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The article presents information on sulfur. Sulfur is said to be among the few solid elements found in elemental form in nature and has industrial uses. Changes in the sulfur production process over the years are discussed as well as the mining process developed by German engineer Herman Frasch that involves melting the sulfur underground and pumping it to the surface.
Pictures of the Earth's surface obtained from satellites are providing scientists with new tools to investigate tne Earth and its environment. A growing population and an everexpanding technology place demands on our natural resources. However, man can no longer treat his resources strictly according to immediate economic dictates; a balance must be struck between the short-term demands of technological and industrial development and the long-term effects on the environment. Intelligent development, management, and conservation of resources are goals that represent an unprecedented challenge in the acquisition and use of information.
Limiting this tableland In the northern part of Isla de Mona are sheer sea cliffs chiefly exposing the Isla de Mona Dolomite. Around the southern part of the island are Irregular cliffs and steep slopes that chiefly expose the Lirio Limestone. The structure of Isla de Mona consists of two gentle complex folds a broad anticline that trends and plunges gently south-southeast through the central and western parts of Isla de Mona, and a parallel syncline through-the eastern part of the Island that also has a chiefly south-southeast plunge. A near-vertical fault that strikes northwest, then north from the central part to the north coast of Isla de Mona displaces bedrock of the eastern block downward about 10 m. Many caves, including one cave system more than 100,000 m2 in total area, are localized in the lower 10 m of the Lirio Limestone, adjacent to the cliffs peripheral to the upland surface, and numerous small caves occur higher in the Lirio. A few small caves also are found In the Isla de Mona Dolomite. However, the total floor area of all caves on Isla de Mona probably is less than 1 percent of the area of the Island. Almost all caves on Isla de Mona contain phosphorite, which was mined extensively during the late 19th and early 20th centuries. Phosphorite accumulation locally may have exceeded 3.5 m in thickness, but probably averaged less than 1.5 m thick. A fair estimate of original reserves of phosphorite in 12 surveyed caves is about 151,000 m3 of which about 125,500 m3 probably has been removed in mining. Original reserves in the entire island are estimated to have been in the range 158,000 to 235,500 m3. Converted to metric tons, remaining reserves of cave phosphorite probably are considerably less than 50,000. The very pure limestone and calcitic dolomite that form the bedrock of Isla de Mona are abundant industrial-mineral resources. In addition, these carbonate rocks and the beach deposits are sources of construction materials for some classes of engineering works. The structure of Isla de Mona suggests some possibility of favorable zones for accumulation of oil and gas, but no source rocks are known, and there are no confirmed reports of oil and gas from any nearby area. Known supplies of fresh water on Isla de Mona are very small, but wells dug in coastal lowlands or drilled In the upland surface might yield moderate quantities of groundwater.
Sediment in Wisconsin streams causes economic and engineering problems in water management and reduces the value of water for nearly all uses. Sediment produces problems such as reduced reservoir capacity, navigation hazards, increased cost of water treatment, property damage, temporary loss of farmland, destruction of feeding and nesting grounds of fish, and destruction of wildlife habitat. Sediment in water also reduces the aesthetic value of surface waters and is detrimental to the State's tourist and recreation industry. The yield of sediment from a drainage basin is subject to many environmental influences. Most sediment results from the weathering and erosion of soil and rock materials. Other factors such as rainfall intensity, runoff rate, topography, rock type, soil characteristics, vegetal cover, and land use also influence the rate of sediment production and movement. An understanding of the many parameters that influence sediment yield is a basic need for managing the State's water resources. The purpose of this report is to describe the magnitude and variability of sediment in Wisconsin streams, to relate sediment yields to the local environment, and to identify areas that need further study. The report is based on sediment data from 44 stream-gaging sites throughout the State. Determination of local areas of erosion and deposition are beyond the scope of the report.
Mountain Creek Lake is a reservoir adjacent to the Naval Weapons Industrial Reserve Plant and the former Naval Air Station in Dallas, Texas. The U.S. Geological Survey began studies of water, sediment, and biota in the reservoir in 1994 after a Resource Conservation and Recovery Act Facility Investigation detected concentrations of organic chemicals on both facilities. Additional reservoir bottom sediment samples were collected during December 1999–January 2000 at the request of the Southern Division Naval Facilities Engineering Command to further define the occurrence and distribution of selected constituents and to supplement available data. The U.S. Geological Survey National Water Quality Laboratory analyzed bottom-sediment samples from 16 box cores and 5 gravity cores for major and trace elements, organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, grain size, and cesium-137.
Prospectors have contributed much to the development of this Nation's mineral resources. Since the time of the earliest settlement, the need for iron for tools and guns, lead for bullets, and copper for utensils has prompted a search for sources of these metals. The lure of gold and silver provided the impetus for much of the development in the West between 1850 and 1910. Later, prospectors carried out successful ventures to fulfill the country's expanding industrial demands for other metals such as zinc, molybdenum, tungsten, chromium, vanadium, and many others. Even America's uninhabited rugged mountains or barren deserts have been prospected although perhaps only at a reconnaissance scale.
The article presents facts about lime, which is said to be a caustic chemical manufactured from limestone or other calcium carbonates in a kiln at temperatures ranging from 935 to 1,350 degrees Celsius. It states that lime is widely used in industries such as steelmaking, paper production and chemical manufacturing. It also mentions that global lime production amounts up to 280 million metric tons annually. However, it notes that international trade in lime is limited.
Subsurface waste disposal by means of wells is the practice of using drilled wells to inject unwanted substances into underground rock formations. The use of wells for this purpose is not a new idea. As long ago as the end of the last century, it was common practice to drill wells for the express purpose of draining swamps and small lakes to reclaim the land for agricultural purposes. A few decades later in the 1920's and 1930's many oil companies began using injection wells to dispose of oil-field brines and to repressurize oil reservoirs. During World War II, the Atomic Energy Commission began using injection wells to dispose of certain types of radioactive wastes. More recently, injection wells have been drilled to dispose of a variety of byproducts of industrial processes. The number of such wells has increased rapidly since Congress passed the Clean Streams Act of 1966, which restricted the discharge of waste into surface waters. Many scientists and public officials question the propriety of using the term "disposal" when referring to the underground injection of wastes. Their reasons are that underground injection is not, as many advocates claim, "a complete and final answer" to the waste-disposal problem. Rather, it is merely a process wherein the injected wastes are committed to the subsurface with uncertainty as to their ultimate fate or limits of confinement. In effect, the wastes, undiminished and unchanged, are removed from the custody of man and placed in the custody of nature. Although the concept of waste-injection wells is relatively simple, the effects of waste injection can be very complex, particularly when dealing with the exotic and complex components of some industrial wastes. Besides the physical forces of injection, there are many varied interactions between the injected wastes and the materials within the injection zone. Because these changes occur out of sight in the subsurface, they are difficult to assess and not generally understood. In addition, the various aspects of the problem involve a wide spectrum of science and engineering. Hence, articles published on the subject are widely dispersed in the technical and scientific literature.
US GeoData tapes are computer tapes which contain cartographic data in digital form. The 1:2,000,000-scale data are available in two forms. The graphic form can be used to generate computer-plotted maps. The content and scale of the maps can be varied to meet your needs. The topologically-structured form of US GeoData is suitable for input to geographic information systems for use in spatial analysis and geographic studies. Both forms must be used in conjunction with appropriate software. US GeoData tapes offer convenience, accuracy, flexibility, and cost effectiveness to many map users. Business, industry, and government users who are involved in network planning and analysis, transportation, demography, land use, or any activity where data can be related to, or plotted on a map will find US GeoData a valuable resource.
The Mississippi Sound, an estuarine environment located between the mainland and barrier islands bordering the northern Gulf of America (formerly the Gulf of Mexico), serves as a vital ecosystem for the States of Mississippi and Alabama. Spanning approximately 100 kilometers from east to west and covering 1,400 square kilometers, the sound is home to marine industry and ports, and its shallow and brackish waters sustain a diverse array of marine life. Barrier islands along the southern edge of the sound separate the microtidal estuary from the Gulf of America. This protection from gulf wave action mediates current flow within the sound, resulting in predominantly fine-grained sediment deposition along the seafloor. This study, conducted by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers, provides insight on fluvial and tidal processes spanning the past 5,000 years. The report synthesizes existing research to provide a comprehensive overview of the sound geology, from Pleistocene origins to present-day morphology, and utilizes high-resolution single channel seismic profiles and sediment data to identify and map sedimentary deposits and morphologic features at and below the seafloor. Despite its ecological significance, the Mississippi Sound faces environmental challenges, including water-quality issues, habitat degradation, storm-induced erosion, and the ongoing threats of sea-level rise and environmental changes. This study uses the present-day understanding of the sound's geology to inform coastal management decisions, hazard assessment, and potential mineral resources.
The watershed boundary of the Apalachicola-Chattahoochee-Flint (ACF) River basin defines an aquatic ecosystem whose water quality is the result of complex interactions of natural and human influences on land and water resources. Topics relating to the basin's environmental setting-its physical, biological, and cultural characteristics-are summarized to provide an understanding of factors that influence water quality and the health of aquatic ecosystems. The ACF River basin lies partly in southwestern Georgia, southeastern Alabama, and northwestern Florida and covers 19,800 square miles in the Blue Ridge, the Piedmont, and the Coastal Plain Provinces. The basin includes the drainages of the Chattahoochee River and the Flint River, which meet to form the Apalachicola River. The Apalachicola River flows into the Gulf of Mexico at Apalachicola Bay. Basin hydrology and water quality are influenced by 16 mainstem reservoirs, 13 of which are on the Chattahoochee River. Ground water in the basin is contained in six aquifers-the surficial aquifer system, the Floridan aquifer system, the Claiborne aquifer, the Clayton aquifer, the Providence aquifer, and the crystalline-rock aquifer. Physiography, climate, and hydrology of the ACF River basin provide natural conditions that support a rich and abundant diversity of plants and animals. Although most of the ACF River basin has been altered by human activities, the basin's environment is noteworthy for its remaining biological diversity and the role it plays in sustaining biological productivity in Apalachicola Bay. The Bay produces 90 percent of Florida's and 13 percent of the Nation's oyster harvest; and functions as a nursery for penaeid shrimp, blue crabs, and a variety of fin fish. The diversity of the basin's aquatic fauna is noteworthy because the basin is home to (1) the largest number of fish species among Gulf Coast drainages east of the Mississippi River, (2) the largest assemblage of freshwater fish in Florida, (3) the largest number of mollusc species among western Florida drainages, and (4) the highest species density of amphibians and reptiles on the continent north of Mexico. Population of the ACF River basin in 1990 was estimated at 2.6 million. Nearly 90 percent of the total population lived in Georgia, and nearly 60 percent lived in the Metropolitan Atlanta area. The 1990 basin population is projected to increase by 15 percent to 3.0 million by the year 2000, and by 30 percent to 3.4 million by 2010. The largest increases in populations are projected for the Metropolitan Atlanta area. In 1972-76, approximately 59 percent of the basin was covered by forest, 29 percent was agricultural, 5 percent was wetland, 4 percent was urban, and 3 percent was water or barren land. Most of the original land cover of the basin has been transformed by human activity. Timber is the basin's largest cash crop and most forests consist of second-growth stands or large acreages of planted pine. The dominant agricultural land use in the Piedmont Province is pasture and confined feeding for dairy, livestock, and poultry production. Row-crop agriculture, orchards, and silviculture are most common in the Coastal Plain Province. The top five crops in order from most to least acres harvested in 1990 were peanuts, corn, soybeans, wheat, and cotton. The water in the basin is used for public and industrial supply, irrigation, power generation, navigation, and recreation. Although most public-supply withdrawals in the Blue Ridge and Piedmont Provinces are from surface-water sources, with the exception of counties near or immediately below the Fall Line, all publicly supplied water in the Coastal Plain is withdrawn from ground-water sources. Ground water supplied 18 percent of the basin's population served by public supply. Total water withdrawn in the ACF River basin in 1990 was 2,098 million gallons per day (Mgal/d), of which Georgia withdrew 82 percent and Florida and Alabama each withdrew 9 percent. Power generation is the single largest water use. Sixteen of the basin's 22 power generating plants are located along the mainstem of the Chattahoochee River. The U.S. Army Corps of Engineers maintains a navigation channel from the mouth of the Apalachicola River to Columbus, Ga., on the Chattahoochee River and to Bainbridge, Ga., on the Flint River. Water quality in the basin is influenced by the operation of 137 municipal wastewater-treatment facilities. In 1990, 354 Mgal/d of municipal wastewater was discharged within the ACF River basin. Eighty-eight percent of the wastewater was discharged into the Chattahoochee River basin, 10.6 percent into the Flint River basin, and 1.4 percent into the Apalachicola River basin. Two-thirds of the 938 stream miles in the Georgia portion of the ACF River basin having water quality that does not meet or only partially meets the designated-use criteria in the Chattahoochee River basin. The Chattahoochee River is the most heavily-used water resource both in the ACF River basin and in Georgia. Urban runoff or unknown nonpoint sources are cited as the causes of water-quality regulations in 72 percent of violations. The remaining causes primarily are combined sewer overflows in the Atlanta area, and discharges from municipal or industrial treatment facilities with inadequate treatment capabilities or operational deficiencies.
Technology and engineering have helped make mining safer and cleaner for both humans and the environment. Inevitably, mineral development entails costs as well as benefits. Developing a mine is an environmental, engineering, and planning challenge that must conform to many Federal, State, and local regulations. Community collaboration, creative design, and best management practices of sustainability and biodiversity can be positive indicators for the mining industry. A better understanding of aesthetics, culture, economics, geology, climate, vegetation and wildlife, topography, historical significance, and regional land planning is important in resolving land-use issues and managing mineral resources wisely. Ultimately, the consuming public makes choices about product use (including water, food, highways, housing, and thousands of other items) that influence operations of the mineral industry. Land planners, resource managers, earth scientists, designers, and public groups have a responsibility to consider sound scientific information, society's needs, and community appeals in making smart decisions concerning resource use and how complex landscapes should change. An effort to provide comprehensive geosciences data for land management agencies in central Colorado was undertaken in 2003 by scientists of the U.S. Geological Survey and the Colorado Geological Survey. This effort, the Central Colorado Assessment Project, addressed a variety of land-use issues: an understanding of the availability of industrial and metallic rocks and minerals, the geochemical and environmental effects of historic mining activity on surface water and groundwater, and the geologic controls on the availability and quality of groundwater. The USDA Forest Service and other land management agencies have the opportunity to contribute to the sustainable management of natural aggregate and other mineral resources through the identification and selective development of mineral resources and the reclamation of mines on lands that they administer. The information in this Circular will help them carry out that task.
As United States coal resources continue to be examined for potential development, a critical need exists for a digital database containing locations and status of all Federal coal resources. This Fact Sheet describes the development of such a digital database and presents examples of how the U.S. Geological Survey (USGS) has used these coal ownership data. This database and its products are designed to help policy makers and land-use planners make wise decisions regarding Federal land use while maintaining a healthy domestic energy industry. Although the State of Alaska has vast coal resources, much of which is Federally owned, digital data for Alaskan coal ownership are not currently available. Therefore, information presented here refers only to coal in the conterminous United States.
A rapid method has been developed for the determination of small amounts of molybdenum in tungsten and molybdenum ores. After removing iron and other major constituents the molybdenum thiocyanate color is developed in water-acetone solutions, using ammonium citrate to eliminate the interference of tungsten. Comparison is made by titrating a blank with a standard molybdenum solution. Aliquots are adjusted to deal with amounts of molybdenum ranging from 0.01 to 1.30 mg.
The zirconium-alizarin method has been modified to facilitate the convenient and accurate determination of small amounts of fluoride in a large number of water samples. Sulfuric acid is used to acidify the samples to reduce the interference of sulfate. The pH is accurately controlled to give the most sensitive comparisons. Most natural waters can be analyzed by the modified procedure without resorting to correction curves. The fluoride content of waters containing less than 500 parts per million of sulfate, 500 parts per million of bicarbonate, and 1000 parts per million of chloride may be determined within a limit of about 0.1 part per million when a 100-ml. sample is used.
This report has been prepared as a contribution to the development of southeastern Bucks County, Pa. It summarizes available information on the water resources of this 90-square mile area and evaluates current supplies. Future development of the area may change both the available quantity and the quality of the water supply. The effective development of the area demands a continuing knowledge of the water used and the potential quantity and quality of water available from both underground and surface sources. The area is strategically important to a great industrial section of the Bast. Its eastern boundary is a 26-mile segment of the Delaware River along the extreme southeastern border of Bucks County, Pa. (fig. 1). The present.population of the area is about 40,000, including 24,800 in Bristol Borough and Township and 6,770 in Morrisville. The area is traversed by both the Pennsylvania and the Reading Railroads and also by U.S. Highways 1 and 13. These are main transportation routes connecting the great market outlets of Philadelphia and New York. The Delaware River'is navigable from Morrisville to the sea. The area is only a short distance upstream from the Port of Philadelphia, which ranks second only to New York as the most important seaport in the United States. The area is mostly flat, open land 10 to 60 feet above mean sea level. It contains several large Industries, concentrated chiefly in the Bristol area (pi. 1). There are also scattered industries in the Morrisville, Langhorne, and Bensalem areas. However, Bucks County retains some of the characteristics of a farming region. Truck farming and gardening are still carried on to a considerable extent. Along Delaware River below Morrisville the mining of sand and gravel is an Important industry. The facts summarized in this report have been accumulated over a period of 25 years or more by Federal, State, and local agencies in connection with Investigations for other purposes. Most of the data used in this report have been obtained by the United States Geological Survey in cooperation with the Pennsylvania Department of Forests and Waters, the Pennsylvania Department of Internal Affairs, the Pennsylvania Department of Commerce, and State Planning Board, the City of Philadelphia, the Corps of Engineers, and the Interstate Commission on the Delaware River Basin. This report was prepared in the Water Resources Division of the U.S.Geological Survey by Jack B. Qraham, District Geologist; John W. Mangan, District Engineer; and Walter F. White, Jr., District Chemist, under the general direction of C. G. Paulsen, Chief Hydraulic Engineer.
During 2008-2010, the U.S. Geological Survey conducted a hydrologic investigation in cooperation with the Triangle J Council of Governments Cape Fear River Flow Study Committee and the North Carolina Division of Water Resources to collect hydrologic data in the Cape Fear River between B. Everett Jordan Lake and Lillington in central North Carolina to help determine if suspected flow losses occur in the reach. Flow loss analyses were completed by summing the daily flow releases at Jordan Lake Dam with the daily discharges at Deep River at Moncure and Buckhorn Creek near Corinth, then subtracting these values from the daily discharges at Cape Fear River at Lillington. Examination of long-term records revealed that during 10,227 days of the 1983-2010 water years, 408 days (4.0 percent) had flow loss when conditions were relatively steady with respect to the previous day's records. The flow loss that occurred on these 40 days ranged from 0.49 to 2,150 cubic feet per second with a median flow loss of 37.2 cubic feet per second. The months with the highest number of days with flow losses were June (16. percent), September (16.9 percent), and October (19.4 percent). A series of synoptic discharge measurements made on six separate days in 2009 provided "snapshots" of overall flow conditions along the study reach. The largest water diversion is just downstream from the confluence of the Haw and Deep Rivers, and discharges substantially decrease in the main stem downstream from the intake point. Downstream from Buckhorn Dam, minimal gain or loss between the dam and Raven Rock State Park was noted. Analyses of discharge measurements and ratings for two streamgages-one at Deep River at Moncure and the other at Cape Fear River at Lillington-were completed to address the accuracy of the relation between stage and discharge at these sites. The ratings analyses did not indicate a particular time during the 1982-2011 water years in which a consistent bias occurred in the computations of discharge records that would indicate false flow losses. A total of 34 measured discharges at a streamgage on the Haw River below B. Everett Jordan Lake near Moncure were compared with the reported hourly flow releases from Jordan Lake Dam. Because 28 of 34 measurements were within plus or minus 10 percent of the hourly flow releases reported by the U.S Army Corps of Engineers, use of the current discharge computation tables for reporting Jordan Lake Dam flow releases is generally supported. A stage gage was operated on the Cape Fear River at Buckhorn Dam near Corinth to collect continuous stage-only records. Throughout the study period, flow over the dam was observed along its length, and flow loss within the study reach is not attributed to river-level fluctuations at the dam. Water-use information and (or) data were obtained for five industrial facilities, a regional power utility, two municipalities, one small hydropower facility on the Deep River, and one quarry operation also adjacent to the Deep River. The largest water users are the regional power producer, a small hydropower operation, and the two municipalities. The total water-use diversions for these facilities range from almost 25.5 to 38.5 cubic feet per second (39.5 to 59.5 million gallons per day) during the winter and summer periods, respectively. This range is equivalent to 69 to 104 percent of the 37 cubic feet per second median flow loss. The Lockville hydropower station is on the Deep River about 1 mile downstream from the streamgage near Moncure. Run-of-river operations at the facility do not appear to affect flow losses in the study reach. The largest water user in the study area is a regional power producer at a coal-fired power-generation plant located immediately adjacent to the Cape Fear River just downstream from the confluence of the Haw an Deep Rivers. Comparisons of daily water withdrawals, sup-plied by the regional power producer, and discharge records at a streamgage on the diversion canal indicated many days when consumption exceeded the producer's estimates for the cooling towers. Uncertainty surrounding reasonable estimates of consumption remained in effect at the end of the study. Data concerning evaporative losses were compiled using two approaches-an analysis of available pan-evaporation data from a National Weather Service cooperative observer station in Chapel Hill, North Carolina; and a compilation of reference open-water evaporation computed by the State Climate Office of North Carolina. The potential flow loss by evaporation from the main stem and the Deep River was estimated to be in the range of 4 to 14 cubic feet per second during May through October, equivalent to 10 to 38 percent of the 37 cubic feet per second median flow loss. Daily water-use diversions and evaporation losses were compared to flow-loss occurrences during the period April 2008 through September 2010. In comparing the surface-water, water-use, and evaporation data compiled for 2008-2010, it is evident that documented water diversions combined with flow losses by open-water evaporation can exceed the net flow gain in the study area and result in flow losses from the reach. Analysis of data from a streamgage downstream from the regional power plant on the diversion canal adjacent to the Cape Fear River provided insight into the occurrence of an apparent flow loss at the streamgage at Lillington. Assessment of the daily discharges and subsequent hydrographs for the canal streamgage indicated at least 24 instances during the study when the flows suddenly changed by magnitudes of 100 to more that 200 cubic feet per second, resulting in a noted time-lag effect on the downstream discharges at the Lillington streamgage, beginning 8 to 16 hours after the sudden flow change. A fiber-optic distributed temperature-sensing survey was conducted on the Cape Fear River at the Raven Rock State Park reach August 12-14, 2009, to determine if the presence of diabase dikes were preferentially directing groundwater discharge. No temperature anomalies of colder water were measured during the survey, which indicated that at the time of the survey that particular reach of the Cape Fear River was a "no-flow" or losing stream. An aerial thermal-infrared survey was conducted on the Haw and Cape Fear Rivers on February 27, 2010, from Jordan Lake Dam to Lillington to qualitatively delineate areas of groundwater discharge on the basis of the contrast between warm groundwater discharge and cold surface-water temperatures. Dis-charge generally was noted as diffuse seepage, but in a few cases springs were detected as inflow at a discrete point of discharge. Two reaches of the Cape Fear River (regional power plant and Bradley Road reaches) were selected for groundwater monitoring with a transect of piezometers installed within the flood plain. Groundwater-level altitudes at these reaches were analyzed for 1 water year (October 1, 2009, to September 30, 2010). Data collected as part of this study represent only a brief period of time and may not represent all conditions and all years; however, the data indicate that, during the dry summer months, the Cape Fear River within the study area is losing an undetermined quantity of water through seepage. Analyses completed during this investigation indicate a study reach with complex flow patterns affected by numerous concurrent factors resulting in flow losses. The causes of flow loss could not be solely attributed to any one factor. Among the factors considered, the occurrences of water diversions and evaporative losses were determined to be sufficient on some days (particularly during the base-flow period) to exceed the net gain in flows between the upstream and downstream ends of the study area. Losses by diversions and evaporation can exceed the median flow loss of 3 cubic feet per second, which indicates that flow loss from the study reach is real. Groundwater data collected during 2009-2010 indicate the possibility of localized flow loss during the summer, particularly in the impounded reach above Buckhorn Dam. However, no indication of unusual patterns was noted that would cause substantial flow loss by groundwater and surface-water interaction at the river bottom.
A cooperative observation-well monitoring program was begun in New Mexico in 1925 between the U.S. Geological Survey and the New Mexico State Engineer Office. The majority of the wells are located in New Mexico; however, a few are in Texas east of Curry and Roosevelt County, New Mexico, and in Colorado along the Rio Grande. The program presently includes 22 wells equipped with continuous water-level recorders and 34 monitoring areas in which selected wells are measured periodically, usually every 5 years, to record changes in ground-water levels. These monitoring areas are those where ground water is used in large quantities for irrigation, municipal, or industrial purposes. Water-level data and water-level changes computed from these data are used to determine areas of ground-water-level rises and declines. This information is necessary for management of ground-water resources in New Mexico. Included in this report are hydrographs of ground-water levels obtained from 22 wells equipped with continuous water-level recorders and maps of ground-water-level changes computed for a 5-year period in each of 34 monitoring areas. Well locations and ground-water-level data for a 5-year period are listed in tables for each monitoring area. Where available, plots of annual precipitation data for climatological stations within or adjacent to each monitoring area are included.