Open File-Report 2014-1022
AbstractMountain Home Air Force Base in southwestern Idaho draws most of its drinking water from the regional aquifer. The base is located within the State of Idaho's Mountain Home Groundwater Management Area and is adjacent to the State's Cinder Cone Butte Critical Groundwater Area. Both areas were established by the Idaho Department of Water Resources in the early 1980s because of declining water levels in the regional aquifer. The base also is listed by the Idaho Department of Environmental Quality as a nitrate priority area. The U.S. Geological Survey, in cooperation with the U.S. Air Force, began monitoring wells on the base in 1985, and currently monitors 25 wells for water levels and 17 wells for water quality, primarily nutrients. This report provides a summary of water-level and nitrate concentration data collected primarily between 2001 and 2013 and examines trends in those data. A Regional Kendall Test was run to combine results from all wells to determine an overall regional trend in water level. Groundwater levels declined at an average rate of about 1.08 feet per year. Nitrate concentration trends show that 3 wells (18 percent) are increasing in nitrate concentration trend, 3 wells (18 percent) show a decreasing nitrate concentration trend, and 11 wells (64 percent) show no nitrate concentration trend. Six wells (35 percent) currently exceed the U.S. Environmental Protection Agency's maximum contaminant limit of 10 milligrams per liter for nitrate (nitrite plus nitrate, measured as nitrogen). |
First posted February 19, 2014 For additional information, contact: Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge. |
Williams, M.L., 2014, Groundwater level and nitrate concentration trends on Mountain Home Air Force Base, southwestern Idaho: U.S. Geological Survey Open-File Report 2014-1022, 49 p., https://dx.doi.org/10.3133/ofr20141022.
ISSN 2331-1258 (online)
Overview
The Problem
Study Area in Context
Monitoring Well Locations
Purpose of the Study
Background
Past Analysis and Studies
Trend Analysis
Criteria
Years of Water-Level Monitoring
Key Findings
Nitrate Concentration by MW Location
Summary Tables
Summary of Findings
Supplementary Information
References