ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03644.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTA common problem with a downhole water sampler consisting of a reservoir for fluids and a remote controlled motor‐operated piston valve assembly has been sample contamination due to damage or destruction of the O‐ring seal on the piston of the sampler. O‐ring damage results from shaving by sharp edges in the entry‐ports area or from erosion by high fluid velocities through the entry ports when sampling at depths below water level greater than 2,500 feet (762 meters). Beveling of sharp edges in the entry ports and modification of the piston by installation of a needle valve and seat solved the problem of O‐ring damage and resultant loss of sample integrity. Other modifications include a high pressure needle valve in the removable reservoir chamber bottom that allows the reservoir to be drained while pressurized, and an O‐ring piston in the reservoir chamber that permits collection of water samples that are essentially free from contamination by surface air. With the latter modifications, the sampler can also be used for injecting brine or other tracers in quantities as large as 34 fluid ounce

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03645.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTThe Orange County Water District in Southern California imports approximately 75 percent of its supply from aqueducts drawing waters from the Colorado River and Northern California. Twenty‐five percent comes from natural flow in the Santa Ana River and local precipitation. Only about one‐half of the aqueduct water is treated and distributed in pipelines. The other one‐half is applied to infiltration basins and ponds for ground‐water recharge. This allows communities within the District to draw ground water as their major supply, which is supplemented by aqueduct water purchased after treatment by the Metropolitan Water District of Southern California. The economic advantages of ground‐water recharge, as opposed to direct use of surface supplies, include eliminating water treatment, minimizing the size of pipe networks to distribute potable supplies, and reducing the requirement for storage reservoirs. However, using the basin aquifers as a reservoir to balance cyclic supply and demand creates two possible problems: excessive pumping lowers the fresh‐water table below sea level, and infiltration can result in a gradual increase in the level of dissolved salts in the ground water. Sea‐water intrusion has been greatly reduced by injection wells that provide a hydraulic barrier between the salt water and fresh inland water. Salt accumulation in the basin is a more serious long‐term problem since the salinity in the Colorado River water is increasing. Greater use of less salty Northern California water and reducing unwanted seepage of waste waters containing high dissolved solids are two of the remedial measures being impleme

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03646.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTAs the volume of hydrogeologic literature increases, researchers are finding it more difficult to identify and locate information. The National Water Well Association's Library/Information Center is a central source of ground‐water information. In addition to collecting books, journals, and reports relevant to ground‐water research, the Library/ Information Center conducts both manual and computer literature searches. A bibliographic data base of hydro‐geologic references is in develo

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03647.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTAt a flyash landfill in southeastern Wisconsin, dry ash has been placed directly in contact with a shallow sand and gravel aquifer. Substantial modification of ground‐water quality has occurred primarily by sulfates, calcium and magnesium. However, after eight years, the contamination has spread less than 200 meters from the site in a permeable aquifer. In addition, toxic metals contained in the ash have proven quite immobile in the ground water. Fortuitous location of the disposal site in alkaline sediment upflow from ground‐water discharge in a marsh appears to have limited the extent of contaminat

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03648.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTThe hydraulic properties (hydraulic conductivity, specific storage and porosity) of coal and the sediments that surround the coal must be known or estimated to properly evaluate the environmental impact of coal strip mining on ground‐water flow systems. Published and unpublished data have been summarized from five study areas in North Dakota, three areas in Wyoming, two areas in Montana and two study sites in Alberta. Coal and sand beds form important aquifers in the region. Both materials have hydraulic conductivities of about 2 × 10−6m.s−1and specific storage values on the order of 5 × 10−6m−1. Aquitards in the region consist of clayey silt to clay bedrock and pebble−loam (in parts of the region). The aquitards are fractured to varying degrees resulting in a wide range of measured hydraulic conductivity values. The aquitards are, in general, 100 to 1,000 times less permeable than the aquifers. Specific storage values of the aquitard material is on the order of 3 × 10−4m−1. The hydraulic conductivity of strip mine spoils has a six order of magnitude range with a mean of 8 × 10−7m.s−1. Variability is due to a number of factors including spatial variation of overburden lithology, method of spoil handling and contouring and time of year during which the spoil is handled. The hydraulic conductivity of the coal shows wide spatial variability within a given mine site. Variability of coal hydraulic conductivity between mines within North Dakota is less than within a given mine. Within the Northern Great Plains the permeability of coal may increase sli

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03649.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTThe time‐consuming curve construction and, in some cases, curve matching, and the gross approximations of aquifer geohydrologic properties, can be supplanted by a simple, speedy, accurate, and inexpensive analysis of pumping test data by a handheld programmable calculator.With such calculators—in actuality, minicomputers‐pumping test data can be analyzed within seconds, while the test is ongoing, and pumping test time and expense can be reduced, while still securing representative values for transmissivity and storage coeffic

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03650.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTGround‐water modeling is an area of current research. As such, new techniques and applications continually evolve. In addition to being influenced by the necessity to solve certain problems, recent developments in modeling are influenced by the state of model evolution and computer capabilitie

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03651.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTA serious type of clogging occurs in wells which abstract anaerobic water from the shallow aquifer in the river region in The Netherlands. These clogged wells can easily be regenerated by means of sodium hypochlorite (15%). The figure for the specific yield after regeneration approximates to the figure on commissioning.During the pumping to waste to clear the well after regeneration, the types of reaction products present in the spent chlorine solution were investigated. From this it can be deduced that the chlorine solution added was utilised mostly for the oxidation of iron sulphides. The remainder was used mainly for the oxidation of organic material. At the same time, calcium carbonate went into solution and iron carbonate was formed. During the regeneration of a number of wells, some silt was also removed.Although information can be obtained in this way about the composition of the materials removed, it is impossible to form any concept of the nature in which these substances are present around the clogged wells.

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03652.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTIt was proposed that the horizontal extent of the ground‐water mound is limited for finite times of recharge from strip basins even in infinite aquifers. A method of identifying the extent of the ground‐water mound using solutions of the equation of flow for finite aquifers was suggested. These solutions were obtained using two different procedures of linearization, those of Baumann and Hantush, and Laplace transforms. The resulting expressions were of a general nature and the equations of Hantush for infinite aquifers were shown to follow as a special case. The range of validity of the two procedures of linearization was tested using experimental results from sand tank models of finite aquifers, available in literature. The Baumann linearization was valid (correct to within ±5 percent of experimental values) up to a water table rise less than 0.4 times the initial height of the water table. The Hantush linearization was valid (correct to within ±2 percent of experimental values) for the entire range of water table rise studied, i.e. up to three times the initial height of the water table. The Hantush procedure was thus shown to have wider applicability. However, both procedures were found to yield results which have satisfactory agreement with experimental results over larger ranges than earlier reported for infinite aquifers.The effect of variation of the horizontal extent of the recharge mound on the water table profile was studied by treating the limit of the horizontal mound itself as a parameter. The water table rise was computed using the Hantush linearization procedure for different values of the ratio B/L (B/L = 15, 20, 25, 30, 35, 40 and ∞) where 2B is the horizontal extent of the mound and 2L the width of the recharge strip. The finite extent of the ground‐water mound in an infinite aquifer was given by that value of B/L for which the predicted profile was identical to that produced wh

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1980.tb03653.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY