The Mercer Island City Council will once again discuss a Puget Sound Energy (PSE) plan to bury electricity distribution lines along S.E. 68th Street, thereby reducing the length of power outages on the South end.

The proposal, named the PSE South-end reliability project, was brought up in response to the December 2006 power outage, during which much of the South end was left without electricity for days. The city turned to PSE for a possible solution in preventing future cases. Installing underline distribution lines along SE 68th Street, the company said, would reduce single-contact outages to less than one minute and prevent South-end residents from going without power for days after a severe storm.

PSE also proposed creating a second transmission “loop through” feed to the South Mercer Substation (SME), which it would pay for in full ($500,000). The current feed is only tapped from the transmission system along SE 68th Street and Island Crest Way. Yet the proposal has its costs.

According to PSE experts, several dozen trees between 68th Street and the northwest quadrant of Pioneer Park would have to be removed for the new transmission lines. Many of these large trees assist in shielding the park from the noise and congestion of 68th Street, the visual eyesore of the South-end shopping center and its neighboring electrical substation. The project would also require the installation of several tall support poles, wiring, and other electrical equipment along 68th Street.

In April of 2008, the city brought the PSE project to the Board of the Open Space Conservancy Trust for consideration. After thoroughly reviewing the proposal — which included an on-site visit and presentations by PSE engineers, an arborist and other personnel — the board urged the city to reject the project due to its environmental consequences.

“Although the project is intended to provide some level of electrical system reliability improvement to the south end of the city, the trust board believes that the project’s adverse impacts on Pioneer Park substantially outweigh its anticipated benefits,” the board’s statement read.

Although there was an alternative PSE plan to install underground power lines along East Mercer Way, from SE 53rd Place to the South Mercer Substation (SME), the city determined that this option — at $1.5 million — was “prohibitively expensive” and dismissed it.

“We simply don’t have the funding for this option,” said Mercer Island Finance Director Chip Corder. “If we were to do it, we’d have to go to Capital Improvement Program and cut other projects in the current biennium to free up funding for this PSE project.”

Corder favors the smaller-scale, 68th Street installation project because PSE will cover much of the costs.

“From a financial perspective, that’s the one that’s doable,” he said.

If approved, the design of this proposal would cost the city between $40,000 and $50,000 to design. This includes approximately $30,000 in services provided by PSE and its contractor, Potelco, and another $10,000 to $20,000 for detailed survey work and other pre-design activities.

As for construction costs, a reliable estimate is not possible until design work is complete. Yet estimates range from $1 million to $1.4 million for approximately 4,800 feet of underground installation. Once the project is finished, PSE has agreed to reimburse the city for 60 percent of design costs. PSE would also fund 60 percent of the cost of materials for the new underground system as well as labor. The cost of trenching, restoration, converting other utilities, and street lighting falls upon the city.

The issue is an item to be discussed at the Jan. 20 City Council meeting. According to a summary of the agenda, the project may not be realized for some time.

“For the new transmission feed to the SME to move forward, the Council would need to direct staff and PSE to proceed despite the opposition of the Conservancy Trust Board. It’s not clear at this time when PSE funding might become available for the project,” the summary read. “Restrained by its tight budget, the City cannot afford to proceed immediately with the South-end reliability project. Staff is hopeful that later [this year], the city may enter into a design agreement, with the goal of constructing the project in the next biennium.”