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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...
This data release documents nine Microsoft Excel tables that contain data for understanding groundwater ages in the Glacial aquifer system. Results for the three sample networks (PAS, principal aquifer study; MSS, modeling support study; FPS, flow path study) are described by three tables each: dissolved gas modeling results, environmental tracer concentrations (tritium, tritiogenic helium-3, sulfur hexafluoride, carbon-14, and radiogenic helium-4), and results for the mean age and age distribution. Tables are labeled by network and data type (as described below) separated by an underscore (_). For example, dissolved gas modeling results from the PAS network is label ‘PAS_NGmodel’. Dissolved gas modeling results...
This data release documents eight Microsoft Excel tables; four which contain data for understanding groundwater ages in the South East Coastal Plain (SECP), Coastal Lowlands (CLOW) and Mississippi Embayment and Texas Coastal Uplands (METX) aquifer systems and four that describe the data fields. Results described include dissolved gas modeling results, environmental tracer concentrations (tritium, tritiogenic helium-3, sulfur hexafluoride, and radiogenic helium-4), mean age and age distribution, and carbon-14 geochmical modeling results Dissolved gas modeling results (DGmodel) contains detailed information on the calibration of dissolved gas models to dissolved gas concentrations (neon, argon, krypton, xenon, and...
We computed mean groundwater ages and age distributions at eight wells by calibrating lumped parameter models (LPMs) to concentrations of tracers (3H, CFCs, SF6) in samples using the computer program TracerLPM (Jurgens and others, 2012). We also measured 14C but all samples contained ancient carbonate from the limestone bedrock, and we were unable to resolve the atmospherically-derived 14C sufficiently to use it as a tracer. Tritium was below the detection level in two of the eight well-water samples, indicating the water was recharged prior to about 1950. Groundwater from the other six wells could be fitted to LPMs that were either piston flow models (PFM), exponential – piston flow models (EPM), or binary mixing...
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...
This data release documents two Microsoft Excel tables; one contains data for understanding groundwater ages in the Spanish Valley watershed, and one that describe the data fields. Mean ages and age distributions from 19 groundwater samples were estimated in support of an evaluation of the groundwater resources of the Spanish Valley watershed (Masbruch and others, 2019). Individual groundwater well and spring vulnerability to land-surface contamination and changes in hydraulic conditions (for example, water extraction or reduced recharge) can be assessed using environmental tracer-based groundwater age. The detailed interpretation of groundwater age reported here supplements the apparent tracer ages of Masbruch...
Continuous monitoring and discrete water-quality sampling were coupled in a karst aquifer to assess drivers and timescales of water-quality change. Water-quality data included environmental tracers of groundwater age (tritium [3H], tritiogenic helium-3 [3He-trit], sulfur hexafluoride [SF6], carbon-14 [14C], and radiogenic helium-4 [4He-rad]). All water quality data is available from the U.S. Geological Survey NWIS database (U.S. Geological Survey, 2019). Groundwater ages were estimated by calibration of environmental tracers to lumped parameter models of groundwater age for multiple samples collected at six groundwater wells using the program TracerLPM (Jurgens and others, 2012). The final estimates for mean groundwater...
This data release documents four Microsoft Excel tables; one contains data for understanding water ages, one contains noble gas model data, two that describe the data fields. Results described include environmental tracer concentrations (tritium, tritiogenic helium-3, choloroflourocarbons, and radiogenic helium-4), mean age and age distribution, noble gas concentrations, and groundwater recharge conditions. Mean age and age distribution results (LPM) contain final models of groundwater age by calibration of lumped parameter models to tracer concentrations (Jurgens and others, 2012). Please see the main manuscript for additional details on the results presented in this table. Noble gas model results (CEmodel) contain...
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...
Dissolved Gas and Tracer Concentrations for the High Plains Aquifer, Vertical Flowpath Study Network
This data release documents three Microsoft Excel tables that contain data for understanding environmental tracer concentrations in groundwater of the High Plains aquifer system. Results of dissolved-gas modeling using environmental tracer concentrations (tritium, tritiogenic helium-3, and radiogenic helium-4), for the sample network (VPFS, vertical flow path study) are described. Dissolved gas modeling results (ModOut) contains detailed information on the calibration of dissolved gas models to measured dissolved-gas concentrations (neon, argon, krypton, xenon, and nitrogen). Calibration was done using methods described by Aeschbach-Hertig and others (1999 & 2000) with modifications to include nitrogen gas (Weiss,...
Categories: Data;
Tags: Dissolved gas,
Environmental tracers,
High Plains Aquifer,
Hydrology,
Nebraska,
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...
These data include water chemistry from springs, streams, rivers, and shallow groundwater collected in the Arctic National Wildlife Refuge in northern Alaska. Chemical analyses were performed for hydrochemical parameters including field parameters, major ions, nutrients, metals, stable isotopes of water, and tritium, as well as for dissolved gases useful for determining the timescale over which the water was in the subsurface (i.e. age dating tracers), including noble gases and chlorofluorocarbons.
This data release documents four tables that contain data for assessing the susceptibility of groundwater using environmental tracers collected from public-supply wells located in the Northern Atlantic Coastal Plain (NACP) Aquifer System and Piedmont and Blue Ridge Crystalline-Rock Aquifers of Eastern United States. Results for two modeling support studies located within the NACP are also included. Table 1 provides the primary results of this study and it contains condensed results from dissolved gas modeling and calculated environmental tracer concentrations, as well as results of the tritium age classification, susceptibility index, the mean groundwater age, fraction of Modern water (water that was recharged after...
This data release documents three Microsoft Excel tables that contain data for understanding environmental tracer concentrations in groundwater of the Columbia Plateau aquifer system. Results of dissolved-gas modeling using environmental tracer concentrations (tritium, tritiogenic helium-3, and radiogenic helium-4), for the sample network (VPFS, vertical flow path study) are described. Dissolved gas modeling results (ModOut) contains detailed information on the calibration of dissolved gas models to measured dissolved-gas concentrations (neon, argon, krypton, xenon, and nitrogen). Calibration was done using methods described by Aeschbach-Hertig and others (1999 & 2000) with modifications to include nitrogen gas...
Categories: Data;
Tags: Columbia Plateau Aquifer,
Dissolved gas,
Environmental tracers,
Geochemistry,
Hydrology,
This data release documents three Microsoft Excel tables; one contains noble gas isotopic data, one contains data for understanding groundwater ages in the South Rim of the Grand Canyon, and one that describe the data fields. Results described include raw noble gas concentrations, environmental tracer concentrations (tritium, tritiogenic helium-3, sulfur hexafluoride, carbon-14, and chlorofluorocarbons), and mean age and age distribution. Noble gas isotopes (NobleGas) contain noble gas isotope concentrations measured for South Rim springs. Samples were collected in pinch clousure copper tubes (Weiss, 1968) and analyzed at the University of Utah Dissolved Gas Lab. Mean age and age distribution...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Arizona,
Dissolved gas,
Geochemistry,
Grand Canyon,
Grand Canyon,
This data release documents seven tables that contain environmental tracer data and lumped parameter model (LPM) results that are used for assessing the distribution of groundwater age in 21 Principal Aquifers of the continental United States. Groundwater samples were collected from 1,279 sites and analyzed for environmental tracers: tritium, tritiogenic helium-3, sulfur hexafluoride, carbon-14, and radiogenic helium-4. For each sample, groundwater age distributions were estimated by fitting LPMs to the environmental tracers using the computer program TracerLPM (Jurgens and others, 2012). Calibrated lumped parameter models provide the optimal distribution of ages in a sample that explain the measured concentrations...
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