FEW PESTICIDES FOUND IN GROUND WATER IN THE UPPER RIO GRANDE VALLEY
(Map Area 46)
In an area of intense agriculture in the San Louis Valley,
Colorado, the northern part of the Rio Grande Valley Study Unit,
pesticides were detected in only 5 of the 35 wells installed in the
shallow aquifer . The monitor wells are dispersed among 2000
center-pivot irrigation systems covering about 270,000 acres. Major crops
include alfalfa, potatoes, small grains, and vegetables. Samples from the
wells were analyzed for 90 pesticides and their degradation products. A
total of four pesticides (metolachlor, p,p'DDE, metribuzin, and prometon)
were detected in the upper 10 feet of the saturated zone, with a maximum
concentration of .07 micrograms per liter.
Return to main document about
USGS National Water-Quality Assessment (NAWQA) Program
||
USGS National Water-Quality Assessment (NAWQA) Program home page
The URL for this page is
<http://water.usgs.gov/nawqa/overview.docs/riogrande.html>.
Last modified: Tue Oct 31 15:35:36 1995