The US Environmental Protection Agency (EPA) has proposed new air toxics standards that would reduce the evaporation of volatile organic compounds (VOCs) in gasoline vapors from smaller emitting gasoline distribution sources (“area sources”) including bulk terminals, bulk plants, pipeline facilities, and gasoline dispensing facilities (such as service stations, convenience stores, rental and fleet gasoline tanks).
The proposed standards will annually eliminate the emissions of 45,000-46,000 tons of VOCs in gasoline vapors. That reduction includes 3,300-3,400 tons of hazardous air pollutants, which includes 120-125 tons of benzene. This represents about a 9-10 percent reduction of emissions from this source category.
Area sources are those that have the potential to emit less than 10 tons per year of a single toxic air pollutant or less than 25 tons per year of any combination of toxic air pollutants. If sources emit more than these amounts, they are called “major” sources. In 1994, EPA issued final rules for the larger major source bulk terminals and pipeline facilities.
EPA is proposing two alternatives. The first alternative proposes controls only on the bulk gasoline distribution facilities (terminals and bulk plants, and pipeline facilities). The second alternative proposes controls at the gasoline service stations in urban areas as well as area source bulk gasoline distribution facilities nationwide.
Controls on gasoline distribution facilities would require:
Best seals on storage tanks at terminals and pipeline facilities;
Use of submerged fill pipes when loading storage tanks at bulk plants;
Vapor processors to control tank truck loadings at bulk terminals;
Use of submerged fill pipes to control tank truck loading emissions at bulk plants;
Leak testing of tank trucks and railcars; and
Checking for leaks and using good housekeeping procedures to prevent evaporation of gasoline.
The second alternative would require use of submerged fill pipes when loading storage tanks at service stations.
EPA is taking public comment on the proposed rules for 60 days. The agency is also requesting comment on the need for additional controls, called vapor balancing, at gasoline service stations in more populated urban areas.
The proposed standards would cost $60-65 million to implement at mostly large bulk facilities. There would be an annual benefit of about $6 million for either of the proposed alternatives, based on the value of the recovered gasoline and gasoline not allowed to evaporate.
Proposed Air Toxics Rule fact sheet