AWWA MTC64633

The Orange County Water District (OCWD) carried out a competitive bid for antiscalant in 2005 for its 5 mgd interim (Phase 1) facility, in anticipation of the 70 mgd RO capacity Groundwater Replenishment (GWR) System, currently under construction. The OCWD competitive bid included an additional refinement beyond assessing the lowest annual cost and demonstration-based performance testing. In addition to providing an antiscalant product and dosage, the vendors were required to provide a feed pH setpoint that would allow optimal performance of the bid antiscalant product in preventing scale formation within the RO system. The consumption rate of acid was included in the determination of low bid by calculation of an annual cost of antiscalant and acid. The focus of this paper is on documenting the antiscalant procurement process employed at OCWD. This procurement process not only demonstrated successful performance of the low-bid product prior to implementation on the full-scale RO system, but also resulted in optimized acid consumption and significantly reduced chemical costs. It is estimated that implementing the low-bid product will save OCWD over $1,500,000 annually in antiscalant and sulfuric acid costs, with potentially more savings related to stabilization of the final product. Includes 6 references, tables, figures.