Exhibit No. 12. Questar Pipeline Company and Subsidiaries Ratio of Earnings to Fixed Charges 12 months ended September 30, 1999 1998 (Dollars in Thousands) Earnings Income before income taxes $41,359 $40,549 Plus debt expense 16,518 14,062 Plus allowance for borrowed funds used during construction 2,257 448 Plus interest portion of rental expense 212 312 $60,346 $55,371 Fixed Charges Debt expense $16,518 $14,062 Plus allowance for borrowed funds used during construction 2,257 448 Plus interest portion of rental expense 212 312 $18,987 $14,822 Ratio of Earnings to Fixed Charges 3.18 3.74