.

Gasoline belongs to a category of chemicals frequently referred to as volatile organic compounds (VOC) which have a physical tendency to vaporize easily. VOCs are one of the main precursors of ozone.

APCD’s regulations control the manner in which gasoline is transferred from large refinery tanks to distribution trucks, from those trucks to underground storage tanks at retail service stations and how the gasoline is pumped from the underground tanks into vehicles.

The regulations require very specific control measures at each of these points of distribution and the Stage II staff make inspections of those points with sufficient frequency, usually at least once per year, to assure compliance. The Stage II staff makes visual inspections of equipment and uses sophisticated testing equipment to test for leaks in systems, escaping vapors and similar problems. When a noncompliant situation is found during an inspection a Notice of Violation is usually issued to the responsible party. 

APCD regulates approximately 430 gasoline-dispensing facilities in Jefferson County. This results in the reduction of VOC emissions estimated at 4.9 tons per day.

Stage I Vapor Recovery System

As a tank of volatile fuel such as gasoline is gradually emptied, the empty space will be occupied by vapors of the fuel, or by a mixture of air and vapors, if an inlet air vent is provided. When a tanker truck delivers fuel to a gas station, the new fuel entering the underground tank would force accumulated gasoline vapors out of the tank into the air. With a properly-functioning Stage I vapor recovery system, vapors are forced out of the underground storage tank into the tanker truck through a vapor recovery line. The recovered vapors in the tanker truck can then be recycled.

District regulations 6.15 and 7.15 require gasoline dispensing facilities to use Stage I systems.

Stage II Vapor Recovery System

Stage II vapor recovery systems use specially-designed nozzles and hoses. Both nozzle and hose have two passageways, one for dispensing gasoline and the other for returning vapors from the vehicle fuel tank to the underground fuel tank. As gasoline is pumped into the vehicle, vapors are forced out of the vehicle's fuel tank and through the vapor return hose and underground vapor-only piping into the underground storage tank. Returning vapors to the underground storage tank or to an incinerator prevents additional evaporation.

District regulation 6.40, adopted December 1992, requires most gasoline-dispensing facilities to use Stage II systems. See this regulation for applicability requirements. Currently, about 280 facilities are controlled at the Stage II level.


The Stage I and Stage II permit form can be picked up at APCD offices and is available here:  Form 201D.

The monthly throughput form (submitted annually) for Stage II gasoline dispensing facilities is available here:  Form E55 (Excel)Form E55 (PDF).

The monthly throughput form (submitted annually) for Stage I facilties is available here:  Form E54 (Excel), Form E54 (PDF).

For More Information

For more information, call (502) 574-7332 and ask for the Stage II office, or send a fax to (502) 574-5607, attention Stage II or e-mail us.