Groundwater resources

About 1.3 billion is projected to be spent monitoring pesticides in wells and groundwater resources if an effective program were initiated (Pimentel, D., in manuscript). 

Barbash J, Roberts PV. 1986. Volatile organic chemical contamination of groundwater resources in the U.S. J Water Pollut Control Fed 58 343-348. 

Lawrence Livermore National Laboratory, An Evaluation of MTBE Impacts to California Groundwater Resources, UCRL-AR-130897, July 11, 1998. Available at http //www-erd.llnl.gov/MTBE/pdf/MTBE. pdf, 2009. 

Arid areas (0.05 < P/PET < 0.20) mean annual precipitation values up to about 200 mm in winter rainfall areas and 300 mm in summer rainfall areas but more importantly inter-annual variability in the 50-100% range. Pastoralism is possible but without mobility or the use of groundwater resources is highly susceptible to climatic variability. 

Welch A.H., Watkins S.A., Helsel D.R., Focazio M.F. Arsenic in groundwater resources of the United States U.S. Geological Survey Fact Sheet 063-00, On line at http //co.water.usgs.gov/trace/pubs/fs-063-00/. US Geological Survey, 2000. 

Application of integrated stable hydrogen isotope and hydrogeochemical models to the present free waters systems provides important information on their sources, mixing phenomena and underground dynamics that can be profitably used in problems of groundwater resources management, as well as in environmental protection. 

Ford, D. L., 1980, Technology for Removal of Plydrocarbon from Surface and Groundwater Resources. Engineering Science, Inc. and the University of Texas, Austin, Texas. 

Without appropriate cleanup measures, BTEX often persist in subsurface environments, endangering groundwater resources and public health. Bioremediation, in conjunction with free product recovery, is one of the most cost-effective approaches to clean up BTEX-contaminated sites [326]. However, while all BTEX compounds are biodegradable, there are several factors that can limit the success of BTEX bioremediation, such as pollutant concentration, active biomass concentration, temperature, pH, presence of other substrates or toxicants, availability of nutrients and electron acceptors, mass transfer limitations, and microbial adaptation. These factors have been recognized in various attempts to optimize clean-up operations. Yet, limited attention has been given to the exploitation of favorable substrate interactions to enhance in situ BTEX biodegradation. 

Previous exposure to benzoate, but not to acetate, shortened the acclimation period to BTX degradation and enhanced the short-term bio-attenuation potential of the indigenous consortium, suggesting that benzoate could potentially be used to establish and sustain in situ reactive zones to attenuate BTX migration and protect downgradient groundwater resources. 

Surface waters as well as groundwater resources are of paramount importance for the various purposes for which water is consumed. Using the example of Switzerland, Fig. 1 shows the significance of various forms of intervention in the natural water... 

Albu, M., Banks, D. Nash, H. 1997. Mineral and Thermal Groundwater Resources. Chapman and Hall, London. 

Point sources are mainly responsible for the pollution of surface waters (rivers, lakes, seas), whereas nonpoint sources mainly contribute to the pollution of groundwater resources. Moreover, releases from point sources can be treated by wastewater treatment plants, whereas nonpoint source releases can only be minimized. 

A re-evulualinn of the water quality problem has revealed that surface water resources, rather than groundwater resources, are at higher risk of contamination from agricultural chemicals. 

Action levels for decisions related to drinking water quality are the Maximum Contaminants Levels of the Safe Drinking Water Act (SDWA). The MCLs are the maximum permissible contaminant concentrations in the drinking water that is delivered to the user through a public water system. First enacted in the USA in 1974 and reauthorized in 1996, the SDWA protects drinking water and groundwater resources. This law establishes two kinds of standards for drinking water quality primary standards for the contaminants that pose a risk to human health (EPA, 1985), and secondary standards for the contaminants that affect the physical characteristics of water (odor, taste, and appearance). 

Meade, R.H., and Parker, R.S. (1985) Sediment in rivers of the United States. In National Water Summary 1984—Hydrologic Events, Selected Water Quality Trends, and Groundwater Resources. U.S. Geol. Survey Water Supply Paper no. 2275, 1—467. 

In Europe, America, and other areas cities grew most commonly on the banks of large rivers, and until recently most urban water supplies came from dammed surface reservoirs. To overcome years of drought and cope with pollution of the surface waters, these cities incorporate in their supply systems an ever-growing number of wells, and their dependence on the groundwater resource is constantly growing. 

Winslow, J.D., Stewart, Jr., H.G., Johnston, R.H., and Crain, L.J. (1965) Groundwater resources of eastern Schenectudy County, New York, with emphasis on infiltration from the Mohawk River. State of New York Conservation Department Water Resources Commission Bull. 57, 148. 

It is known that only a small amount of the extracted groundwater originates from recent groundwater resources (Table 36). The rest is extracted from a reservoir of fossil water that has been formed 20.000 years ago when temperatures were considerably lower in that area than they are today. 

The EPA goal is to manage pesticides to protect the groundwater resource. This would include the use of maximum contamination levels (MCLs), the enforceable drinking water standards, established under the Safe Drinking Water Act (SDWA), as reference points to determine the unacceptable levels of pesticides in groundwater sources. 

Bradley E. and Rainwater F. H. (1956) Geology and groundwater resources of the Upper Niobrara River basin, Nebraska and Wyoming. US Geol. Surv. Water-Supply Pap. 1368, USGS, Washington, DC. 

Focazio M. J., Welch A. H., Watkins S. A., Helsel D. R., and Horng M. A. (1999) A Retrospective Analysis of the Occurrence of Arsenic in Groundwater Resources of the United States and Limitations in Drinking Water Supply Characterizations. US Geological Survey, Water Resources Investigation Report 99—4279, 11pp. 

Leaney F. W., Herczeg A. L., and Walker G. R. (2(X)3) Salinization of a fresh paaeo-groundwater resources by enhanced recharge. Ground Water 41, 84-92. 

Clark, I.D., 1987. Groundwater resources in the Sultanate of Oman origin, circulation times, recharge processes and palaeoclimatology. Doctoral thesis, Universite de Paris Sud, France, 264 pp. 

Upadhyay, S. K., 1993, Use of groundwater resources to alleviate poverty in Nepal policy issues. in Kahnert, F., and Levine, G., eds., Groundwater irrigation and the rural poor options for development in the Gangetic Basin Washington D.C., World Bank. 

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