Exhibit 10j.(15)

Rate Schedule TP-2 Service Agreement

Contract: No. 100308

THIS SERVICE AGREEMENT (Agreement) by and between Northwest Pipeline GP
(Transporter) and Northwest Natural Gas Company, Inc. (Shipper) restates the
Service Agreement made and entered into on January 12, 1994.

Whereas:

A Pursuant to Section 11.4 of the General Terms and Conditions of Transporter’s
FERC Gas Tariff, Transporter and Shipper desire to restate the Service Agreement
dated January 12, 1994 (Contract 100308) in the format of Northwest’s currently
effective Form of Service Agreement and to make certain additional
non-substantive changes, while preserving all pre-existing, substantive
contractual rights.

B. The storage redelivery service hereunder is related to that certain Rate
Schedule SGS-2F service agreement (100502), dated January 1, 1998.

C. Significant events and previous amendments of Contract 100308 reflected in
the contract restatement include:

1. Shipper originally entered into Contract #100308 pursuant to the provisions
of the approved Joint Offer of Settlement in Docket No. RP93-5-011 which
unbundled the storage and redelivery transportation services, effective April 1,
1994.

2. By Amendment dated May 1, 1999, Shipper’s Contract Demand, Annual Contract
Quantity and Monthly Billing Quantity were increased subordinating 9,586 Dths of
primary rights south of the Jackson prairie Receipt Point to reflect Shipper’s
request of additional storage redelivery transportation capacity related to a
portion of its storage rights under SGS-2F Storage Service Agreement {#100502)
dated January 1, 1998.

Therefore, in consideration of the premises and mutual covenants set: forth
herein, Transporter and Shipper agree as follows:

1. Tariff Incorporation Rate Schedule TF-2 and the General Terms and Conditions
(GT&C) that apply to Rate Schedule TF-2, as such may be revised from time to
time in Transporter’s FERC Gas Tariff (Tariff), are incorporated by reference as
part of this Agreement, except to the extent that any provisions thereof may ne
modified by nonconforming provisions herein.

2. Transportation Service. Subject to the terms and conditions that apply to
service under this Agreement, Transporter agrees to receive, transport and
deliver natural gas for Shipper, on a firm basis. The Transportation Contract
Demand, the Annual Contract Quantity, the maximum Daily Quantity at the Primary
Receipt Point, and the Maximum Daily Delivery Obligation at each Primary
Delivery Point are set forth on Exhibit A.

3. Transportation Rates. Shipper agrees to pay Transporter for all services
rendered under this Agreement at the rates set forth or referenced herein. The
Monthly Billing Quantity for reservation charges is set forth on Exhibit A. The
maximum currently effective rates (Recourse rates) for Rate Schedule TF-2 set
forth in the Statement of Rates in the Tariff, as revised from time to time,
will apply to service hereunder unless and to the extent that discounted
Recourse Rates or awarded capacity release rates apply as set forth on Exhibit A
or negotiated rates apply as set forth on Exhibit D. Additionally, if applicable
under Section 21 of the GT&C, Shipper agrees to pay Transporter a facility
reimbursement charge as set forth on Exhibit C.

4. Transportation Term. This Agreement becomes effective on the date first set
forth above. The primary term begin date for the transportation service
hereunder is set forth on Exhibit A. This Agreement will remain in full force
and effect through the primary term end date set forth on Exhibit A and, if
Exhibit A indicates that an evergreen provision applies, through the established
evergreen rollover periods thereafter until terminated in accordance with the
notice requirements under the applicable evergreen provision.

5. Non-Confirming Provisions. All aspects in which this Agreement deviates from
the Tariff, if any, are set forth as non-conforming provisions on Exhibit B. If
Exhibit B includes any material non-conforming provisions, Transporter will file
the Agreement with the Federal Energy Regulatory Commission (Commission) and the
effectiveness of such non-conforming provisions will be subject to the
Commission acceptance of Transporter’s filing of the nonconforming Agreement.

6. Capacity Release. If Shipper is a temporary capacity release Replacement
Shipper, any capacity release conditions, including recall rights, are set forth
on Exhibit A.

7. Exhibit incorporation. Exhibit A is attached hereto and incorporated as part
of this Agreement. If Exhibit B, C and/or D apply, as noted on Exhibit A to this
Agreement, then such Exhibits also are attached hereto and incorporated as part
of this Agreement.

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8. Regulatory Authorization. Transportation service under this Agreement is
authorized pursuant to the Commission regulations set forth on Exhibit A.

9. Superseded Agreements. When this Agreement takes effect, it supersedes,
cancels and terminates the following agreement(s): Original Firm Redelivery
Transportation Contract dated January 12, 1994 as amended, including Amendment
dated May 1, 1999.

IN WITNESS WHEREOF, Transporter and Shipper have executed this on January 21,
2008.

 

Northwest Natural Gas Company     Northwest Pipeline GP By:  

 

    By:  

 

Name:  

 

    Name:  

 

Title:  

 

    Title:  

 

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EXHIBIT A

(Dated, January 21, 2008, Effective January 21, 2008)

To the

Rate Schedule TF-2 Service Agreement

(Contract No. 100308)

between Northwest Pipeline GP and Northwest Natural Gas Company

SERVICE DETAILS

1. Transportation Contract Demand: 32,624 Dth per day

2. Annual Contract Quantity: 835,046 Dth

3. Monthly Billing Quantity: 2,299 Dth

4. Primary Receipt Point :

 

Point ID Name

   Maximum Daily Quantities (Dth)

235 Jackson Prairie receipt

   32,624     

Total

   32,624

5. Primary Delivery Points

 

Point ID Name

  

Maximum Daily Delivery Obligation (Dth)

  

Delivery Pressure (psig)

217 Camas

   2000    300

219 Battleground

   10    250

301 Washougal

   500    300

303 Portland Northeast

   8000    400

307 Portland Southeast

   5000    400

312 Molalla

   100    400

313 Monitor

   10    150

315 McMinnville Amity

   920    400

319 Salem

   921    400

322 Marion

   20    150

324 Jefferson/Scio

   150    400

327 Albany

   2071    400

332 Coburg

   100    400

334 North Eugene

   920    400

336 South Eugene

   576    400

339 Creswell

   100    150

342 Cottage Grove

   300    400

447 White Salmon/bingen

   300    225

448 Hood River

   1100    225

467 Portland West/Scappoose

   7536    400

470 Deer Island

   8000    510

474 The Dalles

   1500    150

TOTAL

   40,134   

6. Recourse of Discounted Recourse Transportation Rates:

a. Reservation charge (per Dth of Monthly Billing Quantity):

Maximum Base Tariff Rate

b. Volumetric Charge (per Dth):

Maximum Base Tariff Rate

c. Rate Discount Condition Consistent with Section 3.3 of Rate Schedule TF-2:

Not Applicable

7. Transportation Term:

a. Primary Term Begin Date: April 1, 1994

b. Primary Term End Date: October 31, 2004

c. Evergreen Provision: Yes, grandfathered unilateral evergreen under
Section 14.3 of Rate Schedule TF-2

8. Regulatory Authorization: 18 CFR 284.223

9. Additional Exhibits:

Exhibit B – Yes, dated January 21, 2008

Exhibit C – No

Exhibit D – No

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EXHIBIT B

(Dated January 21, 2008, Effective January 21, 2008)

to the

Rate Schedule TF -2 Service Agreement

(Contract No. 100308)

Between Northwest Pipeline GP

And Northwest Natural Gas Company

NON-CONFORMING PROVISIONS

The following provision, as reflected in the May 1, 1999 amendment to contract
100308, was accepted as non-conforming by the Commission on December 3, 1999 in
Docket No. GT00-07;

Contract 100308 was modified to condition 9,586 Dths of Shipper’s primary rights
through any constraint point south of the Jackson Prairie Receipt Point on
Exhibit A to have a scheduling subordinate to the scheduling priority for any
firm shipper with unconditional primary corridor rights through such constraint.