Unregulated Water Source on the Navajo Nation: Assessing Risk of Unregulated Water Supplies and Optimal Placement of Regulated Water Supply Points.

摘要

The Navajo Nation is the largest federally granted area given to Native American people in the United States, with more than 300,000 federally recognized Navajo tribal members. Approximately 58% of the people living on the Navajo Nation do not have access to public utilities, including treated drinking water (EPA 2010). Without access to drinking water sources that meet the requirements of the Federal Safe Drinking Water Act, rural residents use unregulated water sources, such as windmill driven wells designed to supply water for livestock. Approximately 30% of the population use unregulated supplies because they are not connected to the public water supply and 29% of people haul water from unregulated supplies even though they are connected to the public water supply (NNEPA 2011).;From 2008 until 2011, students from Dine College and University of Nevada, Reno sampled unregulated water supplies in 11 Chapters located within the Northern Navajo region. 10% of the stock tank wells had naturally occurring uranium and 40% had arsenic concentrations that exceeded the federal maximum contaminant level (MCL) for drinking water. Nearly 80% of these sources were also contaminated with bacteria.;Based on sampling results for arsenic and uranium, and an analysis of census data, approximately 5,000 people have a high likelihood of using contaminated unregulated sources as a drinking water supply. Although the analysis identified areas where unregulated water source use is highly likely, this has not been verified with a survey of residents. This study provides guidance for (a) educational efforts to inform residents of the potential risks associated with drinking water from unregulated sources, (b) construction of watering points by the Navajo Nation Tribal Utilities Authority and (c) setting priorities for hauling tankers of treated water periodically to chapters included in this study.