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At least 523 records · Page 29Linked to original sources
USGS1993

Options for water-level control in developed wetlands

Wetland habitats in the United States currently are lost at a rate of 260,000 acres/year (105,218 ha/year). Consequently, water birds concentrate in fewer and smaller areas. Such concentrations may deplete food supplies and influence behavior, physiology, and survival. Continued losses increase the importance of sound management of the remaining wetlands because water birds depend on them. Human activities modified the natural hydrology of most remaining wetlands in the conterminous United States, and such hydrologic alterations frequently reduce wetland productivity. The restoration of original wetland functions and productivity often requires the development of water distribution and discharge systems to emulate natural hydrologic regimes. Construction of levees and correct placement of control structures and water-delivery and water-discharge systems are necessary to (1) create soil and water conditions for the germination of desirable plants, (2) control nuisance vegetation, (3) promote the production of invertebrates, and (4) make foods available for wildlife that depends of wetlands (Leaflets 13.2.1 and 13.4.6). This paper provides basic guidelines for the design of wetlands that benefit wildlife. If biological considerations are not incorporated into such designs, the capability of managing wetlands for water birds is reduced and costs often are greater. Although we address the development of palustrine wetlands in migration and wintering areas, many of the discussed principles are applicable to the development of other wetland types and in other locations.

Book chapter↗
USGS2005

Tropical cyclones and the flood hydrology of Puerto Rico

Some of the largest unit discharge flood peaks in the stream gaging records of the U.S. Geological Survey (USGS) have occurred in Puerto Rico. Many of these flood peaks are associated with tropical cyclones. Hurricane Georges, which passed directly over the island on 21–22 September 1998, produced record flood peaks at numerous USGS stations in Puerto Rico. The hydrology and hydrometeorology of extreme flood response in Puerto Rico are examined through analyses of rainfall, based on Weather Surveillance Radar–1988 Doppler (WSR‐88D) radar reflectivity observations and USGS rain gage observations and discharge from USGS stream gaging stations. Peak rainfall accumulations of more than 700 mm occurred in the central mountain region of the island. The largest unit discharge flood peaks, however, were located in the eastern portion of the island in areas with smaller storm total rainfall accumulations but markedly larger rainfall rates at 5–60 min timescale. Orographic precipitation mechanisms played an important role in rainfall distribution over the island of Puerto Rico. Amplification of rainfall accumulations was associated with areas of upslope motion. Elevated low‐level cloud water content in regions of upslope motion played an important role in the maximum rainfall accumulations in the central mountain region of Puerto Rico. The largest unit discharge flood peaks, however, were produced by a decaying eye wall mesovortex, which resulted in a 30–45 min period of extreme rainfall rates over the eastern portion of the island. This storm element was responsible for the record flood peak of the Río Grande de Lóiza. The role of terrain in development and evolution of the eye wall mesovortex is unclear but is of fundamental importance for assessing extreme flood response from the storm. Hydrologic response is examined through analyses of rainfall and discharge from five pairs of drainage basins, extending from east to west over the island. These analyses point to the importance of short‐term rainfall rates for extreme flood response. The hydrologic response of Puerto Rico is compared with two other extreme flood environments, the central Appalachians and Edwards Plateau of Texas. These analyses suggest that the high rainfall environment of Puerto Rico is linked to the development of a hydraulically efficient drainage system.

Water Resources Research↗
USGS2019

The potential role of very high-resolution imagery to characterise lake, wetland and stream systems across the Prairie Pothole Region, United States

Aquatic features critical to watershed hydrology range widely in size from narrow, shallow streams to large, deep lakes. In this study we evaluated wetland, lake, and river systems across the Prairie Pothole Region to explore where pan-sharpened high-resolution (PSHR) imagery, relative to Landsat imagery, could provide additional data on surface water distribution and movement, missed by Landsat. We used the monthly Global Surface Water (GSW) Landsat product as well as surface water derived from Landsat imagery using a matched filtering algorithm (MF Landsat) to help consider how including partially inundated Landsat pixels as water influenced our findings. The PSHR outputs (and MF Landsat) were able to identify ~60–90% more surface water interactions between waterbodies, relative to the GSW Landsat product. However, regardless of Landsat source, by documenting many smaller (<0.2 ha), inundated wetlands, the PSHR outputs modified our interpretation of wetland size distribution across the Prairie Pothole Region.

Prairie Pothole Region↗
USGS2022

Assessing runoff and erosion on woodland-encroached sagebrush steppe using the Rangeland Hydrology and Erosion Model

The transition of sagebrush-dominated ( Artemisia spp.) shrublands to pinyon ( Pinus spp.) and juniper ( Juniperus spp.) woodlands markedly alters resource-conserving vegetation structure typical of these landscapes. Land managers and scientists in the western United States need knowledge and predictive tools for assessment and effective targeting of tree-removal treatments to conserve or restore sagebrush vegetation and associated hydrologic function. This study developed modeling approaches to quantify the hydrologic vulnerability and erosion potential of sagebrush rangelands in the later stages of woodland encroachment and in response to commonly applied tree-removal treatments. Using experimental data from multiple sites in the Great Basin Region, USA, and process-based knowledge from decade-long vegetation and rainfall simulation studies at those sites, we (1) assessed the capability of the Rangeland Hydrology and Erosion Model (RHEM) to accurately predict patch-scale (12 m 2 ) measured runoff and erosion from tree canopy and intercanopy hydrologic functional units in untreated and burned woodlands 9 years postfire, and (2) developed and evaluated multiple RHEM approaches/frameworks to model aggregated effects of tree canopy and intercanopy areas on patch- and hillslope-scale (50 m length) runoff and erosion processes in untreated and treated (burned, cut, and masticated) woodlands. The RHEM accurately predicted measured runoff and sediment yield from patch-scale rainfall simulations as partitioned on untreated and treated tree canopy and intercanopy areas and effectively parameterized the dominant controls on runoff and erosion process in woodlands. With few exceptions, evaluated hillslope-scale RHEM frameworks similarly predicted reduced hydrologic vulnerability and erosion potential for conditions 9 years following tree removal by burning, cutting, and mastication treatments. Regressions of RHEM-predicted hillslope runoff, sediment, and hydraulic/erosion parameters with bare ground and ground cover attributes indicate all RHEM frameworks effectively represented the dominant controls on hydrologic and erosion processes for rangelands and woodlands. The results provide RHEM frameworks and recommendations for assessing hydrologic vulnerability and erosion potential on woodland-encroached sites and predicting the effectiveness of tree removal to reestablish a water and soil resource-conserving vegetation structure on sagebrush rangelands. We anticipate our RHEM or similar modeling approaches may be applicable to analogous water-limited landscapes elsewhere subject to woody plant encroachment.

Nevada, Utah↗
USGS2016

Analyses of infrequent (quasi-decadal) large groundwater recharge events in the northern Great Basin: Their importance for groundwater availability, use, and management

There has been a considerable amount of research linking climatic variability to hydrologic responses in the western United States. Although much effort has been spent to assess and predict changes in surface water resources, little has been done to understand how climatic events and changes affect groundwater resources. This study focuses on characterizing and quantifying the effects of large, multiyear, quasi-decadal groundwater recharge events in the northern Utah portion of the Great Basin for the period 1960–2013. Annual groundwater level data were analyzed with climatic data to characterize climatic conditions and frequency of these large recharge events. Using observed water-level changes and multivariate analysis, five large groundwater recharge events were identified with a frequency of about 11–13 years. These events were generally characterized as having above-average annual precipitation and snow water equivalent and below-average seasonal temperatures, especially during the spring (April through June). Existing groundwater flow models for several basins within the study area were used to quantify changes in groundwater storage from these events. Simulated groundwater storage increases per basin from a single recharge event ranged from about 115 to 205 Mm 3 . Extrapolating these amounts over the entire northern Great Basin indicates that a single large quasi-decadal recharge event could result in billions of cubic meters of groundwater storage. Understanding the role of these large quasi-decadal recharge events in replenishing aquifers and sustaining water supplies is crucial for long-term groundwater management.

Utah↗
USGS2007

Accumulation of dechlorination daughter products: A valid metric of chloroethene biodegradation

In situ reductive dechlorination of perchloroethene (PCE) and trichloroethene (TCE) generates characteristic chlorinated (cis-dichloroethene [cis-DCE] and vinyl chloride [VC]) and nonchlorinated (ethene and ethane) products. The accumulation of these daughter products is commonly used as a metric for ongoing biodegradation at field sites. However, this interpretation assumes that reductive dechlorination is the only chloroethene degradation process of any significance in situ and that the characteristic daughter products of chloroethene reductive dechlorination persist in the environment. Laboratory microcosms, prepared with aquifer and surface-water sediments from hydrologically diverse sites throughout the United States and amended with [1,2- 14 C] TCE, [1,2- 14 C] DCE, [1,2- 14 C] DCA, or [1,2- 14 C] VC, demonstrated widely variable patterns of intermediate and final product accumulation. In predominantly methanogenic sediment treatments, accumulation of 14 C-DCE, 14 C-VC, 14 C-ethene, and 14 C-ethane predominated. Treatments characterized by significant Fe(III) and/or Mn(IV) reduction, on the other hand, demonstrated substantial, and in some cases exclusive, accumulation of 14 CO 2 and 14 CH 4 . These results suggest that relying on the accumulation of cis-DCE, VC, ethene, and ethane may substantially underestimate overall chloroethene biodegradation at many sites.

Remediation Journal↗
USGS2023

Luminescence ages and new interpretations of the timing and deposition of Quaternary sediments at Natural Trap Cave, Wyoming

Natural Trap Cave, located in the Big Horn Mountains of north-central Wyoming, has a history of trapping and preserving a range of North American fauna that plummeted into the deep vertical entrance. These animal remains were buried and preserved within sediments of the main chamber and, in turn, have helped elucidate the procession of faunal dynamics during the latest glacial cycle. The cave location, south of the Laurentide and Cordilleran Ice Sheets, and proximal to Yellowstone, is at an ideal geographical juncture to provide insights to ecological changes in North America. The sediments that the animals are buried in inform us about transport and deposition both inside and outside of the cave that relate to catchment dynamics. We report on a series of optically stimulated luminescence (OSL) ages derived from samples obtained within the cave during excavation work in 2014 and in 2018. We also examine chronology produced by argon, tephrochronology, fission track, and luminescence techniques that have been used for understanding the infilling of the cave. The cave sediment ages and in situ measured gamma spectroscopy as measured in this study helped resolve an improved chronological age model when combined with previous data. The suite of OSL ages is interpreted through the stratigraphic relationships (and vertebrates contained within) which requires the use of an adequate age model; we use either the central age model or minimum age model where appropriate and with justification. Lowest sediments are dated to ∼150 ka with a hiatus at ∼130 to 52 ka. Above this, sediment deposition and entrainment of paleontological materials are representative of Pleistocene and early Holocene times, between 37 ± 6 ka and 7.6 ± 0.5 ka. The stratigraphic architecture suggests that deposition of materials into the cave is episodic and rapid, followed by quiescent periods where hydrologic scour, heavy overland flow , or possibly a cryo-hydrologic process may have altered unit relationships. Thus, the complementary geochronometers and the characteristics of quartz versus feldspar luminescence signals improve temporal interpretations of these complex deposits. This adapted understanding of mixing also sets the stage for future work with the aim to improve our understanding of ages and sources for ash units within these cave deposits. The three ash units recognized in the cave may represent an in-situ reworking of the same ash or may be representative of previously undocumented eruptions from the Yellowstone Caldera.

Wyoming↗
USGS2014

Pluvial lakes in the Great Basin of the western United States: a view from the outcrop

Paleo-lakes in the western United States provide geomorphic and hydrologic records of climate and drainage-basin change at multiple time scales extending back to the Miocene. Recent reviews and studies of paleo-lake records have focused on interpretations of proxies in lake sediment cores from the northern and central parts of the Great Basin. In this review, emphasis is placed on equally important studies of lake history during the past ∼30 years that were derived from outcrop exposures and geomorphology, in some cases combined with cores. Outcrop and core records have different strengths and weaknesses that must be recognized and exploited in the interpretation of paleohydrology and paleoclimate. Outcrops and landforms can yield direct evidence of lake level, facies changes that record details of lake-level fluctuations, and geologic events such as catastrophic floods, drainage-basin changes, and isostatic rebound. Cores can potentially yield continuous records when sampled in stable parts of lake basins and can provide proxies for changes in lake level, water temperature and chemistry, and ecological conditions in the surrounding landscape. However, proxies such as stable isotopes may be influenced by several competing factors the relative effects of which may be difficult to assess, and interpretations may be confounded by geologic events within the drainage basin that were unrecorded or not recognized in a core. The best evidence for documenting absolute lake-level changes lies within the shore, nearshore, and deltaic sediments that were deposited across piedmonts and at the mouths of streams as lake level rose and fell. We review the different shorezone environments and resulting deposits used in such reconstructions and discuss potential estimation errors. Lake-level studies based on deposits and landforms have provided paleohydrologic records ranging from general changes during the past million years to centennial-scale details of fluctuations during the late Pleistocene and Holocene. Outcrop studies have documented the integration histories of several important drainage basins, including the Humboldt, Amargosa, Owens, and Mojave river systems, that have evolved since the Miocene within the active tectonic setting of the Great Basin; these histories have influenced lake levels in terminal basins. Many pre-late Pleistocene lakes in the western Great Basin were significantly larger and record wetter conditions than the youngest lakes. Outcrop-based lake-level data provide important checks on core-based proxy interpretations; we discuss four such comparisons. In some cases, such as for Lakes Owens and Manix, outcrop and core data synthesis yields stronger and more complete records; in other cases, such as for Bonneville and Lahontan, conflicts point toward reconsideration of confounding factors in interpretation of core-based proxies.

Great Basin↗
USGS2025

Water withdrawal and consumption trends for thermoelectric-power plants in the conterminous United States, 2008-2020

Freshwater-using utility-scale thermoelectric (TE) plant water-use estimates were evaluated for annual trends from 2008 to 2020 across the conterminous United States (CONUS) and within hydrologic regions. Overall, TE water withdrawal and consumption trends declined across CONUS by 14,335 and 278 million liters/day, respectively. Decreasing water withdrawal and consumption trends for TE plants are driven largely by switching from coal-fired plants to other generation technologies. TE plant cooling system technology has also changed, with large declining trends for TE plants using once-through cooling systems and small increasing consumption trends for TE plants using recirculating tower cooling systems. Fifteen hydrologic regions have decreasing trends in withdrawals and consumption. The largest decreases are for coal-fired plants using once-through freshwater cooling systems in the Great Lakes and Ohio hydrologic regions. Natural gas combined cycle plants with recirculating tower cooling systems have increased water consumption trends across most of the CONUS hydrologic regions. Some TE plants with recirculating tower or once-through cooling systems withdraw water volumes that on average are close to or exceed average simulated streamflows. Most of these situations occur in the central and eastern U.S., potentially leading to water availability issues among competing water needs, ecosystem impacts from thermal pollution, and power generation constraints.

conterminous United States↗
USGS2009

Digital representation of 1:1,000,000-scale hydrographic areas of the Great Basin

Hydrographic areas (HA) in Nevada were delineated by the U.S. Geological Survey (USGS) and Nevada Division of Water Resources in the late 1960s for scientific and administrative purposes. The official HA names, numbers, and boundaries continue to be used in USGS scientific reports and Nevada State Division of Water Resources administrative activities. HAs for the Great Basin region of the United States were mapped in the late 1980’s as part of a USGS regional assessment of aquifer systems in the Great Basin. The Great Basin HAs are being published in digital format to document the data as the basic accounting unit for past and recent hydrologic investigations in the Great Basin.

Great Basin↗
USGS2010

Summary of hydrologic testing of the Floridan aquifer system at Hunter Army Airfield, Chatham County, Georgia

A 1,168-foot deep test well was completed at Hunter Army Airfield in the summer of 2009 to investigate the potential of using the Lower Floridan aquifer as a source of water supply to satisfy increased needs as a result of base expansion and increased troop levels. The U.S. Geological Survey conducted hydrologic testing at the test site including flowmeter surveys, packer-slug tests, and aquifer tests of the Upper and Lower Floridan aquifers. Flowmeter surveys were completed at different stages of well construction to determine the depth and yield of water-bearing zones and to identify confining beds that separate the main producing aquifers. During a survey when the borehole was open to both the upper and lower aquifers, five water-bearing zones in the Upper Floridan aquifer supplied 83.5 percent of the total pumpage, and five water-bearing zones in the Lower Floridan aquifer supplied the remaining 16.5 percent. An upward gradient was indicated from the ambient flowmeter survey: 7.6 gallons per minute of groundwater was detected entering the borehole between 750 and 1,069 feet below land surface, then moved upward, and exited the borehole into lower-head zones between 333 and 527 feet below land surface. During a survey of the completed Lower Floridan well, six distinct water-producing zones were identified; one 17-foot-thick zone at 768-785 feet below land surface yielded 47.9 percent of the total pumpage while the remaining five zones yielded between 2 and 15 percent each. The thickness and hydrologic properties of the confining unit separating the Upper and Lower Floridan aquifers were determined from packer tests and flowmeter surveys. This confining unit, which is composed of rocks of Middle Eocene age, is approximately 160 feet thick with horizontal hydraulic conductivities determined from four slug tests to range from 0.2 to 3 feet per day. Results of two separate slug tests within the middle confining unit were both 2 feet per day. Aquifer testing indicated the Upper Floridan aquifer had a transmissivity of 40,000 feet squared per day, and the Lower Floridan aquifer had a transmissivity of 10,000 feet squared per day. An aquifer test conducted on the combined aquifer system, when the test well was open from 333 to 1,112 feet, gave a transmissivity of 50,000 feet squared per day. Additionally, during the 72-hour test of the Lower Floridan aquifer, a drawdown response was observed in the Upper Floridan aquifer wells.

Georgia↗
USGS1997

Summary of data concerning radiological contamination at well PM-2, Nevada Test Site, Nye County, Nevada

Analysis of water collected during August and September 1993 from well PM-2, on Pahute Mesa at\x11the Nevada Test Site, indicated tritium concentrations of\x1121,000 Bq/L at 610 m below land surface. The Schooner event (U-20u) was detonated in 1968 approximately 270 meterssoutheast of well PM-2 at a working depth of 108.2 meters. The crater created by the Schooner event was about 129.8 meters in radius and\x1163.4 meters in depth. Geologic and hydrologic properties of the stratigraphic units are summarized from historical data. The soil around the well and water in the well were analyzed for radionuclides and water in the well was also analyzed for inorganic constituents and organic (volatile and semivolatile) substances. Close agreement between tritium analyses of water from well PM-2, at different times and at the same depths, confirms the elevated levels of tritium. The highest tritium values in the borehole were at 610 meters below land surface-above the shallowest perforations at 765 meters below land surface. These values were only slightly higher than values found at greater depth in the well.

Open-File Report↗
USGS2004

Water Resources Data, New Jersey, Water Year 2003; Volume 1. Surface-Water Data

Water-resources data for the 2003 Water Year for New Jersey are presented in three volumes, and consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and water levels and water quality of ground water. Volume 1 contains discharge records for 100 gaging stations; tide summaries at 29 tidal gaging stations; and stage and contents at 39 lakes and reservoirs. Also included are stage and discharge for 106 crest-stage partial-record stations, stage-only at 33 tidal crest-stage gages, and discharge for 142 low-flow partial- record stations. Locations of these sites are shown in figures 8-11. Additional discharge measurements were made at 143 miscellaneous sites that are not part of the systematic data-collection program. Discontinued station tables for gaging stations, crest-stage gages, tidal crest-stage and tidal gaging stations show historical coverage. The data in this report represent that part of the National Water Information System (NWIS) data collected by the United States Geological Survey (USGS). Hydrologic conditions are also described for this water year, including streamflow, precipitation, reservoir conditions, and air temperatures.

Water Data Report↗
USGS2005

Water resources data, New Jersey, water year 2004-volume 1. surface-water data

Water-resources data for the 2004 water year for New Jersey are presented in three volumes, and consists of records of stage, discharge, and water-quality of streams; stage and contents of lakes and reservoirs; and water levels and water-quality of ground water. Volume 1 contains discharge records for 105 gaging stations; tide summaries at 27 tidal gaging stations; stage and contents at 39 lakes and reservoirs; and diversions from 51 surface-water sources. Also included are stage and discharge for 108 crest-stage partial-record stations, stage-only at 34 tidal crest-stage gages, and discharge for 124 low-flow partial-record stations. Locations of these sites are shown in figures 8-11. Additional discharge measurements were made at 131 miscellaneous sites that are not part of the systematic data-collection program. Discontinued station tables for gaging stations, crest-stage gages, tidal crest-stage and tidal gaging stations show historical coverage. The data in this report represent that part of the National Water Information System (NWIS) data collected by the United States Geological Survey (USGS). Hydrologic conditions are also described for this water year, including stream-flow, precipitation, reservoir conditions, and air temperatures.

Water Data Report↗
USGS2006

Water resources data, New Jersey, water year 2005. Volume 1 - surface-water data

Water-resources data for the 2005 water year for New Jersey are presented in three volumes, and consists of records of stage, discharge, and water-quality of streams; stage and contents of lakes and reservoirs; and water levels and water-quality of ground water. Volume 1 contains discharge records for 103 gaging stations; tide summaries at 28 tidal gaging stations; stage and contents at 34 lakes and reservoirs; and diversions from 50 surface-water sources. Also included are stage and discharge for 116 crest-stage partial-record stations, stage-only at 33 tidal crest-stage gages, and discharge for 155 low-flow partial-record stations. Locations of these sites are shown in figures 8-11. Additional discharge measurements were made at 222 miscellaneous sites that are not part of the systematic data-collection program. Discontinued station tables for gaging stations, crest-stage gages, tidal crest-stage and tidal gaging stations show historical coverage. The data in this report represent that part of the National Water Information System (NWIS) data collected by the United States Geological Survey (USGS). Hydrologic conditions are also described for this water year, including stream-flow, precipitation, reservoir conditions, and air temperatures.

Water Data Report↗
USGS1993

Wetland modeling and information needs at Stillwater National Wildlife Refuge

The marshes in and around Stillwater National Wildlife Refuge (the Refuge) are extremely dynamic; expanding and contracting in size both seasonally, due to runoff and subsequent evapotranspiration, and over longer periods, due to climatic variation. The dynamic nature of these marshes results in a diversity of wetland habitats, which support a variety of migratory birds. To maintain this wetland diversity and control the loss of migratory bird habitat in the Lahontan Valley, the Refuge was established and currently manages a complex of marsh units. However, changes in the hydrology, and changes that will occur as a result of the Fallon Paiute-Shoshone and Truckee-Carson-Pyramid Lake Water Rights Settlement Act (Public Law 101-618, 104 Stat. 3389), greatly affect the Refuge's wetland management capability. In light of these changes, and the legal requirements associated with environmental impact assessments, the Refuge convened a workshop to discuss several aspects of wetland management in the Lahontan Valley. The workshop, described in this report, had three primary objectives: 1. discuss the types and relative proportions of primary wetland habitats that should be provided as described in the settlement act; 2. discuss wetland management models that might be developed to help manage these marshes under hydrologic regimes likely in the future; and 3. discuss future information and monitoring needs, including proposals for valley-wide biodiversity surveys, which would be helpful when considering withdrawn Bureau of Reclamation (BR) lands for possible incorporation into the Refuge. Several presentations at the beginning of the workshop provided a common basis for discussing these objectives. Refuge staff provided background on the history and past management. The Nature Conservatory discussed their role in the settlement act, proposals for valley-wide biodiversity surveys, and results of a literature review for Stillwater Marsh and the Lahontan Valley (Nachlinger 1993). Kay Fowler provided an historical context of changes in vegetation and waterbird use of the marshes based on her ethnography of the local Paiute Indians (Fowler 1993). Finally, Bob Elston discussed a model that predicts archaeological sites based on environmental variables (Raven and Elston 1989). The workshop was organized by staff from the Refuge and facilitated by the authors of this report. Participants included Ron Anglin, Bill Henry, Anne Janik, Cliff Creger, Fred Paveglio, and Mary Jo Elpers of the U.S. Fish and Wildlife Service (the Service); Jeff Baumgartner, Jan Nachlinger, Hope Humphries, and Graham Chisholm of The Nature Conservancy; David Yardas of the Environmental Defense Fund; David Robertson of Robertson Software, Inc.; Norm Saake, Terry Retterer, and Larry Neel of the Nevada Department of Wildlife; Lew Oring and Kay Fowler of the University of Nevada; and Robert Elston of Intermountain Research.

Report↗
USGS1977

Hydrologic characteristics of the Madison Limestone, the Minnelusa Formation, and equivalent rocks as determined by well-logging formation evaluation, Wyoming, Montana, South Dakota, and North Dakota

Geophysical logs from wells distributed throughout the Powder River Basin were digitized, processed, and interpreted to get a regional understanding of the lithologic and ground-water characteristics of aquifers in the Madison Limestone and Minnelusa Formation. The percentage of sand, porosity, and apparent ground-water resistivity of the Minnelusa closely follow structural trends in the basin. Values increase from the structural axis of the basin toward the flanks. Close correlations between the water resistivities in the Madison and the Minnelusa indicate possible hydrologic connection between the two units. The low primary porosity from geophysical logs in the Madison indicates that secondary porosity is necessary to develop water supplies of economic importance from the Madison. Because of increased porosity and better water quality, the flanks of the basin appear to be the most favorable places for water production from either the Madison or the Minnelusa.

Wyoming, Montana, South Dakota, North Dakota↗
USGS1989

Water-quality data for the Potomac-Raritan-Magothy aquifer system in the northern coast plain of New Jersey, 1923-86

Ground-water-quality data for the upper and middle aquifers of the Potomac-Raritan-Magothy aquifer system in Middlesex and Monmouth Counties are compiled for the period 1923-86. A total of 330 wells were sampled: 192 wells in the upper aquifer and 138 wells in the middle aquifer. Most of the complete water-quality analyses were collected after September 1984, as part of a regional ground-water assessment. Well-construction data for the sampled wells also are presented. Public-supply, domestic-supply, industrial, commercial, irrigation, and observation wells were sampled for the study. Field measurements made at the time of sample collection include water temperature, specific conductance , dissolved oxygen, pH, alkalinity, and bicarbonate concentration. Laboratory determinations include common ions, silica, dissolved solids, trace metals, volatile organic compounds, and pesticides. A quality-assurance program was followed to evaluate and assure the quality of the data. The report also contains a table of lithologic and hydrologic characteristics of the geologic units in the study area, a table of chloride concentrations and field measurements from 1923-86, and statistical summaries of selected water-quality data for the upper and middle aquifers. Many constituents were found in a wide range of concentrations. Water from more than 25 percent of the wells sampled contained lead concentrations above the detection limit of 10 ug/L (micrograms per liter). Included in this number are some wells that had lead concentrations greater than the U.S. Environmental Protection Agency (USEPA) primary drinking-water regulation of 50 ug/L. Cadmium concentrations, although lower than lead concentrations, followed a similar pattern. Water from approximately 25 percent of the wells in the upper aquifer, contain cadmium concentrations equal to or greater than the detection limit of 1 ug/L. Dissolved iron concentrations ranged from 5 ug/L to 480,000 ug/L. Water from more than 50 percent of the wells sampled contained iron concentrations in excess of the USEPA secondary drinking-water recommended limit of 300 ug/L. Chloride concentrations greater than the USEPA secondary drinking-water recommended limit of 250 milligrams per liter were found in samples from wells located in the cities of Perth Amboy and South Amboy; in the boroughs of Keansburg, Sayreville, Keyport, and Union Beach; and in the townships of Old Bridge and Woodbridge. Of 21 samples collected from wells screened in the upper aquifer and analyzed for 30 volatile organic compounds (VOCs), 5 samples contained at least 1 VOC at or above the detection limit. In the middle aquifer, 12 of the 21 samples collected and analyzed for VOCs contained at least 1 VOC greater than the detection limit. Concentrations of pesticides generally were low. Of the 43 samples collected from wells screened in the upper aquifer and analyzed for pesticides, 4 samples contained concentrations of pesticides at or greater than the detection limit. In the middle aquifer, 6 of 38 samples collected and analyzed for 32 pesticides had at least 1 pesticide with a concentration greater than the detection limit.

New Jersey↗