RedN NAWQA
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National Water-Quality Assessment Program
Tornes, L.H. and Brigham, M.E., 1994,
Agricultural Chemicals in Streams of the Red River of the North
Drainage Basin, Minnesota Water `94
Conference Oral Presentations Abstracts, April 21-22, 1994, Minneapolis,
Minnesota, p. 3.
Abstract
The U.S. Geological Survey is studying the agricultural chemicals in streams
within the Red River of the North drainage basin as part of the National
Water-Quality Assessment (NAWQA) Program. Selected historical data and data
collected during the unusually wet summer of 1993 are summarized. The most
frequently detected pesticides in the Red River of the North Basin are
compared to pesticide usage. Since Lindane and DDT were banned in the United
States, available data indicate downward trends in environmental
concentrations of these compounds; low levels of these compounds continue to
be detected many years after they were banned. Triazine herbicides and 2,4-d
also were frequently detected. Nitrogen and phosphorus concentration in
streams generally were less than 2 mg/L and 0.5mg/L, respectively; this is
less than might be expected given the intense agricultural activity in the
region. Concentrations of these nutrients are generally higher downstream
from cities, indicating that the nutrients are more closely related to urban
sources than to agriculture.
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U.S. Department of the Interior |
U.S. Geological Survey