Puget Sound Energy on Friday completed a $46.4 million natural gas system upgrade to improve reliability and increase capacity in the South King County area, specifically Auburn, Kent, Federal Way and Vashon Island.

Last week, PSE installed the final 6.8 miles of 16.3 miles of new 16-inch natural gas pipeline that spans from PSE’s limit station in Kent to a tie-in point near Star Lake Road and South 272nd Street in Federal Way. The six-year project also included the construction of two new limit stations in Kent and a new district regulator, also in Kent.

“The Kent-Black Diamond natural gas upgrade provides a strategic link in our natural gas system that improves reliability and increases capacity for our customers in this growing area of South King County,” said PSE Gary Nomensen, manager of local government and community relations.

Construction began in 2004 when PSE built the new Sequoia district regulator and installed 5.25 miles of 16-inch natural gas line between the Sequoia district regulator and PSE’s gate station in Black Diamond. Two years later, in 2006, PSE built the first of two new limit stations in Kent and installed 4.25 miles of 16-inch natural gas pipeline between the limit station and PSE’s Sequoia district regulator. Gate and limit stations regulate the pressure of the natural gas, typically decreasing the pressure of the natural gas distribution system for use in homes and businesses.

In 2008, PSE installed more than 3,000 feet of natural gas pipeline under the Green River, and along SR 167 and the Union Pacific Railway in Kent. The utility completed the second limit station in Kent earlier this year. Restoration of the project site, including road asphalt overlays, will continue into 2010.

While PSE planned and initiated construction on this upgrade long before the Howard Hanson Dam showed signs of problems leading to potential Green River Valley flooding, the new Kent-Black Diamond natural gas line provides more options in our underground natural gas system for addressing potential flood scenarios.

For more information, please visit PSE’s Kent-Black Diamond natural gas project Web page at www.PSE.com.