Post Date: November 15, 2001 
Category: MAINTENANCE 
Subcategory: NWP MONTHLY MAINTENANCE 
Subject: December 2001 Monthly Maintenance 

Notice Text: 
All Shippers Letter            #01-317 
Date:           11/15/01 
Time:           16:30 MST                       



TO:             ALL SHIPPERS 

SUBJECT:        DECEMBER 2001 MAINTENANCE SCHEDULE 

The following maintenance work is scheduled on Northwest Pipeline for 
the month of December.  Potential system impacts are identified below. 
Volume impact and scheduled maintenance out of service date estimates 
are stated as accurately as possible, but are subject to change based 
on factors such as ambient temperatures, actual market demand, etc. 
Any variance from this notice will be communicated to customers as 
quickly as possible before commencing work.  All capacities listed in 
this maintenance schedule are in Dekatherms. 


**** Denotes capacity impacts that are in addition to those posted on the Annual Maintenance Letter. 



DECEMBER 2001 MAINTENANCE: 


Replace Engine Chocks at the Snohomish Compressor station 

Date:                   October 22, 2001 to December 8, 2001 
Design Cap:             720,000 Dth 
Available Cap:  614,000 Dth 

Replace the Chocks on the units at the Snohomish compressor station.  Only one unit will be unavailable at a time during this work.  Based on current nominations, which are below available capacity, there is no anticipated impact to customers.


Semi-Annual unit inspections at Sumas Compressor station 

Date:                   December 4, 2001 to December 5, 2001 
Design Cap:             724,000 Dth 
Available Cap:  607,000 Dth 

Perform annual inspections on C Plant units #7 and #8 at the Sumas compressor station.  Inspection of unit #7 is scheduled for December 4, and unit #8 is scheduled for December 5.  A and B Plants will accommodate any lost capacity.  Based on current nominations, there is no anticipated impact to customers.


Semi-Annual unit inspection at Mount Vernon Compressor station 

Date:           December 6, 2001 
Design Cap:             722,000 Dth 
Available Cap:  696,000 Dth 

Perform annual inspections on unit #3 at the Mount Vernon compressor station. Based on current nominations, which are below available capacity, there is no anticipated impact to customers.



Please contact your Marketing Services Representative or the Northwest Pipeline Hotline at (801) 584-7301, for further information.


WGP-W 
JR