Applied Research and Development Center, Southern Nevada Water Authority, PO Box 99954, Las Vegas, NV 89193-9954, USA.
J Environ Qual. 2010 Jul-Aug;39(4):1196-200. doi: 10.2134/jeq2009.0072.
The concentrations of selected wastewater contaminants, including conductivity, nitrate, and pharmaceuticals and endocrine disrupting compounds (EDCs), were monitored from 2003 to 2007 in Lake Mead, the raw (untreated) drinking water for southern Nevada. Monitoring was also conducted in two inflows to Lake Mead: the Colorado River and the wastewater-dominated Las Vegas Wash. There was a statistically significant increase in source water conductivity, nitrate, and pharmaceutical and EDC concentrations over this time period, concomitant with a statistically significant decline in the volume of Lake Mead. There was no statistically significant increase in conductivity and nitrate in the Colorado River or the Las Vegas Wash over this period, nor was there an increase in flow of the Las Vegas Wash or Colorado River. Thus, the deterioration of source drinking water quality is due to the decrease in the volume of Lake Mead which has been attributed to drought. This phenomenon may also be a harbinger of how water quality may be adversely affected by climate change as patterns of surface water flow shift and treated wastewater becomes a larger fraction of surface water flow in some areas.
从 2003 年到 2007 年，对米德湖（内华达州南部的原水，未经处理的饮用水）中的选定废水污染物浓度（包括电导率、硝酸盐以及药品和内分泌干扰化合物 (EDC)）进行了监测。同时还对米德湖的两个入流：科罗拉多河和以废水为主的拉斯维加斯冲沟进行了监测。在此期间，水源的电导率、硝酸盐以及药品和 EDC 浓度呈统计上显著增加，而米德湖的水量呈统计上显著减少。在此期间，科罗拉多河或拉斯维加斯冲沟的电导率和硝酸盐均未呈统计上显著增加，且拉斯维加斯冲沟或科罗拉多河的流量也没有增加。因此，水源饮用水水质的恶化是由于米德湖水量减少所致，而米德湖水量的减少归因于干旱。随着地表水流量模式的变化以及在某些地区处理后的废水成为地表水流量的更大一部分，这种现象可能预示着水质如何受到气候变化的不利影响。
