Public service company of Colorado. Rates Head explains rising costs, blames environmentalists. Post My 7, 1978 p.7G Rate increase asked. Post Je l, 1978 p.18 RMN Je 1, 1978 p.38 Colo. Public Utilities Commission orders PSC to end declining block rates. Post Ag 1, 1978 p.l PSC given $29 million increase in gas rates. RMN Ag 2, 1978 p.5 Effects of new flat rate system. RMN Ag 30 , 1978-8 Pos Ag 3, 1978 p.2,24