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At least 37 records · Page 2Linked to original sources
USGS1981

Water-quality assessment of Cache Creek, Yolo, Lake, and Colusa counties, California

Cache Creek and its tributaries from Clear Lake to Yolo Bypass have been the subject of quality and quantity of water studies by several governmental agencies since the early 1900's. Water-quality data from these studies showed that water in the basin is of good quality for most of the beneficial uses defined by the California State Water Resources Control Board. Concentrations of dissolved constituents are substantially higher in the water in the two largest tributaries than in Cache Creek. Seasonal variations in dissolved constituents are also greater in the tributaries than in Cache Creek. Clear Lake has a major effect on water quality, resulting in little seasonal fluctuation in water quality in Cache Creek. Excessive voron and suspended-sediment concentrations are the greatest water-quality problems, according to existing data. Both of these problems are from natural sources. Water-quality monitoring is presently being conducted monthly at four sites by the California Department of Water Resurces and at several other sites by other agencies. Modifications in current monitoring are proposed to gain further information on diel dissolved-oxygen cycles, pesticides, and biological constituents that may adversely affect beneficial uses. (USGS)

Open-File Report↗
USGS2013

The 3D Elevation Program: summary for California

Elevation data are essential to a broad range of applications, including forest resources management, wildlife and habitat management, national security, recreation, and many others. For the State of California, elevation data are critical for infrastructure and construction management; natural resources conservation; flood risk management; wildfire management, planning, and response; agriculture and precision farming; geologic resource assessment and hazard mitigation; and other business uses. Today, high-quality light detection and ranging (lidar) data are the sources for creating elevation models and other elevation datasets. Federal, State, and local agencies work in partnership to (1) replace data, on a national basis, that are (on average) 30 years old and of lower quality and (2) provide coverage where publicly accessible data do not exist. A joint goal of State and Federal partners is to acquire consistent, statewide coverage to support existing and emerging applications enabled by lidar data. The new 3D Elevation Program (3DEP) initiative, managed by the U.S. Geological Survey (USGS), responds to the growing need for high-quality topographic data and a wide range of other three-dimensional representations of the Nation’s natural and constructed features.

California↗
USGS2015

Assessment of interim flow water-quality data of the San Joaquin River restoration program and implications for fishes, California, 2009-11

After more than 50 years of extensive water diversion for urban and agriculture use, a major settlement was reached among the U.S. Departments of the Interior and Commerce, the Natural Resources Defense Council, and the Friant Water Users Authority in an effort to restore the San Joaquin River. The settlement received Federal court approval in October 2006 and established the San Joaquin River Restoration Program, a multi-agency collaboration between State and Federal agencies to restore and maintain fish populations, including Chinook salmon, in the main stem of the river between Friant Dam and the confluence with the Merced River. This is to be done while avoiding or minimizing adverse water supply effects to all of the Friant Division contractors that could result from restoration flows required by the settlement. The settlement stipulates that water- and sediment-quality data be collected to help assess the restoration goals. This report summarizes and evaluates water-quality data collected in the main stem of the San Joaquin River between Friant Dam and the Merced River by the U.S. Bureau of Reclamation for the San Joaquin River Restoration Program during 2009-11. This summary and assessment consider sampling frequency for adequate characterization of variability, sampling locations for sufficient characterization of the San Joaquin River Restoration Program restoration reach, sampling methods for appropriate media (water and sediment), and constituent reporting limits. After reviewing the water- and sediment-quality results for the San Joaquin River Restoration Program, several suggestions were made to the Fisheries Management Work Group, a division of the San Joaquin River Restoration Program that focuses solely on the reintroduction strategies and health of salmon and other native fishes in the river. Water-quality results for lead and total organic carbon exceeded the Surface Water Ambient Monitoring Program Basin Plan Objectives for the San Joaquin Basin, and results for copper exceeded the U.S. Environmental Protection Agency Office of Pesticide Programs' aquatic-life chronic and acute benchmarks for invertebrates. One sediment sample contained detections of pyrethroid pesticides bifenthrin, lambda-cyhalothrin, and total permethrin at concentrations above published chronic toxicity thresholds.

California↗
USGS2024

Status of water quality in groundwater resources used for drinking-water supply in the southeastern San Joaquin Valley, 2013–15—California GAMA Priority Basin Project

The California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP) investigated water quality of groundwater resources used for drinking-water supplies in the Madera-Chowchilla, Kings, Kaweah, Tule, and Tulare Lake groundwater subbasins of the southeastern San Joaquin Valley during 2013–15. The study focused primarily on groundwater resources used for domestic-supply wells in the southeastern San Joaquin Valley (SESJV-D), which correspond mostly to shallower parts of aquifer systems, compared to the groundwater resources used for public-supply wells in the southeastern San Joaquin Valley (SESJV-P). The investigation had three components: (1) characterization of the status of water quality in the SESJV-D, (2) comparison between water quality in the SESJV-D and SESJV-P, and (3) identification of natural and anthropogenic factors that potentially could affect water quality in these resources. The characterization of water quality in the SESJV-D was based on data collected from 198 domestic wells sampled during 2013–15 by the U.S. Geological Survey (USGS); characterization of water quality in the SESJV-P was based on data collected from 124 wells sampled by the USGS during 2005–18 and an additional 1,577 wells with publicly available data reported to the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW). Measured concentrations were compared to regulatory and non-regulatory drinking-water quality benchmarks. A grid-based method was used to estimate the areal proportions of each study area and the whole southeastern San Joaquin Valley with high (greater than benchmark concentration), moderate (greater than half of the benchmark for inorganic and one-tenth of the benchmark for organic), and low concentrations relative to those benchmarks. Natural and anthropogenic factors that could affect groundwater quality for the SESJV-D were identified in the context of the hydrogeologic setting of the southeastern San Joaquin Valley. The considered factors represented hydrologic conditions and position in the groundwater flow system (well depth, lateral position, presence of hydric soils, percentage of coarse-grained sediment, and aridity index), land-use characteristics (percentages of agricultural, urban, and natural land use, percentage of orchard or vineyard land use, and densities of septic tanks and underground storage tanks near the wells), and geochemical conditions (groundwater age class, oxidation-reduction class, pH, and dissolved oxygen and bicarbonate concentrations). Factors are compared between SESJV-D and SESJV-P at the scale of the five study areas. One or more inorganic constituents with U.S. Environmental Protection Agency (EPA) or California maximum contaminant levels (MCLs) were detected at high concentrations in 47 percent of the SESJV-D and in 32 percent of the SESJV-P. The inorganic constituents most commonly present at high concentrations in the SESJV-D were nitrate, uranium, and arsenic. Within the SESJV-D, the proportion of the study area with high concentrations of inorganic constituents ranged from 19 percent in Madera-Chowchilla to 60 percent in Kings and Tulare Lake. One or more inorganic constituents with California State Water Resources Control Board Division of Drinking Water secondary maximum contaminant levels (SMCL-CAs) were detected at high concentrations in 14 percent of the SESJV-D and in 19 percent of the SESJV-P. The constituents most commonly present at high concentrations were manganese, iron, and total dissolved solids (TDS). Although the proportion of SESJV-D and SESJV-P with high concentrations of TDS greater than the upper SMCL were similar at 4 percent, the proportion of the SESJV-D with moderate concentrations (between the recommended and upper SMCL-CA), 30 percent, was greater than the proportion of the SESJV-P with moderate concentrations, 12 percent. One or more organic constituents with MCLs were present at high concentrations in 19 percent of the SESJV-D and in 12 percent of the SESJV-P. All the constituents detected at high concentrations in the SESJV-D were fumigants, primarily 1,2,3-trichloropropane (1,2,3-TCP) and 1,2-dibromo-3-chloropropane (DBCP). Fumigants also were the constituents most commonly detected at high concentrations in the SESJV-P, although high concentrations of solvents also were detected. The SESJV-D dataset included analysis of many organic constituents without MCL benchmarks and with detection levels far below drinking water benchmark concentrations; detections at these low concentrations can be used as tracers of anthropogenic influence on groundwater. Pesticides and degradates of pesticides were detected in 60 percent of the SESJV-D; the most frequently detected pesticides were the herbicides simazine, didealkylatrazine (CAAT, a degradate of simazine and atrazine), diuron, and bromacil.

California↗
USGS2003

Water temperature, streamflow, and ground-water elevation in and adjacent to the Russian river between Hopland and Guerneville, California from 1998-2002

Temperature, water level elevation, stage height, and river discharge data for this report were collected in and adjacent to the Russian River from Hopland to Guerneville, CA over a four-year period from 1998 to 2002 to establish baselines for long-term water quality, water supply and habitat. Data files presented in this report were collected by the USGS and the Sonoma County Water Agency's Engineering Resource and Planning, and Natural Resource Divisions. Temperature data were collected in single-channel submersible microloggers or temperature data were collected simultaneously with water-elevation data in dual-channel down-hole data loggers. Stream stage and streamflow data were collected at USGS stream gaging stations located near Hopland, Healdsburg, and Guerneville over a 130 km reach of the Russian River. During the period of record stream flow ranged from 3 to 1458 m3/s. Stream temperature ranged from 8 to 29 oC while groundwater temperature ranged from 10 to 38 oC. Stream stage varied 5 m seasonly, while ground-water level varied 19 m over the same time scale.

California↗
USGS2003

Applying ecological criteria to marine reserve design: A case study from the California Channel Islands

Using ecological criteria as a theoretical framework, we describe the steps involved in designing a network of marine reserves for conservation and fisheries management. Although we describe the case study of the Channel Islands, the approach to marine reserve design may be effective in other regions where traditional management alone does not sustain marine resources. A group of agencies, organizations, and individuals established clear goals for marine reserves in the Channel Islands, including conservation of ecosystem biodiversity, sustainable fisheries, economic viability, natural and cultural heritage, and education. Given the constraints of risk management, experimental design, monitoring, and enforcement, scientists recommended at least one, but no more than four, reserves in each biogeographic region. In general, the percentage of an area to be included in a reserve network depends on the goals. In the Channel Islands, after consideration of both conservation goals and the risk from human threats and natural catastrophes, scientists recommended reserving an area of 30–50% of all representative habitats in each biogeographic region. For most species of concern, except pinnipeds and seabirds, information about distributions, dispersal, and population growth was limited. As an alternative to species distribution information, suitable habitats for species of concern were used to locate potential reserve sites. We used a simulated annealing algorithm to identify potential reserve network scenarios that would represent all habitats within the smallest area possible. The analysis produced an array of potential reserve network scenarios that all met the established goals.

California↗
USGS2022

Hydrology of the Yucaipa groundwater subbasin: Characterization and integrated numerical model, San Bernardino and Riverside Counties, California

Executive Summary Water management in the Santa Ana River watershed in San Bernardino and Riverside Counties in southern California is a complex task with various water purveyors navigating geographic, geologic, hydrologic, and political challenges to provide a reliable water supply to stakeholders. As the population has increased throughout southern California, so has the demand for water. The Yucaipa groundwater subbasin (hereafter referred to as “Yucaipa subbasin”), one of nine groundwater subbasins in what the California Department of Water Resources (DWR) refers to as the Upper Santa Ana Valley groundwater basin (California Department of Water Resources, 2016; the DWR naming convention is used within this report), is no exception; steady population growth since the 1940s and changes in water use has forced local water purveyors to regularly adapt their water infrastructure to meet demand. Groundwater has historically been the dominant source of water in the Yucaipa subbasin although recently, imported water via the California State Water Project has augmented the total water supply. Despite the influx of imported water, overall demand for groundwater continues to rise, and there is concern by local water managers that groundwater levels may adversely impact water supply and (or) decline to a point where it will be uneconomical to produce water, severely limiting the ability of local agencies to meet water-supply demand. To better understand the hydrogeology and water resources in the Yucaipa subbasin, the U.S. Geological Survey (USGS) and the San Bernardino Valley Municipal Water District initiated a cooperative study to understand the hydrogeologic system of the Yucaipa subbasin and in the encompassing Yucaipa Valley watershed (YVW). A three-dimensional hydrogeologic framework model was constructed to quantify the structure and extent of hydrogeologic units. Historical and present-day groundwater conditions were characterized to evaluate the groundwater-flow system. Lastly, the Yucaipa Integrated Hydrological Model (YIHM) was developed to simulate the integrated surface-water and groundwater systems, including natural and anthropogenic (that is, human influenced) recharge and discharge throughout the study area from 1947 to 2014. The Yucaipa subbasin is an inland groundwater basin located about 12 miles (mi) southeast of the City of San Bernardino and about 75 mi east of Los Angeles, California. The subbasin encompasses about 39 square miles (mi 2 ), including the City of Yucaipa. The geographic extent of the Yucaipa subbasin was established by the California Department of Water Resources, who defined the boundaries of the subbasin based on hydrogeologic transitions between crystalline rock and basin-fill sediments, active fault strands, surface-water drainage divides, and a portion of an adjudicated groundwater management boundary. Two groundwater subbasins of the Upper Santa Ana Valley groundwater basin are adjacent to the Yucaipa subbasin, the San Bernardino groundwater subbasin to the west and the San Timoteo groundwater subbasin to the south. The Yucaipa subbasin is encompassed by the YVW, which is in turn comprised of three sub-watersheds that represent surface-water flow across and within the Yucaipa subbasin. Although the Yucaipa subbasin is the specific area of interest for this study, the entire YVW was considered for the purposes of characterizing the hydrogeology of the Yucaipa subbasin and for development of the YIHM. The purposes of this report are to (1) describe the hydrologic and hydrogeologic settings of the Yucaipa subbasin and aquifer system, (2) describe the construction and calibration of the fully coupled groundwater and surface-water flow model for the Yucaipa subbasin and the encompassing YVW, referred to as the YIHM, and (3) present numerical results, including water budgets and hydraulic heads, and the effect of pumping and climate stresses (precipitation and temperature) on water-budget components.

California↗
USGS2017

Southern sea otter range expansion and habitat use in the Santa Barbara Channel, California

The re-colonization of the Santa Barbara channel by sea otters brings these ESA-listed marine mammals closer to active oil and gas production facilities, shipping lanes and naturally occurring oil and gas seeps. However, the degree to which sea otters may actually be affected by human-caused oil spills or exposure to natural oil seeps is currently unknown. Between 2012 and 2014, the U.S. Geological Survey and collaborating agencies conducted a telemetry-based study of sea otters in Santa Barbara channel, in order to provide critical information for resource managers (specifically the Bureau of Ocean Energy Management, henceforth BOEM, and the U.S. Fish and Wildlife Service, henceforth USFWS) about the spatial ecology, population status, and potential population threats to sea otters in Santa Barbara Channel, with particular reference to exposure to manmade structures and sources of oil and natural gas. Analysis of spatial monitoring data using a Bayesian-based synoptic model allowed for description of sea otter home ranges, identification of hot-spots of use, and insights into habitat selection behavior by male and female sea otters. Important findings included the deeper modal depth preferred by males versus females, strong preferences by both sexes for areas with persistent kelp canopy, and greater use of soft-sediment areas by males. The synoptic model also provided the ability to predict population-level density distribution for each sex in new habitats: by calculating the value of these probability density distributions at the known locations of natural seeps, we were able to identify those seeps with higher potential for sea otter encounters. The relative probability of occurrence at locations near to some seeps was sufficiently high (about 1% likelihood of occurrence for some of our study animals) that one would anticipate occasional encounters. Data on male and female survival, reproductive success, activity budgets, and body condition all indicated that sea otters in Santa Barbara Channel are not resource limited, and thus we would expect to see continued strong population growth in this area. However, the principal cause of death for study animals was lethal bites by white sharks, suggesting that shark bite mortality represents the single biggest threat to continued population growth in the Santa Barbara Channel.

California↗
USGS2018

Maps showing predicted probabilities for selected dissolved oxygen and dissolved manganese threshold events in depth zones used by the domestic and public drinking water supply wells, Central Valley, California

The purpose of the prediction grids for selected redox constituents—dissolved oxygen and dissolved manganese—are intended to provide an understanding of groundwater-quality conditions at the domestic and public-supply drinking water depths. The chemical quality of groundwater and the fate of many contaminants is influenced by redox processes in all aquifers, and understanding the redox conditions horizontally and vertically is critical in evaluating groundwater quality. The redox condition of groundwater—whether oxic (oxygen present) or anoxic (oxygen absent)—strongly influences the oxidation state of a chemical in groundwater. The anoxic dissolved oxygen thresholds of <0.5 milligram per liter (mg/L), <1.0 mg/L, and <2.0 mg/L were selected to apply broadly to regional groundwater-quality investigations. Although the presence of dissolved manganese in groundwater indicates strongly reducing (anoxic) groundwater conditions, it is also considered a “nuisance” constituent in drinking water, making drinking water undesirable with respect to taste, staining, or scaling. Three dissolved manganese thresholds, <50 micrograms per liter (µg/L), <150 µg/L, and <300 µg/L, were selected to create predicted probabilities of exceedances in depth zones used by domestic and public-supply water wells. The 50 µg/L event threshold represents the secondary maximum contaminant level (SMCL) benchmark for manganese (U.S. Environmental Protection Agency, 2017; California Division of Drinking Water, 2014), whereas the 300 µg/L event threshold represents the U.S. Geological Survey (USGS) health-based screening level (HBSL) benchmark, used to put measured concentrations of drinking-water contaminants into a human-health context (Toccalino and others, 2014). The 150 µg/L event threshold represents one-half the USGS HBSL. The resultant dissolved oxygen and dissolved manganese prediction grids may be of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to anoxic conditions. Prediction grids for selected redox constituents and thresholds were created by the USGS National Water-Quality Assessment (NAWQA) modeling and mapping team.

California↗
USGS1982

Water-quality assessment of the Merced River, California

The Merced River and its major tributaries have been subject of water-quality and water-quantity studies by local, State, and Federal agencies since before 1900. Data have been compiled and analyzed, and even though water-quality problems exist in the basin, the water generally is of good quality for most of the beneficial uses defined by the California State Water Resources Control Board. Water-quality objectives for dissolved oxygen, pesticides, and pH were violated in some parts of the basin. The most likely cause of the dissolved-oxygen and pesticide violations is the return of agricultural irrigation water to the river in the lower 30 miles of the river. Violations of pH objectives occurred only in the upper drainage and were likely due to naturally occurring, poorly buffered water. Water quality is currently being monitored at three stations in the basin by California Department of Water Resources, at one station by the U.S. Geological Survey, and at several sites by the National Park Service. Modifications to the current water-quality monitoring program are proposed to gain further information on dissolved-oxygen fluctuations and pesticide concentrations in the lower river and to investigate nutrient input to Lake McClue. (USGS)

Open-File Report↗
USGS2021

Status and understanding of groundwater quality in the northern Sierra Nevada foothills domestic-supply aquifer study units, 2015–17—California GAMA Priority Basin Project

Groundwater quality in the northern Sierra Nevada foothills region of California was investigated as part of California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring Assessment Priority Basin Project (GAMA-PBP). The region was divided into two study units: the Yuba-Bear watersheds (YBW) study unit and the American-Cosumnes-Mokelumne watersheds (ACMW) study unit. The GAMA-PBP made a spatially unbiased assessment of aquifer systems used for domestic drinking-water supply in the study region, which are predominantly composed of fractured, hard-rock aquifers of varying lithology. These assessments characterized the quality of raw groundwater to evaluate ambient conditions in the domestic-supply aquifer and not the quality of treated drinking water. The study included three components: (1) a status assessment , which characterized the quality of groundwater resources used for domestic drinking-water supply in the YBW and ACMW study units; (2) an understanding assessment , which evaluated natural and anthropogenic explanatory factors that could potentially affect groundwater quality in the study region; and (3) a comparative assessment between the groundwater resources used for domestic and public drinking-water supply in the study region. The status assessment was based on data collected by the GAMA-PBP from 74 sites in the YBW study unit during 2015–16 and 67 sites in the ACMW study unit from 2016 to 2017. To contextualize water-quality results, concentrations of water-quality constituents in ambient groundwater were compared to regulatory and non-regulatory benchmarks typically used by the State of California and Federal agencies as health-based or aesthetic standards for public drinking water. The status assessment used a grid-based method to estimate proportions of groundwater resources with concentrations approaching or exceeding benchmark thresholds. This method provides spatially unbiased results and allows inter-comparability with similar groundwater-quality assessments. Inorganic constituents with health-based benchmarks were present at high relative concentration (RC), meaning they exceeded the benchmark threshold, in 5.4 and 10 percent of domestic-supply aquifer systems in the YBW and ACMW study units, respectively. Inorganic constituents with aesthetic-based benchmarks were detected at high-RCs in 20 and 28 percent of the YBW and ACMW study units, respectively. The inorganic constituents present at high RC were arsenic, barium, boron, molybdenum, strontium, nitrate, adjusted gross-alpha particle activity, chloride, total dissolved solids, specific conductance, iron, manganese, and hardness. Groundwater samples were tested for presence or absence of three microbial indicators (total coliform, Escherichia coli , and Enterococci ). At least one microbial indicator was present in 26 and 28 percent of the YBW and ACMW study units, respectively. At least one organic constituent was detected in 30 and 42 percent of the YBW and ACMW study units, respectively. Organic constituents were not present at high RC, but tetrachloroethene (PCE), trichloroethene (TCE), and toluene were detected in the YBW study unit at moderate RC (between the benchmark concentration and one-tenth of the benchmark concentration). Methyl tert -butyl ether (MTBE) and chloroform were present at low RC (less than one-tenth of the benchmark concentration) in the YBW and ACMW study units with detection frequencies greater than 10 percent. Perchlorate, a constituent of special interest, was detected in 31 and 41 percent of the YBW and ACMW study units, respectively, at either low or moderate RCs. Relations among select water-quality constituents and potential explanatory factors were evaluated using statistical and graphical approaches. Nitrate, microbial indicators, and perchlorate were all correlated to elevation-dependent variables relating to climate, land use, and recharge condition. Isotopic and dissolved noble-gas tracers indicated these water-quality constituents are associated with recharge conditions associated with irrigation during the summer dry-season, which is common in areas of rural-residential or agricultural land uses. Higher concentrations of iron and manganese were primarily associated with anoxic groundwater in aquifers of metasedimentary lithology. Increased hardness was primarily associated with anoxic groundwater in aquifers of mafic-ultramafic or metavolcanics lithologies at lower elevations in the study region in the Melones fault zone. Chloroform and MTBE were associated with shallow groundwater (wells depths less than 130 m) under oxic and anoxic redox conditions, respectively. The comparative assessment evaluated differences between the aquifer systems used for domestic- and public-supply in study region based on (1) well-construction characteristics, and (2) water quality. Analysis of over 60,000 well-completion reports in the study region showed that although domestic-supply wells span the deepest depth zones in regional aquifers, median depths for public-supply wells were significantly greater than those of domestic-supply wells in both study units. Water-quality data from more than 300 public-supply wells in the study region were assessed using a spatially weighted method for calculation aquifer-scale proportions and compared with the domestic-supply assessment results. Detections of inorganic constituents at high RC and detection frequencies for organic constituents were generally similar between the domestic- and public-supply aquifer systems in both study units, with a few notable exceptions in the ACMW study unit: nitrate was greater for the public- compared to domestic-supply aquifer system and both manganese, hardness, and MTBE were greater in the domestic- compared to public-supply aquifer system. These differences are likely related to contrasting land uses, aquifer lithologies, landscape positions, and depths characterizing domestic- and public-supply wells in the ACMW study unit. Overall, fewer samples from domestic-supply wells in the northern Sierra Nevada foothills exceeded health-based benchmarks compared to aesthetic-based benchmarks for groundwater quality. Exceedences of health-based benchmarks were primarily caused by nitrate and coliform bacteria, which were associated with recharge from diverted surface water used primarily for irrigation. Exceedences of aesthetic-based benchmarks were primarily caused by iron, managanese, and hardness, which were associated with geologic factors. Regional irrigation practices and aquifer lithology can affect groundwater quality in fractured-rock aquifers in the northern Sierra Nevada foothills used for domestic drinking-water supply.

California↗
USGS1977

Map showing general availability of ground water in the Kaiparowits coal-basin area, Utah

This is one of a series of maps that describe the geology and related natural resources in the Kaiparowits coal-basin area. This map is based partly on records of water wells, springs, and coal and petroleum exploration holes, partly on unpublished reports of field evaluations of prospective stock-water well sites by personnel of the U.S. Geological Survey, and partly on a 6-day field reconnaissance by the writer in parts of the mapped area. Most of the data used to compile this map were collected by the U.S. Geological Survey in cooperation with State, local, and other Federal agencies. Published sources of data included Phoenix (1963), Iorns, Hembree, and Phoenix (1964), Cooley (1965), Feltis (1966), Goode (1966, 1969), and the final environmental impact statement for the proposed Kaiparowits power project (U.S. Bureau of Land Management, 1976). Few data about the availability or depth of ground water could be obtained for large areas in the Kaiparowits coal basin. In those areas, expected yields of individual wells are inferred from the geology as compiled by Stokes (1964) and Hackman and Wyant (1973), and depths of ground water in wells are inferred largely from the local topography. El Paso Natural Gas Co., Resources Co., Kaiser Engineers, and Southern California Edison Co. provided specific information regarding the availability and depth of ground water in their exploratory holes on the Kaiparowits Plateau. The cooperation of those firms is gratefully acknowledged.

Utah↗
USGS2024

Incorporating climate data into emergency planning and exercises: A primer for emergency management practioners and data developers

Climate change has and will continue to sharpen climate-related risks to communities and natural resources in California and elsewhere, as the probabilities of more extreme weather, floods, and fires continue to increase. This poses a problem of novel situations for emergency management. Progress has been made in terms of formally incorporating climate projections, data, and research on expected changes in climate-driven hazards into long-term hazard mitigation and climate adaptation strategies at both state and national levels. However, there are fewer examples of how climate change considerations have, or could be, incorporated into shorter-term emergency preparedness and response strategies. This is an important gap to fill, as climate resilience depends not only on mitigation and prevention measures, but also on the ability of agencies to coordinate and effectively minimize impacts when prevention measures fall short. The goal of this primer is to provide guidance on how to incorporate the best available information on climate variability and change into emergency management planning, with a focus on the development and use of extreme weather event scenarios for use in exercises. The first section is aimed toward a broad audience, including emergency management practitioners who use extreme weather event scenarios. It provides an overview of available data and tools that can inform scenario design as well as techniques for scenario design based on the hazard of interest, the audience and application, and the technical skills and resources required to develop, summarize, and/or visualize the data. This section concludes with an overview of approaches and lessons learned related to extreme event response planning and exercise design. Overall, this section highlights the advantages of developing quantitative scenarios based on spatial data, which allows visualizations and interactive data explorations that can provide greater specificity in discussions related to preparedness and response strategies. It further highlights the advantages of developing a core expert working group to guide planning, holding pre-exercise workshops to engage diverse communities outside of the emergency management sector, and engaging decisionmakers post-exercise to communicate key issues and outcomes as well as potential approaches for mitigating consequences that were identified by participants. The second section is aimed toward the scientific community and data developers involved in the creation of extreme weather event scenarios. This section provides technical guidance and detailed descriptions of four types of data resources and five analytical approaches that can be used to create extreme weather event scenarios based on the design considerations highlighted in section one. The computational resources and expertise required varies substantially across the options presented and is a primary consideration. These requirements, in addition to considerations related to audience and application, may determine the novelty and detail of the event, the detail of weather forecast information that can be provided, and the spatial extent across which the event can reasonably be modeled. The importance of, and approaches for, delivering information in a form that is accessible to emergency management practitioners is also discussed.

Report↗
USGS2017

Selenium

Selenium (Se) was discovered in 1817 in pyrite from copper mines in Sweden. It is a trace element in Earth’s crust, with an abundance of three to seven orders of magnitude less than the major rock-forming elements. Commercial use of selenium began in the United States in 1910, when it was used as a pigment for paints, ceramic glazes, and red glass. Since that time, it has had many other economic uses—notably, in the 1930s and 1940s, when it was used in rectifiers (which change alternating current to direct current), and in the 1960s, when it began to be used in the liner of photocopier drums. In the 21st century, other compounds have replaced selenium in these older products; modern uses for selenium include energy-efficient windows that limit heat transfer and thin-film photovoltaic cells that convert solar energy into electricity. In Earth’s crust, selenium is found as selenide minerals, selenate and selenite salts, and as substitution for sulfur in sulfide minerals. It is the sulfide minerals, most commonly those in porphyry copper deposits, that provide the bulk of the selenium produced for the international commodity market. Selenium is obtained as a byproduct of copper refining and recovered from the anode slimes generated in electrolytic production of copper. Because of this, the countries that have the largest resources and (or) reserves of copper also have the largest resources and (or) reserves of selenium. Because selenium occurs naturally in Earth’s crust, its presence in air, water, and soil results from both geologic reactions and human activity. Selenium is found concentrated naturally in soils that overlie bedrock with high selenium concentrations. Selenium mining, processing, use in industrial and agricultural applications, and disposal may all contribute selenium to the environment. A well-known case of selenium contamination from agricultural practices was discovered in 1983 in the Kesterson National Wildlife Refuge in California. There, waters draining from agricultural fields created wetlands with high concentrations of dissolved selenium in the water. The selenium was taken up by aquatic wildlife and caused massive numbers of embryonic deformities and deaths. Regulatory agencies have since worked to safeguard ecological and human health by creating environmental exposure guidelines based upon selenium concentrations in water and in fish tissue. Any attempt to regulate selenium concentrations requires a delicate balance because selenium occurs naturally and is also a vital nutrient for the health of wildlife, domestic stock, and humans. Selenium is commonly added as a vitamin to animal feed, and in some regions of the United States and the world, it is added as an amendment to soils for uptake by agricultural crops. The important role of selenium in economic products, energy supply, agriculture, and health will continue for well into the future. The challenge to society is to balance the benefits of selenium use with the environmental consequences of its extraction. Increased understanding of the elemental cycle of selenium in the earth may lead to new (or unconventional) sources of selenium, the discovery of new methods of extraction, and new technologies for minimizing the transfer of selenium from rock to biota, so to protect environmental and human health.

Professional Paper↗
USGS2010

Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: NLCD 2001 Tree Canopy

This tabular data set represents the mean percent tree canopy from the Canopy Layer of the National Land Cover Dataset 2001 (LaMotte and Wieczorek, 2010), compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). The source data set represents tree canopy percentage for the conterminous United States for 2001. The Canopy Layer of the National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

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USGS2010

Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: NLCD 2001 Imperviousness

This tabular data set represents the mean percent impervious surface from the Imperviousness Layer of the National Land Cover Dataset 2001, (LaMotte and Wieczorek, 2010), compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data set represents imperviousness for the conterminous United States for 2001. The Imperviousness Layer of the National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002;Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

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USGS2008

Ground-water quality data in the Southern Sacramento Valley, California, 2005 — Results from the California GAMA Program

Ground-water quality in the approximately 2,100 square-mile Southern Sacramento Valley study unit (SSACV) was investigated from March to June 2005 as part of the Statewide Basin Assessment Project of Ground-Water Ambient Monitoring and Assessment (GAMA) Program. This study was designed to provide a spatially unbiased assessment of raw ground-water quality within SSACV, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 83 wells in Placer, Sacramento, Solano, Sutter, and Yolo Counties. Sixty-seven of the wells were selected using a randomized grid-based method to provide statistical representation of the study area. Sixteen of the wells were sampled to evaluate changes in water chemistry along ground-water flow paths. Four additional samples were collected at one of the wells to evaluate water-quality changes with depth. The GAMA Statewide Basin Assessment project was developed in response to the Ground-Water Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The ground-water samples were analyzed for a large number of man-made organic constituents (volatile organic compounds [VOCs], pesticides and pesticide degradates, pharmaceutical compounds, and wastewater-indicator constituents), constituents of special interest (perchlorate, N -nitrosodimethylamine [NDMA], and 1,2,3-trichloropropane [1,2,3-TCP]), naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, and carbon-14, and stable isotopes of hydrogen, oxygen, and carbon), and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, matrix spikes) were collected at ten percent of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Assessment of the quality-control data resulted in censoring of less than 0.03 percent of the analyses of ground-water samples. This study did not evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, and (or) blended with other waters to maintain acceptable water quality. Regulatory thresholds apply to treated water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Health Services (CADHS) (Maximum Contaminant Levels [MCLs], notification levels [NLs], or lifetime health advisories [HA-Ls]) and thresholds established for aesthetic concerns (Secondary Maximum Contaminant Levels [SMCLs]). All wells were sampled for organic constituents and selected general water quality parameters; subsets of wells were sampled for inorganic constituents, nutrients, and radioactive constituents. Volatile organic compounds were detected in 49 out of 83 wells sampled and pesticides were detected in 34 out of 82 wells; all detections were below health-based thresholds, with the exception of 1 detection of 1,2,3-trichloropropane above a NL. Of the 43 wells sampled for trace elements, 27 had no detections of a trace element above a health-based threshold and 16 had at least one detection above. Of the 18 trace elements with health-based thresholds, 3 (arsenic, barium, and boron) were detected at concentrations higher an MCL. Of the 43 wells sampled for nitrate, only 1 well had a detection above the MCL. Twenty wells were sampled for radioactive constituents; only 1 (radon-222) was measured at activities higher than the proposed MCL. Radon-222 was detected below the threshold in 7 wells and above the threshold in 13 wells. SMCLs have been established for nine constituents or parameters analyzed in SSACV. Six were measured at levels higher than an SMCL: chloride, iron, manganese, pH, specific conductance, and total dissolved solids. Chloride, iron, manganese, pH, and total dissolved solids were measured in 43 wells: 27 wells had no measurements above a threshold and 16 wells had a measurement above a threshold. Specific conductance was measured in 83 wells. In 68 wells, specific conductance was measured lower than the threshold and in 15 wells it was measured above the threshold.

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USGS2025

Quality of groundwater used for domestic supply in the Gilroy-Hollister basin and surrounding areas, California, 2022

More than 2 million Californians rely on groundwater from domestic wells for drinking-water supply. This report summarizes a 2022 California Groundwater Ambient Monitoring and Assessment Priority Basin Project (GAMA-PBP) water-quality survey of 33 domestic and small-system drinking-water supply wells in the Gilroy-Hollister Valley groundwater basin and the surrounding areas, where more than 20,000 residents are estimated to utilize privately owned domestic wells. The study area includes the Llagas subbasin in the north, the North San Benito subbasin in the south, and the surrounding uplands. The study was focused on groundwater resources used for domestic drinking-water supply, which are mostly drawn from shallower parts of aquifer systems rather than those of groundwater resources used for public drinking-water supply in the same area. This assessment characterized the quality of ambient groundwater in the aquifer before filtration or treatment, rather than the quality of drinking water delivered to the tap. To provide context, the measured concentrations of constituents in groundwater were compared to Federal and California State regulatory and non-regulatory benchmarks for drinking-water quality. A grid-based method was used to estimate the areal proportions of groundwater resources used for domestic drinking wells that have water-quality constituents present at high concentrations (above the benchmark), moderate concentrations (between one-half of the benchmark and the benchmark for inorganic constituents, or between one-tenth of the benchmark and the benchmark for organic constituents), and low concentrations (less than one-half or one-tenth the benchmark for inorganic and organic constituents, respectively). This method provides statistically representative results at the study-area scale and permits comparisons to other GAMA-PBP study areas. In the study area, inorganic constituents in groundwater were greater than regulatory benchmarks (U.S. Environmental Protection Agency [EPA] or State of California maximum contaminant levels [MCLs]) for public drinking-water quality in 24 percent of domestic groundwater resources. The inorganic constituents present at concentrations greater than MCLs for drinking water were nitrate (as nitrogen), barium, chromium, and selenium. Total dissolved solids (TDS) or manganese were present at concentrations greater than the secondary maximum contaminant levels (SMCLs) that the State of California uses as aesthetic-based benchmarks in 48 percent of domestic groundwater resources. No volatile organic compounds or pesticide constituents were present at concentrations greater than regulatory benchmarks. Total coliform bacteria and enterococci were detected in 4 percent of domestic groundwater resources. Per- and polyfluoroalkyl substances (PFAS) were detected in 19 percent of domestic groundwater resources, and 10 percent had concentrations greater than recently enacted (April 2024) EPA MCLs. Physical and chemical factors from natural and anthropogenic sources that could affect the groundwater quality were evaluated using results from statistical testing of associations between constituent concentrations and potential explanatory variables. In this study, relevant physical factors include well construction characteristics, groundwater age, site proximity to groundwater recharge or discharge zones, and potential sources of contamination. Relevant chemical factors include the initial chemistry of the recharge water, the mineralogy of the aquifer sediments, and the subsequent shifts in chemistry as biologic and geologic reactions alter groundwater in the subsurface. Nitrate concentrations were correlated to agricultural land use, distance from the boundary of the Gilroy-Hollister Valley groundwater basin, and the proportion of modern (post-1950s) water captured by the well. Denitrification under anoxic redox conditions can mitigate some nitrate derived from fertilizer application. Total dissolved solids primarily were derived from water-rock interactions with soils and aquifer materials in the study area, but there were high concentrations where agricultural practices contributed additional TDS. Mineralogy of aquifer sediments and rocks also affect barium, selenium, boron, and chromium concentrations in the Gilroy-Hollister Valley groundwater basin. PFAS were positively correlated with urban land use and the proportion of modern water captured by the well.

California↗