RedN NAWQA
USGS IN YOUR STATE
USGS Water Science Centers are located in each state.
|
Cowdery, T.K. 1998, Ground-water quality in the
Red River of the North Basin, Minnesota and North Dakota, 1991-95. U.S.
Geological Survey Water-Resources Investigations Report 98-4175 21 p.
Abstract
Surveys of water quality in surficial, buried glacial, and Cretaceous aquifers
in the Red River of the North Basin during 1991-95 showed that some major-ion,
nutrient, pesticide, and radioactive-element concentrations differed by
physiographic Aarea and differed among these aquifer types. Waters in
surficial aquifers in the Drift Prairie (west) and Lake Plain (central)
physiographic areas were similar to each other but significantly higher than
those in the Moraine (east) area in dissolved solids, sodium, potassium,
sulfate, fluoride, silica, and uranium concentrations. Radium, iron, nitrate,
and nitrite concentrations were also significantly different among these
areas. Pesticides were detected in 12 percent of waters in surficial aquifers
in the Drift Prairie area, 20 percent of those in the Lake Plain area, and 52
percent of those in the Moraine area. Triazines and bentazon accounted for 98
percent of summed pesticide concentrations in waters in surficial
aquifers. Waters in buried glacial aquifers in the central one-third of the
basin had significantly higher concentrations of dissolved solids, sodium,
potassium, chloride, fluoride, and iron than did waters in surficial
aquifers. No pesticides were detected in five samples from buried glacial
aquifers or six samples from Cretaceous aquifers. Waters in all sampled
aquifers had a calcium-magnesium ratio of about 1.75 +- 0.75 across the basin
regardless of anionic composition.
Agricultural land use and soil texture can explain pesticide distributions;
soil texture best explains nutrient distributions in waters in surficial
aquifers. Confining beds protect waters in buried glacial aquifers from land
use effects, resulting in no or low concentrations of nutrients and
pesticides. Upward movement of bedrock waters high in dissolved solids
concentration can increase concentrations in waters in buried glacial and, to
a lesser degree, waters in surficial aquifers in the Lake Plain and Drift
Prairie areas. Waters in surficial aquifers exceeded the U.S. Environmental
Protection Agency (USEPA) maximum contaminant level in drinking water for
nitrate in the Drift Prairie (27 percent) and Moraine (8 percent) areas. Their
limited areal extent and susceptibility to contamination restrict the
usefulness of surficial aquifers as a drinking water source. Waters in buried
glacial aquifers exceeded USEPA health advisories for dissolved solids,
sodium, and manganese. Sixty-six percent of waters in surficial aquifers also
exceeded the Health Advisory for manganese.
|
U.S. Department of the Interior |
U.S. Geological Survey