Questar Pipeline Company

First Revised Volume No. 1

Effective Date: 03/23/2001, Docket: RP01-233-000, Status: Effective

Fourth Revised Sheet No. 151 Fourth Revised Sheet No. 151 : Effective

Superseding: Third Revised Sheet No. 151

RATE SCHEDULE ISS

INTERRUPTIBLE STORAGE SERVICE

CLAY BASIN

(a) Usage Charges.

(i) An inventory charge equal to the

applicable inventory rate multiplied by shipper's average

monthly working gas balance as defined in 1.2 of the

General Terms and Conditions of this part.

(ii) An injection charge equal to the

applicable injection rate multiplied by the quantity of gas

injected into Questar's facilities each month for shipper.

(iii) A withdrawal charge equal to the

applicable withdrawal rate multiplied by the quantity of gas

withdrawn from Questar's facilities each month for shipper.

(b) Fuel Reimbursement. Shipper shall reimburse

Questar in kind for fuel use in accordance with 16 of the

General Terms and Conditions of this part.

reimburse Questar for any additional facilities according to

the General Terms and Conditions of Part 1 of this tariff.

(d) Annual Charge Adjustment (ACA) Charge. The

ACA listed on the Statement of Rates shall apply to all

quantities of gas injected into storage for shipper under

this rate schedule for which Questar is not providing

associated transportation service.

(e) Other Charges. Questar shall charge shipper

for any other FERC-approved charges that may apply to

service under this rate schedule.

(f) Negotiated Rates. Notwithstanding anything to

the contrary contained in this tariff, Questar and Shipper

may, as provided in 30 (Negotiated Rates) of the General

Terms and Conditions of Part 1 of this tariff, negotiate a

rate for service under this rate schedule. Questar's rates,

as shown on its Statement of Rates, are available as

recourse rates for any Shipper that does not desire to

negotiate a rate with Questar. An agreement by the Shipper

to accept a negotiated rate does not, in any manner,

restrict the Shipper's right to elect recourse rates for

other services not covered by the negotiated-rate agreement.

Questar may limit a negotiated-rate shipper's rights to