Trace Organic Compound Removal at Clark County – Lessons Learned from an Indirect Potable (IPR) System

Over the years, the Clark County Water Reclamation District (CCWRD) has worked closely with the Southern Nevada Water Authority (SNWA), Water Environment Research Foundation (WERF), American Water Works Association Research Foundation (AwwaRF), and WateReuse, conduction research to determine the level of removal of estrogenicity when using ozone for disinfection and to predict the impace ozonation would have on trace organic compound removal. As a result, numerous bench scale and full scale pilot tests have been performed. In 2008, CCWRD determined that 30mgd of its older teritary sand filters and ultra violet (UV) disinfection processes needed to be replaced. Based on years of research, ozone was chosen to replace the UV disinfection. Membrane filtration, which would better remove phosphorus, would also assist in disinfection, and reduce the ozone demand, was selected to replace the teritary sand filters. Utilizing ozone for disinfection will oxidize the vast majority of trace organic compounds.