IDENTIFYING SOURCES OF ARSENIC AND SALINITY IN GROUNDWATER AND SURFACE WATER IN THE SNAKE CREEK WATERSHED, UTAH

The Provo River, located in northern Utah, is an important water source for over 1 million people who live along the Wasatch Front. However, water quality in the Provo River is severely altered by Snake Creek, a small tributary that is located above water storage reservoirs and distribution systems. Snake Creek contains elevated salinity and high concentrations of many trace elements and is listed with impaired status by the EPA due to arsenic. Although it contributes only 1/5 of the annual flow to the Provo River, Snake Creek is responsible for 70% of the arsenic loading. Our study focuses on identifying the source of elevated levels of salinity and arsenic in Snake Creek. During 2012-14, we sampled Snake Creek and several natural springs in the watershed in order to identify contaminant sources. At its headwaters in the Wasatch Mountains, Snake Creek has low conductivity (<400 µS/cm) and low arsenic concentrations (<2 µg/L). However, water quality deteriorates rapidly as the stream passes through an area of hot springs and tufa mounds. At the confluence with the Provo River, the conductivity of Snake Creek exceeds 800 µS/cm and arsenic concentrations exceed 15 µg/L. This presentation will discuss geochemistry and arsenic concentrations of hot springs and surface waters in the Snake Creek watershed.