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How Southern Nevada Water Authority Researches, Detects, and Removes Pharmaceutical Contamination
The SNWA’s Compliance Laboratory conducts more than 300,000 analyses on water samples collected thought southern Nevada to ensure compliance with the SDWA.
David Rexing and SNWA’s postdoctoral researchers operate a highly specialized hybrid mass spectrometer used at the SNWA’s Water Quality Research and Development Laboratory.
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he Southern Nevada Water Authority (SNWA), which provides wholesale water to more than 2 million people in southern Nevada, is highly proactive when it comes to water purity and safety. Beginning around 2000, it has done significant research into detecting and removing pharmaceutical contaminants and other contaminants of emerging concern from the water supplies it delivers. David Rexing, the SNWA’s water quality research and development manager, has worked for Las Vegas’s not-for-profit water agencies since 1975. In this interview, he tells Municipal Water Leader about the development of the agency’s compliance laboratory and its research activities today. Municipal Water Leader: Please tell us about your background and how you came to be in your current position.
12 | MUNICIPAL WATER LEADER | September 2020
David Rexing: When I started in 1975, the Safe Drinking Water Act (SDWA) had just passed, and the SNWA had not yet been formed. At that time, I was employed by the LVVWD, which wanted to start a big compliance laboratory to take care of all the monitoring activities it required. I started from nothing and built a laboratory by myself. When the district and other local water and wastewater agencies formed the SNWA in 1991, the water quality compliance functions became part of the SNWA’s responsibilities. Today, approximately 40 individuals work in the SNWA lab, taking care of all the monitoring and analytical requirements of the SDWA. In 2000, the director of our plant decided that we needed to get a little more specialized in our research. I had always done some research in the compliance lab, but it took second place to compliance. I left the compliance group and started up yet another division, the Water Quality Research and Development Division, which today has about 25 individuals on staff. We solicit external funding and receive between half a million and a million dollars a year to do water quality research work. In addition to the work we do for external agencies who are trying to advance the field, we try to solve water quality problems within our own water treatment plant and distribution system. We are trying to optimize our internal process and stay ahead of the curve in terms of water quality. municipalwaterleader.com
PHOTOS COURTESY OF THE SNWA.
David Rexing: In my undergraduate studies, I majored in chemistry, but I was not sure what particular facet of chemistry I was interested in. Luckily, a professor came to me during my senior year and asked if I would like to do an internship at the local water treatment plant. He explained that a water treatment plant dealt with microbiology, hydraulics, and other scientific applications. I went to work at the local waterworks half time during my senior year, working 4 hours a day and taking classes 4 hours a day. I split the weekends with another intern. That was the springboard for me. I became so interested in the field that I pursued graduate studies in hydrology and water resources, and after graduating, I was hired into my current position.
Municipal Water Leader: Please tell us about your positions at the SNWA and the Las Vegas Valley Water District (LVVWD).
