Occurrence of selected pesticides, nutrients, selected trace elements, and radionuclides in ground and surface water from west-central Missouri; July 1990-March 1991

Abstract

During 1990, pesticides were detected in water from 29 of 92 wells and the 5 surface-water sites sampled in Bates, Cass, St. Clair, and Vernon Counties in west-central Missouri. Atrazine concentrations exceeded 3 micrograms per liter in samples from 5 wells and 2 surface-water sites. During 1991, pesticides were detected in water from 27 of 100 wells sampled in Bates, Cass, and Vernon Counties. During 1991, the mean tritium concentration was 28.3 picocuries per liter in water samples from 20 wells. Water samples from three wells had tritium concentrations less than 9.0 picocuries per liter. During 1990, nitrate, as nitrogen, concentrations exceeded 10 milligrams per liter in water samples from 21 of 89 wells. During 1991, nitrate concentrations exceeded 10 milligrams per liter in water samples from 23 of 99 wells and 1 of 3 springs. During 1991, the 815N (ratio of 15nitrogen to 14nitrogen in nitrate, relative to atmospheric nitrogen, expressed in per mil) in water samples from 22 wells ranged from +4.2 to +29.2 per mil. All but two of the samples had 815N of nitrate values equal to or greater than +10 per mil. During 1990, alpha radiation concentrations ranged from less than 1 to 33 picocuries per liter. Beta radiation concentrations ranged from less than 1 to 110 picocuries per liter. During 1991, arsenic concentrations ranged from less than 5 to 10 micrograms per liter. Iron concentrations ranged from less than 50 to 8,600 micrograms per liter. Manganese concentrations ranged from less than 20 to 7,800 micrograms per liter.

OCCURRENCE OF PESTICIDES IN GROUND WATER OF THE OZARK PLATEAUS PROVINCE1

“…The presence of pesticides in ground-water samples of the Ozark Plateaus is somewhat surprising because, unlike the study areas of Kolpin et at. (1994) and Ziegler et at. (1994), row-crop agriculture constitutes a small percentage of land use in this study area.…”

“…Concentrations of pesticides in ground-water samples generally were low compared to concentrations in ground-water samples collected in adjacent study areas (Kolpin et al, 1994;Ziegler et al, 1994). Low pesticide concentrations probably result from the generally low pesticide usage throughout most of the study area and the types of sites from which samples were collected.…”

“…Ground-water samples were collected in four counties in west-central Missouri and analyzed for selected herbicides (Ziegler et al, 1994). Row-crop agriculture accounted for 25 to 38 percent of the land use in the four counties.…”

Controls on nitrate‐N concentrations in groundwater in a Missourian claypan watershed

“…The fate and transport of NO 3 ‐N in groundwater have been very well studied over the world [e.g., Burow et al , ; DeSimone , ; Lin et al , ; Noland and Stoner , ; Adamski and Pugh , ; Wilkinson and Maley , ; Mueller et al , ; Kolpin et al , ; Wilkinson and Maley , ; Ziegler et al , ; Sievers and Fulhage , ; Mesko and Carlson , ; Madison and Burnett , ]. However, our understanding of the processes or factors controlling NO 3 ‐N concentrations in groundwater of claypan soil areas is lacking.…”