Current Regulations Impacting Exhaust Emissions From Stationary Internal Combustion Engines

The San Francisco Bay Area is in a nonattainment area for both ozone and carbon monoxide. A significant amount of air pollution emanates from the combustion of fuels in stationary internal combustion engines. The NO_x emissions output from stationary I.C. engines in the Bay Area Air Quality Management District (BAAQMD) is around 14.2 Mg/day (15.6 tons / day). The contributions from other pollutant factors are not nearly as large; nonetheless, they are still noteworthy. BAAQMD has imposed New Source Review (NSR) requirements and Best Available Control Technology (BACT) levels for new stationary I.C. engines. The purpose of BACT is to achieve the lowest level of engine exhaust emissions using today’s proven control technology. The BACT level for NO_x is presently set at 0.00056 mg/J (1.5 g/bhp-hr) or less for stationary I.C. engines. The BACT level for each of the other exhaust pollutants has not been set since they seldom require a BACT determination. In the event BACT is triggered, a case-by-case BACT evaluation will be performed. The placement of BACT and NSR standards on stationay I.C. engines has aided the BAAQMD in achieving better local air quality. More stringent standards may be imposed as long as the need for better air quality exists.