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At least 127 records · Page 7Linked to original sources
USGS2010

Shallow groundwater quality in the Village of Patchogue, Suffolk County, New York

The onsite disposal of wastewater within the Patchogue River Basin-a riverine estuary that discharges into Great South Bay, Suffolk County, Long Island, N.Y. -has adversely affected water quality and aquatic habitats within both the tidal and non-tidal portions of the river. In response to increased development within the approximately 14 square mile basin, the Village of Patchogue has expanded efforts to manage and protect the local groundwater resources, which sustain freshwater base flow and aquatic habitats. Water-quality samples from 10 shallow wells within the Village were collected in March 2009, before the start of seasonal fertilizer application, to document the effects of onsite wastewater disposal on groundwater discharging into the Patchogue River. Each sample was analyzed for physical properties (pH, dissolved oxygen, specific conductance, and temperature), nutrients, organic carbon, major ions, and trace elements. Water samples from eight wells were analyzed for stable isotopes of nitrogen. The nitrate concentration in one well was 40 milligrams per liter (mg/L), which exceeded the U.S. Environmental Protection Agency (USEPA) and New York State Department of Health (NYSDOH) maximum contamination level in drinking water of 10 mg/L. Sodium concentrations at nine wells exceeded the USEPA Drinking Water Advisory Taste Threshold of 60 mg/L. Dissolved iron concentrations at three wells exceeded the NYSDOH and USEPA Secondary Drinking Water Standard of 300 micrograms per liter (?g/L). Nitrogen isotope signatures (d15N) were determined and compared with those reported from previous studies in Nassau and Suffolk Counties to identify possible sources of the nitrate. Local variations in measured ammonia, nitrate, total nitrogen, phosphorus, and organic carbon concentrations and d15N signatures indicate that nitrate enters the surficial aquifer from several sources (fertilizer, septic waste, and animal waste) and reflects biogeochemical processes such as denitrification.

Scientific Investigations Report↗
USGS2021

Near-real-time volcanic cloud monitoring: Insights into global explosive volcanic eruptive activity through analysis of Volcanic Ash Advisories

Understanding the location, intensity, and likely duration of volcanic hazards is key to reducing risk from volcanic eruptions. Here, we use a novel near-real-time dataset comprising Volcanic Ash Advisories (VAAs) issued over 10 years to investigate global rates and durations of explosive volcanic activity. The VAAs were collected from the nine Volcanic Ash Advisory Centres (VAACs) worldwide. Information extracted allowed analysis of the frequency and type of explosive behaviour, including analysis of key eruption source parameters (ESPs) such as volcanic cloud height and duration. The results reflect changes in the VAA reporting process, data sources, and volcanic activity through time. The data show an increase in the number of VAAs issued since 2015 that cannot be directly correlated to an increase in volcanic activity. Instead, many represent increased observations, including improved capability to detect low- to mid-level volcanic clouds (FL101–FL200, 3–6 km asl), by higher temporal, spatial, and spectral resolution satellite sensors. Comparison of ESP data extracted from the VAAs with the Mastin et al. (J Volcanol Geotherm Res 186:10–21, 2009a ) database shows that traditional assumptions used in the classification of volcanoes could be much simplified for operational use. The analysis highlights the VAA data as an exceptional resource documenting global volcanic activity on timescales that complement more widely used eruption datasets.

Bulletin of Volcanology↗
USGS2026

Comparing in vivo methylmercury detoxification in hunted duck: Implications for wildlife and human health

Great Salt Lake (GSL) waterfowl have elevated mercury (Hg) concentrations, and in vivo detoxification of neurotoxic and bioaccumulative methylmercury (MeHg) can occur through Hg-selenium (Se) complexation, influencing the suitability of Hg consumption advisories. Here, we present Hg chemical speciation and Hg stable isotope measurements of brain, breast muscle, liver, and kidney samples from two GSL duck species─northern shoveler ( Spatula clypeata ) and cinnamon teal (Spatula cyanoptera). Chemical and stable isotope measurements, along with high energy resolution fluorescence detected X-ray absorption near-edge structure (HERFD-XANES) spectroscopy, indicate the occurrence of in vivo MeHg demethylation in both bird species. The percentage of total Hg (THg) as MeHg (% MeHg) varied with tissue type (brain > breast muscle > kidney > liver), and differences between δ 202 THg and δ 202 MeHg were linearly correlated with % MeHg. Demethylated inorganic Hg was a mixture of Hg-dithiolate (Hg(SR) 2 ) and Hg-tetraselenolate (Hg(Sec) 4 ) in both bird species. Notably, liver THg concentrations were elevated in northern shoveler liver tissues relative to those of cinnamon teal (7.54 ± 4.69 mg/kg versus 2.19 ± 1.27 mg/kg, dry weight, respectively) and % MeHg liver values were significantly lower (40% ± 19% versus 68% ± 14%), indicating taxonomic differences in Hg detoxification and depuration. THg concentrations in waterfowl species from this study were comparable to previously reported levels, indicating that elevated Hg concentrations in northern shoveler and cinnamon teal at GSL have persisted over the past two decades. Due to in vivo demethylation, we show that THg is not an effective proxy for MeHg within duck species, carrying implications for current GSL waterfowl consumption advisories and assessments exposure risk. This study highlights important differences in MeHg detoxification between waterbird taxa and provides further insights into Hg toxicity risk to GSL waterbirds.

Utah↗
USGS1999

The ecological condition of estuaries in the Gulf of Mexico

The Gulf of Mexico is a vast natural resource encompassing the coastal areas of western Florida, Alabama, Mississippi, Louisiana, and Texas, as well as a portion of Mexico. Many estuaries flow into the Gulf of Mexico and serve as nursery grounds for fish, habitat for a wide variety of wildlife, shipping routes, and a source of recreation. Estuarine-dependent species constitute more than 95 percent of the commercial fishery harvests from the Gulf of Mexico, and many important recreational fishery species depend on estuaries during some part of their life cycle. Gulf estuaries are diverse and productive ecosystems that provide a variety of valuable resources, including fish and shellfish, recreation, transportation, and water supply. Assessing the overall condition of Gulf of Mexico estuaries required incorporating data from other federal, state, and local monitoring programs to augment the information on ecological indicators collected by the U.S. Environmental Protection Agency’s (USEPA) Environmental Monitoring and Assessment Program (EMAP). The resulting document would provide a synthesis of the available knowledge about the condition of Gulf of Mexico estuaries. This document is intended for use by scientists and other citizens concerned with the ecological condition of estuaries, as well as by managers and lawmakers interested in the sustained use of estuaries for commercial and recreational purposes. It also addresses public concerns about the aesthetic quality of coastal areas vital to tourism and recreation. By producing this report on the ecological condition of estuaries in the Gulf of Mexico, we have taken one step in assessing the health of this environmental resource. We have produced an environmental “report card” to be used as a guide in the evaluation of management decisions and research directions. This report is organized in three parts: (1) an introduction that gives background information on the Gulf of Mexico, estuarine ecology, and the factors that impact estuaries in the gulf, (2) the main section on priority ecological indicators used to measure the condition of estuaries in the gulf and (3) an ecological report card that summarizes the data on ecological indicators and provides a rating of the condition of estuaries in each gulf state and for gulf estuaries overall. Many of the ratings were based on the percent area of estuaries in each state exhibiting degraded or adverse levels of an indicator. Eutrophication, a condition of high nutrients often resulting in low oxygen levels and other adverse effects, is an important water quality concern for estuaries along the gulf coast. The National Oceanic and Atmospheric Administration (NOAA) has compared the Gulf of Mexico to other coastal regions like the middle Atlantic and has ranked the Gulf of Mexico as having the highest number of point sources of nutrients and the highest percentage of land use devoted to agriculture. We evaluated monitoring data for nitrogen, chlorophyll, and dissolved oxygen as indicators of eutrophication. Although most of the estuaries exhibited high nitrogen or chlorophyll or low dissolved oxygen concentrations at least once during a survey, many times these conditions were observed in small rivers or bayous rather than in the entire estuary. Often, the percent area affected was low. The gulf estuaries had moderate conditions overall for nutrients and dissolved oxygen. Definite nutrient problems were observed in >25% of the estuarine area in Louisiana and Texas and definite dissolved oxygen problems were observed in Alabama. Contaminants in estuarine sediments provide evidence of the accumulation of chemicals from anthropogenic sources. We compared the concentrations of sediment contaminants to established guideline values to determine the proportion of estuarine area that could have potential adverse effects on living organisms. Although detectable levels of contaminants were measured in almost every estuary in the Gulf of Mexico, <25% of the estuarine area in all states had contaminant concentrations that exceeded these guidelines. Wetlands are integral parts of estuarine systems. Declining acreage means habitat loss that may be the result of commercial and residential development, hydrologic alterations, or dredge and fill operations. The Gulf of Mexico region contains more than 50% of the coastal wetland acreage in the U.S. and yet it also has the highest rate of coastal wetland loss. Nine of the top ten estuarine drainage areas ranked by total wetland area are in the Gulf of Mexico region. The most current estimates of total wetland loss over the past 200 years range from 41% to 54% for the gulf states. Although coastal wetlands continue to be altered or destroyed, some estimates indicate that the rate of loss has slowed. All gulf states were rated as having severe problems with wetland loss. The condition of benthic (bottom-dwelling) invertebrates, fish and shellfish, birds, and threatened and endangered species was used to evaluate the health of estuarine fauna. Degraded benthic communities inhabited <25% of the estuarine area in all gulf states except for Texas. Commercial fish and shellfish landings may be used as an indicator of population stability while fish biomarkers are used to measure the health of individuals in the population. Commercial landings of the top four fisheries (shrimp, menhaden, blue crab, and oyster) are stable in the gulf states while fish biomarkers indicate fair to poor fish health in Alabama and Texas and good fish health elsewhere. Coastal and marine bird populations appear to be in good condition throughout the gulf. Four threatened or endangered species inhabit coastal areas in the Gulf of Mexico: brown pelican, Gulf sturgeon, manatee, and Kemp’s ridley sea turtle. In general, populations of these species are in good to fair condition in the gulf states. Public health indicators include shellfish bed closures and chemicals found in edible fish tissue. Harvest of shellfish (primarily oyster in the Gulf of Mexico) is restricted or prohibited when concentrations of bacteria or other pathogens reach levels that could impair human health. The gulf states contain the most acreage of shellfish-growing waters in the U.S. but also have the most acreage restricted for harvest. All gulf states except Mississippi have >25% of their shellfish-growing waters restricted for harvest, mostly due to pollution from wastewater treatment plants or other upstream sources. Advisories may be issued that limit consumption when the concentrations of chemicals in fish tissue exceed levels known to be harmful to humans. Although seafood consumption advisories have been issued in all gulf states, the percent of the fish population with high concentrations of contaminants is relatively low in the gulf overall.

Alabama, Florida, Louisiana, Mississippi, Texas↗
USGS2010

A Natural Resource Condition Assessment for Rocky Mountain National Park

We conducted a natural resource assessment of Rocky Mountain National Park (ROMO) to provide a synthesis of existing scientific data and knowledge to address the current conditions for a subset of important park natural resources. The intent is for this report to help provide park resource managers with data and information, particularly in the form of spatially-explicit maps and GIS databases, about those natural resources and to place emerging issues within a local, regional, national, or global context. With an advisory team, we identified the following condition indicators that would be useful to assess the condition of the park: Air and Climate: Condition of alpine lakes and atmospheric deposition Water: Extent and connectivity of wetland and riparian areas Biotic Integrity: Extent of exotic terrestrial plant species, extent of fish distributions, and extent of suitable beaver habitat Landscapes: Extent and pattern of major ecological systems and natural landscapes connectivity These indicators are summarized in the following pages. We also developed two maps of important issues for use by park managers: visitor use (thru accessibility modeling) and proportion of watersheds affected by beetle kill. Based on our analysis, we believe that there is a high degree of concern for the following indicators: condition of alpine lakes; extent and connectivity of riparian/wetland areas; extent of exotic terrestrial plants (especially below 9,500’); extent of fish distributions; extent of suitable beaver habitat; and natural landscapes and connectivity. We found a low degree of concern for: the extent and pattern of major ecological systems. The indicators and issues were also summarized by the 34 watershed units (HUC12) within the park. Generally, we found six watersheds to be in “pristine” condition: Black Canyon Creek, Comanche Creek, Middle Saint Vrain Creek, South Fork of the Cache la Poudre, Buchanan Creek, and East Inlet. Four watersheds were found to have strong restoration opportunities: Big Thompson River West, Cache la Poudre South, Colorado River North, and Onahu Creek. Ten watersheds were found to have substantial near-term issues: Aspen Brook, Big Thompson River West, Black Canyon Creek, Cabin Creek, Cache la Poudre South, Fall River, Hague Creek, La Poudre Pass Creek, North Fork Big Thompson (East), and Colorado River North.

Report↗
USGS2020

Geologic map of the Dog River and northern part of the Badger Lake 7.5′ quadrangles, Hood River County, Oregon

The Dog River and northern part of the Badger Lake 7.5' quadrangles encompasses an area of ~201 km2 (77.6 mi2) of the High Cascades of north-central Oregon, lying across the eastern slopes of Mount Hood volcano (Figure 1-1; Plate 1; referred to herein as Dog River–Badger Lake area). Mount Hood, known as Wy’east to Native Americans, is Oregon’s tallest peak (3,427 m [11,241 ft]). The volcano has erupted episodically for the past 500,000 years, experiencing two major eruptive periods during the last 1,500 years (Scott and others, 1997a; Scott and others, 2003; Scott and Gardner, 2017). Cascade Range volcanism and structural development in the area dates back longer, with eruptive activity dating from latest Miocene to recent time; part of that volcano-tectonic record is detailed by new high-resolution geologic mapping presented here. The geology of the Dog River–Badger Lake area was mapped by the Oregon Department of Geology and Mineral Industries (DOGAMI) between 2017 and 2020, in collaboration with geoscientists from the U. S. Geological Survey Cascade Volcano Observatory (USGS CVO) and Hamilton College, New York. The primary objective of this investigation is to provide an updated and spatially accurate geologic framework for the Dog River–Badger Lake area as part of a multi-year study of the geology of the larger Middle Columbia Basin (Figure 1-1, Figure 1-2). Additional key objectives of this project are to: 1) determine the geologic history of volcanic rocks in this part of the northern Oregon Cascade Range, including lava flows and volcaniclastic deposits erupted from Middle Pleistocene to Holocene Mount Hood volcano; 2) provide significant new details about the structure and fault history along the northern segment of the High Cascades intra-arc graben (Hood River graben); and 3) better understand geologic hazards in the region, related to earthquakes, volcanoes, and landslides. New detailed geologic data presented here also provides a basis for future geologic, geohydrologic, and geohazard studies in the greater Middle Columbia Basin. Detailed geologic mapping in this part of the Middle Columbia Basin is a high priority of the Oregon Geologic Map Advisory Committee (OGMAC), supported in part by grants from the STATEMAP component of the USGS National Cooperative Geologic Mapping Program (G17AC00210, G19AC00160). Additional funds were provided by the State of Oregon. The core products of this study are this report, an accompanying geologic map and cross sections (Plate 1), an Esri ArcGIS™ geodatabase, and Microsoft Excel® spreadsheets tabulating point data for geochemistry, geochronology, magnetic polarity, orientation points, and well data. The geodatabase presents the new geologic mapping in a digital format consistent with the USGS National Cooperative Geologic Mapping Program Geologic Map Schema (GeMS) (U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020). This geodatabase contains spatial information, including geologic polygons, contacts, structures, geochemistry, geochronology, magnetic observation, orientation points, and well data, as well as data about each geologic unit such as age, lithology, mineralogy, and structure. Digitization at scales of 1:8,000 or better was accomplished using a combination of high-resolution lidar topography and imagery. Surficial and bedrock geologic units contained in the geodatabase are depicted on the Plate 1 at a scale of 1:24,000. Both the geodatabase and geologic map are supported by this report describing the geology in detail.

Oregon↗
USGS2026

Spatial and temporal trends of mercury in fish from Duck Valley Reservation Reservoirs, southwestern Idaho and northern Nevada, 2007–24

The Shoshone-Paiute (Sho-Pai) Tribes of the Duck Valley Reservation, Nevada, manage reservoirs that support commercial and recreational activities, including robust Oncorhynchus mykiss (rainbow trout) fisheries that attract anglers year-round. Reservoirs are common environments for methylation and bioaccumulation of mercury, which is a potent neurotoxin when elevated levels are consumed. The U.S. Geological Survey (USGS), in cooperation with the Sho-Pai Tribes, measured total mercury concentrations in the muscle tissue of rainbow trout from three Reservation reservoirs in Idaho and Nevada in 2007, 2009, 2013, and 2024. This report highlights spatial and temporal trends of mercury concentrations in rainbow trout in the Duck Valley Reservation reservoirs from 2007 through 2024, and presents limited data on other commonly consumed species, specifically Perca flavescens (yellow perch), Micropterus dolomieu (smallmouth bass), and Micropterus salmoides (largemouth bass). Mercury data are also presented for nearby sites and lower trophic level species. In 2024, two fish sampling methods were used and compared: biopsy muscle plugs and muscle fillets. Results show good agreement between mercury concentrations of biopsy and fillet muscle samples taken from the same fish, with most sample pairs differing by less than 20 percent, though biopsied fish had an unexpectedly high mortality rate. Mercury concentrations increased in Sheep Creek Reservoir during the study period, but no significant trend was observed in Mountain View Reservoir or Lake Billy Shaw. Only 1 rainbow trout out of 160 sampled in the Reservation reservoirs during the study period exceeded the U.S. Environmental Protection Agency’s recommended methylmercury criterion of 0.3 milligram per kilogram of wet weight (mg/kg ww). Largemouth bass, smallmouth bass, and yellow perch had higher mercury concentrations than rainbow trout and may pose a greater risk to consumers. Mercury concentrations in largemouth bass exceeded 0.3 mg/kg ww, although only two fish were sampled, both from Sheep Creek Reservoir. Fish consumption advisories on Tribal lands are determined by the Tribes, and these results may help Sho-Pai managers determine the mercury exposure risk to Tribal members and visiting anglers.

Idaho, Nevada↗
USGS1999

Summary of information on synthetic organic compounds and trace elements in tissue of aquatic biota, Clark Fork-Pend Oreille and Spokane River basins, Montana, Idaho, and Washington, 1974-96

As part of the Northern Rockies Intermontane Basins study of the National Water-Quality Assessment Program, data collected between 1974 and 1996 were compiled to describe contaminants in tissue of riverine species. Tissue-contaminant data from 11 monitoring programs and studies representing 28 sites in the study area were summarized. Tissue-contaminant data for most streams generally were lacking. Many studies have focused on and around mining-affected areas on the Clark Fork and Coeur d'Alene Rivers and their major tributaries. DDT and PCBs and their metabolites and congeners were the synthetic organic contaminants most commonly detected in fish tissue. Fish collected from the Spokane River in Washington contained elevated concentrations of PCB arochlors, some of which exceeded guidelines for the protection of human health and predatory wildlife. Tissue samples of fish from the Flathead River watershed contained higher-than-expected concentrations of PCBs, which might have resulted from atmospheric transport. Trace element concentrations in fish and macroinvertebrates collected in and around mining areas were elevated compared with background concentrations. Some cadmium, copper, lead, and mercury concentrations in fish tissue were elevated compared with results from other studies, and some exceeded guidelines. Macroinvertebrates from the Coeur d'Alene River contained higher concentrations of cadmium, lead, and zinc than did macroinvertebrates from other river systems in mining-affected areas. A few sportfish fillet samples, most from the Spokane River in Washington, were collected to assess human health risk. Concentrations of PCBs in these fillets exceeded screening values for the protection of human health. At present, there is no coordinated, long-term fish tissue monitoring program for rivers in the study area, even though contaminants are present in fish at levels considered a threat to human health. Development of a coordinated, centralized national data base for contaminants in fish tissue is needed. The National Water-Quality Assessment Program can provide a framework for other agencies to evaluate tissue contaminants in the Northern Rockies Intermontane Basins study area. As of 1996, there are no fish consumption advisories or fishing restrictions as a result of elevated contaminants on any rivers within the study area.

Idaho, Montana, Washington↗
USGS2004

Quality of water on the Prairie Band Potawatomi Reservation, northeastern Kansas, May 2001 through August 2003

Water-quality samples were collected from 20 surface-water sites and 11 ground-water sites on the Prairie Band Potawatomi Reservation in northeastern Kansas in an effort to describe existing water-quality conditions on the reservation and to compare water-quality conditions to results from previous reports published as part of a multiyear cooperative study with the Prairie Band Potawatomi Nation. Water is a valuable resource to the Prairie Band Potawatomi Nation as tribal members use the streams draining the reservation, Soldier, Little Soldier, and South Cedar Creeks, to fulfill subsistence hunting and fishing needs and as the tribe develops an economic base on the reservation. Samples were collected once at 20 surface-water monitoring sites during June 2001, and quarterly samples were collected at 5 of the 20 monitoring sites from May 2001 through August 2003. Ground-water-quality samples were collected once from seven wells and twice from four wells during April through May 2003 and in August 2003. Surface-water-quality samples collected from May through August 2001 were analyzed for physical properties, nutrients, pesticides, fecal indicator bacteria, and total suspended solids. In November 2001, an additional analysis for dissolved solids, major ions, trace elements, and suspended-sediment concentration was added for surface-water samples. Ground-water samples were analyzed for physical properties, dissolved solids, major ions, nutrients, trace elements, pesticides, and fecal indicator bacteria. Chemical oxygen demand and volatile organic compounds were analyzed in a sample from one monitoring well located near a construction and demolition landfill on the reservation. Previous reports published as a part of this ongoing study identified total phosphorus, triazine herbicides, and fecal coliform bacteria as exceeding their respective water-quality criteria in surface water on the reservation. Previous ground-water assessments identified occasional sample concentrations of dissolved solids, sodium, sulfate, boron, iron, and manganese as exceeding their respective water-quality criteria. Forty percent of the 65 surface-water samples analyzed for total phosphorus exceeded the aquatic-life goal of 0.1 mg/L (milligrams per liter) established by the U.S. Environmental Protection Agency (USEPA). Concentrations of dissolved solids and sodium occasionally exceeded USEPA Secondary Drinking-Water Regulations and Drinking-Water Advisory Levels, respectively. One of the 20 samples analyzed for atrazine concentrations exceeded the Maximum Contaminant Level (MCL) of 3.0 ?g/L (micrograms per liter) as an annual average established for drinking water by USEPA. A triazine herbicide screen was used on 63 surface-water samples, and triazine compounds were frequently detected. Triazine herbicides and their degradates are listed on the USEPA Contaminant Candidate List. Nitrite plus nitrate concentrations in two ground-water samples from one monitoring well exceeded the MCL of 10 mg/L established by USEPA for drinking water. Arsenic concentrations in two samples from one monitoring well also exceeded the proposed MCL of 10 ?g/L established by the USEPA for drinking water. Concentrations of dissolved solids and sulfate in some ground-water samples exceeded their respective Secondary Drinking-Water Regulations, and concentrations exceeded the taste threshold of the USEPA?s Drinking-Water Advisory Level for sodium. Consequently, in the event that ground water on the reservation is to be used as a drinking-water source, additional treatment may be necessary to remove excess dissolved solids, sulfate, and sodium.

Scientific Investigations Report↗
USGS1992

Techniques for estimating peak-flow frequency relations for North Dakota streams

This report presents techniques for estimating peak-flow frequency relations for North Dakota streams. In addition, a generalized skew coefficient analysis was completed for North Dakota to test the validity of using the generalized skew coefficient map in Bulletin 17B of the Hydrology Subcommittee of the Interagency Advisory Committee on Water Data, 1982, "Guidelines for Determining Flood Flow Frequency." The analysis indicates that the generalized skew coefficient map in Bulletin 17B provides accurate estimates of generalized skew coefficient values for natural-flow streams in North Dakota. Peak-flow records through 1988 for 192 continuous- and partial-record streamflow gaging stations that had 10 or more years of record were used in a generalized least-squares regression analysis that relates peak flows for selected recurrence intervals to selected basin characteristics. Peak-flow equations were developed for recurrence intervals of 2, 10, 15, 25, 50, 100, and 500 years for three hydrologic regions in North Dakota. The peak-flow equations are applicable to natural-flow streams that have drainage areas of less than or equal to 1,000 square miles. The standard error of estimate for the three hydrologic regions ranges from 60 to 70 percent for the 100-year peak-flow equations. Methods are presented for transferring peak-flow data from gaging stations to ungaged sites on the same stream and for determining peak flows for ungaged sites on ungaged streams. Peak-flow relations, weighted estimates of peak flow, and selected basin characteristics are tabulated for the 192 gaging stations used in the generalized skew coefficient and regression analyses. Peak-flow relations also are provided for 63 additional gaging stations that were not used in the generalized skew coefficient and regression analyses. These 63 gaging stations generally represent streams that are significantly controlled by regulation and those that have drainage areas greater than 1,000 square miles.

North Dakota↗
USGS2025

Designs for cyanobacterial harmful algal bloom monitoring in the Sacramento–San Joaquin Delta, California

Cyanobacterial harmful algal blooms (CHABs) are a growing concern in freshwater environments. These blooms can lead to degraded water quality, ecosystem disruptions, and public health threats due to the production of potent cyanotoxins. The Sacramento–San Joaquin Delta (California, USA; the Delta) has experienced CHABs since 1999, including CHABs that produce cyanotoxins at concentrations exceeding recreational advisory threshold levels. In response to the CHAB monitoring needs in the Delta, in 2024 a CHAB monitoring strategy for the Sacramento–San Joaquin Delta was released. The CHAB monitoring strategy recommended implementing a comprehensive monitoring program aligned with regional priorities, and this report responds directly to that recommendation. Building on the CHAB monitoring strategy, it describes three example monitoring designs that draw from past studies to address present needs. To develop designs, the report outlines key components and considerations for implementing a CHAB monitoring program in the Delta. It provides: background on monitoring and modeling approaches, an overview of current monitoring programs in the region, guidance for selecting monitoring locations, indicators, and sampling frequencies, and example designs to guide program planning and budgeting. The overarching goal of the report is to help agencies and stakeholders move from high-level recommendations to practical, actionable designs that are tailored to the Delta’s physical, anthropogenic, and ecological landscape.

ESS Open Archive↗
USGS1996

Peak data for U.S. Geological Survey gaging stations, Texas network and computer program to estimate peak-streamflow frequency

About 23,000 annual peak streamflows and about 400 historical peak streamflows exist for about 950 stations in the surface-water data-collection network of Texas. These data are presented on a computer diskette along with the corresponding dates, gage heights, and information concerning the basin, and nature or cause for the flood. Also on the computer diskette is a U.S. Geological Survey computer program that estimates peak-streamflow frequency based on annual and historical peak streamflow. The program estimates peak streamflow for 2-, 5-, 10-, 25-, 50-, and 100-year recurrence intervals and is based on guidelines established by the Interagency Advisory Committee on Water Data. Explanations are presented for installing the program, and an example is presented with discussion of its options.

Open-File Report↗
USGS2008

2005 volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory

The Alaska Volcano Observatory (AVO) responded to eruptive activity or suspected volcanic activity at or near 16 volcanoes in Alaska during 2005, including the high profile precursory activity associated with the 2005–06 eruption of Augustine Volcano. AVO continues to participate in distributing information about eruptive activity on the Kamchatka Peninsula, Russia, and in the Kurile Islands of the Russian Far East, in conjunction with the Kamchatkan Volcanic Eruption Response Team (KVERT) and the Sakhalin Volcanic Eruption Response Team (SVERT), respectively. In 2005, AVO helped broadcast alerts about activity at 8 Russian volcanoes. The most serious hazard posed from volcanic eruptions in Alaska, Kamchatka, or the Kurile Islands is the placement of ash into the atmosphere at altitudes traversed by jet aircraft along the North Pacific and Russian Trans East air routes. AVO, KVERT, and SVERT work collaboratively with the National Weather Service, Federal Aviation Administration, and the Volcanic Ash Advisory Centers to provide timely warnings of volcanic eruptions and the production and movement of ash clouds.

Alaska, Kamchatka↗
USGS1966

An appraisal of the mineral potential of the Peter's Mine area, Northwest District, Guyana

This brief appraisal of the mineral potential of the Peter's Mine area in the Northwest District on the Puruni River, Guyana, was made by the writer in company with Mr. C. N. Barron, Staff Geologist, Guyana Geological Survey, over a five-day period in April, 1966. This study constitutes a part of the U. S. Geological Survey's advisory services to the Government of Guyana's central geological service, under the auspices of the Agency for International Development, U. S. Department of State.

Open-File Report↗
USGS2012

Development of regional skews for selected flood durations for the Central Valley Region, California, based on data through water year 2008

Flood-frequency information is important in the Central Valley region of California because of the high risk of catastrophic flooding. Most traditional flood-frequency studies focus on peak flows, but for the assessment of the adequacy of reservoirs, levees, other flood control structures, sustained flood flow (flood duration) frequency data are needed. This study focuses on rainfall or rain-on-snow floods, rather than the annual maximum, because rain events produce the largest floods in the region. A key to estimating flood-duration frequency is determining the regional skew for such data. Of the 50 sites used in this study to determine regional skew, 28 sites were considered to have little to no significant regulated flows, and for the 22 sites considered significantly regulated, unregulated daily flow data were synthesized by using reservoir storage changes and diversion records. The unregulated, annual maximum rainfall flood flows for selected durations (1-day, 3-day, 7-day, 15-day, and 30-day) for all 50 sites were furnished by the U.S. Army Corps of Engineers. Station skew was determined by using the expected moments algorithm program for fitting the Pearson Type 3 flood-frequency distribution to the logarithms of annual flood-duration data. Bayesian generalized least squares regression procedures used in earlier studies were modified to address problems caused by large cross correlations among concurrent rainfall floods in California and to address the extensive censoring of low outliers at some sites, by using the new expected moments algorithm for fitting the LP3 distribution to rainfall flood-duration data. To properly account for these problems and to develop suitable regional-skew regression models and regression diagnostics, a combination of ordinary least squares, weighted least squares, and Bayesian generalized least squares regressions were adopted. This new methodology determined that a nonlinear model relating regional skew to mean basin elevation was the best model for each flood duration. The regional-skew values ranged from -0.74 for a flood duration of 1-day and a mean basin elevation less than 2,500 feet to values near 0 for a flood duration of 7-days and a mean basin elevation greater than 4,500 feet. This relation between skew and elevation reflects the interaction of snow and rain, which increases with increased elevation. The regional skews are more accurate, and the mean squared errors are less than in the Interagency Advisory Committee on Water Data's National skew map of Bulletin 17B.

California↗
USGS2018

Understanding the influence of nutrients on stream ecosystems in agricultural landscapes

Sustaining the quality of the Nation’s water resources and the health of our diverse ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and long-term economic, social, and environmental benefits that make a difference to the lives of the almost 400 million people projected to live in the United States by 2050. In 1991, Congress established the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) to address where, when, why, and how the Nation’s water quality has changed, or is likely to change in the future, in response to human activities and natural factors. Since then, NAWQA has been a leading source of scientific data and knowledge used by national, regional, State, and local agencies to develop science-based policies and management strategies to improve and protect water resources used for drinking water, recreation, irrigation, energy development, and ecosystem needs ( https://water.usgs.gov/nawqa/applications/ ). Plans for the third decade of NAWQA (2013–23) address priority water-quality issues and science needs identified by NAWQA stakeholders, such as the Advisory Committee on Water Information and the National Research Council, and are designed to meet increasing challenges related to population growth, increasing needs for clean water, and changing land-use and weather patterns. Excess nutrients are a pervasive problem of streams, lakes, and coastal waters. The current report, “The Quality of Our Nation’s Waters—Understanding the Effects of Nutrients on Stream Ecosystems in Agricultural Landscapes,” presents a summary of results from USGS investigations conducted from 2003 to 2011 on processes that influence nutrients and how nutrient enrichment can alter biological components of agricultural streams. This study included collecting data from 232 sites distributed among eight study areas. This report summarizes findings on processes that influence nutrients and how nutrient enrichment can alter biological communities in agricultural streams. These findings are relevant to local, State, regional, and national decision-makers involved in efforts to (1) better understand the influence of nutrients on agricultural streams, (2) develop nutrient criteria for streams and rivers, (3) reduce nutrients to streams and downstream receiving waters, and (4) develop tools for tracking nutrient and biological conditions following nutrient reduction strategies. All NAWQA reports are available online at https://water.usgs.gov/nawqa/bib/ . We hope this publication will provide you with insights and information to meet your water-resource needs and will foster increased citizen awareness and involvement in the protection and restoration of our Nation’s waters. The information in this report is intended primarily for those interested or involved in resource management and protection, conservation, regulation, and policymaking at the regional and national levels.

Central Columbia-Yakima River Basins, Great River ↗
USGS2006

California GAMA program: Ground-water quality data in the northern San Joaquin Basin Study Unit, 2005

Growing concern over the closure of public-supply wells because of ground-water contamination has led the State Water Board to establish the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. With the aid of the U.S. Geological Survey (USGS) and Lawrence Livermore National Laboratory, the program goals are to enhance understanding and provide a current assessment of ground-water quality in areas where ground water is an important source of drinking water. The Northern San Joaquin Basin GAMA study unit covers an area of approximately 2,079 square miles (mi2) across four hydrologic study areas in the San Joaquin Valley. The four study areas are the California Department of Water Resources (CADWR) defined Tracy subbasin, the CADWR-defined Eastern San Joaquin subbasin, the CADWR-defined Cosumnes subbasin, and the sedimentologically distinct USGS-defined Uplands study area, which includes portions of both the Cosumnes and Eastern San Joaquin subbasins. Seventy ground-water samples were collected from 64 public-supply, irrigation, domestic, and monitoring wells within the Northern San Joaquin Basin GAMA study unit. Thirty-two of these samples were collected in the Eastern San Joaquin Basin study area, 17 in the Tracy Basin study area, 10 in the Cosumnes Basin study area, and 11 in the Uplands Basin study area. Of the 32 samples collected in the Eastern San Joaquin Basin, 6 were collected using a depth-dependent sampling pump. This pump allows for the collection of samples from discrete depths within the pumping well. Two wells were chosen for depth-dependent sampling and three samples were collected at varying depths within each well. Over 350 water-quality field parameters, chemical constituents, and microbial constituents were analyzed and are reported as concentrations and as detection frequencies, by compound classification as well as for individual constituents, for the Northern San Joaquin Basin study unit as a whole and for each individual study area. Results are presented in a descending order based on detection frequencies (most frequently detected compound listed first), or alphabetically when a detection frequency could not be calculated. Only certain wells were measured for all constituents and water-quality parameters. The results of all of the analyses were compared with U.S. Environmental Protection Agency (USEPA) and California Department of Health Services (CADHS) Maximum Contaminant Levels (MCLs), Secondary Maximum Contaminant Levels (SMCLs), USEPA lifetime health advisories (HA-Ls), the risk-specific dose at a cancer risk level equal to 1 in 100,000 or 10E-5 (RSD5), and CADHS notification levels (NLs). When USEPA and CADHS MCLs are the same, detection levels were compared with the USEPA standard; however, in some cases, the CADHS MCL may be lower. In those cases, the data were compared with the CADHS MCL. Constituents listed by CADHS as 'unregulated chemicals for which monitoring is required' were compared with the CADHS 'detection level for the purposes of reporting' (DLR). DLRs unlike MCLs are not health based standards. Instead, they are levels at which current laboratory detection capabilities allow eighty percent of qualified laboratories to achieve measurements within thirty percent of the true concentration. Twenty-three volatile organic compounds (VOCs) and seven gasoline oxygenates were detected in ground-water samples collected in the Northern San Joaquin Basin GAMA study unit. Additionally, 13 tentatively identified compounds were detected. VOCs were most frequently detected in the Eastern San Joaquin Basin study area and least frequently detected in samples collected in the Cosumnes Basin study area. Dichlorodifluoromethane (CFC-12), a CADHS 'unregulated chemical for which monitoring is required,' was detected in two wells at concentrations greater than the DLR. Trihalomethanes were the most frequently detected class of VOC constituents. Chloroform (trichloromethane) was the m

California↗
USGS1996

Meeting summary - Coastal meteorology and oceanography: Report of the third prospectus development team of the U.S. Weather Research Program to NOAA and NSF

U.S. Weather Research Program (USWRP) prospectus development teams (PDTs) are small groups of scientists that are convened by the USWRP lead scientist on a one-time basis to discuss critical issues and to provide advice related to future directions of the program. PDTs are a principal source of information for the Science Advisory Committee, which is a standing committee charged with the duty of making recommendations to the Program Office based upon overall program objectives. PDT-1 focused on theoretical issues, and PDT-2 on observational issues; PDT-3 is the first of several to focus on more specialized topics. PDT-3 was convened to identify forecasting problems related to U.S. coastal weather and oceanic conditions, and to suggest likely solution strategies. There were several overriding themes that emerged from the discussion. First, the lack of data in and over critical regions of the ocean, particularly in the atmospheric boundary layer, and the upper-ocean mixed layer were identified as major impediments to coastal weather prediction. Strategies for data collection and dissemination, as well as new instrument implementation, were discussed. Second, fundamental knowledge of air-sea fluxes and boundary layer structure in situations where there is significant mesoscale variability in the atmosphere and ocean is needed. Companion field studies and numerical prediction experiments were discussed. Third, research prognostic models suggest that future operational forecast models pertaining to coastal weather will be high resolution and site specific, and will properly treat effects of local coastal geography, orography, and ocean state. The view was expressed that the exploration of coupled air-sea models of the coastal zone would be a particularly fruitful area of research. PDT-3 felt that forecasts of land-impacting tropical cyclones, Great Lakes-affected weather, and coastal cyclogenesis, in particular, would benefit from such coordinated modeling and field efforts. Fourth, forecasting for Arctic coastal zones is limited by our understanding of how sea ice forms. The importance of understanding air-sea fluxes and boundary layers in the presence of ice formation was discussed. Finally, coastal flash flood forecasting via hydrologic models is limited by the present accuracy of measured and predicted precipitation and storm surge events. Strategies for better ways to improve the latter were discussed.

Conference Paper↗