Interim White Paper - Midwest RPO Candidate Control Measures
3/10/2006 Page 5
Requirements for the control of gasoline vapors at GDFs date back to the 1970’s. In general, there are three regulatory programs related to GDFs:
Stage I Vapor Recovery. The U.S. EPA initially established design criteria for Stage I vapor control systems at gasoline service stations in 1975. Many State and local agencies promulgated Stage I vapor control system regulations during the 1980s, requiring the use of submerged fill pipes to minimize the creation of vapors and, in some cases, a vapor balancing system that allows gasoline vapors from the UST to be displaced back to the tank truck during UST loading
operations. Stage II Vapor Recovery.
The 1990 Clean Air Act Amendments (CAAA) established two
distinct approaches for controlling Stage II vehicle refueling emissions. The first approach uses a vapor recovery system installed on the dispensing nozzle to capture vapors displaced from the vehicle fuel tank during filling and return them to the underground storage tank. This type of vapor recovery system was required in ozone nonattainment areas that were designated as moderate, serious, severe, and extreme. A second CAAA approach requires the use of on-board refueling vapor recovery (ORVR) canisters to capture and adsorb vapors from the vehicle fuel tank and eventually release them to the vehicle’s engine. ORVR is required to be installed on some new vehicles in 1998, and all new vehicles will be required to have ORVR installed by 2006.
Low Volatility Fuels. There are also Federal fuel measures to limit gasoline volatility. The first measure set low Reid vapor pressure (RVP) gasoline requirements for each state, and also allowed States to establish more stringent RVP programs as a control measure in nonattainment areas. The second measure established requirements for reformulated gasoline (RFG) that is less volatile and otherwise blended to burn cleaner and reduce ozone-forming pollutants.
The following paragraphs describe the currently applicable regulations for controlling emissions from GDFs in the LADCO region. This is followed by a discussion of enhanced vapor recovery programs in other States that are more stringent than the Federal requirements or the programs in place in the LADCO states.
All five States in the LADCO region currently have regulations governing Stage I operations.
comparison of Federal requirements and current State regulations is presented in Attachment 1 for Stage I vapor control systems. In general, the State rules require submerged loading and vapor balancing or vapor control system to achieve a 90 percent reduction in VOC emissions. In the Chicago/Metro East area, there is also a requirement to have a pressure/vacuum relief valve connected to each vent pipe. Pressure/vacuum relief valves on vent pipes have been shown to improve the effectiveness of Stage I systems and enhance the performance of many Stage II systems. Stage I controls only apply to facilities that either exceed a throughput limit (e.g., 10,000 gallons per month) or have tanks storing gasoline which exceed a size limit (e.g., 575 gallons).
As required by the 1990 CAAA, LADCO states have required the installation of Stage II vapor recovery systems in areas that were designated as moderate, serious, and severe for ozone nonattainment. Most states require a 95 percent control efficiency for Stage II systems. The in-use efficiency achieved, however, is affected by rule effectiveness and rule penetration. The CAA exempts from the Stage II requirement stations that sell less than 10,000 gallons of gasoline per month. EPA has issued guidance that states that the exemption levels, along with a semi-annual inspection frequency, results in an 83
Disclaimer: The control measures identified in this document represent an initial set of possible measures. The Midwest RPO States have not yet determined which measures will be necessary to meet the requirements of the Clean Air Act. As such, the inclusion of a particular measure here should not be interpreted as a commitment or decision by any State to adopt that measure. Other measures will be examined in the near future. Subsequent versions of this document will likely be prepared for evaluation of additional potential control measures.