Areal, Vertical, and Temporal Differences in Ground Water Chemistry: II. Organic Constituents

Abstract

Selected organic components in samples collected from monitoring wells and from surface water are shown to follow definite areal, vertical, and temporal trends in concentration. Atrazine (2‐chloro‐4‐[ethylamino]‐6‐[isopropylamino]‐s‐triazine), alachlor (2‐chloro‐2′ ,6′ ‐ diethyl‐N‐[methoxymethyl]acetanilide) and dieldrin (1,2,3,4,10,10‐hexachloro‐exo‐6,7‐epoxy‐1,4,4a,5,6,7,8,8a‐octahydro‐1,4‐endo, exo‐5,8‐dimethanonaphthalene) were measured in 64, 35, and 35 water samples, respectively. The atrazine amounts ranged from < 0.01 to 88 µg/liter. Peak concentrations were observed in shallow well water downgradient from irrigated fields at the end of the irrigation season. The areal and vertical distributions of atrazine are closely associated with those of nitrate‐nitrogen (NO3‐N), which was measured as an indicator of deep percolation from irrigated croplands. However, temporal variations in atrazine concentrations suggest that it is a nonconservative constituent of ground water. Alachlor and dieldrin amounts were extremely low, being less than 0.1 µg/liter in all but one water sample which was taken from a well located in an excessively well‐drained area. Dissolved organic carbon (DOC) was measured in 95 water samples and the amounts ranged from 0.2 to 4.8 mg/liter. Maximums occurred in shallow wells and there were no seasonal associations with either atrazine or NO3‐N. The DOC data suggest percolation from the unsaturated zone and partial removal from solution during vertical transport within the saturated zone.

Characterization of agricultural nonpoint pollution: Pesticide migration in a West Tennessee watershed

“…There was a strong correlation between nitrate and atrazine concentrations in the runoff from the first storm (Table 3). Vertical distributions of atrazine in the subsurface were previously reported to be correlated with those of nitrate [9]. These data indicate that the migration of these two pollutants is also similar in surface runoff.…”

“…Atrazine contamination of ground water in the corn belt has been reported by several investigators, with concentrations as high as 88 pg/L i n ground water beneath irrigated fields in Nebraska [9,10]. Atrazine concentrations in Iowa ground water increased from a maximum of 2.5 pg/L in 1982 to a maximum of 10 pg/L in 1984 [11,12].…”

Atrazine and Alachlor Inputs to Surface and Ground Waters in Irrigated Corn Cultivation Areas of Castilla-Leon Region, Spain

“…As a result, the presence of specific pesticides in surface and ground waters is well documented for different agricultural regions of the world (Junk et al, 1980;Hallberg, 1989;Leistra and Boesten, 1989;Frank et al, 1990;Bushway et al, 1991;Gomez de Barreda and Lorenzo, 1991;Legrand et al, 1991;Wade et al, 1998;Garrido et al, 2000;Barbash et al, 2001;Spalding et al, 2003). Among the pesticides detected with certain frequency are atrazine and alachlor (especially the former); this has generally been associated with their widespread use in corn cultivation in all countries.…”

Removal of Atrazine Contamination in Soil and Liquid Systems Using Bioaugmentation

“…7 Bioremediation is an established approach for cleaning up contaminated soils and waters. Forsyth et al8 suggest three types of bioremediation systems : (1) solidphase, (2) slurry-phase, (3) in-situ /ex-situ systems for cleanup of contaminated soil and ground water. In-situ and slurry-phase (ex-situ) bioremediation have been suggested for soils and ground water contaminated with atrazine.9 Ex-situ remediation, such as solid-phase bioremediation, coupled with in-situ bioremediation has also been suggested for atrazine-contaminated soils.…”