APPROACH, METHODS, AND CHALLENGES TO COLLECTING SUSPENDED SEDIMENT AND SURFACE WATER SAMPLES FROM REMOTE EPHEMERAL CHANNELS IN SAN JUAN RIVER’S FOUR CORNERS REGION, USA

Navajo Nation Environmental Protection Agency (NNEPA) has detected elevated concentrations of metals such as aluminum, arsenic, and lead in the San Juan River as it flows through Navajo Nation. Residents of Navajo Nation rely on the San Juan River for drinking water, irrigation, and watering stock. The U.S. Geological Survey (USGS) is collaborating with NNEPA to determine the relative sources of these and other metals in the San Juan River from 28 ephemeral and 5 perennial channels from Navajo Lake, in northwestern New Mexico, downstream to Mexican Hat, UT. Due to the remote location and short duration of flow during thunderstorms, this project required new approaches to collecting suspended sediment and water samples with a limited budget. Thirty-three monitoring gages were designed and deployed, equipped with a suspended sediment settling trap, a water quality sampler including two 1-liter Nalgene bottles, and a pressure transducer gage. The goal of these gages was to collect suspended sediments, water samples, and stage during short duration flow events using low-cost, readily available materials. This poster will present the approach, methods, and challenges associated with this study.