Analysis of an Evaporative Controls Retrofit Program for the South Coast Air Basin

Abstract

The retrofitting of evaporative control systems to pre-l970 model light duty vehicles is one of the few viable options available to speed up the rate of reduction of reactive hydrocarbon emissions over the next few years. (All l970 and later light duty vehicles were required by California how to be fitted with evaporative control systems.) The purpose of this paper is to give a more detailed analysis of this particular retrofit option. The pre-l970 vehicle population of the South Coast Air Basin is analyzed back to 1962 to find which makes and models will continue to constitute a major fraction of the vehicle population over the next few years. These are the vehicles that it will be most practical to retrofit, since a retrofit kit can cover a large number of vehicles. On the basis of this population analysis, we have made a series of case studies, illustrating how the new vehicle control technology can be adopted to the retrofit situation. The cost of the materials and labor are estimated in detail, in order to obtain a realistic idea of typical retrofit costs. The possibility of a partial retrofit of controls covering either the carburetor or the fuel tank is also discussed. Finally, the legal status of the retrofit situation is reviewed. The cost of a retrofit program covering 65 percent of the eligible vehicles is estimated at about 200 million dollars for the South Coast Air Basin. This is a 'one time' cost, which could be spread over a 1-2 year retrofit program.