Exhibit No. 12. Questar Pipeline Company Ratio of Earnings to Fixed Charges 12 months ended March 31, 1998 1999 (Dollars in Thousands) Earnings Income before income taxes $42,548 $44,325 Plus debt expense 13,619 15,199 Plus allowance for borrowed funds used during construction 226 1,326 Plus interest portion of rental expense 263 342 $56,656 $61,192 Fixed Charges Debt expense $13,619 $15,199 Plus allowance for borrowed funds used during construction 226 1,326 Plus interest portion of rental expense 263 342 $14,108 $16,867 Ratio of Earnings to Fixed Charges 4.02 3.63