Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Resources”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,729 records · Page 96Linked to original sources

Numerical simulation of groundwater flow, resource optimization, and potential effects of prolonged drought for the Citizen Potawatomi Nation Tribal Jurisdictional Area, central Oklahoma

A hydrogeological study including two numerical groundwater-flow models was completed for the Citizen Potawatomi Nation Tribal Jurisdictional Area of central Oklahoma. One numerical groundwater-flow model, the Citizen Potawatomi Nation model, encompassed the jurisdictional area and was based on the results of a regional-scale hydrogeological study and numerical groundwater flow model of the Central Oklahoma aquifer, which had a geographic extent that included the Citizen Potawatomi Nation Tribal Jurisdictional Area. The Citizen Potawatomi Nation numerical groundwater-flow model included alluvial aquifers not in the original model and improved calibration using automated parameter-estimation techniques. The Citizen Potawatomi Nation numerical groundwater-flow model was used to analyze the groundwater-flow system and the effects of drought on the volume of groundwater in storage and streamflow in the North Canadian River. A more detailed, local-scale inset model was constructed from the Citizen Potawatomi Nation model to estimate available groundwater resources for two Citizen Potawatomi Nation economic development zones near the North Canadian River, the geothermal supply area and the Iron Horse Industrial Park. Groundwater pumping rates at potential well locations were optimized using the most recent version of the U.S. Geological Survey Groundwater-Management Process for MODFLOW. The objectives of optimization were to determine if a total pumping rate of 500 gallons per minute could be pumped from 5 wells at the geothermal supply area and to maximize discharge from 16 wells at the Iron Horse Industrial Park without exceeding specified head drawdown constraints at the pumping wells and thus prevent groundwater depletion. The inset model was used to estimate North Canadian River streamflow depletion caused by optimized pumping at the Iron Horse Industrial Park because water quality was a concern, and the river may have degraded water quality compared to water in other parts of the alluvial aquifer. The fate of streamflow that infiltrates into groundwater because of pumping was not directly determined, but it was assumed that this water could end up in the well discharge, and was considered to be a maximum proportion of well discharge derived from the North Canadian River. The total optimized continuous pumping rate from five managed wells at the geothermal supply area was 638 gallons per minute, which exceeded the target pumping rate of 500 gallons per minute. The total continuous pumping rate from 16 wells at the Iron Horse Industrial Park was 1,472 gallons per minute, which induced stream infiltration of approximately 4.1 gallons per minute (approximately 0.3 percent of the total well discharge) from the North Canadian River. To estimate the effects of drought on water resources in the Citizen Potawatomi Nation Tribal Jurisdictional Area, a hypothetical 10-year drought during which precipitation would decrease by 50 percent was simulated by decreasing model groundwater recharge by the same proportion for the period 1990–2000 of the transient model. The effects of the drought were estimated by calculating the change in the volume of groundwater storage and groundwater flow to streams at the end of the drought period, and the change in simulated streamflow in the North Canadian River at the streamflow-gaging station at Shawnee, Okla., during and after the drought. The hypothetical decrease in recharge during the simulated drought caused groundwater in storage over the entire model in the study area to decrease by 361,500 acre-feet (14,100 acre-feet in the North Canadian River alluvial aquifer and 347,400 acre-feet in the Central Oklahoma aquifer), or approximately 0.2 percent of the total groundwater in storage over the drought period. This small percentage of groundwater loss showed that the Central Oklahoma aquifer as a bedrock aquifer has relatively low rates of recharge from the surface relative to the approximate storage. The budget for base flow to the North Canadian River indicated that the change in groundwater flow to the North Canadian River decreased during the 10-year drought by 386,500 acre-feet, or 37 percent. In all other parts of the Citizen Potawatomi Nation Tribal Jurisdictional Area, base flow decreased by 292,000 acre-feet, or 28 percent. Streamflow in the North Canadian River at the streamflow-gaging station at Shawnee, Okla., decreased during the hypothetical drought by as much as 28 percent, and the mean change in streamflow decreased as much as 16 percent. Streamflow at the Shawnee streamflow-gaging station did not recover to nondrought conditions until about 3 years after the simulated drought ended, during the relatively wet year of 2007.

Oklahoma↗

Hydrogeologic and geochemical characterization of groundwater resources in Deep Creek Valley and adjacent areas, Juab and Tooele Counties, Utah, and Elko and White Pine Counties, Nevada

The water resources of Deep Creek Valley were assessed during 2012–13 with an emphasis on better understanding the groundwater flow system and groundwater budget. Surface-water resources are limited in Deep Creek Valley and are generally used for agriculture. Groundwater is the predominant water source for most other uses and to supplement irrigation. Most groundwater withdrawal in Deep Creek Valley occurs from the unconsolidated basin-fill deposits, in which conditions are generally unconfined near the mountain front and confined in the lower-altitude parts of the valley. Productive aquifers are also present in fractured bedrock that occurs along the valley margins and beneath the basin-fill deposits. The consolidated-rock and basin-fill aquifers are hydraulically connected in many areas with much of the recharge occurring in the consolidated-rock mountain blocks and most of the discharge occurring from the lower-altitude basin-fill deposits. Average annual recharge to the Deep Creek Valley hydrographic area was estimated to be between 19,000 and 29,000 acre-feet. Groundwater recharge occurs mostly from the infiltration of precipitation and snowmelt at high altitudes. Additional, but limited recharge occurs from the infiltration of runoff from precipitation near the mountain front, infiltration along stream channels, and possible subsurface inflow from adjacent hydrographic areas. Groundwater moves from areas of recharge to springs and streams in the mountains, and to evapotranspiration areas, springs, streams, and wells in the basins. Discharge may also occur as subsurface groundwater outflow to adjacent hydrographic areas. Average annual discharge from the Deep Creek Valley hydrographic area was estimated to be between 21,000 and 22,000 acre-feet, with the largest portion of discharge occurring as evapotranspiration. Groundwater samples were collected from 10 sites for geochemical analysis. Dissolved-solids concentrations ranged from 126 to 475 milligrams per liter, and none of the sites sampled during this study had dissolved-solids concentrations that exceeded the Environmental Protection Agency secondary standard for drinking water of 500 milligrams per liter. Tritium concentrations from 1.6 to 10.1 tritium units at 3 of the 10 sample sites indicate the presence of modern (less than 60 years old) groundwater, and apparent tritium/helium-3 ages calculated for these sites ranged from 7 to 29 years. The other seven sample sites had tritium concentrations less than or equal to 0.4 tritium units and are assumed to be pre-modern. Adjusted minimum radiocarbon ages of these seven pre-modern water samples ranged from 1,000 to 8,000 years with the ages of at least four of the samples being more than 3,000 years. Noble-gas recharge temperatures indicate that groundwater sampled along the valley axis recharged at both mountain and valley altitudes, providing evidence for both mountain-block and mountain-front recharge. Water-level altitude contours and groundwater ages indicate the potential for a long flow path from southwest to northeast between northern Spring and Deep Creek Valleys through Tippett Valley. Although information gathered during this study is insufficient to conclude whether or not groundwater travels along this interbasin flow path, dissolved sulfate and chloride data indicate that a small fraction of the lower altitude, northern Deep Creek Valley discharge may be sourced from these areas. Despite the uncertainty due to limited data collection points, a hydraulic connection between northern Spring Valley, Tippett Valley, and Deep Creek Valley appears likely, and potential regional effects resulting from future groundwater withdrawals in northern Spring Valley warrant ongoing monitoring of groundwater levels across this area.

Nevada, Utah↗

Compilation and assessment of resource values and hazards to inform transportation planning and associated land-use planning

Land-use planning has an important role in local, regional, State, and Federal land management, and planning efforts can benefit from consistent, spatially explicit information that can help guide priorities and decisions. The credibility and relevance of information used to inform planning activities depends on the availability of consistent information about the resources and values of interest or concern within the planning area. To support long-range transportation planning and other regional land-use planning efforts, the U.S. Geological Survey gathered, processed, interpreted, and compiled spatial datasets representing a wide range of information on terrestrial and aquatic ecosystem condition and importance, cultural (historical) features and places, and natural hazards. This report describes the spatial data compiled to represent natural landscape conditions (including social, cultural, and natural attributes) to estimate the potential importance of lands for wildlife, wild habitats, recreation, and conservation based on abundance of species, habitats, land and water conditions, and conservation designations. Abundance of resources, including the potential number of species, presence of important habitats and protected areas, and proximity to particular features or habitats, indicates the potential sensitivity of the natural landscape to land use, especially transportation networks. The source data, derived indices, and the methods for processing these data are described in this final report. The datasets referenced in the report are available from the U.S. Geological Survey ( https://www.sciencebase.gov/catalog/ and https://doi.org/10.5066/F7MW2F8W ) or the Central Federal Lands Highway Division of the Office of Federal Lands Highway ( https://flh.fhwa.dot.gov ).

Scientific Investigations Report↗

Water resources on Guam—Potential impacts of and adaptive response to climate change

The goals of this joint U.S. Geological Survey, University of Hawaiʻi, University of Guam, University of Texas, and East-West Center study were to (1) provide basic understanding about water resources for U.S. Department of Defense installations on Guam and (2) assess the resulting effect of sea-level rise and a changing climate on freshwater availability, on the basis of historic information, sea-level rise projections, and global-climate model temperature and rainfall projections. Downscaled regional climate models, informed by a multimodel ensemble of global climate models provided projections of future climate conditions for Guam. These projected climate conditions provided input to surface-water and groundwater models developed for Guam’s hydrology. Guam’s water resources in a future climate condition (2080–99) are projected to diminish relative to the recent climate condition. Projected average temperature increases, and average rainfall decreases will lead to reduced streamflow in southern Guam and reduced groundwater recharge to the Northern Guam Lens Aquifer (NGLA). Projected average temperatures in southern Guam will increase about 5.8 °F (3.22 °C), overall rainfall will decrease about 7 percent, and streamflow will consequently decrease 18 percent in important areas of southern Guam. Similarly, across the NGLA, future groundwater recharge will be 19 percent less than estimated recharge from 2012. Reduced future streamflow will decrease water availability from the Fena Valley Reservoir; however, the reservoir is expected to be able to supply water at recent demand rates without lowering the reservoir level to the elevation of the water-supply intakes throughout the simulated period of a future climate. A twelve-year simulation indicates that the reservoir can supply about twice the 2018 demand without lowering the reservoir level to the water-supply intakes. By following mitigation strategies to increase reservoir water availability, the withdrawal rate can be increased by 1.7 percent if the water-supply intakes are lowered 5 ft, by 3.5 percent if the spillway height is raised 5 ft, and by 5.3 percent if both strategies are combined. Higher sea level and reduced future recharge will decrease water availability from the NGLA. An index of composite chloride concentration from production wells increases to 300 milligrams per liter (mg/L) for future climate conditions and at 2010 withdrawal rates, compared with 130 mg/L under historic climate conditions. Most of this increase is due to reduced recharge as higher (+3.2 ft) sea level only has a small role in increasing withdrawn water salinity. A redistributed withdrawal scenario in which the composite chloride concentration is 290 mg/L offers only slight improvement. Should future droughts reduce recharge proportionally to the decreases observed during historic droughts, the composite concentration would be about 900 mg/L, and more than 70 percent of Guam’s production wells would produce water with a composite concentration greater than 500 mg/L. Potential mitigation strategies for increasing the potable yield of the NGLA in a future climate include reducing depths of deep production wells and reducing the withdrawal rates in selected wells projected to have higher chloride concentrations. Simulations show both strategies are effective in lowering the composite concentration of the withdrawn water.

Scientific Investigations Report↗

Water resources in the Cheyenne and Arapaho Tribal jurisdictional area, west-central Oklahoma, with an analysis of data gaps through 2015

This report provides an overview of existing hydrologic information describing the quality, quantity, and extent of the major surface-water and groundwater resources in the Cheyenne and Arapaho Tribal jurisdictional area, west-central Oklahoma. Hydrologic information is provided for five major river systems (Cimarron River, North Canadian River, Canadian River, Washita River, and North Fork Red River), two reservoirs (Foss Reservoir and Canton Lake), and eight aquifers consisting of the alluvial aquifers associated with each of the five major river systems and three major bedrock aquifers (Ogallala aquifer, Elk City aquifer, and Rush Springs aquifer). Types of information provided about rivers and reservoirs for the Cheyenne and Arapaho Tribal jurisdictional area include diversion sites and amounts of water allocated and diverted for permitted uses in 2015; treated wastewater discharge sites and amounts discharged in 2015; and characteristics describing water-quality field properties, major ions, nutrients, and selected trace elements. Major ions, nutrients, and selected trace elements are compared to secondary maximum contaminant levels and maximum contaminant levels for finished drinking water. Additionally, statistics are provided describing daily, monthly, and annual streamflow characteristics at 12 U.S. Geological Survey streamgages. Streamflow statistics include the magnitudes and frequencies of floods, base-flow characteristics, and long-term streamflow trends. Types of information provided about the aquifers include amounts of water allocated and pumped for permitted uses in 2015; characteristics of groundwater describing water-quality field properties, major ions, nitrate (measured as nitrogen), and selected trace elements with comparisons to secondary maximum contaminant levels and maximum contaminant levels for finished drinking water; groundwater levels and long-term changes in water levels; and ranges of hydraulic conductivity, aquifer recharge, specific yield, transmissivity, and well yields from reports and groundwater-flow models. Surface water is used primarily for irrigation and mining and other nonconsumptive uses in the Cheyenne and Arapaho Tribal jurisdictional area, except from the Washita and North Fork Red Rivers, where water is treated for use as a public-water supply. Large concentrations of dissolved solids are the primary limiting factor affecting the use of surface water. Median concentrations of dissolved solids in surface water range from less than 1,000 milligrams per liter (mg/L) in samples from the North Canadian River to greater than 9,000 mg/L in samples from the Cimarron River. Large dissolved solids concentrations are correlated with hard water. Median hardness as calcium carbonate concentrations in surface water ranges from 427 mg/L in samples from Canton Lake to 1,000 mg/L in samples from the Washita River. In 2015, groundwater was used at more than twice the rate of surface water in the Cheyenne and Arapaho Tribal jurisdictional area. Although the alluvial aquifers are considered reliably good sources of water in the Cheyenne and Arapaho Tribal jurisdictional area, concentrations of nitrate (measured as nitrogen) exceed the maximum contaminant level of 10 mg/L established by the U.S. Environmental Protection Agency for finished drinking water in parts of all of the alluvial aquifers. Water from the three major bedrock aquifers is used for irrigation, mining, public-water supply, and other uses; however, large concentrations of dissolved solids, nitrate (measured as nitrogen), and naturally occurring trace elements such as arsenic and uranium may limit the use of groundwater as a source of public-water supply in some areas. As of 2015, the depletion of groundwater from the major aquifers in west-central Oklahoma is a minor concern to the Oklahoma Water Resources Board. Groundwater levels and other hydrologic information show that recharge rates exceed the rates of water pumped from aquifers, except in areas that may be affected locally by groundwater depletions.

Oklahoma↗

Groundwater flow model investigation of the vulnerability of water resources at Chaco Culture National Historical Park related to unconventional oil and gas development

Chaco Culture National Historical Park (CCNHP), located in northwestern New Mexico, protects the greatest concentration of Chacoan historical sites in the American Southwest. Geologically, CCNHP is located within the San Juan structural basin, which consists in part of complex Cretaceous stratigraphy and hosts a variety of energy resources. As part of a larger study to investigate the vulnerability of water resources at CCNHP related to oil and natural gas extraction activities, a MODFLOW groundwater model of the Mancos Shale and Gallup Sandstone units was created by the U.S. Geological Survey, as a part of a cooperative study with the National Park Service, to assess advective groundwater flow paths and traveltimes. The model determined that groundwater flow directions currently trend from south-southeast to north-northwest within the vicinity of CCNHP, groundwater traveltime through the Gallup Sandstone ranges from thousands to tens of thousands of years, and traveltime through the Mancos Shale may range from millions to tens of millions of years. The capture zone of the main CCNHP well (referred to as the “Chaco well”) extends to the south-southeast and ranges in width from approximately 1 to 12 miles, depending on pumping rate. Eighteen inactive hydrocarbon related wells are located within the capture zone and within 10 kilometers of the Chaco well. Given model estimates of traveltimes of groundwater in the Gallup Sandstone aquifer, advective groundwater transport to the Chaco well would take approximately 430 years from the nearest inactive hydrocarbon related wells. Differencing of historical and modern-day potentiometric surfaces of the Gallup Sandstone indicate a drop in groundwater levels between 34 and 96 feet within the CCNHP boundaries. Hydraulic fracturing, simulated as increased hydraulic conductivity zones, decreased groundwater traveltimes (from millions to thousands of years) and acted as permeable pathways from the Mancos Shale to the Gallup Sandstone.

Arizona, New Mexico↗

Assessment of per- and polyfluoroalkyl substances in water resources of New Mexico, 2020–21

Per- and polyfluoroalkyl substances (PFAS) have been detected in public and private drinking-water wells, springs, and surface waters in New Mexico; however, the presence and distribution of PFAS in water resources across the State are not well characterized. From August 2020 to October 2021, the U.S. Geological Survey, in cooperation with the New Mexico Environment Department, collected water-quality samples from groundwater and surface-water sites throughout New Mexico. One hundred and seventeen groundwater wells were sampled from unconfined water-table aquifers for PFAS and a geochemical suite including major ions, trace elements, nutrients, dissolved organic carbon (DOC), stable isotopes of oxygen and hydrogen, tritium, and carbon-14 to provide context for groundwater age and geochemical evolution. Eighteen surface-water samples were analyzed for PFAS, and select samples were analyzed for wastewater tracers, major ions, trace elements, and DOC. Blanks and replicates indicated low bias and variability for PFAS, wastewater tracers, and geochemical compounds. Twenty-seven of the 117 groundwater sites had PFAS concentrations reported above the detection level, and there were no exceedances of the 2016 U.S. Environmental Protection Agency health advisory of 70 nanograms per liter (ng/L) perfluorooctanoic acid plus perfluorooctane sulfonic acid. Twenty-two sites were resampled and showed similar signatures, excluding some springs. Total PFAS concentrations ranged from 0.91 to 80.3 ng/L. The most frequently detected PFAS at groundwater sites were perfluorobutanesulfonic acid (PFBS; 11 sites), perfluoropentanoic acid (10 sites), and perfluorohexanoic acid (9 sites). Correlations were found between certain PFAS compounds that suggest similar sources. PFAS were also correlated with tritium, DOC, and nitrate, which indicated that a presence of anthropogenic compounds could in turn indicate a likelihood of PFAS occurrence. In addition, a cluster analysis showed that varying geochemical processes and sources of anthropogenic compounds likely contribute to the PFAS signature of each groundwater sample. Surface-water samples showed variable total PFAS concentrations ranging from 1.0 to 155.4 ng/L. Sites downstream from urban areas showed numerous PFAS detections. Some undeveloped areas where minimal PFAS detections would be expected had PFAS detections. Correlations between PFAS were found that suggested similar sources. Perfluoropentanoic acid and PFBS were the most frequently detected PFAS, and PFBS had the highest single concentration of 93 ng/L. Results of the study provide an overview of PFAS occurrences in the water resources of New Mexico along with geochemical context and are used to identify areas for further scientific investigations that could further characterize PFAS occurrences in New Mexico.

New Mexico↗

Water-resources inventory and assessment at Katahdin Woods and Waters National Monument

The U.S. Geological Survey, in cooperation with the National Park Service, prepared a water-resources inventory and assessment for Katahdin Woods and Waters National Monument (KAWW). This compilation includes published and publicly accessible hydrologic data and resource assessments of streams, rivers, ponds, lakes, wetlands, vernal pools, and groundwater in and near KAWW. It also includes reports and datasets summarizing attributes of KAWW’s hydrologic infrastructure, such as stream crossings, dams, wastewater discharge plants, groundwater monitoring wells, and U.S. Geological Survey streamflow-gaging stations. Descriptions of data and details of current limitations in available datasets are included. Wetland, groundwater, streamflow, and water-quality information are all limited. Hydrography data are available; however, there are limited ground-truth data. Accurate streamlines within KAWW were developed from light detection and ranging (lidar) as a part of this work. Hydrologic infrastructure information is available from multiple sources; however, differences exist among the datasets. Datasets are summarized in appendix 1.

Maine↗

Background and geologic model for the 2024 U.S. Geological Survey assessment of undiscovered conventional petroleum resources in the Norphlet Formation, U.S. Gulf Coast

The Upper Jurassic Norphlet Formation is a stratigraphic unit located in the subsurface of the United States Gulf coastal plain and offshore Gulf of America (Gulf of Mexico). The Norphlet consists of clastic sediments derived from the southern Appalachian highlands, and was deposited in a continental dryland setting on the margins of the early Gulf of America rift basin. The formation contains a variety of sedimentary facies, including facies representing updip alluvial fans, wadis, red beds, and a widespread erg, or eolian sand sea. The erg facies form the primary reservoirs from which hydrocarbons sourced from the overlying Smackover Formation are produced. Development of the Norphlet began in earnest in the late 1960s, with new discoveries, including large fields at Flomaton, Hatters Pond, and Mobile Bay, continuing through the 2000s–2010s with the discovery of major oil fields in the offshore Desoto Canyon area. Onshore, Norphlet hydrocarbon traps typically are faulted salt anticlines, although many fields also have a stratigraphic trapping component because of the preservation of dune-scale bedforms. Thermal maturity across the Norphlet play varies significantly with depth, resulting in oil production transitioning downdip to natural gas liquids production, then dry gas production; production depths reach to greater than 21,000 feet. A 2024 U.S. Geological Survey assessment divided the Norphlet into four conventional assessment units defined by the type and frequency of trapping mechanisms, sedimentology, and thermal maturity of each area, with little potential for hydrocarbon development observed west of the Mississippi River. Although petroleum resources in the Norphlet were revised downward, it is probable that significant resources remain to be discovered.

Alabama, Florida, Mississippi↗

Water resources data for Arizona, 1966: Part 2. Water quality records

Water-resources investigations of the U.S. Geological Survey include the collection of water-quality data on the chemical and physical characteristics of surface and ground-water supplies of the Nation. These data for the 1966 water year for the quality of surface waters in Arizona are presented in this report. The data were collected by the Water Resources Division of the U.S. Geological Survey under the di rection of H. M. Babcock, district chief. Water-quality information is presented for chemical quality, fluvial sediment, and water temperatures. The chemical quality includes concentrations of individual dissolved constituents and certain properties or characteristics, such as hardness, sodium-adsorption ratio, specific conductance, and pH. Fluvial-sediment information is given for suspended-sediment discharges and concentrations and for particle-size distribution of suspended sediment and bed material. Water temperature data represent once-daily observations, except for stations where a continuous temperature recorder furnishes information from which daily minimums and maximums are obtained. The Geological Survey published the annual series of water-supply papers, "Quality of Surface Waters of the Unit ed States," from 1941 through 1963, which contained the chemical-quality, temperature, and suspended sediment data of the water. Each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records for Arizona are contained in part 9 of the water-supply paper series. (See table, p. 12.) These publications are available in most public libraries. Beginning with the 1964 water year, water quality records for surface water obtained by the Geological Survey have been published in a new series of annual releases on a State boundary basis. This report is primarily for local and immediate use, and its distribution is limited. The records will be published in Geological Survey water-supply papers at 5-year intervals. The first compilation will cover only the 1964 and 1965 water years.

Arizona↗

Water resources data for Arizona, 1967: Part 2. Water quality records

Water-resources investigations of the U.S. Geological Survey include the collection of water-quality data on the chemical and physical characteristics of surface and ground-water supplies of the Nation. These data for the 1967 water year for the quality of surface waters in Arizona are presented in this report. The data were collected by the Water Resources Division of the U.S. Geological Survey under the direction of H. M. Babcock, district chief. Water-quality information is presented for chemical quality, fluvial sediment, and water temperatures. The chemical quality includes concentrations of individual dissolved constituents and certain properties or characteristics, such as hardness, sodium-adsorption ratio, specific conductance, and pH. Fluvial-sediment information is given for suspended-sediment discharges and concentrations and for particle-size distribution of suspended sediment and bed material. Water-temperature data represent once-daily observations, except for stations where a continuous temperature recorder furnishes information from which daily minimums and maximums are obtained. The Geological Survey published the annual series of water-supply papers, "Quality of Surface Waters of the United States," from 1941 through 1963, which contained the chemical-quality, temperature, and suspended-sediment data of the water. Each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records for Arizona are contained in part 9 of the water-supply paper series. (See table, p. 12.) These publications are available in most public libraries. Beginning with the 1964 water year, water-quality records for surface water obtained by the Geological Survey have been published in a new series of annual releases on a State boundary basis. These reports are primarily for local and immediate use, and their distribution is limited. The records also will be published in Geological Survey water-supply papers.

Arizona↗

Water resources data for Arizona, 1968: Part 2. Water quality records

Water-resources investigations of the U.S. Geological Survey include the collection of water-quality data on the chemical and physical characteristics of surface and groundwater supplies of the Nation. These data for the 1968 water year for the quality of surface waters in Arizona are presented in this report. The data were collected by the Water Resources Division of the U.S. Geological Survey under the direction of H. M. Babcock, district chief. Water-quality information is presented for chemical quality, fluvial sediment, and water temperatures. The chemical quality includes concentrations of individual dissolved constituents and certain properties or characteristics, such as hardness, sodium-adsorption ratio, specific conductance, and pH. Fluvial-sediment information is given for suspended-sediment discharges and concentrations and for particle-size distribution of suspended sediment and bed material. Water-temperature data represent once-daily observations, except for stations where a continuous temperature recorder furnishes information from which daily minimums and maximums are obtained. The Geological Survey published the annual series of water supply papers, "Quality of Surface Waters of the United States," from 1941 through 1963, which contained the chemical-quality. temperature, and suspended-sediment data of the water. Each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records for Arizona are contained in part 9 of the water-supply paper series. (See table, p. 13.) These publications are available in most public libraries. Beginning with the 1964 water year, water-quality records for surface water obtained by the Geological Survey have been published in a new series of annual releases on a State boundary basis. These reports are primarily for local and immediate use, and their distribution is limited. The records also will be published in Geological Survey water-supply papers.

Arizona↗

Water resources data for Arizona, 1969: Part 2. Water quality records

Water-resources investigations of the U.S. Geological Survey include the collection of water-quality data on the chemical and physical characteristics of surface- and ground-water supplies of the Nation. These data for the 1969 water year for the quality of surface waters in Arizona are presented in this report. The data were collected by the Water Resources Division of the U.S. Geological Survey under the direction of H. M. Babcock, district chief. The Geological Survey published the annual series of water-supply papers, "Quality of Surface Waters of the United States, " from 1941 through 1965, which contained the chemical-quality, temperature, and suspended-sediment data of the water. Each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records for Arizona are contained in part 9 of the water-supply paper series. (See table 4.) These publications are available in most public libraries. Beginning with the 1964 water year, water-quality records for surface water obtained by the Geological Survey have been published in a series of annual releases on a State boundary basis. These reports are primarily for local and immediate use, and their distribution is limited. The records also will be published in Geological Survey water-supply papers.

Arizona↗

Water resources data for Arizona, 1970: Part 2. Water quality records

Water-resources investigations of the U.S. Geological Survey include the collection of water-quality data on the chemical and physical characteristics of surface and ground-water supplies of the Nation. These data for the 1970 water year for the quality of surface waters in Arizona are presented in this report. The data were collected by the Water Resources Division of the U.S. Geological Survey under the direction of H. M. Babcock, district chief. The Geological Survey published the annual series of water-supply papers, ''Quality of Surface Waters of the United States,'' from 1941 through 1965, which contained the chemical-quality, temperature, and suspended-sediment data of the water. Each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records for Arizona are contained in part 9 of the water-supply paper series. (See table 4.) These publications are available in most public libraries. Beginning with the 1964 water year, water-quality records for surface water obtained by the Geological Survey have been published in a series of annual releases on a State boundary basis. These reports are primarily for local and immediate use, and their distribution is limited. The records also will be published in Geological Survey water-supply papers.

Arizona↗

Water resources data for Arizona, water year 1971: Part 1. Water quality records

Water-resources investigations of the U.S. Geological Survey include the collection of water-quality data on the chemical and physical characteristics of surface- and ground- water supplies of the Nation. These data for the 1971 water year for the quality of surface waters in Arizona are presented in this report. The data were collected by the Water Resources Division of the U.S. Geological Survey under the direction of H. M. Babcock, district chief. The Geological Survey published the annual series of watersupply papers, "Quality of Surface Waters of the United States, " from 1941 through 1965, which contained the chemical-quality, temperature, and suspended-sediment data of the water. Each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records for Arizona are contained in part 9 of the water-supply paper series. (See table 4.) These publications are available in most public libraries. Beginning with the 1964 water year, water-quality records for sur face water obtained by the Geological Survey have been published in a series of annual releases on a State boundary basis. These reports are primarily for local and immediate use, and their distribution is limited. The records also will be published in Geological Survey watersupply papers.

Arizona↗

Water resources data for Arizona, water year 1972

Water resources data for the 1972 water year for Arizona include records of data for the chemical and physical characteristics of surface water. Data on the quality of surface water (chemical, temperature, and sediment) were collected from designated sampling sites at predetermined intervals, such as once daily, weekly, monthly, or less frequently; at some sites, data were collected continuously by means of automatic recording devices . Records are given for 77 sampling stations, of which 46 are continuous record stations, 8 are partial-record stations, and 23 are miscellaneous sampling stations. Locations of surface water-quality stations are shown in figures 1 and 2. A few pertinent stations in bordering States are also included. The records were collected by the Water Resources Division of the U.S. Geological Survey under the direction of H. M. Babcock, district chief. These data represent that portion of the National Water Data System collected bythe U.S. Geological Survey and cooperating State and Federal agencies in Arizona. The Geological Survey has published records of chemical quality, water temperatures, and sediment since 1941 in an annual s eries of water-supply papers entitled, ''Quality of Surface Waters of the United States." Beginning with the 1964 water year, water - quality records have been released by the Geological Survey in annual reports on a State boundary basis. These reports are for limited distribution and are designed primarily for rapid release of data shortly after the end of the water year. These records will be published later in Geological Survey water-supply papers.

Arizona↗

Water resources data for Arizona, water year 1973: Part 2. Water quality records

Water resources data for the 1973 water year for Arizona include records of data for the chemical and physical characteristics of surface water. Data on the quality of surface water (chemical, temperature, and sediment) were collected from designated sampling sites at predetermined intervals, such as once daily, weekly, monthly, or less frequently; at some sites, data were collected continuously by means of automatic recording devices. Records are given for 81 sampling stations, of which 48 are continuous record stations, 6 are partial-record stations, and 27 are miscellaneous sampling stations. Locations of surface water-quality stations are shown in figures 1 and 2. A few pertinent stations in bordering States are also included. The records were collected by the Water Resources Division of the U.S. Geological Survey under the direction of H. M. Babcock, district chief. These data represent that portion of the National Water Data System collected by the U. S. Geological Survey and cooperating State and Federal agencies in Arizona. The Geological Survey has published records of chemical quality, water temperatures, and sediment since 1941 in an annual series of water-supply papers entitled, "Quality of Surface Waters of the United States." Beginning with the 1964 water year, water-quality records have been released by the Geological Survey in annual reports on a State boundary basis. These reports are for limited distribution and are designed primarily for rapid release of data shortly after the end of the water year. These records will be published later in Geological Survey water-supply papers.

Arizona↗

Water Resources Data for California, 1965; Part 2: Water Quality Records

Water-resources investigations of the U.S. Geological Survey include the collection of water quality data on the chemical and physical characteristics of surface and ground-water supplies of the Nation. These data for the 1965 water year for the quality of surface waters in California are presented in this report. Data for a few water quality stations in bordering States are also included. The data were collected by the Water Resources Division of the U.S Geological Survey under the direction of Walter Hofmann, district chief. Water quality information is presented for chemical quality, fluvial sediment, and water temperatures. The chemical quality includes concentrations of individual dissolved constituents and certain properties or characteristics such as hardness, sodium-adsorption-ratio, specific conductance, and pH. Fluvial sediment information is given for suspended-sediment discharges and concentrations and for particle-size distribution of suspended sediment and bed material. Water temperature data represent once-daily observations except for stations where a continuous temperature recorder furnishes information from which daily minimums and maximums are obtained.

California↗