Title: Monitoring Groundwater for Pesticides at Selected Mixing/Loading Sites in Arkansas
Abstract: Groundwater monitoring studies have been conducted in recent years to survey contamination due to pesticides, yet few have addressed wells where pesticides are mixed, loaded, or rinsed. Beginning in 1990, a monitoring study conducted over a 2-year period included five collections at each of 16 mixer/loader locations to assess any pesticide and nitrate contamination. At sites in 11 counties, samples for pesticide analysis were extracted with solid-phase extraction (SPE) disks. Samples were screened using gas chromatography-electron capture detection (ECD) and high-performance liquid chromatography−UV detection (LCUV) for 17 pesticides commonly used in Arkansas. Detections were confirmed by gas chromatography−mass spectroscopy (MS) or co-chromatography. Fourteen samples revealed atrazine (1 detection), cyanazine (4), parathion-methyl (2), metolachlor (2), norflurazon (1), pendimethalin (1), propanil (2), or trifluralin (1) at eight locations during the 2-year study. Two detections of parathion-methyl and one detection of trifluralin were above the Lifetime Health Advisory Level (LHAL) of 2 μg L-1. Data suggested a high correlation between pesticide used and pesticide detected at sites sampled. Three wells contained NO3-N concentrations of 10 mg L-1 or higher, but these did not correlate with pesticide concentrations. The pesticide's proximity to the wells during mixing, rinsing, or loading was considered to be a greater influence on temporary contamination of groundwater than chemical or site-specific characteristics.
Publication Year: 1996
Publication Date: 1996-12-30
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 43
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