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Equipment Upgrades Underway at Laurelhurst Substation

Seattle City Light is making several upgrades to the equipment at its Laurelhurst Substation throughout May.

Seattle City Light is making several upgrades to the equipment at its Laurelhurst Substation throughout May.

City Light is replacing and up-grading old 4 kilovolt power lines with 26 kilovolt lines that are standard equipment for most of the utility’s distribution system. As a part of this work, crews will replace three auxiliary transformers known to contain polychlorinated biphenyls (PCBs) with new transformers that do not use PCBs.

“This work will improve the reliability of our distribution system in northeast Seattle and eliminate the risk of PCBs entering the environment,” Superintendent Jorge Carrasco said. “Our customers deserve low-cost, reliable, environmentally sensitive electricity and this project accomplishes that.”

No customer outages are planned as part of this work. There will be trucks and other vehicles on site and in the street adjacent to the substation, 4502 NE 41st St., throughout the duration of these replacements. City Light estimates it will take about 10 days beginning May 17.

PCBs are man-made compounds that were used extensively in hundreds of commercial and industrial applications due to their non-flammability, chemical stability, high boiling point, and electrical insulating properties.

Their manufacture was banned in 1979 because it has been shown that direct exposure can cause cancer and a variety of other adverse health effects on the immune system, reproductive system, nervous system and endocrine system.  City Light has a goal to remove any remaining PCB transformers in our system by the end of 2010. For more information on PCBs, visit

The PCB transformers being removed from the substation will be secured in containers on site, and then moved to another facility for safe removal of the chemicals and proper disposal. Employees working directly with these transformers and their housings will be wearing hazardous material (haz mat) suits to guard against exposure. Seattle City Light workers have considerable experience with transformer removal and have extensive training in the safe handling of these materials.  The transformers will remain sealed throughout the removal process.

Seattle City Light is the ninth largest public electric utility in the United States.  It has some of the lowest cost customer rates of any urban utility, providing reliable, renewable and environmentally responsible power to nearly 1 million Seattle area residents.  City Light has been greenhouse gas neutral since 2005, the first electric utility in the nation to achieve that distinction.