MBR System Upgrade

The Stillaguamish Tribe uses MBR technology to treat wastewater from the Angel of the Winds Casino in Arlington, Washington. MMBR has partnered with the Tribe and other stakeholders for more than 22 years to support the site’s growing treatment needs.

In 2004, the MMBR team worked with project stakeholders to design and deliver a 50,000-gpd MBR system. That first plant utilized Kubota (flat-plate) Submerged Membrane Units® treated wastewater from the casino restrooms and snack bar. Treated effluent was then reused at the casino for toilet flushing. In 2014, as the site expanded to include a hotel, gas station, convenience store, RV park, laundry facility, restaurant, administrative building, and community center, MMBR supported the delivery of a larger 0.075 MGD MBR system near the original plant.

The new plant was built with a flexible flat sheet membrane product (called BIO-CEL 416). In 2021, MMBR installed backward-compatible, higher-capacity membrane module design (BIO-CEL L2) to increase capacity to 120,000 gpd. And, in 2024, MMBR technical services team, with support from a local contractor, upgraded the plant again (using the BIO-CEL L+) making it easier operate, further increasing capacity, and reducing maintenance costs. For the new construction projects, the MMBR technical team provided design, process, automation, and optimization services. For later expansions and upgrades, MMBR designed and delivered complete turnkey system solutions. During the most recent upgrade,

MMBR replaced BIO-CEL L2 membranes with BIO-CEL L+ units, exchanged permeate pumps, modified piping, and updated control programming. The installation was completed in approximately three days, with MMBR managing engineering, procurement, installation coordination, and commissioning. Working closely with the operations team, engineer, and owners, MMBR increased system capacity by 50% – from 0.08 MGD to 0.12 MGD and modernized the facility. The plant is now operating reliably at higher flows with reduced cleaning requirements. The AOTW upgrades are examples of life-cycle-extension services that can maximize infrastructure value while minimizing service interruptions.