Gas Transmission Northwest Corp.

Third Revised Volume No. 1-A

Effective Date: 10/06/2003, Docket: RP04- 23-000, Status: Effective

Original Sheet No. 71 Original Sheet No. 71 : Effective

RATE SCHEDULE AIS-1

AUTHORIZED IMBALANCE SERVICE

1. AVAILABILITY

This rate schedule is available to any party (hereinafter called

"Shipper") qualifying for service pursuant to the Commission's

regulations contained in 18 CFR Part 284, and who has executed an

Authorized Imbalance Service Agreement with GTN in the form

contained in this FERC Gas Tariff, Third Revised Volume No. 1-A.

2. APPLICABILITY AND CHARACTER OF SERVICE

2.1 This rate schedule shall apply to Authorized Imbalance

Service performed by GTN. This service is interruptible

in nature.

2.2 GTN will authorize AIS-1 service for any Shipper only if,

within GTN's best operating judgement and discretion,

such service is not otherwise expected to prevent GTN

from meeting all of its firm and interruptible service

obligations, including GTN's system needs. In the event

that service has already commenced and GTN learns that

the continued furnishing of service may prevent GTN from

meeting all of its firm and interruptible service obligations

then GTN may, at its sole discretion and upon giving

appropriate notice to Shipper(s), interrupt the continuation of

any or all of the services hereunder.

2.3 GTN shall establish and maintain an Authorized Imbalance

Account for Shipper utilizing this service.

2.4 Service hereunder shall consist of the advancement (loan) to

Shipper upon nomination and subsequent confirmation of such

daily quantities of gas, up to Shipper's Maximum Quantity

(MQ) as specified in the executed Authorized Imbalance

Service Agreement between GTN and Shipper. Quantities

of gas advanced to Shipper shall be debited to Shipper's

Authorized Imbalance Account. Shipper and GTN, at the

time such advances are confirmed, will agree to a redelivery

(return of loaned gas) schedule setting out the daily

quantities of gas Shipper will deliver to GTN and the

point at which gas will be delivered to GTN to reduce

Shipper's Authorized Imbalance to zero.

(Continued)