Pesticides in Surface Drinking-Water Supplies of the Northern Great Plains

Abstract

BackgroundHuman health anomalies have been associated with pesticide exposure for people living in rural landscapes in the northern Great Plains of North America.ObjectiveThe objective of this study was to investigate the occurrence of 45 pesticides in drinking water from reservoirs in this area that received water primarily from snowmelt and rainfall runoff from agricultural crop lands.MethodsWater from 15 reservoirs was sampled frequently during the spring pesticide application period (early May to mid-August) and less frequently for the remainder of the year. Drinking water was sampled in early July. Sample extracts were analyzed for pesticide content using mass spectrometric detection.ResultsWe detected two insecticides and 27 herbicides in reservoir water. Consistent detection of a subset of 7 herbicides suggested that atmospheric deposition, either directly or in rain, was the principal pathway from fields to the reservoirs. However, the highest concentrations and number of herbicides in drinking water were associated with runoff from a localized 133-mm rainfall over 15 days toward the end of spring herbicide application. Water treatment removed from 14 to 86% of individual herbicides. Drinking water contained 3–15 herbicides (average, 6.4).ConclusionsWe estimated the mean annual calculated concentration of herbicides in drinking water to be 75 ng/L (2,4-dichlorophenoxy)acetic acid, 31 ng/L (2-chloro-4-methylphenoxy)acetic acid, 24 ng/L clopyralid, 11 ng/L dichlorprop, 4 ng/L dicamba, 3 ng/L mecoprop, and 1 ng/L bro-moxynil. The maximum total concentration of herbicides in drinking water was 2,423 ng/L. For the seven herbicides with established drinking water guidelines, all concentrations of the individual chemicals were well below their respective guideline. However, guidelines have not been established for the majority of the herbicides found in drinking water or for mixtures of pesticides.

Occurrence and distribution of organic trace substances in waters from the Three Gorges Reservoir, China

“…This might indicate that the surface water used for drinking water supply for at least some parts of the city is taken from Jialing River, and treatment technologies are insufficient to remove these pesticides having high water solubilities (7,850 and 430 mg/L for clopyralid and picloram, respectively). Donald et al (2007) detected maximum concentrations of 0.39 and 0.17 μg/L for clopyralid and picloram, respectively, in Canadian drinking water, being one order of magnitude lower compared to this study (Table 3). Some pesticides (clopyralid, picloram, atrazine, beta-HCH, and pentachlorophenol) were detected also in effluents of WWTPs in significant concentrations with a range of 0.020-0.38 μg/L (Table 2).…”

“…The pesticide concentrations in TGR surface water are comparable to those found in Canadian reservoirs (Table 3). Donald et al (2007) detected mean surface water concentrations for clopyralid, picloram, and atrazine of 0.002-0.91, 0.17-0.22, and 0.005-0.034 μg/L, respectively (Table 2). Müller et al (2008) analyzed pesticides in Yangtze surface water downstream of the TGD, but concentrations for picloram, triclopyr, and atrazine in their samples were below LOD, i.e., 1.0, 0.50, and 0.50 μg/L, respectively (Table 3).…”

A comparative study of the activity of TiO2 Wackherr and Degussa P25 in the photocatalytic degradation of picloram

“…These properties, combined with persistence, mean that the use of picloram can cause groundwater contamination. As reported in the literature, it is one of the pesticides that is most often found in drinking water [9]. The degradation and removal of picloram was investigated by several authors.…”

Comparative Assessment of the Photocatalytic Efficiency of TiO2 Wackherr in the Removal of Clopyralid from Various Types of Water

“…The acidic form of CLP and three CLP salts (triethylamine, triisopropylamine, and monoethanolamine), which are very soluble in water, are commonly used in commercial herbicide products. Its chemical stability along with its mobility allows this herbicide to penetrate through the soil, causing long-term contamination of the ground water, as well as surface water supplies (Cox, 1998;Huang et al, 2004;Donald et al, 2007;Sakaliene et al, 2009). Due to these properties, CLP has recently been reported to occur in drinking water at concentrations above the Permitted Concentration Value of 0.1 μg L -1 for an individual pesticide (EU directive 98/83/EC).…”