The first significant step towards developing a constructive area wide response and mitigation program for chemical plants is to be able to quantify the seismic risk potential of hazardous materials release and its effect on surrounding communities. Thus, the objective of this project was to develop a methodology that would enable local jurisdictions to determine the magnitude of the problem and identify areas most susceptible to earthquake-induced hazardous materials release. The generalized methodology, as developed, includes five major steps; inventory development, seismic hazard analysis, component vulnerability assessment, regional vulnerability assessment, and population risk assessment. The results enable local emergency managers to prepare for and mitigate potential earthquake-induced releases. This report illustrates the application of the methodology for assessing the risk of earthquake-induced hazardous materials release and its impact on surrounding population. The methodology is demonstrated on the Los Angeles area using data from a survey conducted by the South Coast Air Quality Management District, limited to 22 plants using ammonia and/or chlorine within Los Angeles County.