California Air Resources Board 2004 Almanac (web) Table C-10 Appendix C County Emissions for Ten Toxic Air Contaminants - Salton Sea Air Basin TAC Imperial Riverside Acetaldehyde 101 37 Benzene 155 80 "1,3-Butadiene" 39 18 Carbon Tetrachloride 0.00 0.00 Chromium (Hexavalent) 0.02 < .01 para-DiChlorobenzene 9 17 Formaldehyde 293 112 Methylene Chloride 20 64 Perchloroethylene 26 42 Diesel PM 273 166