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USGS2009

Occurrence and distribution of iron, manganese, and selected trace elements in ground water in the glacial aquifer system of the northern United States

Dissolved trace elements, including iron and manganese, are often an important factor in use of ground water for drinking-water supplies in the glacial aquifer system of the United States. The glacial aquifer system underlies most of New England, extends through the Midwest, and underlies portions of the Pacific Northwest and Alaska. Concentrations of dissolved trace elements in ground water can vary over several orders of magnitude across local well networks as well as across regions of the United States. Characterization of this variability is a step toward a regional screening-level assessment of potential human-health implications. Ground-water sampling, from 1991 through 2003, of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey determined trace element concentrations in water from 847 wells in the glacial aquifer system. Dissolved iron and manganese concentrations were analyzed in those well samples and in water from an additional 743 NAWQA land-use and major-aquifer survey wells. The samples are from monitoring and water-supply wells. Concentrations of antimony, barium, beryllium, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, selenium, strontium, thallium, uranium, and zinc vary as much within NAWQA study units (local scale; ranging in size from a few thousand to tens of thousands of square miles) as over the entire glacial aquifer system. Patterns of trace element concentrations in glacial aquifer system ground water were examined by using techniques suitable for a dataset with zero to 80 percent of analytical results reported as below detection. During the period of sampling, the analytical techniques changed, which generally improved the analytical sensitivity. Multiple reporting limits complicated the comparison of detections and concentrations. Regression on Order Statistics was used to model probability distributions and estimate the medians and other quantiles of the trace element concentrations. Strontium and barium were the most frequently detected and usually were present in the highest concentrations. Iron and manganese were the next most commonly detected and next highest in concentrations. Iron concentrations were the most variable with respect to the range of variations (both within local networks and aquifer-wide) and with respect to the disparity between magnitude of concentrations (detections) and the frequency of samples below reporting limits (nondetections). Antimony, beryllium, cadmium, silver, and thallium were detected too infrequently for substantial interpretation of their occurrence or distributions or potential human-health implications. For those elements that were more frequently detected, there are some geographic patterns in their occurrence that primarily reflect climate effects. The highest concentrations of several elements were found in the West-Central glacial framework area (High Plains and northern Plains areas). There are few important patterns for any element in relation to land use, well type, or network type. Shallow land-use (monitor) wells had iron concentrations generally lower than the glacial aquifer system wells overall and much lower than major-aquifer survey wells, which comprise mostly private- and public-supply wells. Unlike those for iron, concentration patterns for manganese were similar among shallow land-use wells and major-aquifer survey wells. An apparent relation between low pH and relatively low concentrations of many elements, except lead, may be more indicative of the relatively low dissolved-solids content in wells in the Northeastern United States that comprise the majority of low pH wells, than of a pH dependent pattern. Iron and manganese have higher concentrations and larger ranges of concentrations especially under more reducing conditions. Dissolved oxygen and well depth were related to iron and manganese concentrations. Redox conditions also affect several trace elements such as arsenic and copper; however, a comparison of redox categories, based in part on iron and manganese concentrations, indicated that the concentrations of many redox-sensitive elements were not significantly different among redox categories. Some of the redox-related patterns were not what would be expected on the basis of solubility constraints. Furthermore, barium is affected by redox conditions in at least one well network even though it is not a redox-sensitive element. Concentrations of barium in portions of the glacial aquifer system are limited by sulfate, which is strongly affected by redox conditions. Few samples had concentrations of any trace element that exceeded drinking-water standards (Maximum Contaminant Levels), for compounds regulated in drinking water or Health-Based Screening Levels for unregulated trace elements. More unregulated trace elements had concentrations greater than benchmarks than regulated trace elements. More samples had manganese concentrations greater its benchmark than any other element in the glacial aquifer system wells. Of the 1,590 wells sampled for manganese, only 556 are for private or public drinking-water supplies, and of those, 9.9 percent (55) exceeded the manganese Lifetime Health Advisory. Concentrations of arsenic, selenium, and uranium less frequently exceeded Maximum Contaminant Levels. There are 29 wells that had 2 element concentrations that exceeded their respective benchmarks. Most concentrations that exceeded a health-based benchmark were from wells in the West-Central area (Iowa, Minnesota, North and South Dakota, Nebraska, and Kansas); however, there is little geographical pattern to the wells with element concentrations of concern.

Scientific Investigations Report↗

USGS2019

Geochemical and mineralogical maps, with interpretation, for soils of the conterminous United States

Between 2007 and 2013, the U.S. Geological Survey conducted a low-density (1 site per 1,600 square kilometers, 4,857 sites) geochemical and mineralogical survey of soils in the conterminous United States. The sampling protocol for the national-scale survey included, at each site, a sample from a depth of 0 to 5 centimeters, a composite of the soil A horizon, and a deeper sample from the soil C horizon or, if the top of the C horizon was at a depth greater than 1 meter, a sample from a depth of approximately 80–100 centimeters. The <2-millimeter fraction of each sample was analyzed for a suite of 45 major and trace elements by methods that yield the total or near-total elemental concentration. The major mineralogical components in the samples from the soil A and C horizons were determined by a quantitative X-ray diffraction method using Rietveld refinement. This report presents all the maps and statistical information for each determined element and mineral along with an interpretive section discussing the possible processes that caused the observed national-scale geochemical and mineralogical patterns. Most often, the geochemical and mineralogical patterns reflect the composition of the underlying soil parent material with some modifications caused by leaching of the more mobile elements (for example, calcium and sodium) in the humid areas of the country.

Scientific Investigations Report↗

USGS2021

A multidisciplinary investigation into the eruptive style, processes, and duration of a Cascades back-arc tholeiitic basalt: A case study of the Brushy Butte flow field, northern California, United States

The Cascades back-arc in northern California is dominated by monogenetic tholeiitic basalts that erupted throughout the Pleistocene. Elucidating their eruptive history and processes is important for understanding potential future eruptions here. We focus on the well-exposed monogenetic volcano that emplaced the Brushy Butte flow field, which constructed a ∼150 m tall edifice, has flow lobes up to >10 km long, and in total covers ∼150 km 2 with an eruptive volume of 3.5 km 3 . We use a multidisciplinary approach of field mapping, petrography, geochemistry, paleomagnetism, geochronology, and lidar imagery to unravel the eruptive history and processes that emplaced this flow field. Tholeiitic basalts in northern California have diverse surface morphology and vegetation cover but similar petrographic appearances, which makes them hard to distinguish in the field. Geochemistry and paleomagnetism offer an independent means of distinguishing tholeiitic basalts. Brushy Butte flow field lavas are similar in major-oxide and trace-element abundances but differ from adjacent tholeiitic basalts. This is also apparent in remanent magnetic directions. Additionally, paleomagnetism indicates that the flow field was emplaced during a geologically brief time interval (10–20 years), which 36 Cl cosmogenic dating puts at 35.7 ± 1.7 ka. Lidar imagery shows that these flows erupted from at least 28 vents encompassing multiple scoria cones, spatter cones, and craters. Flows can be grouped into four pulses using stratigraphic position and volume. Pulse 1 is the most voluminous, comprising eight eruptions and ∼2.3 km 3 . Each subsequent pulse started rapidly but decayed quickly, and each successive pulse erupted less lava (i.e., 2.3 km 3 for pulse 1, 0.6 km 3 for pulse 2, 0.3 km 3 for pulse 3, and 0.2 km 3 for pulse 4). Many of these flows host well-established lava channels and levees (with channel breakouts) that lead to lava fans, with some flows hosting lava ponds. Similar flow features from tholeiitic eruptions elsewhere demonstrate that these morphologies generally occur over weeks, months, or longer (e.g., Puʻu ʻŌʻō eruption at K–llauea, Hawaiʻi). This multidisciplinary study shows the range of eruptive styles and durations of a Cascades back-arc eruption and illustrates how potential future tholeiitic eruptive activity in the western United States might progress.

California↗

USGS1996

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Vermejo Project area and the Maxwell National Wildlife Refuge, Colfax County, northeastern New Mexico, 1993

Based on findings of limited studies during 1989-92, a reconnaissance investigation was conducted in 1993 to assess the effects of the Vermejo Irrigation Project on water quality in the area of the project, including the Maxwell National Wildlife Refuge. This project was part of a U.S. Department of the Interior National Irrigation Water-Quality Program to determine whether irrigation drainage has caused or has the potential to cause significant harmful effects on human health, fish, and wildlife and whether irrigation drainage may adversely affect the suitability of water for other beneficial uses. For this study, samples of water, sediment, and biota were collected from 16 sites in and around the Vermejo Irrigation Project prior to, during the latter part of, and after the 1993 irrigation season (April, August-September, and November, respectively). No inorganic constituents exceeded U.S. Environmental Protection Agency drinking-water standards. The State of New Mexico standard of 750 micrograms per liter for boron in irrigation water was exceeded at three sites (five samples), though none exceeded the livestock water standard of 5,000 micrograms per liter. Selenium concentrations exceeded the State of New Mexico chronic standard of 2 micrograms per liter for wildlife and fisheries water in at least eight samples from five sites. Bottom-sediment samples were collected and analyzed for trace elements and compared to concentrations of trace elements in soils of the Western United States. Concentrations of three trace elements at eight sites exceeded the upper values of the expected 95-percent ranges for Western U.S. soils. These included molybdenum at one site, selenium at seven sites, and uranium at four sites. Cadmium and copper concentrations exceeded the National Contaminant Biomonitoring Program 85th percentile in fish from six sites. Average concentrations of selenium in adult brine flies (33.7 μ g/g dry weight) were elevated above concentrations in other invertebrates. Concentrations of other elements were below their respective toxicity levels. Plants, invertebrates, fish, and fish fillets were collected and analyzed. These analyses were compared to diagnostic criteria and to each other to determine the extent of bioaccumulation of trace elements. Plants contained larger dry weight concentrations of aluminum, arsenic, boron, chromium, iron, lead, magnesium, manganese, nickel, and vanadium than invertebrates and fish. Adult brine flies, gathered from playas, contained larger geometric mean dry weight concentrations of boron, magnesium, and selenium than other invertebrates. Of all samples collected, the largest mercury concentrations were found in fish fillets, although these concentrations were below levels of concern. Mercury and selenium bioaccumulation was evident in various habitats of the study area. Biological samples from Natural playa, an endemic wetland, and Half playa, a playa that receives additional water through seepage and irrigation delivery canals, generally had elevated concentrations of boron, iron, magnesium, and selenium than samples from reservoir and river sites. Selenium concentrations were lowest in biota from the two reservoir sites, although a wetland immediately downstream from the dam impounding Lake No. 13 (created by seepage from the reservoir) had elevated concentrations of selenium in biota. The geometric mean selenium concentration of whole-fish samples, except those from Lakes No. 13 and No. 14, exceeded the 5- μ g/g dry weight selenium concentration that demarcates the approximate lower limit of the threshold range of concentrations that have freen associated with adverse effects on piscine reproduction. Biota collected on and in the area around Maxwell National Wildlife Refuge contained concentrations of selenium that are in the lower range of threshold values that have been associated (dietarily) with risks of avian reproductive abnormalities. Bottom-sediment samples from two sites downstream from the irrigation project were collected and analyzed for 23 organic compounds (principally organochlorine pesticide residues). Three compounds were detected at the two sites: DDD was found at 0.2 microgram per kilogram, DDE was detected at 0.1 microgram per kilogram at both sites, and chlordane was detected at 1 microgram per kilogram. None of the 28 whole-fish and fillet samples analyzed for PCB and organochlorine pesticide residues contained any of the 23 organic compounds tested for at concentrations higher than the analytical reporting limit (less than 0.01 μ g/g wet weight). Concentrations of inorganic analytes were generally within established guidelines or expected concentrations for water, sediment, and biota. lirigation-return flows were found to be unrelated to adverse effects in biota.

New Mexico↗

USGS2005

Baseline water-quality characteristics of the Alaska Army National Guard Stewart River Training Area near Nome, Alaska

The Alaska Army National Guard Stewart River Training Area is approximately 23 miles north of Nome on the Seward Peninsula in northwest Alaska. The Stewart River Training Area encompasses much of the Stewart River Basin and a small part of the Snake River Basin. Hydrologic, water-quality, and physical-habitat data were collected at seven surface-water sites within the Stewart River Training Area during the summer runoff months (late-May to early-September) in 2004. Two of the sampling sites selected for this study were on the main stem Stewart River, one at the upstream boundary and one at the downstream boundary of the training area. Continuous hydrologic, precipitation, and water temperature data were collected at these two sites throughout the summer of 2004. Three pond sites, along the upper, middle, and lower reaches of the Stewart River within the training area, were each sampled twice during the summer of 2004 for analysis of water-quality constituents. Two tributaries to the Snake River Basin, Goldbottom Creek and North Fork Snake River, within the Stewart River Training Area boundary, also were sampled twice during the summer of 2004. Water-quality data collected from the Stewart River at the upstream and downstream study sites indicate similar constituent concentrations. Concentrations of most water-quality constituents collected during the summer of 2004 did not exceed standards for drinking water or recreational contact. Analysis of trace-element concentrations in bed sediment samples indicate the threshold effect concentration (below which no adverse effects on organisms is expected) was exceeded for arsenic, chromium, and nickel concentrations at all sample sites within the Stewart River Training Area and cadmium, copper, zinc, and lead concentrations were found to exceed the threshold effect concentration in varying degrees at the sample sites. The probable effect concentration (above which toxic effects on organisms is likely) was exceeded by arsenic concentrations at all sites except the lower pond site. Chromium and nickel concentrations exceeded the probable effect concentration at the upstream Stewart River site and at the North Fork Snake River site.

Scientific Investigations Report↗

USGS1989

Hydrogeology and ground-water-quality conditions at the Geary County landfill, northeast Kansas, 1988

Chemical analysis of water from monitoring wells upgradient and downgradient of the Geary County Landfill in Kansas near Junction City indicate the presence of several chemically distinct water types. For the dominant calcium bicarbonate water type, concentrations of inorganic and organic constituents indicate the presence of reducing conditions within the landfill and increased concentrations of calcium, magnesium, sodium, bicarbonate, sulfate, chloride, ammonia, iron, manganese, and other trace elements downgradient within a leachate plume that extends northeasterly away from the landfill. The orientation of the long axis of the leachate plume does not coincide with the August or September directions of groundwater flow, possibly due to the effect of abundant rainfall and high river stages at other times of the year or preferential flow in very transmissive zones, and thus may indicate the dominant direction of groundwater flow. None of the organic-constituent or inorganic-constituent concentrations exceeded secondary drinking-water standards. Concentrations of benzene, vinyl chloride, and 1,2-trans-dichloroethene exceeded Kansas notification levels. (USGS)

Water-Resources Investigations Report↗

USGS1995

Trace metals and major and rare earth elements in cuttings from five high-temperature wells in the northwest region of The Geysers, California, vapor-dominated geothermal system

Temperatures within the main vapor-dominated steam reservoir at The Geysers geothermal field generally are in the range 238°C to 244°C. A few deep wells in the northwestern part of the field have penetrated beneath this reservoir into a second vapor-dominated reservoir where temperatures are >315°C, while vapor pressure remains nearly constant at about 35.9 bars (Walters et al., 1992). Vapor-dominated reservoirs generally are thought to operate like heat pipes in which steam formed near the base of the system convects upward (along with other gases, such as CC>2 and H2S), while liquid that has condensed from steam near the top of the reservoir counterflows downward (White et al., 1971). To the extent that this steam condensate carries H2S in solution, it may dissolve gold from the surrounding rock during the counterflow. Re-evaporation of the down-flowing condensate and precipitation of dissolved material might occur at the base of the upper reservoir where there is a relatively sharp increase in temperature while vapor pressure remains nearly constant. In addition, brine that once was present throughout the system (Moore, 1992) may have deposited a variety of ore minerals when and where boiling was vigorous during the transition from previous hot water-dominated to present-day vapor-dominated conditions. The investigation reported here was a geochemical reconnaissance survey looking for evidence of accumulation of Au and other metals in the transition zone between the two reservoirs. The petrology of the cuttings was not examined as part of the investigation.

Open-File Report↗

USGS2007

Selected water-quality data for the Standard Mine, Gunnison County, Colorado, 2006-2007

Mine drainage and underground water samples were collected for analysis of inorganic solutes as part of a 1-year, hydrogeologic investigation of the Standard Mine and vicinity. The U.S. Environmental Protection Agency has listed the Standard Mine in the Elk Creek drainage near Crested Butte, Colorado, as a Superfund Site because discharge from the Standard Mine enters Elk Creek, contributing dissolved and suspended loads of zinc, cadmium, copper, and other metals to Coal Creek, which is the primary drinking-water supply for the town of Crested Butte. Water analyses are reported for mine-effluent samples from Levels 1 and 5 of the Standard Mine, underground samples from Levels 3 and 5 of the Standard Mine, mine effluent from an adit located on the Elk Lode, and two spring samples that emerged from waste-rock material below Level 5 of the Standard Mine and the adit located on the Elk Lode. Reported analyses include field parameters (pH, specific conductance, water temperature, dissolved oxygen, and redox potential) and major constituents and trace elements.

Open-File Report↗

USGS1995

Ground-water data for the Suck Creek area of Walden Ridge, southern Cumberland Plateau, Marion County, Tennessee

An investigation was made of the ground-water resources of the Suck Creek area, Marion County, Tennessee, 1990-91. Suck Creek is located on the Walden Ridge section of the Cumberland Plateau, and is about 16 miles northwest of Chattanooga. Eight wells were drilled into bedrock of Pennsylvania age. Drilling sites were chosen at or near fracture traces. Yields of the eight wells ranged from less than 1 to as much as 80 gallons of water per minute. Three wells had yields of 50 gallons per minute or more; two of these had estimated yields of 75 to 80 gallons per minute. These three wells produced water from a well- developed fracture within the Sewanee Conglomerate. Specific capacities for these three wells were 1.1, 1.3, 2.2 gallons per minute per foot of drawdown. Samples of water from six test wells and three domestic wells were analyzed for major inorganic constituents, nurients, major metals, trace elements, and bacteria. In addition, water samples from two of the test wells were analyzed for volatile organic compounds and scanned for the presence of semi-volatile organic compounds. Iron exceeded 300 micrograms per liter in five of the nine samples, and manganese exceeded 50 micrograms per liter in seven of the nine water samples. Toluene, a volatile organic compound, was detected in a concentration slightly above the reporting level; no other volatile organic compounds were detected.

Tennessee↗

USGS2008

Stratigraphic framework of Cambrian and Ordovician rocks in the Appalachian Basin from Sequatchie County, Tennessee through eastern Kentucky, to Mingo County, West Virginia

Cross section H-H' is the seventh in a series of restored cross sections constructed by the lead author to show the stratigraphic framework of Cambrian and Ordovician rocks in the Appalachian basin from Pennsylvania to Tennessee. The sections show complexly intertongued carbonate and siliciclastic lithofacies, marked thickness variations, key marker horizons, unconformities, stratigraphic nomenclature of the Cambrian and Ordovician sequence, and major faults that offset Proterozoic basement and overlying lower Paleozoic rocks. Several of the drill holes along the cross section have yielded a variety of whole and (or) fragmented conodont elements. The identifiable conodonts are used to differentiate strata of Late Cambrian, Early Ordovician, and Middle Ordovician age, and their conodont color alteration index (CAI) values are used to establish the thermal maturity of the sequence. Previous cross sections in this series are G-G', F-F', E-E', D-D', C-C', and B-B'. Many of these cross sections (B-B', C-C', D-D', and G-G') have been improved with the addition of gamma-ray log traces, converted to digital images, and made accessible on the Web.

Kentucky, Tennessee, Virginia, West Virginia↗

USGS1984

Reconnaissance of the shallow-unconfined aquifer in Salt Lake Valley, Utah

The shallow-unconfined aquifer in Salt Lake (Jordan) Valley, Utah, seldom is used for domestic or industrial purposes because it yields water slowly and is readily contaminated. The water in the aquifer, however, can flood basements and is a potential source of contamination to other water supplies. In about one-half of the valley, water in the shallow-unconfined aquifer is less than 10 feet below land surface. The general direction of flow in the shallow aquifer is toward the Jordan River. Water levels in the north part of the valley and along the Jordan River are highest in March or April and in the south part of the valley are highest in late summer. The smallest concentrations of dissolved solids in water from wells along the east side of the valley, and the greatest concentrations are in the northwest part of the valley near the Great Salt Lake. Large dissolved-solids concentrations are found near some landfills and tailings areas. Nitrate-nitrogen concentrations ranged from less than 0.1 to 86 milligrams per liter and nitrate-nitrogen concentrations from less than 0.02 to 0.85 milligram per liter. Some of the largest nitrate-nitrogen concentrations were found in water wells near animal pens. The greatest concentrations of trace elements generally came from wells near landfills and tailings area. The greatest measured concentration of cadmium was 200 microgram per liter, of mercury 0.1 microgram per liter, of lead 46 micrograms per liter, of iron 37,000 micrograms per liter and of arsenic 360 micrograms per liter. Synthetic organic chemicals were found in water from several wells. The greatest measured concentration of benzene was 400 micrograms per liter, of phenol 660 micrograms per liter, of 1,1 dichloroethane 20 micrograms per liter, of tichloroethylene 8 micrograms per liter , and of chloroethylene, 11 micrograms per liter. The greatest concentrations were in water from wells near landfills. (USGS)

Water-Resources Investigations Report↗

USGS1993

Ground-water quality near an inactive landfill and sludge-spreading area, Tallahassee, Florida

Ground-water quality of a 120-acre area encompassing an inactive landfill southwest of Tallahassee, Florida, was assessed by installing and sampling 21 monitoring wells. Sludge from a municipal sewage-treatment plant was also applied to the land surface near the landfill site. Water samples were collected from the 21 monitoring wells from June 1987 through September 1990 and analyzed for concentrations of major ions, nitrogen species, trace metals, field measurements, and more than 140 organic constituents. Water quality in the Upper Floridan aquifer at the study site was compared to background water quality in other areas of Leon County. Ground-water quality of the study site was evaluated by the location of wells sampled in relation to the landfill and the sludge-spreading areas. Results of nonparametric statistical analysis indicated that potassium and nitrite plus nitrate as nitrogen concentrations in water samples from wells completed in the Upper Floridan aquifer at the study site were significantly different at the 5 percent probability level from those in samples from background wells completed in this aquifer in Leon County. Median potassium concentrations were 0.4 mg/L (milligrams per liter) in water from wells at the study site and 0.7 mg/L in water from background wells in Leon County. Median nitrite plus nitrate concentrations were 6.48 mg/L in water samples from wells at the study site and 0.51 mg/L in water samples from background wells. Graphical comparison of the water quality characteristics in water from six categories of wells; upgradient, landfill, adjacent to the landfill, downgradient onsite, downgradient offsite, and background Leon County, indicated that sodium, bicarbonate, sulfate, iron, manganese, and dissolved solids concentrations and specific conductance values were highest within the landfill. Upgradient and downgradient well categories include wells in areas affected by sludge spreading. Localized reducing conditions were indicated in a downgradient area by median iron concentrations of 930 and 30 ug/L (micrograms per liter) in samples from wells only 5 feet apart. Nitrite plus nitrate concentrations were lowest in water from wells in the landfill compared to water from the other categories. Concentrations of most trace elements and organic compounds were mostly below detection limits, although State maximum contaminant levels of 1 ug/L for benzene and vinyl chloride and 3 ug/L for tetrachloroethene were exceeded in 14 samples. Concentrations of sodium, potassium, chloride, sulfate, nitrite plus nitrate, total organic and ammonia nitrogen, and ammonia nitrogen in ground water were statistically analyzed in areas affected by sludge-spreading and other areas. Only nitrite plus nitrate and chloride concentrations were significantly different between the two areas. Median nitrite plus nitrate and chloride concentrations in sludge-spreading areas were 6.9 mg/L and 2.9 mg/L, respectively, compared to 1.1 mg/L and 1.8 mg/L in other areas.

Florida↗

USGS2015

Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California: 2014

Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica ), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer (km) south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2014 to December 2014. These append to long-term datasets extending back to 1974, and serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994. Following significant reductions in the late 1980s, silver (Ag) and copper (Cu) concentrations in sediment and M. petalum appear to have stabilized. Data for other metals, including chromium (Cr), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn), have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2014, concentrations of Ag and Cu in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported previously. Seasonal patterns for other elements, including Cr, Ni, Zn, Hg, and Se, were generally similar in timing and magnitude as those for Ag and Cu. In M. petalum , all observed elements showed annual maxima in January–February and minima in April, except for Zn, which was lowest in December. In sediments, annual maxima also occurred in January–February, and minima were measured in June and September. In 2014, metal concentrations in both sediments and clam tissue were among the lowest on record. This record suggests that regional-scale factors now largely control sedimentary and bioavailable concentrations of Ag and Cu, as well as other elements of regulatory interest, at the Palo Alto site. Analyses of the benthic community structure of a mudflat in South San Francisco Bay over a 40-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum , from the same area. Analysis of M. petalum shows increases in reproductive activity concurrent with the decline in metal concentrations in the tissues of this organism. Reproductive activity is presently stable (2014), with almost all animals initiating reproduction in the fall and spawning the following spring. The entire infaunal community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundance, a pattern that indicates a more stable community that is subjected to fewer stressors. In addition, two of the opportunistic species ( Ampelisca abdita and Streblospio benedicti ) that brood their young and live on the surface of the sediment in tubes have shown a continual decline in dominance coincident with the decline in metals; both species had short-lived rebounds in abundance in 2008, 2009, and 2010. Heteromastus filiformis (a subsurface polychaete worm that lives in the sediment, consumes sediment and organic particles residing in the sediment, and reproduces by laying its eggs on or in the sediment) showed a concurrent increase in dominance and, in the last several years before 2008, showed a stable population. H. filiformis abundance increased slightly in 2011–2012 and returned to pre-2011 numbers in 2014. An unidentified disturbance occurred on the mudflat in early 2008 that resulted in the loss of the benthic animals, except for deep-dwelling animals like Macoma petalum . However, within two months of this event animals returned to the mudflat. The resilience of the community suggested that the disturbance was not due to a persistent toxin or to anoxia. The reproductive mode of most species present in 2014 is reflective of species that were available either as pelagic larvae or as mobile adults. Although oviparous species were lower in number in this group, the authors hypothesize that these species will return slowly as more species move back into the area. The use of functional ecology was highlighted in the 2014 benthic community data, which showed that the animals that have now returned to the mudflat are those that can respond successfully to a physical, nontoxic disturbance. Today, community data show a mix of species that consume the sediment, or filter feed, have pelagic larvae that must survive landing on the sediment, and those that brood their young. USGS scientists view the 2008 disturbance event as a response by the infaunal community to an episodic natural stressor (possibly sediment accretion or a pulse of freshwater), in contrast to the long-term recovery from metal contamination. We will compare this recovery to the long-term recovery observed after the 1970’s when the decline in sediment pollutants was the dominating factor.

California↗

USGS2016

Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California; 2015

Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica ), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, California. This report includes data collected by U.S. Geological Survey (USGS) scientists for the period from January 2015 to December 2015. These data are appended to long-term datasets extending back to 1974, and serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994. Following significant reductions in the late 1980s, silver (Ag) and copper (Cu) concentrations in sediment and M. petalum appear to have stabilized. Data for other metals, including chromium (Cr), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn), have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2015, concentrations of Ag and Cu in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported previously. Seasonal patterns for other elements, including Cr, Ni, Zn, Hg, and Se, were generally similar in timing and magnitude as those for Ag and Cu. In M. petalum , all observed elements showed annual maxima in January–February and minima in April, except for Zn, which was lowest in December. In sediments, annual maxima also occurred in January–February, and minima were measured in June and September. In 2015, metal concentrations in both sediments and clam tissue were among the lowest on record. This record suggests that regional-scale factors now largely control sedimentary and bioavailable concentrations of Ag and Cu, as well as other elements of regulatory interest, at the Palo Alto site. Analyses of the benthic community structure at the same mudflat over a 40-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum , from the same area. Analysis of M. petalum shows increases in reproductive activity concurrent with the decline in metal concentrations in the tissues of this organism. Reproductive activity is presently stable (2015), with almost all animals initiating reproduction in the fall and spawning the following spring. The entire infaunal community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundance, a pattern that indicates a more stable community that is subjected to fewer stressors. In addition, two of the opportunistic species ( Ampelisca abdita and Streblospio benedicti ) that brood their young and live on the surface of the sediment in tubes have shown a continual decline in dominance coincident with the decline in metals; both species had short-lived rebounds in abundance in 2008, 2009, and 2010 and showed signs of increasing abundance in 2015. Heteromastus filiformis (a subsurface polychaete worm that lives in the sediment, consumes sediment and organic particles residing in the sediment, and reproduces by laying its eggs on or in the sediment) showed an increase in dominance, concurrent with the decrease in Ag and Cu concentrations, and in the last several years before 2008, showed a stable population. H. filiformis abundance increased slightly in 2011–2012 and returned to pre-2011 abundance in 2015. An unidentified disturbance occurred on the mudflat in early 2008 that resulted in the loss of the benthic animals, except for deep-dwelling animals like M. petalum . However, within two months of this event animals returned to the mudflat. The resilience of the community suggested that the disturbance was not due to a persistent toxin or to anoxia. The reproductive mode of most species present in 2015 is reflective of species that were available either as pelagic larvae or as mobile adults. Although oviparous (live-birth) species were lower in number in this group, the authors hypothesize that these species will return slowly as more species move back into the area. The use of functional ecology was highlighted in the 2015 benthic community data, which showed that the animals that have now returned to the mudflat are those that can respond successfully to a physical, nontoxic disturbance. Today, community data show a mix of species that consume the sediment, or filter feed, have pelagic larvae that must survive landing on the sediment, and those that brood their young. USGS scientists view the 2008 disturbance event as a response by the infaunal community to an episodic natural stressor (possibly sediment accretion or a pulse of freshwater), in contrast to the long-term recovery from metal contamination. We will compare this recovery to the long-term recovery observed after the 1970s when the decline in sediment pollutants was the dominating factor.

California↗

USGS2010

Hydrological, geological, and biological site characterization of breccia pipe uranium deposits in Northern Arizona

On July 21, 2009, U.S. Secretary of the Interior Ken Salazar proposed a two-year withdrawal of about 1 million acres of Federal land near the Grand Canyon from future mineral entry. These lands are contained in three parcels: two parcels on U.S. Bureau of Land Management land to the north of the Grand Canyon (North and East Segregation Areas) and one on the Kaibab National Forest south of the Grand Canyon (South Segregation Area). The purpose of the two-year withdrawal is to examine the potential effects of restricting these areas from new mine development for the next 20 years. This proposed withdrawal initiated a period of study during which the effects of the withdrawal must be evaluated. At the direction of the Secretary, the U.S. Geological Survey began a series of short-term studies designed to develop additional information about the possible effects of uranium mining on the natural resources of the region. Dissolved uranium and other major, minor, and trace elements occur naturally in groundwater as the result of precipitation infiltrating from the surface to water-bearing zones and, presumably, to underlying regional aquifers. Discharges from these aquifers occur as seeps and springs throughout the region and provide valuable habitat and water sources for plants and animals. Uranium mining within the watershed may increase the amount of radioactive materials and heavy metals in the surface water and groundwater flowing into Grand Canyon National Park and the Colorado River, and deep mining activities may increase mobilization of uranium through the rock strata into the aquifers. In addition, waste rock and ore from mined areas may be transported away from the mines by wind and runoff.

Scientific Investigations Report↗

USGS1996

Phytoplankton bloom dynamics in coastal ecosystems: A review with some general lessons from sustained investigation of San Francisco Bay, California

Phytoplankton blooms are prominent features of biological variability in shallow coastal ecosystems such as estuaries, lagoons, bays, and tidal rivers. Long-term observation and research in San Francisco Bay illustrates some patterns of phytoplankton spatial and temporal variability and the underlying mechanisms of this variability. Blooms are events of rapid production and accumulation of phytoplankton biomass that are usually responses to changing physical forcings originating in the coastal ocean (e.g., tides), the atmosphere (wind), or on the land surface (precipitation and river runoff). These physical forcings have different timescales of variability, so algal blooms can be short-term episodic events, recurrent seasonal phenomena, or rare events associated with exceptional climatic or hydrologic conditions. The biogeochemical role of phytoplankton primary production is to transform and incorporate reactive inorganic elements into organic forms, and these transformations are rapid and lead to measurable geochemical change during blooms. Examples include the depletion of inorganic nutrients (N, P, Si), supersaturation of oxygen and removal of carbon dioxide, shifts in the isotopic composition of reactive elements (C, N), production of climatically active trace gases (methyl bromide, dimethylsulfide), changes in the chemical form and toxicity of trace metals (As, Cd, Ni, Zn), changes in the biochemical composition and reactivity of the suspended particulate matter, and synthesis of organic matter required for the reproduction and growth of heterotrophs, including bacteria, zooplankton, and benthic consumer animals. Some classes of phytoplankton play special roles in the cycling of elements or synthesis of specific organic molecules, but we have only rudimentary understanding of the forces that select for and promote blooms of these species. Mounting evidence suggests that the natural cycles of bloom variability are being altered on a global scale by human activities including the input of toxic contaminants and nutrients, manipulation of river flows, and translocation of species. This hypothesis will be a key component of our effort to understand global change at the land-sea interface. Pursuit of this hypothesis will require creative approaches for distinguishing natural and anthropogenic sources of phytoplankton population variability, as well as recognition that the modes of human disturbance of coastal bloom cycles operate interactively and cannot be studied as isolated processes.

California↗

USGS1982

Reconnaissance for determining effects of land use and surficial geology on concentrations of selected elements on streambed materials from the coal-mining region, southwestern Indiana, October 1979 to March 1980

Streambed materials were collected in October 1979 from 69 watersheds in Southwest Indiana having predominantly forested, agricultural, reclaimed, and unreclaimed mined land use to determine whether concentrations of sorbed and acid-soluble metals and trace elements were affected by land use and surficial geology. Analysis of variance indicated that 10% or more of the total variation in aluminum, arsenic, cobalt, iron, nickel, selenium, and zinc concentrations on streambed materials was accounted for by differences in land use. Concentrations of aluminum, cobalt, iron, nickel, selenium, and zinc on streambed materials smaller than 0.062-millimeter from mined watersheds were significantly greater than the concentrations of these elements on streambed materials from agricultural and forested watersheds. The greater concentrations of these elements on streambed materials are due to (1) their concentrations in mine drainage and their subsequent absorption and (or) copecipitation with the oxides and hydroxides of aluminum and iron and (2) their concentrations in coal and pyritic material in streambed materials.

Indiana↗

USGS1989

Trace elements in bed sediments of the San Joaquin River and its tributary streams, California, 1985

Bed sediments were sampled at 24 sites on the San Joaquin River, California and its tributaries in October 1985 to assess the distribution of trace elements and factors affecting their concentrations. The proportion of less than 62-micrometer sediment was significantly (alpha=0.05) correlated with organic-carbon concentrations. Bed sediments from tributaries originating in the Sierra Nevada were much coarser than sediments in streams draining the Coast Range and western valley. Selenium concentrations in water have been measured. Interrelations among trace elements were examined using principal component analysis. 57% of the variance was accounted for in the first two principal components, which together show a distinct separation between sites dominated by Coast Range sediments and sites dominated by Sierra Nevada sediments. The third and fourth components accounted for 21% of the variance and distinguished the mixed-source sediments of the intermittent upper San Joaquin River from other parts of the river system. Generally, elements in bed sediments of the San Joaquin River and its tributaries were similar in concentration to elements in San Joaquin Valley soils, and concentrations were far below hazardous waste criteria. Concentrations were lower than in sediments from some polluted urban rivers and water more comparable to other rural agricultural rivers. (USGS)

Water-Resources Investigations Report↗