AWWA ACE71003

This powerpoint presentation begins by providing a brief overview of Fairfax Water (FW), the largest drinking water utility in Virginia. Historical corrosion control facts are presented, and FW changed to a chemical corrosion control inhibitor (ZnPO₄) in 1998. Competing regulations including the Safe Drinking Water Act (SDWA) and the Lead and Copper Rule (LCR) vs. the Clean Water Act (CWA) and NPDES caused FW to change their corrosion control inhibitor. The Virginia Department of Health recommended a pipeloop study to determine whether the change in the corrosion inhibitor chemical would affect Pb concentrations. The study demonstrated that there was not a difference between the use of ZnPO₄ and H₃PO₄ as a corrosion control inhibitor in this application. The pros and cons of the switch from ZnPO₄ to H₃PO₄ are listed. Includes figures.