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High radium (Ra) concentrations in potable portions of the Cambrian-Ordovician (C-O) aquifer system were investigated using water-quality data and environmental tracers ( 3H, 3Hetrit, SF6 , 14C and 4Herad) of groundwater age from 80 public-supply wells (PSWs). Groundwater ages were estimated by calibration of tracers to lumped parameter models and ranged from modern (1 Myr) in the most downgradient, confined portions of the potable system. More than 80 and 40 percent of mean groundwater ages were older than 1000 and 50,000 yr, respectively. Anoxic, Fe-reducing conditions and increased mineralization develop with time in the aquifer system and mobilize Ra into solution resulting in the frequent occurrence of combined...
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Following the May 2005 acid crater lake flood at Chiginagak volcano, DGGS has been monitoring crater lake water that flows into Indecision Creek, Mother Goose Lake, and the King Salmon River.This data table provides information on water samples collected between 2005 and 2011 near Chiginagak volcano, including:sample ID, latitude, longitude, location description, pH, and cation and anion chemistry results.
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Field spikes were prepared at 207 stream and river sites as part of the U.S. Geological Survey (USGS) National Water Quality Assessment (NAWQA) project between December, 2012, and September, 2015. At the field site, a depth-and width-integrated environmental sample was collected, and one subsample of the environmental sample was spiked with a known amount of a spike mixture. Both the spiked subsample ("spike sample") and another subsample ("environmental sample") of the original water sample were analyzed for pesticides at the USGS National Water Quality Laboratory (NWQL) by direct injection liquid chromatography with tandem mass spectrometry (LC-MS/MS), and were used to calculate the spike recovery of each analyte....
There is now a fairly substantial literature that addresses transboundary water allocation both at the international and interstate level. However, most of this literature deals almost exclusively with the question of allocation and ignores quality considerations. At the same time, there is a growing literature on transboundary pollution control and upstream/downstream externalities. What is missing is an attempt to integrate quality consideration into allocation agreements. This paper examines several allocation agreements and disputes in the southwestern United States and Mexico and looks at the ramifications of omitting pollution control and quality considerations in these negotiations. Published in Agricultural...
Floodplains are presumed to be important rearing habitat for the endangered razorback sucker (Xyrauchen texanus). To help recover this endemic Colorado River Basin species, the Upper Colorado River Endangered Fish Recovery Program implemented a floodplain acquisition and enhancement program. Levee removal was initiated in 1996 as one component of this floodplain restoration program. The goal of the Levee Removal Study was to evaluate the system responses to levee removal and make specific recommendations concerning the value of floodplain/river reconnecting for endangered species (specifically razorback sucker) recovery.
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Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the nine Chesapeake Bay River Input Monitoring (RIM) stations for the period 1985 through 2015. Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted Regression on Time, Discharge, and Season). Yields (represents the mass of constituent transported from a unit area of a given watershed) are used to compare the export loads from one basin to another. Yield results are obtained by dividing the annual load (pounds) of a given constituent by the respective watershed...
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To investigate the effects of imidacloprid on natural stream communities under controlled conditions, experimental streams were dosed with imidacloprid at concentrations ranging from 0.061 to 220 micrograms per liter (µg/L) for a period of 10 days. Natural stream macroinvertebrate communities were obtained from the Cache La Poudre River (Larimer County, CO) by colonizing trays full of large gravel for 75 days. The trays were added to laboratory experimental streams (mesocosms) at the USGS Fort Collins Science Center in Fort Collins, CO. At the end of 10 days, invertebrate abundance metrics were analyzed in relation to measured imidacloprid concentrations in water from the experimental streams. Declines in total...
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These data were compiled during a laboratory experiment showing the turbidity response to increasing silt and clay concentration. The sediment used for the laboratory experiment was collected in the Grand Canyon study area, from the bank of the Little Colorado River, approximately 1 kilometer upstream from its confluence with the Colorado River. The sediment was passed through a 63 µm sieve to isolate the silt-and-clay-size fraction. The silt and clay was completely dried in an oven (at 105 degrees Celsius for 12 hours), weighed, mechanically disaggregated, and added in stages to a measured volume of water to calculate concentration. The sediment was kept in suspension with an electric stirrer and turbidity was...
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These datasets contain aquatic macroinvertebrate and water quality data collected from 159 wetlands in Montana and North Dakota within the Prairie Pothole Region of the Williston Basin.


map background search result map search result map Chesapeake Bay Nontidal Network 2005-2014: Average Yields Data for Radium Mobility and the Age of Groundwater in Public-drinking-water Supplies from the Cambrian-Ordovician Aquifer System, North-Central USA: Table 3. Detailed information on calculations of environmental tracer data. Summit crater lake observations, and the location, chemistry, and pH of water samples near Mount Chiginagak volcano, Alaska: 2004-2011 Laboratory experiment data—turbidity response to increasing silt and clay concentration Macroinvertebrate and water quality data from the Prairie Pothole Region of the Williston Basin (2014-2016) Summit crater lake observations, and the location, chemistry, and pH of water samples near Mount Chiginagak volcano, Alaska: 2004-2011 Macroinvertebrate and water quality data from the Prairie Pothole Region of the Williston Basin (2014-2016) Laboratory experiment data—turbidity response to increasing silt and clay concentration Chesapeake Bay Nontidal Network 2005-2014: Average Yields Data for Radium Mobility and the Age of Groundwater in Public-drinking-water Supplies from the Cambrian-Ordovician Aquifer System, North-Central USA: Table 3. Detailed information on calculations of environmental tracer data.