AWWA MTC69663

In 2007, The Irvine Ranch Water District (IRWD) took steps to minimize concentrate disposal for its deep aquifer treatment system by further treating the brine stream with another stage of nanofiltration, naming theplant the Concentrate Treatment System (CTS). In 2008, with a focus on optimizing operating costs attheir reverse osmosis groundwater desalter, IRWD turned its attention towards minimizing theconcentrate stream through an antiscalant procurement process developed specifically for minimizingpretreatment chemical costs while simultaneously increasing operating recovery and decreasingconcentrate disposal volumes.As part of the Irvine Desalter Project, the Potable Treatment Plant (PTP) treats approximately 3 mgd ofbrackish groundwater with reverse osmosis before bypass blending and product stabilization. The planthas operated successfully for over a year, using antiscalant and sulfuric acid as chemical pretreatment toprevent precipitation of sparingly soluble salts (scale) in the tail end of the system. In an effort to reduceO&M costs, IRWD employed a competitive antiscalant procurement process that required prospectivesuppliers to provide proposals for the antiscalant product, dose, RO feed pH setpoint, and operatingrecovery. Proposals were evaluated based on total annual cost of antiscalant, sulfuric acid, andconcentrate disposal. The lowest cost proposal was demonstrated on the pilot scale for 60 days to ensureacceptable performance before implementation on the full scale RO trains.This paper discusses the antiscalant procurement process employed by IRWD and the results of thiscompetitive bid process. Includes 3 references, tables, appendices.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

13

File Size:

1 file , 720 KB