Agenda Date:  May 10, 2000 
Item Number: 

Docket:  UG-000072

Company Name: Puget Sound Energy

Staff:    Al Jones, Pipeline Safety Engineer
   Dennis Lloyd, Pipeline Safety Engineer

Recommendation:
Issue an Order Granting Authorization pursuant to WAC 480-93-020 for Proximity 
Considerations with conditions included in the stipulation marked as Appendix 
A. 
 
Background: 
The purpose of this filing is to install natural gas inlet piping from the 
Williams Pipeline West near Lake Stevens to a proposed North Everett Gate 
Station and distribution main in Snohomish County to North Everett.  Puget 
Sound Energy (PSE) proposes to operate the main at pressures exceeding 500 
pounds per square inch gauge (psig).  The distribution main would provide 
system reinforcement to existing customers by backfeeding the Marysville and 
North Everett supply systems and provide natural gas for a proposed 
cogeneration plant located west of State Route 529 on the south side of the 
Snohomish River.  

The Florida Power & Light Company will own and operate the cogeneration 
facility. The facility will produce less than 250 megawatts of electrical power 
and will not require the review and certification by the Energy Facility Site 
Evaluation Council. The proposed 16-inch diameter pipeline is contingent upon 
the construction of the cogeneration facility.  If the pipeline and the 
cogeneration facility are not constructed, the projected firm load demand 
growth for gas in the next 5 years would result in a gas supply deficiency 
north and south of Marysville and north of Lake Stevens.  If the pipeline and 
cogeneration facility are constructed a deficiency in the gas supply to only 
the area north of Marysville is projected to occur.  A new high-pressure 
distribution main north of Marysville would be required to mitigate this 
projected deficiency.  The above scenarios are based on PSE’s computer modeling 
for a 55-degree day.  

The pipe will be buried and bored underground for a distance of approximately 9 
miles.  The proposed route is within the right-of-ways of State Route 92, Puget 
Sound Energy’s electrical transmission line, Burlington Northern/Santa Fe 
railroad tracks, the County of Snohomish, and the City of Everett.  The borings 
will be located beneath Ebey, Steamboat, and Union Sloughs, Interstate-5 and 
the Snohomish River.  The high-pressure distribution main and the Gate Station 
inlet piping are being designed to yield hoop stresses of approximately 19.98% 
and 34.1% of the pipe material’s specified minimum yield strength, 
respectively.  The most restrictive requirement by federal natural gas pipeline 
safety specifies that natural gas pipelines in a highly populated area be 
operated at pressures producing a hoop stress of no greater than 40% of the 
specified minimum yield strength of the pipe. 

 Considerations:Commission Staff has evaluated the proposed facility to 
determine if public safety will be compromised by the operation of the proposed 
16-inch diameter high-pressure natural gas distribution main.  Puget Sound 
Energy has agreed to construct the pipeline to a more stringent standard than 
federal requirements as stipulated in Appendix A.  At this time, Staff does not 
consider the installation of the proposed facility to significantly impact 
public safety.  If the pipeline is not built in five years then Puget Sound 
Energy, Inc., will need to refile for extended authorization.Since the pipeline 
is contingent upon the construction of the cogeneration facility the Commission’
s Order will have a sunset date of five year from the date of the Order.  If 
the pipeline is not built in five years then Puget Sound Energy will be 
required to refile pursuant to WAC 480-93-020.

Conclusion:Therefore, Staff recommends that the Commission issue an Order 
Granting Authorization pursuant to WAC 480-93-020 for Proximity Considerations 
with conditions included in the stipulation marked as Appendix A.