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This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the lower Susquehanna River basin study unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in...

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the River River of the North basin study unit and to relate these findings to water-quality issues of regional and national concern. The information in primarily intended for those who are...

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the San Joaquin-Tulare Basins Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in water-resource...

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Ozark Plateaus Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in water-resource management....

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Upper Snake River Basin Study Unit and to relate these findings to water-quality issues of regional and national concern. This information is primarily intended for those who are involved in...

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Western Lake Michigan Drainages Study Unit and torelate these findings to water-quality issues of regional and national concern. The information in primarily intended for those who are involved in water-resource...

This report is intended to summarize major findings that emerged between 1991 and 1995 from the water-quality assessment of the Willamette Basin Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in water-resource management....

The NAWQA Program is assessing the water-quality conditions of more than 50 of the Nation's largest river basins and aquifers, known as Study Units. Collectively, these Study Units cover about one-half of the United States and include sources of drinking water used by about 70 percent of the U.S. population....

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Georgia-Florida Coastal Plain Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in water-resource...

Water quality in the Central Columbia Plateau of eastern Washington and western Idaho has been adversely affected by agriculture, especially in irrigated areas, according to the results of a five-year investigation by the U. S. Geological Survey (USGS). Some improvements, however, are noticeable, such as less sediment being washed into...

Increased amounts of recycled materials are being used to supplement natural aggregates (derived from crushed stone, sand and gravel) in road construction. An understanding of the economics and factors affecting the level of aggregates recycling is useful in estimating the potential for recycling and in assessing the total supply picture...

An analysis of the substitution of crushed cement concrete for natural construction aggregates is performed by using a materials flow diagram that tracks all material flows into and out of the cement concrete portion of the products made with cement concrete: highways, roads, and buildings. Crushed cement concrete is only...

Because sediments deposited by the 1993 floods on the Missouri and Mississippi rivers were thought to contain elevated concentrations of nutrients and trace elements, sediment deposits were sampled at 25 floodplain locations. The samples were analyzed for particle size, water content, volatile solids, nutrients, carbon, selected trace elements, pesticides, and...

The purpose of this report is to present consistent and current water-use estimates by state and water-resources region for the United States, Puerto Rico, the U.S. Virgin Islands, and the District of Columbia. Estimates of water withdrawn from surface- and ground-water sources, estimates of consumptive use, and estimates of instream...

The importance of considering ground water and surface water as a single resource has become increasingly evident. Issues related to water supply, water quality, and degradation of aquatic environments are reported on frequently. The interaction of ground water and surface water has been shown to be a significant concern in...

This report describes seven science goals conceived to address pressing issues facing the Nation in the next decade. These goals focus on understanding human interaction with the natural environment and build upon long-term USGS investments in basic research....

Historical and geological data indicate that significant changes can occur in the Earth's climate on time scales ranging from years to millennia. In addition to natural climatic change, climatic changes may occur in the near future due to increased concentrations of carbon dioxide and other trace gases in the atmosphere...

Scheelite and wolframite are the principal minerals currently mined for tungsten. Both occur in hard-rock deposits; wolframite is also recovered from placer deposits. Most current mine production of tungsten is from vein/stockwork, skarn, porphyry, and strata-bound deposits. Minor amounts are produced from disseminated, pegmatite, breccia, and placer deposits.   Most tungsten is...

INTRODUCTION Lakes are among the most valued natural resources of central Florida. The landscape of central Florida is riddled with lakeswhen viewed from the air, it almost seems there is more water than land. Florida has more naturally formed lakes than other southeastern States, where many lakes are created by building...

Factors relating to the estimation of areas contributing recharge to wells, such as complexity of the ground-water flow system, effects of changing hydrologic conditions, and effects of well-screen locations and pumping rates, are reviewed. The point of view that simulation is the best means to obtain physically based estimates of...

This report summarizes the economic component of the 1995 National Assessment of Oil and Gas Resources prepared by the U.S. Geological Survey for onshore and State offshore areas of the United States. Province and regional incremental cost functions for conventional undiscovered oil and gas fields, and selected unconventional oil and...

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Central Nebraska Basins Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in waterresource...