THE HEAT IS ON: STARTUP AT ECCV'S 10.9 MGD INLAND RO FACILITY DURING RECORD BREAKING TEMPERATURES AND DEMANDS

摘要

The East Cherry Creek Valley Water and Sanitation District (ECCV) completed construction ona 10.9 million-gallon-per-day (MGD) brackish water reverse osmosis (RO) treatment facility in2012. The plant provides a renewable water source to areas of southeast metro Denver currentlyserved exclusively by non-renewable groundwater. ECCV selected a combination of brineminimization and deep well injection as the concentrate management and disposal approach forthe RO treatment facility.The complex system was started up during record breaking temperatures from March to Augustof 2012 in Colorado. This resulted in ECCV seeing water demands nearly 50% above thehistorical daily and seasonal averages. Additionally, the District was required to providefiltration to the Beebe Draw well field after May 1st, 2012. As a result, system startup, tuning andoperational adjustments needed to be performed without interrupting production and whilemeeting the new treatment goals. The plant was needed to hit peak production capacity for nearlythe entire month during the 30 day startup testing and much of the following months. Thispresentation will focus on the coordination and methods used to troubleshoot and optimize thesystem while maintaining plant operations.The project operates at RO recoveries of 92-94% and utilizes an adjacent well field with varyingwater quality. Achieving water quality and quantity goals required continual modification of wellmatrices, bypass flow blend ratios, system recoveries and the chemical stabilization approach. Inaddition, numerous HCl injection points were included to provide both long term adjustment ofcalculated LSI values to offset well water quality decline and short term maintenance drivencleaning of pipelines and membrane. A single fixed clean in place system was utilized for bothtreatment trains each containing four cascading stages of RO vessels.The continual operation of the facility also includes maintenance of a deep well injection systemthat sends 200-400 gpm of brine or off-specification water to 10,000 foot deep subsurfacesedimentary formations for final disposal. This presentation will revisit O&M requirements aswell as production costs for long term operations.