Upper Yakima Watershed Study - Sites of Interest

1. Upper Yakima Watershed Study - Sites of Interest “A Fundamental promise we must make to our people is that the food they eat and the water they drink are safe.” – Former President Bill Clinton, Safe Drinking Water Act Reauthorization, August 6, 1996 Figure 1 – Flow Chart for Project Table 1 – USEPA MCLG, MCL for Trace Metals in Drinking Water • The Safe Drinking Water Act (SDWA), originally passed in 1974 and amended in 1986 and 1996, gives the United States Environmental Protection Agency (USEPA) the authority to set drinking water standards. • Drinking water standards are regulations that the USEPA sets to control the level of contaminants in the nation’s drinking water supply. • This project is aimed at identifying study sites of interest in regard to these USEPA drinking water standards for trace metals. (See Figure 1 & Table 1) • There are two categories of drinking water standards: • National Primary Drinking Water Regulation – legally enforceable standards, contaminants that adversely affect public health and are known or are anticipated to occur in water. • Set by Maximum Contaminant Level (MCL), the maximum permissible level of a contaminant in water which is delivered to any user of a public water system. • National Secondary Drinking Water Regulation – non-enforceable standards, contaminants that result in cosmetic or aesthetic effects. • Set by Maximum Contaminant Level Goal (MCLG), the max level of a contaminant in drinking water at which no known or anticipated adverse effect on the health of person would occur, allowing for an adequate margin of safety. • The MCL is set as close as possible to the MCLG, which the SDWA defines as the level that can be achieved with the use of best available technology and treatment techniques, taking cost into consideration. • For this study if there was no set MCL, the set MCLG was used. • The Interest Level is based on number of contaminants above the permissible limit set by USEPA. An interest level of 3 or higher is sufficient for a site to be considered for future monitoring measures. Figure 2 – Study Sites in the Upper Yakima Watershed Figure 3 – Sites of Interest in the Upper Yakima Watershed Table 2 – Study Sites Recommended For Future Monitoring Hydrography: Pacific Northwest River Reach Files, USGS; Base map modified from USGS data, USGS; Study Sites: digitized from various hard maps; Trace Metal Data: CWU-Env. Geochemistry 2008 Projection: Lambert Conformal Conic Datum: North American Datum of 1983 HARN Standard Parallels: 45 59 98 and 47 19 60 Central Meridian: 120 30 00