Questar Southern Trails Pipeline Company

Original Volume No. 1

Effective Date: 02/28/2010, Docket: RP10-332-000, Status: Effective

First Revised Sheet No. 91 First Revised Sheet No. 91

Superseding: Original Sheet No. 91

GENERAL TERMS AND CONDITIONS

(f) Neither the Shipper nor the TPP may transport or trade gas

to which they do not hold title.

(g) Shipper shall remain primarily liable for its imbalances

under the provisions of § 15 of Southern Trails' tariff governing the curing

of imbalances.

(h) The TPP will not be permitted to act as a Shipper's agent

until Southern Trails has received written notice from Shipper. Shipper

agrees to be bound by all transactions conducted by the TPP in the Shipper's

name.

15.13 Maintenance of System Integrity. Nothing in this section limits

Southern Trails' right to take action as may be required, including the

issuance of OFOs, to adjust receipts and deliveries of gas in order to

alleviate conditions that threaten the integrity of its system, including

maintenance of service to higher priority customers. The declaration to the

affected parties of OFOs, critical periods, and/or critical notices shall

describe the conditions and the specific responses required from the affected

parties.

15.14 Incidental Purchase and Sale. Southern Trails is not providing a

supply service under any rate schedule of this Tariff. Southern Trails may

buy and sell gas to the extent necessary to maintain system pressure, to

maintain line pack and provide additional line pack for new facilities, to

implement the cashout procedures, and perform other functions in providing

transportation services.

16. BILLING AND PAYMENT

16.1 Billing Schedule. On or before the 9th business day of each

month, Southern Trails shall furnish to Shipper a monthly statement of the

total payment due for the transportation of gas during the preceding month

(including any other applicable charges). Unless otherwise agreed,

transportation invoices shall state the net billing rate, rather than the

maximum discount tariff rate and the discount amount. Imbalance statements

shall be generated at the same time or prior to the generation of the

transportation invoice. Shipper's imbalance statement will be included in

this billing. Invoices shall be based on actuals (if available) or best

available data. Quantities at points where OBAs exist shall be invoiced

based on scheduled quantities.