Nation's Ground-water Research Articles

Accurate Chemical Analysis of MTBE in Environmental MediaTechnical Note

The new millennium ushers in changes for refiners of automobile gasoline in the United States, as well as for the state and federal regulators who establish guidelines for gasoline formulation and environmental regulation governing the fate of gasoline-related chemicals in the nation's air, soil and groundwater. One current issue in the gasoline formulation debate centers on the comparison of the proven benefits of the addition of chemical oxygenates--especially methyl tert -butyl ether (MTBE)--to gasoline (to improve tailpipe emission quality) against the presumed environmental problems caused by the presence of oxygenates in ground- and surface waters due to fugitive releases of gasoline. Credible debate on this subject presumes that current and past environmental monitoring data for MTBE in environmental samples is accurate and precise. Experience suggests that this assumption is not correct, in part because certain analytical methodologies--particularly older methods supported by the U.S. Environmental Protection Agency--can fall short of reasonable data quality goals for measurement of MTBE. This Technical Note summarizes the standard EPA methods available to site investigators who need to measure MTBE in environmental media, the limitations and advantages of these measurement techniques, and recommendations for improving these standard EPA methods to yield the highest quality MTBE environmental residue data.

A Small‐Scale Ground Water Leaching Study for a Primisulfuron Herbicide

AbstractPrimisulfuron is a sulfonyl urea herbicide designed lo control broad‐leaf weeds in fields of small grain crops. The pesticide is potent, requiring only a low dosage. It is designed to replace many existing pesticides that are suspected to contaminate the nation's ground water resources. Under the auspices of the Federal Insecticide Fungicide and Rodenticide Act (FIFRA), the pesticides must be demonstrated to be environmentally safe in a field study for registration with the U.S. Environmental Protection Agency (EPA). This paper presents the design and results of a ground water leaching study for the successful registration of primisulfuron.A systematic approach was employed to identity a suitable site for the ground water study. Agricultural, ground water, and soil databases were carefully reviewed lo quickly determine, from a national level down to an individual farmer, a suitable candidate site. The site selected had a shallow ground water table and a highly permeable soil matrix. The site ground water was highly vulnerable to pesticide contamination exceeding EPA site requirements. A total of eight monitoring wells, 12 lysimeters, four tensiometers, and four rain gauges were installed in four sampling clusters to collect ground water and soil‐pore water samples. Bromide was used as a tracer to follow the movement of infiltrating water.The results showed that the downward migration of primisulfuron was retarded by the site soils. The average breakthrough lime for the pesticide at 3‐foot lysimeters was equal to 109±19 days, which was 36 days longer than that of bromide (73±12 days). The retardation was apparently caused by the adsorption of primisulfuron to the site soils, which could be attributed to the hydrophobicity of the compound and the organic matter of the site soils. The field half‐life for primisulfuron was determined to be 5.1 days, which was much shorter than the 14 days required by EPA. It was concluded that primisulfuron did not leach to the ground water table at the site under normal use conditions.

A Method for Installing Piezometers in Large Cobble Bed Rivers

An impact drive point method is described for emplacing piezometers in a cobble river bottom where this has previously been difficult without the use of drilling rigs. To force the drive point piezometers through coble, the vibrational impact of an air-powered hammer was carried directly to the drive point by the use of an internal drive rod. After insertion to depth, the drive rod was removed from the lower portion of the piezometer and a standpipe was added to extend the piezometer above the river level. Piezometers installed in this way have permitted water quality analysis and dynamic measurement of vertical potentials in cobble sediments ranging in size from 2.5 to >30 cm and the method has been successfully used in the Columbia River, USA, and Töss River, Switzerland. This innovative method provides information on the hydrodynamics of pore water in highly permeable, cobble deposits that are common in high-energy river and lake bottoms. Piezometers installed using the internal drive rod method facilitate the assessment of the temporal and spatial dynamics of recharge and discharge at the ground water/surface water interface and analyses of the ecological connectivity between the hyporheic zone and surface water of rivers and streams. This information will lead to improved management decisions related to our nation's ground water and surface water supplies.

Remedies proposed for China's groundwater problems

Groundwater experts and hydrologists from China and 10 other nations recently gathered in Beijing to exchange state‐of‐the‐art scientific and technological knowledge on groundwater hydrology, modeling, remediation, and management. The participants also reviewed groundwater environmental conditions in China, identified key problems, and made recommendations to help guide the nation's groundwater policy.The Regional Workshop on Ground Water Contamination, held from July 31 to August 4, 1995, was the fifth of a series of regional workshops sponsored by the Scientific Committee on Problems of the Environment of the United Nations Environmental Program. Earlier workshops were held in Thailand (1991), Costa Rica (1993), the Czech Republic (1994), and Australia (1994).

IS GROUND WATER PROTECTED AGAINST RELEASES FROM ABOVEGROUND STORAGE FACILITIES?

ABSTRACT Growing concern about the threat to our nation's ground water from leaking above-ground oil storage facilities has prompted a reevaluation of regulatory and nonregulatory programs to prevent such contamination. Government and industry have begun efforts to address this concern.

Risk‐Based Evaluation of Ground‐Water Contamination by Agricultural Pesticides

AbstractThe recently completed National Pesticide Survey conducted by the United States Environmental Protection Agency (EPA) has identified the presence of various pesticides in ground water. The detection of pesticides in the nation's ground water has raised concerns for public health which has led resource managers in federal and state agencies to recognize that risk assessment is vital for water quality protection. This paper presents a methodology for risk‐based evaluation of ground‐water contamination by agricultural pesticides. The methodology utilizes the Risk of Unsaturated/Saturated Transport and Transformation of Chemical Concentrations (RUSTIC) model to provide simulations that yield the probable risks associated with a given pesticide. Risk is expressed in terms of the probability of predicted pesticide mass exceeding its recommended health standards. Three widely used agricultural herbicides, simazine, atrazine, and alachlor, were evaluated using long‐term (1960–1986) meteorological data for Ames, Iowa. Results indicate that for a well 8 m deep located 200 m horizontally from a pesticide application area in an alluvial sand and gravel setting, the probability of exceeding the maximum contaminant level (MCL) for simazine is about 35%, whereas it is nearly zero for both atrazine and alachlor. Prudent use of simazine in very susceptible areas is recommended.

Record budgets for groundwater

A record $225 million is expected to be allocated for management of the nation's groundwater resources for the 1990 budget year by federal funds. The recent report by the White House Office of Science and Technology, Federal Ground‐Water Science and Technology Programs: The Role of Science and Technology in the Management of the Nation's Ground‐Water Resources, noted, “As the demands on the water resources of the nation increase, there will be an increasing need to apply the science of groundwater hydrology to find ways to provide reliable water supplies.”The report identifies emerging scientific issues and needs and the major challenges faced in providing science and technology to support informed management of the nation's groundwater resources. In particular, the report notes that the most viable approach to groundwater quality management is prevention rather than restoration and that that scientific uncertainties, lack of adequate technologies, lack of basic data, and shortage of skilled scientific personnel are hindrances to federal, state, and local governments and the private sector developing and implementing groundwater management, protection, and remediation policies and programs.

USGS Groundwater Report

The quality of the nation's groundwater is good, overall, according to Assistant Secretary of the Interior for Water and Science, James W. Ziglar. But “its management and protection present a major challenge.” Ziglar was speaking at a press conference October 7 in Washington, D.C. The U.S. Geological Survey recently released its fourth National Water Summary 1986—Hydrologic Events and Ground‐Water Quality.The summary says that most fresh groundwater meets federal and state drinking water standards and is suitable for most uses. Groundwater is the source of more than half the nation's drinking water, including almost all of its rural population. The 560‐page report covers hydrologie conditions and waterrelated events for water year 1986 (Oct. 1, 1985 to Sept. 30, 1986), hydrologie perspectives on water issues, and a state‐by‐state summary of groundwater quality.

Environmental semivolatiles and nonvolatiles analysis by hyphenated spectral techniques.

Environmental sample extracts contain a variety of volatile and nonvolatile organic compounds exhibiting a range of polarities and concentrations. Although gas chromatography/mass spectrometry (GC/MS) is the method of choice thus far for such analyses, this technique used alone cannot adequately characterize the volatiles in such samples and is not amenable to environmental nonvolatiles. A more complete characterization of environmental and hazardous waste samples is required to assess the dangers posed to the nation's groundwater by hazardous waste dumps. Online spectral confirmation by directly linked GC/Fourier transform infrared (FTIR)/MS is shown to provide useful structural information on environmental volatiles in hazardous wastes, even when the analyte's spectrum is not in either spectral database. This information can lead to biological-hazard estimation. The diffuse reflectance Fourier transform infrared (DRIFT) technique, used in conjunction with thermospray MS or fast atom bombardment (FAB) MS, provides confirmed identifications or confirmed compound class assignments of organic nonvolatiles in solid wastes. This is believed to be the first report of spectral confirmation (identification or functionality) of organic volatiles and nonvolatiles in environmental samples.

USGS sets goals for U.S. Earth science needs

Citing the importance of the earth sciences in meeting the resource needs of the nation, the U.S. Geological Survey (USGS) has outlined its current goals in meeting its mission to provide essential geologic, topographic, and hydrologic information in service to the public. Some highlights of selected USGS goals that are designed to meet national needs related to the hydrologic sciences include Timely Reporting of Events and Conditions: Provide timely reporting, and forecasts when possible, of important hydrologic and geologic events and conditions of immediate concern to the public and to government bodies. Water Resources Assessment: Increase knowledge of the distribution and quality of the nation's groundwater and surface water resources for use in the formulation and evaluation of policies and programs that assure the most efficient use of the nation's water resources. Hydrologic Processes: Increase understanding of the processes that affect the properties and movement of water and its dissolved and suspended constituents through hydrologic systems.

In situ restoration techniques for aquifers contaminated with hazardous wastes

Improper disposal of hazardous wastes is a threat to the nation's ground water supply. Methods which prevent contamination are probably the most effective techniques to protect ground water. Once contamination problems occur, there are a number of in situ techniques that can be used to cleanse the ground water and at least partially restore the aquifer. Before any treatment program can be implemented, a thorough investigation of the hydrogeology and contamination problems of the site must be made. Plume management techniques such as barriers to ground water flow or hydrodynamic control can be effective when properly installed. One of the options used frequently is to remove the contaminated material to a secure site; while this cleans up the contaminated site, the material is not treated and the potential for contamination of the second site exists. Chemical and physical treatment techniques include processes such as neutralization, chemical reaction, extraction and immobilization. Biological techniques for in situ treatment generally involve enhancing the degradative capacity of the indigenous microflora or the addition of organisms acclimated to degrade the contaminants. Combinations of chemical and biological processes are often effective. Aquifer restoration is likely to be costly, time-consuming, and often only partially effective.

Regulating Pollution Sources under a Differential Groundwater Protection Strategy

For many years economists have lobbied long and hard for site-specific environmental controls, arguing that national uniform standards create significant inefficiencies. Even when uniform standards are successful at maximizing net social benefits for average national conditions, they are overly stringent at some sites and inadequately protective at others. The fact that most environmental protection regulations are of the national uniform variety indicates the weight of the arguments used against tailored regulatory schemes. Tailored standards are considered difficult and costly to administer, politically unpalatable to the extent that they appear to offer more protection to some constituencies than to others, and inequitable in that they impose different regulatory burdens on similar polluters. Despite these drawbacks, the Environmental Protection Agency (EPA) and the U.S. Congress have tried, in separate actions, to institute mechanisms for differential protection for the nation's groundwater resources. In this paper I describe and compare EPA's Ground-Water Protection Strategy and the groundwater provisions contained in the Safe Drinking Water Act Amendments of 1986 in terms of their ability to target environmental pollution controls according to resource value.

Irrigated Agriculture and Groundwater Quality—A Framework for Policy Development

paper argues that irrigated agriculture's impact on goundwater is another water quality concern that is rapidly growing in importance and well deserves our profession's attention and research efforts. Groundwater is now the source of 50% of U.S. drinking water supplies and 40% of irrigation withdrawals, with reliance on groundwater varying tremendously across regions. Irrigated agriculture is the largest single user of the nation's groundwater resources, accounting for 70% of annual groundwater use. Groundwater withdrawals are increasing at double the rate of increase for surface water use, with half a million new wells drilled each year (Henderson et al., p. 9). As a part of a broader research effort examining water markets, values, and quality in the western United States (Saliba, Bush, and Martin), this paper explores the potential roles of public regulations and private markets in water quality management. The discussion focuses on nitrates, pesticides, and dissolved solids, the three principal groundwater contaminants associated with irrigated agriculture.

Groundwater Pollution: Environmental and Legal Problems

Groundwater contamination is now receiving long‐overdue attention from scientists, engineers, water managers, politicians, environmental groups, and the general public. As these diverse groups begin to grapple with the causes and effects of and remedies for groundwater contamination, each must acquire at least a basic understanding of the physical, biomedical, and legal problems and processes that influence groundwater management decisions. Groundwater Pollution: Environmental and Legal Problems is a short, useful book that (from the preface) …highlights the methodological and conceptual difficulties inherent in protecting the nation's groundwater supplies and provides up‐to‐date information on groundwater hydrology, the nature and extent of the groundwater pollution problem, and the possible effects of exposure to contaminated drinking water.

Protecting the Nation's Groundwater from Contamination Office of Technology Assessment

Protecting the Nation's Groundwater from Contamination Office of Technology Assessment

Groundwater Contamination in the United States

Seldom has the sociotechnical community been more ready for a broad overview on an environmental issue than it is currently for a book on the subject of groundwater contamination in the United States. Many individuals, organizations, and institutions are asking: How much of our nation's groundwater resources are contaminated? Is our groundwater contamination problem getting worse and what is the longterm prognosis? What are the most significant causes of groundwater contamination and what are the most promising cures?

Second National Symposium on Groundwater Quality Set

The U.S. Environmental Protection Agency and the National Water Well Association are sponsoring a Second National Conference on Groundwater Quality to be held September 25–27, 1974, at the Holiday Inn in downtown Denver, Colorado.The purpose of the meeting is to bring together a nucleus of men, methods, and ideas capable of yielding solutions to problems that must be solved to ensure the protection and restoration of the quality of the nation's groundwater resources. Development of these resources is expected to double and perhaps triple in the coming decade.

U.S. Environmental Protection Agency Policy on Subsurface Emplacement of Fluids by Well Injection: ABSTRACT

The Federal Water Pollution Control Act Amendments of 1972 (public law 92-500) provide for comprehensive controls on surface water, but do not provide for specific regulatory control over subsurface water at the federal level. The only applicable regulatory provision of the act is for a federally approved state permit program which, among other things, requires a qualifying state authority to issue permits to control the disposal of pollutants into wells. Because of provisions in the new legislation requiring upgrading of the quality of discharges to both air and surface water, an increased assault on the quality of the nation's groundwater resources is anticipated. The EPA policy statement does not purport to have legal sanction, but rather puts the Agency on record as b ing opposed to the emplacement of materials by subsurface injection without strict controls and a clear demonstration that such emplacement will not interfere with present or potential use of the subsurface environment, contaminate groundwater resources, or otherwise damage the environment. The EPA policy does have some clout, however, in that it is designed to discourage the diversion of wastes treatable on the surface to the subsurface for the purpose of avoiding discharge permits or other provisions of P.L. 92-500, and most certainly will be used by the states in designing permit programs that will meet federal approval for the disposal of pollutants in wells. End_of_Article - Last_Page 1596------------