Questar Southern Trails Pipeline Company

Original Volume No. 1

Effective Date: 10/24/2003, Docket: RP03-612-000, Status: Effective

First Revised Sheet No. 77 First Revised Sheet No. 77 : Effective

Superseding: Original Sheet No. 77

GENERAL TERMS AND CONDITIONS

12.11 Calibration and Test of Measurement Equipment. Southern Trails

will verify the accuracy of all measurement equipment at reasonable

intervals. Southern Trails will provide notice of regular inspections and

calibrations of measurement equipment and any routine orifice plate changes

to the operators of the interconncecting facilities, and the operators or

other contractually designated representative of shippers may attend the

inspections or plate changes. Southern Trails shall not be required to

verify the accuracy of its equipment more frequently than once in a 90-day

period. In the event an operator of an interconnecting facility or their

contractually designated representative notifies Southern Trails that it

desires a special test of any of Southern Trails' measurement equipment, the

parties shall cooperate to secure prompt verification of the accuracy of such

equipment. Any operator of an interconnecting facility or their

contractually designated representative requesting such a special test of

Southern Trails' measurement equipment shall bear Southern Trails' out-of-

pocket costs of the test if the equipment is found to be accurate within two

percent (2%).

12.12 Correction of Measurement Errors. If any measurement equipment is

found to be inaccurate, the equipment will be adjusted immediately to measure

accurately. If the measurement equipment in the aggregate is found to be

inaccurate by two percent (2%) or more at a recording corresponding to the

average hourly rate of gas flow for the period since the last preceding test,

any payments based upon inaccurate measurement will be corrected at the rate

of such inaccuracy for any period that is known definitely or agreed upon. In

the case where the period is not known or agreed upon, such correction will be

for a period extending over one half of the time elapsed since the date of the

last test.

12.13 Failure of Measurement Equipment. If any measurement equipment is

out of service or is found registering inaccurately and the error is not

determinable by test, or by previous recordings, receipts or deliveries

through such equipment will be estimated and agreed to by the parties upon the

first of the following methods that is feasible:

(a) By correcting the error if the percentage of error is

ascertainable by calibration, special test, or mathematical calculation, or,

in the absence of (a);

(b) By using the registration of any check meter or meters, if

installed and accurately registering, or, in the absence of (a) and (b);

based on receipts or deliveries during preceding periods under similar

conditions when the measurement equipment was registering accurately.