Equipment Upgrades Underway at Laurelhurst Substation

Seattle City Light is making several upgrades to the equipment at its Laurelhurst Substation, located at the base of the park at  4502 NE 41st Steet.

The work started Monday and will continue go on for about 10 days.  There will be trucks and other vehicles on site and in the street adjacent to the substation.


City Light will be installing higher-voltage lines and replacing three transformers. No customer outages are planned as part of this work.

The press release says:

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.


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.


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.

Here is the full press release.