Groundwater contamination by pesticides

The risk of groundwater contamination by pesticides stems mainly from the use made of aquifers for irrigation purposes, way by which pesticides can enter the food chain, and from its use also as resource for the production of drinking water. 

Litwin, Y. "Groundwater Contamination by Pesticides A California Assessment , Ramlit Assoc., Berkeley, CA, 1983. 

Groundwater Contamination by Pesticides. California State Water Resources Control Board, Publication No. 83-45 sp, 1983. 

Burnam, William L. Burin, Gary J. "Assessment of Groundwater Contamination by Pesticides," prepared for FIFRA Scientific Advisory Panel Meeting, June 21-23, 1983. 

An interesting example on the question of by-products is provided by the surface and groundwater contamination by pesticides. Triazines are among the most abvmdant pesticides and since 1997, atrazine has been found in more than 50% of samples of both surface water and groundwater, while its degradation product, desethylatrazine, is the most frequently found (about half of all analyses). Other frequently found herbicides include diuron and isoproturon (urea substitute... 

Groundwater contamination by agrochemicals from non-point sources has been well documented in a number of countries [26-28, 30-32], The pesticides that have been detected in regional council groundwater surveys include 2,4-D, Amitrole, Picloram, Simazine and Atrazine [20]. 

Despite the strengthening of environmental policies, problems in relation to cadmium and cyanide, dioxin, organic pollution, lake eutrophication, residential sewage, pesticide runoff, industrial discharges, and groundwater contamination by toxics and nitrates also need to be tackled. 

As already mentioned, three soil fumigants, shown below, along with their chemical structures, are presenting probably the greatest problem of groundwater chemical contamination by pesticides in California. 

An extensive pesticide properties database was compiled, which includes six physical properties, ie, solubiUty, half-life, soil sorption, vapor pressure, acid pR and base pR for about 240 compounds (4). Because not all of the properties have been measured for all pesticides, some values had to be estimated. By early 1995, the Agricultural Research Service (ARS) had developed a computerized pesticide property database containing 17 physical properties for 330 pesticide compounds. The primary user of these data has been the USDA s Natural Resources Conservation Service (formerly the Soil Conservation Service) for leaching models to advise farmers on any combination of soil and pesticide properties that could potentially lead to substantial groundwater contamination. 

In order to ascertain the degree of accomplishment of the aforementioned Directive 2006/118/EC in Catalonia (NE, Spain) and better characterise the nature of the contamination of these aquifers by pesticides, a monitoring programme was carried out on various selected hydrological units intended to be among the most vulnerable and relevant ones because of intensive agricultural activity and use for human consumption. The number of aquifers analysed depends more or less on the extension of the groundwater body. Eor example, bodies M46 and M21 present extensions of 18 and 72 km, respectively, and just one and two aquifers of each body were analysed, respectively. In contrast, body Ml8 (Maresme) presents an extension of more than 400 km, and nine different aquifers were analysed. 

Milhome MAE, de Sousa DDB, Lima PDF et al (2009) Assessment of surface and groundwater potential contamination by agricultural pesticides applied in the region of Baixo Jaguaribe, CE, Brazil. Engenharia Sanitaria E Ambiental 14 363-372... 

Abiotic hydrolysis, sorbed pesticides, 221-43 Acetanilide herbicide, groundwater contamination, 299 Acid-catalyzed hydrolysis aldlcarb by RIEX, 257f kinetics, disappearance rate, 223 Acid hydrolysis, sorbed pesticides, 242... 

The tables and maps in this appendix list the locations of prominent areas with arsenic-contaminated groundwater, geothermal waters, and/or substantial arsenic-bearing rocks and mining wastes. Additionally, there are countless sites that have local waters, sediments, and soils that have been contaminated by arsenic from chemical manufacturing facilities, pesticide applications, and individual mines. These small-scale areas, which include hundreds of Superfund sites in the United States, are too numerous and poorly documented to list in this appendix. Appendix B in US Environmental Protection Agency (US EPA) (2002) lists the locations of Superfund sites where arsenic is a contaminant of concern. 

The response actions would be coordinated jointly by the federal and state governments. Under the specific state management plans, the state would take the necessary action to prevent further contamination when unacceptable levels of contamination in groundwater are reported. Under this strategy the states and the EPA would coordinate closely on the enforcement of FIFRA, SDWA, and CERCLA to identify parties responsible for groundwater contamination as a result of the misuse, spills, leaks, and/or illegal disposal of pesticides. 

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