City of Portland Bureau of Environmental Services
KJ provided engineering services for the condition evaluation and design of improvements to the aging 4.32 MGD (average) premanufactured Lahaina Wastewater Pump Station No. 2.
The team evaluated the existing capacity, operating condition, equipment condition, and assessed alternatives to rehabilitate, expand and/or replace the facility. Construction of a new pump station adjacent to the limited space existing facility was selected as the preferred option. Preliminary engineering included an analysis of alignment alternatives for reconnecting an existing 30-inch gravity sewer line to the pump station, interconnecting the existing 20-inch DI force main and a new 20-inch PVC force main, and analysis of pump station bypass pumping alternatives. KJ also participated in odor control demonstration testing and resultant evaluation of odor control system alternatives and high-performance coating alternatives. Following preliminary engineering, we provided final design and permitting support.
Rehabilitation design included:
- Conducting work sessions with the County’s team to flush design issues
- Upsizing the pump station to 10 MGD (peak flow) – Replacing drypit centrifugal pumps with wetpit submersible pumps
- Installing a 2,000-gallon surge tank to mitigate surge conditions
- Installing a new biofilter odor control system with carbon scrubber
- Developing force main flushing and bypass connection plans
After our team prepared construction plans and specifications, KJ provided bid support services. During the construction phase, we supported the County’s team with responding to RFIs, performed submittal reviews, prepared contract modification documents in support of County driven changes. KJ also prepared an electronic O&M manual for the facility.
