Filters: Tags: aquifer vulnerability (X)
4 results (7ms)|
Filters
Date Range
Extensions Types Contacts
Categories Tag Types Tag Schemes |
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...
Summary Tritium/helium-3 (3H/3He) and chlorofluorocarbons (CFCs) were investigated as environmental tracers in ground water from Jeju Island (Republic of Korea), a basaltic volcanic island. Ground-water mixing was evaluated by comparing 3H and CFC-12 concentrations with lumped-parameter dispersion models, which distinguished old water recharged before the 1950s with negligible 3H and CFC-12 from younger water. Low 3H levels in a considerable number of samples cannot be explained by the mixing models, and were interpreted as binary mixing of old and younger water; a process also identified in alkalinity and pH of ground water. The ground-water CFC-12 age is much older in water from wells completed in confined zones...
Categories: Publication;
Types: Citation;
Tags: Aquifer vulnerability,
Environmental tracers,
Ground
Groundwater samples collected from the Edwards aquifer in south-central Texas were analyzed for water-quality data to assess aquifer susceptibility to contaminants. Water-quality data included environmental tracers of groundwater age (tritium, tritiogenic helium-3, sulfur hexafluoride, carbon-14, and radiogenic helium-4), calibrated to lumped parameter models (LPMs). Groundwater samples were collected from monitoring wells, domestic-supply wells, and public-supply wells during 2017 and 2018. This data release includes seven tables detailing these data. The final estimates for mean groundwater ages determined for samples from 65 wells ranged from 4 years to 45,400 years, with a median of 25 years. Table 1 provides...
This data release documents water-quality data collected from April 2010 through December 2016 by the U.S. Geological Survey in cooperation with the San Antonio Water System from across the San Antonio segment of the Edwards aquifer with particular emphasis on nutrients and pesticides. Additional data regarding inorganic compounds and selected stable isotopes were obtained to provide a geochemical framework for characterizing source inputs and observed chemical changes during periods of hydrologic transition. Water-quality data were collected from surface-water and groundwater sites representing rural and urban land cover types. Data were obtained from unconfined wells in the recharge zone to characterize the rapid...
|
|
