From the City of Portland Environmental Services:
Work continues on a long-term project to reconstruct the Triangle Lake lagoon just north of the Columbia Boulevard Wastewater Treatment Plant on the north bank of the Columbia Slough. Environmental Services is draining parts of the lagoon, removing solids and installing a lagoon lining. To maintain daily plant operations, Environmental Services will complete the project in phases over several years.
TRAIL CLOSURES: The city’s contractor uses the Peninsula Crossing Trail/ Columbia Slough Trail to access the lagoon area during construction. This intermittently closes a portion of the trail northeast of the treatment plant and along North Portland Road (see map). That trail section is currently closed on weekdays between 7:00 a.m. and 6:00 p.m. The trail is open after work hours and on weekends. The city posts signs at trail entrances to advise trail users of any closures.
For more information, see the construction website >>