Portland, OR 97203 The Columbia Boulevard Wastewater Treatment
Plant is part of a collection and treatment system that serves
nearly 600,000 residential and commercial customers. The plant
operates every day around the clock to manage, monitor and
adjust the treatment process. Sewage pump stations and pipes
convey wastewater to the facility 24 hours a day. - 1952 Plant
completed - 1969 Primary expansion - 1974 Addition of secondary
treatment - 1982 Digester expansion - 1994 Secondary
modification complete - 1996 New headworks complete - 2000 New
dry weather primary clarifiers added - 2005 Switched from liquid
chlorine to sodium hypochlorite for wastewater disinfection -
2008 Adopted new CBWTP facilities plan - 2008 Activated
cogeneration facility to use biogas to fuel plant operations
2011 Two new digesters (9 and 10) put into service, adding 5.6
million gallons of sludge treatment capacity and 8 to 10 days of
detention time to the process. 2011 Willamette River CSO tunnel
systme becomse fully functional with