USGS Washington Water Science Center
|U.S. Department of the Interior
U.S. Geological Survey
Release: March 17, 2000
Lonna Frans, Hydrologist
(253) 428-3600, ext. 2694
USGS releases first statistical report for Columbia Basin Ground Water Management Area
An intensive ground-water sampling study in three eastern Washington counties has found that in almost 1 of every 4 sampled wells, nitrate concentrations exceeded drinking-water health standards.
But that's no surprise to investigators or local officials. It was precisely because earlier studies had found elevated levels of nitrate in ground water that the Columbia Basin Ground Water Management Area (GWMA) was formed by County Commissioners in 1998 to reverse that decades-old trend. At the request of the GWMA, the U.S. Geological Survey designed a random well-sampling program to establish baseline nitrate data against which progress could be measured. The results of the program have just been published in a new report from the USGS, Department of the Interior.
In addition, the GWMA expects to release a draft ground-water management plan this summer. Committees of local citizens representing a wide range of interests are now preparing a management plan to provide workable, commonsense recommendations of how to reduce the nitrate reaching local ground water.
The USGS-designed program featured a mass sampling of 574 wells in Adams, Franklin, and Grant Counties in the fall of 1998. The three counties were divided into 17 Community Producer Groups (CPGs) or sampling regions, and the wells were grouped by their completion depth categories of shallow, medium, or deep. The CPGs were based on such factors as soil type, crop type, irrigation systems, natural borders, and historical community relationships. Local health officials and conservation district staff were specially trained to conduct the voluntary well sampling effort. The sampling results were handed over to the USGS scientists for analysis.
The aim, said Sarah Ryker, lead author of the USGS report, "was to fill in the gaps of what we know and to provide the first large data set collected with consistent methods at one time."
The study found that the water from 23 percent of sampled wells contained nitrate concentrations greater than the U.S. Environmental Protection Agency's maximum contaminant level for safe drinking water of 10 milligrams per liter. Another 37 percent of samples had elevated nitrate concentrations between 3 and 10 milligrams per liter.
In Franklin County, 30 percent of samples exceeded the drinking-water standards, while in Grant and Adams Counties, about 20 percent exceeded the standards.
"Now that we have these data, we are using them to develop a model that can evaluate how vulnerable the ground water is to elevated nitrate concentrations," said the Lonna Frans, coauthor of the USGS report.
The report, Summary of Nitrate Concentrations in Ground Water of Adams, Franklin, and Grant Counties, Washington, Fall 1998--a Baseline for Future Trend Analysis, by Sarah J. Ryker and Lonna M. Frans, is published as U.S. Geological Survey Water-Resources Investigations Report 99-4288. It is available for reading at the U.S. Geological Survey office at 1201 Pacific Avenue, Suite 600, Tacoma, Washington 98402. It can be purchased from the U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225-0286, telephone (303) 202-4610.
As the nation's largest water, earth, and biological science and civilian mapping agency, the USGS works in cooperation with more than 2,000 organizations across the country to provide reliable, impartial, scientific information to resource managers, planners, and other customers. This information is gathered in every state by USGS scientists to minimize the loss of life and property from natural disasters, contribute to sound economic and physical development of the nation's natural resources, and enhance the quality of life by monitoring water, biological, energy, and mineral resources.
*** USGS ***
For more information about the USGS study, contact Lonna Frans in Tacoma, WA at (253) 428-3600, x2694.
For more information about the Columbia Basin GWMA, contact Deanna Clarkson in Othello, WA at (509) 488-2802, extension 108 (voice) or (509) 488-6080 (fax). The GWMA maintains a web page which contains current information on GWMA activities at http://www.gwma.org/.
Press releases and in-depth information about USGS programs may be found on the USGS home page: https://www.usgs.gov. To receive the latest USGS news releases automatically by email, send a request to email@example.com. Specify the listserver(s) of interest from the following names: water-pr; geologic-hazards-pr; biological-pr; mapping-pr; products-pr; lecture-pr. In the body of the message write: subscribe (name of listserver) (your name). Example: subscribe water-pr Joe Smith.