BPA Line Impairment on Brockdale
In July 2018, the Bonneville Power Administration told us that our distribution line on Brockdale was too close to their transmission line as it crosses the road between Hickam Lane and Meyer Lake Road.
The distribution and transmission lines have been in place for many years. However, BPA has recently been required by NERC to ensure there is adequate clearance from their transmission lines. This led them to analyze their facilities to ensure appropriate clearances between wires (and the ground) as required by the National Electrical Safety Code (NESC).
Even though our facilities are installed in the Mason County right of way, BPA asked us to move our three-phase distribution feeder down eight feet. That was impossible without putting the line underground.
DID YOU KNOW: It’s PUD 3’s standard to build main distribution feeders overhead:
They are much less expensive to build and maintain.
Damage can be quickly diagnosed and repaired.
They are easier to access for distribution taps and road crossings.
Being air-cooled, there are efficiency benefits for increased capacity in colder weather, when loads are high.
After we were contacted by BPA, our engineering staff including Tom Johnson and Tim DeVries, surveyed the site. They found that BPA’s transmission tower east of our distribution line was too short, causing the low clearance. We suggested that BPA think about installing a taller, more appropriately sized tower there. To give the proper clearance, they quoted a project cost of between $100,000 and $150,000. We operate much leaner than that, so Tom designed an underground replacement for this section of distribution feeder.
Foreman Rob Coleman, a line crew, and dirt crew set several 50’ poles and dug a trench for the power lines to riser down, run through conduit, then riser back up and continue out Brockdale Road.
We did the work for about $16,000 in materials, saving PUD 3 rate payers over $100,000 compared to BPA’s estimate. Rob’s crew did the work “hot”, meaning our customers didn’t even experience an outage when cutting over to the new cable.
Good work, everyone!