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R.M. Leggette

Publications and source records attributed to R.M. Leggette.

13 recordsLinked to original sources

The transmission of pressure in artesian aquifers

The water in artesian aquifers is confined under pressure . Under ideal conditions in a perfectly rigid artesian reservoir a change of pressure in one part of the reservoir should produce a corresponding change of pressure in all other parts of the reservoir. Theoretically, the transmission of pressure should take place rapidly and without any movement of water other than the small amount resulting from the compressibility of water. However, observations under natural conditions show that the transmission of pressure is not always rapid and that the rate of transmission appears to be determined in great part by the distance traversed and the magnitude of the change of pressure . There are many reasons for believing that artesian aquifers and their confining beds are not perfectly rigid but that they are elastic and capable of compression and dilation (O. E. Meinzer, Compressibility and elasticity of artesian aquifers , Econ. Geol., v. 23, pp. 263–291, 1928). This appears to be the cause of the lack of rapidity of transmission of pressure in artesian aquifers .

Eos, Transactions, American Geophysical Union

Long‐time records of ground‐water levels on Long Island, New York

As early at 1851 the need for information as to the position of the water‐table was recognized by workers on Long Island. In that year water‐level measurements were made in about 32 domestic wells in the southern part of Kings and Queens counties, New York (W. J. McAlpine, Report made to the water committee of the common council of the City of Brooklyn on supplying the City with water, p. 113, Brooklyn, I. Van Anden, 1852). Although specific water‐level data are given in this report, it has not been possible to determine the exact locations of the old wells that were measured, or the months during which measurements were made.

Eos, Transactions, American Geophysical Union

The channel‐storage method of determining effluent seepage

Some years ago the senior author, in collaboration with Norah Dowell Stearns, undertook to make a monthly inventory of the water‐supply of the Pomperaug River Basin, in Connecticut, from a study of data obtained by A. J. Ellis from 1913 to 1916. For this purpose approximate determinations or estimates were made of the ground‐water runoff, that is, of the part of the daily discharge of the river that consisted of water derived from the zone of saturation by effluent seepage. The determinations or estimates were essentially based on the assumption that after a week of fair weather the storm‐water was all discharged and that until the next rain the runoff was essentially all ground‐water (U.S. Geol, Surv. Water‐Supply Paper 597, pp. 107–116 and pi. 19, 1929). In the discussion of the methods and results of this investigation, the following statement was made (Water‐Supply Paper 597, pp. 145–146): “In this investigation the estimates of ground‐water runoff were based on the discharge of the Pomperaug at Bennetts Bridge—that is, on the discharge during the periods between rains, when there was virtually no direct runoff left in the stream‐system. Much better results could be obtained by basing the estimates on periods beginning as soon after rains as all of the direct runoff has reached the streams. With this method the ground‐water runoff during any particular day would be the total runoff minus the decrease in stream‐storage. The decrease in stream‐storage could be estimated by maintaining gages at several points on the trunk‐stream and on selected tributaries and making surveys of the stream‐system showing the approximate water‐areas of different parts of the system at different gage‐heights.”

Eos, Transactions, American Geophysical Union

The mutual interference of artesian wells on Long Island, New York

The withdrawal of water from a well necessarily produces a drop in water‐level in the well. The ground‐water level in the vicinity of the well from which the water is withdrawn likewise declines, but the amount of decline decreases with increasing distance from the well, so that a cone of depression of the water‐surface in the vicinity of the well is produced. The cone of depression is an actual water‐surface if the ground‐water is not confined under pressure. If the ground‐water is under artesian pressure, the cone of depression is a depression in the piezometric surface. If the cones of depression of two or more wells ending in the same formation overlap, interference of the wells occurs. In this case (the combined yield of the wells when pumped simultaneously will be less than the sum of the individual yields if the wells are pumped separately. In choosing the proper spacing of wells from the operator's point of view, it is important to know the lateral extent of the cones of depression of supply‐wells ending in a given formation. In many installations two or more wells are so closely spaced that their mutual interference is excessive.

New York

Ground‐water for air‐conditioning on Long Island, New York

During the last five years ground‐water has been more and more extensively used for air‐conditioning on Long Island, New York. The wide‐spread occurrence of highly permeable water‐bearing material and the relatively small cost of installation and operation of a ground‐water, air‐conditioning system has resulted in many such installations by theaters, restaurants, stores, and other establishments. Many companies likewise have taken advantage of these favorable factors and are utilizing low‐temperature ground‐water for cooling purposes in the manufacture of ice. This new use of ground‐water has considerably increased the draft in the western end of Long Island where there had already been so much over‐development that the watertable was below sea‐level in an area of more than 40 square miles. In 1933 the State Legislature, recognizing the seriousness of this over‐development, passed a law requiring that the approval, of the State Water Power and Control Commission be secured before constructing a well with a capacity greater than 100,000 gallons a day. Since the passage of the law the‐policy of the Commission has been to require water pumped from new‐wells for cooling purposes to be returned to the ground. This requirement has resulted in the construction of many recharge‐wells (locally called diffusion‐wells) through which the warm water is returned to the ground.

New York

Ground water in the Jordan Valley, Utah

The Jordan Valley is a small part of a larger area that during the glacial epoch was covered by an ancient lake known as Lake Bonneville. The Jordan River, the natural drainage path from Utah Lake, flows northward through the center of the valley and empties into Great Salt Lake. The Jordan Valley is a rockbottomed valley in which a great thickness of clay, silt, sand, and gravel has been laid down irregularly. The thickness of this material is not definitely known, but wells in the valley have penetrated as much as 2,000 feet without encountering bedrock. These sediments are chiefly stream and lake deposits. The material at the surface of the valley was deposited in an ancient lake which at its highest stage stood about 1,000 feet above the level of Great Salt Lake. The shore deposits laid down in this lake occur in the form of terraces or benches around the margin of this basin. The two most prominent benches are known as the Bonneville and Provo benches. The Bonneville bench was formed during the highest stage of the lake, and the Provo bench during a later stage about 400 feet lower. Ground water occurs in the valley as (1) shallow ground water overlying the confining layer creating the artesian basin, (2) local perched water bodies, and (3) an artesian basin or reservoir including the recharge area. It occurs chiefly in the pore spaces of the sand and gravel of the stream and lake deposits. The most permeable water-bearing material occurs near the foot of the Wasatch Mountains in the area occupied by the Provo and Bonneville benches. At some distance from the mountains beds of finer material dense silt and clay alternate with more permeable beds of sand and gravel, giving rise to artesian conditions. On the Provo and Bonneville benches the water levels lie at considerable distances below the surface; but in the lower areas along the Jordan River and west of Salt Lake City as far as the lake, artesian conditions exist and many flowing wells have been drilled. The principal sources of ground water in the Jordan Valley are the water that seeps into the ground from the streams entering the valley, the water that penetrates directly from the ram and snow that fall upon the bench lands on the east side of the valley, and the water that percolates downward from irrigation canals and from irrigated lands, chiefly derived from Utah Lake. In addition some deep-seated thermal water rises along the Wasatch fault. Field determinations of the chloride content of the ground water show that nearly all the waters from the main part of the area of artesian flow, extending from Salt Lake City to Murray have a chloride content of less than 100 parts per million, and most of them have less than 50 parts per million. The distribution of waters of different chloride content indicates that the water of the main part of the area of artesian flow is derived chiefly from supplies that contain only small amounts of chloride namely, seepage from the streams that head in the Wasatch Mountains and rain and snow that fall upon the Provo and Bonneville benches and penetrate downward through the permeable materials that underlie these benches

Utah

Geology and ground-water resources of Ogden Valley, Utah

Ogden Valley is a fault trough bounded on both the east and west by faults that dip toward the middle of the valley. This fault trough contains unconsolidated deposits of clay, sand, and gravel, whose thickness is more than 600 feet. These materials are stream and lake deposits and in places are well sorted and stratified. The lake sediments were laid down in a small lake that occupied Ogden Valley and that was connected with glacial Lake Bonneville at its high stage by an arm of water that occupied Ogden Canyon. During this stage of Lake Bonneville the Ogden Valley was completely filled with lake sediments up to an altitude of about 4,900 feet. These sediments include about 70 feet of clay, sand, and gravel in alternating layers, below which is a bed of varved clay whose maximum thickness is about 70 feet. This clay is continuous under the lower parts of the valley and is the confining bed that produces the artesian conditions. Below the varved clay is a deposit of silt, sand, and gravel of unknown thickness, most of which is believed to be pre-Bonneville alluvium. In most summers the streams entering Ogden Valley are diverted for irrigation, and the upper parts of their channels are generally dry during the irrigation season. Lower down in the valley seepage water appears in the channels, and below these points there is continuous flow. The flow of the Ogden River increases as it passes through Ogden Canyon. This gain in flow is believed to be derived chiefly from ground-water seepage from the canyon walls, although there is probably some groundwater underflow from Ogden Valley at the head of Ogden Canyon. Some of the gain is also due to leakage from pipe lines in the canyon. Of the 146 wells whose records are given in this report, 70 are flowing wells.

Utah