Environmental Services is working on a long-term project to reconstruct the Triangle Lake Lagoon at the Columbia Boulevard Wastewater Treatment Plant. The project includes dewatering parts of the settling lagoon, removing accumulated solids and reconstructing an improved, lined lagoon system. The lagoon is just north of the treatment plant main campus next to the Columbia Slough. In order to maintain daily plant operations, Environmental Services will complete the project in phases over several years.
The south monofill section has been lined and leak tested. Dry solids will be deposited there starting in summer 2014.
Columbia Slough Trail Closures
The city’s contractor uses the Columbia Slough Trail to access the lagoon area during construction. This will intermittently close portions of the trail between the railroad tracks to the east and North Portland Road to the west (see map below). The city posts signs advising trail users of periodic closures at the following locations for the duration of the lagoon reconstruction project:
- On the trail at the corner of North Portland Road and Marine Drive
- At the construction site entrance at the intersection of North Portland Road and the Columbia Slough Trail
- At the Columbia Slough Trailhead at Columbia Court
- At the Columbia Slough Trailhead at Denver Avenue
- On the Columbia Slough Trail east of the plant’s east entrance
- At the main plant entrance on Columbia Boulevard
Odor Advisory and Reporting
During construction, the contractor will dewater portions of the existing lagoon area to allow the solids at the bottom to dry out before removal. A slight increase in odor may be noticeable during the drying and solid removal process. The contractor will use special equipment and techniques to minimize increased odors during construction. Neighbors can subscribe to the Plant’s Odor Notification System to receive notice when maintenance and construction projects will result in odors beyond treatment plant boundaries. Go to www.portlandonline.com/bes/odors to sign up for odor notifications, or to report an odor online.
For More Information
Contact Joe Annett at 503-823-2934.