Questar Southern Trails Pipeline Company

Original Volume No. 1

Effective Date: 01/23/2006, Docket: RP06-154-000, Status: Effective

First Revised Sheet No. 88 First Revised Sheet No. 88 : Effective

Superseding: Original Sheet No. 88

GENERAL TERMS AND CONDITIONS

must be specifically designated for that purpose. Southern Trails will

consider each Shipper's request to exercise its option under this section and

will, on a nondiscriminatory basis, and subject to prudent operational

practices, honor the request.

15.6 Cash Out. All remaining imbalances that exceed the imbalance

tolerance at the end of the month will be subject to the following cashout

provisions. However, if Shipper cannot cure an imbalance due to force

majeure, Southern Trails will extend the time period for the Shipper to pay

back an imbalance for a period equal to the length of the force majeure event.

(a) Cashout volumes are those volumes that exceed the ±2.5%

imbalance tolerance at the end of the month following the month the imbalance

occurred less any imbalance trades and specific payback volumes. The cashout

process will reduce the Shippers imbalance to be within the imbalance

tolerance upon payment or credit of the cashout amount.

(b) Shippers' imbalance that exceeds the imbalance tolerance

shall be cashed out at a price calculated by multiplying the portion that

exceeds the imbalance tolerance by the applicable rates as determined in the

subsection below.

first-of-the-month posting for the San Juan Basin delivered into El Paso

Natural Gas Company published for the first of the month following final

determination of the cashout volume to set an index price. If "Inside FERC

Gas Market Report" ceases publication or to the extent prices are not

reported, Southern Trails will select a similar index or publication and

notify Shippers of the selection via Questline. The cashout price will be the

index price multiplied by a premium factor for volumes due Southern Trails or

a discount factor for volumes due Shipper. The premium or discount factor

will be according to the tiered schedule below:

Imbalance Level Due Southern Trails Due Shipper

Greater than 2.5% up to 5% Index * 1.20 Index * 0.80

Greater than 5% up to 7% Index * 1.30 Index * 0.70

Greater than 7% up to 10% Index * 1.40 Index * 0.60

Greater than 10% up to 15% Index * 1.60 Index * 0.40