Membrane Bioreactor Accepted as Compliant Filtration Technology

The ClearLogic® Membrane Bioreactor (MBR) from WesTech (USA) has received acceptance from the California Department of Health Services (CDHS) as an acceptable filtration technology for compliance with the State of California Water Recycling Criteria (Title 22).

“We are excited to receive this key certification for our MBR system.” said Brad Hansen, production leader at WesTech. “This milestone not only confirms our membrane performance as a positive barrier, but also provides our customers the confidence that our system is a certified solution for their wastewater reuse applications.”

The CDHS criteria for membrane wastewater filtration as an acceptable filtration technology requires that effluent turbidity does not exceed 0.2 NTU for more than 5 percent of the time during a 24-hour period, and never to exceed a turbidity of 0.5 NTU at anytime. The ClearLogic® system far surpassed the Title 22 criteria by achieving average turbidity readings less than 0.07 NTU, with peak values of 0.11 NTU. Although the CDHS no longer requires testing for a maximum flux, testing was conducted for typical design fluxes of 5 – 25 gfd (8.5 – 42.5 LMH).

The ClearLogic® system was tested and operated by a third party consulting engineer, ECO:LOGIC Engineering, at the City of Lincoln Waste Water Treatment Plant in Lincoln, CA. The WesTech ClearLogic® MBR filtration system utilizes a submerged Hollow Sheet™ PVDF membrane with a nominal pore size of 0.2 micron that is manufactured by Alfa Laval. The Hollow Sheet™ membrane combines the advantages of hollow fiber and flat sheet technologies, creating a design with even flux distribution and ultra-low transmembrane pressures (TMP). Typical TMP levels for the Title 22 testing ranged from 3” (H2O) at average flows, and up to 30” (H2O) for peak hourly events.