Behind the scenes: Not all electrical lines go underground

When you’re sitting in a cold, dark house with nothing warm to eat, and you’ve been without electricity for hours on end, it’s easy to question why all power lines aren’t placed underground.

by Leslie Kelly

Special to the Sounder

When you’re sitting in a cold, dark house with nothing warm to eat, and you’ve been without electricity for hours on end, it’s easy to question why all power lines aren’t placed underground.

And that’s what a lot of Orcas and Shaw island residents were thinking recently.About 3,300 customers of the Orcas Power and Light Company were without electricity for about 30 hours beginning at 6:30 p.m. Dec. 6.

According to Theresa Haynie, communication specialist for OPALCO, a major gust of wind — at possibly 60 miles an hour — blew down a large tree that hit a major transmission line along Indian Cove Road on Shaw Island. Seven transmission poles snapped at their bases and toppled towards the OPALCO submarine terminal at the end of the road.

OPALCO dispatched crews, material and equipment from Lopez, San Juan and Orcas islands to repair the transmission lines, Haynie said. OPALCO line crews worked late into night on Dec. 6, continuing well into the night Dec. 7 and the early hours of Dec. 8 to restore service.

As is often the case after a long power outage, Haynie and others at OPALCO began hearing questions about why the cooperative’s lines aren’t buried underground to prevent falling trees from taking down the lines.According to Haynie, about 86 percent of OPALCO’s lines are underground. She explained that the co-op gets its power from Bonneville Power Administration and power is carried to the islands through massive underwater submarine cables. The power then comes ashore to transmission lines that run overhead on poles to distribution lines that are buried underground. The distribution lines service both residential and business customers.

“Throughout the 20 islands that we serve, there are some 1,800 to 2,000 power poles,” she said. “Most the lines that are visible are transmission lines.”

And she said those are the lines that are impractical to bury underground.

“It’s not just digging a hole and putting down lines,” Haynie said. “The easements we now have on the overhead lines aren’t transferable to the ground. We would have to go through an environmental approval process because we would be digging huge trenches.”

Too, the lines would have to be insulated.

“These are very high voltage lines,” she said. “They have to be encased in conduit and then put in cement before they can go underground. And, we have to build vaults, so that we can have access to the lines.

“Repairing underground lines is expensive, running $20,000 to $60,000 for each splice.”And generally, those types of repairs to underground lines can take from five to nine days before the power is restored,” Haynie added.

To give a perspective, the cost to OPALCO to bury just half of its transmission lines would be nearing $50 million.

“The cost of underground lines can be anywhere from four to 14 times the cost of overhead lines,” she said, noting that as a co-op that would send members rates beyond a reasonable cost. “We are aware of the vulnerability of some of our lines, but as a co-op our financial structure is based on the cost of service.”

Another issue, she said, is the geography of the islands.

“There’s a lot of rough terrain,” she said. “There are rocky areas. We’d have to blast through the rock to bury lines in some places.”

In the most recent storm, seven transmission lines were taken down. The tree that fell was 120 feet tall, and nearly 60 feet from OPALCO’s right-of-way. The company’s right-of-way ranges from 10’ – 200’ around the power poles (depending on location and type of line), which it must maintain. All of Shaw Island and most of Orcas was without power during the most recent wind storm. OPALCO was able to re-route some power to allow for a grocery store and schools to be open, Haynie said.

General Manager Foster Hildreth said many people went “above and beyond the call of duty to assist us.”

He mentioned the Washington State Ferries captain and crew, who came back to the terminal to help load equipment on the ferries, the Orcas Village Store that delivered coffee and pizza, Hardy Schmidt, local equipment operator on Shaw Island, the OPALCO engineering staff members, and “most importantly, our dedicated and professional field and line crew.

The last time power was out on the islands for any significant amount of time, Haynie said, was during ice and wind storms in 1989 and 1991.

“In some parts of the islands, people were without power for two weeks,” she said.

Since then, the company has buried more of its distributions to homes and businesses to help ease the potential of customers being without power.

The board of directors for OPALCO meets monthly and each month they review an outage report, Haynie said.

“They look at the causes — storms, trees, humans, even animals,” Haynie said. “It (burying more lines) does get discussed.”