Filling station operators in Taichung signed an agreement with the city government on Friday, committing station attendants to help control air pollution by not topping off when customers fill their gasoline tanks.
Lee Li-teh (李立德), director of the city government's Bureau of Environmental Protection, signed the agreement with executives of four companies that operate filling stations in the city.
Lee said that Taichung has 108 filling stations, or 0.66 stations per square kilometer -- the second-highest density in the country.
Although the city government has required that all gas stations in Taichung install gasoline vapor recovery equipment on fuel pump nozzles to help reduce air pollution since 2004, nearly 55 percent have become ineffective because filling stations continue to top off, Lee said.
Gasoline vapor, a source of air pollution, endangers health and contribute to "bad ozone days."
Lee said that starting on April 1 next year, inspectors from the Bureau of Environmental Protection would enforce new regulations governing air pollution from dispensing nozzles at gas stations.
Regulations state that a filling station is liable to a fine of between NT$100,000 and NT$1 million (US$31,000) if they allow fuel vapors to pollute the air.
If a filling station attendant has received appropriate training in how to correctly handle the gas nozzle but still tops off a fuel tank, he or she will face a fine of between NT$5,000 and NT$100,000.
Experts say that adding more gasoline after the nozzle has automatically shut off is not only bad for the environment, but can also result in drivers paying more for gasoline that is drawn back into the vapor recovery line and fed back into the station's storage tanks.
Overfilling can also cause the station's vapor recovery system to operate improperly or to break down, experts say.