Using multiple chemical indicators to characterize and determine the age of groundwater from selected vents of the silver springs group, Central Florida, USA

L. Knowles; B. G. Katz; D. J. Toth

doi:10.1007/s10040-010-0669-y

Home/Archive/USGS

USGS · 70037634

Using multiple chemical indicators to characterize and determine the age of groundwater from selected vents of the silver springs group, Central Florida, USA

L. Knowles·B. G. Katz·D. J. Toth

View original source ↗Export metadata ↓

Abstract

The Silver Springs Group, Florida (USA), forms the headwaters of the Silver River and supports a diverse ecosystem. The 30 headwater springs divide into five subgroups based on chemistry. Five selected spring vents were sampled in 2007 to better understand the contaminant sources and groundwater flow system. Elevated nitrate-N concentrations (>0.8mg/L) in the five spring vents likely originate from inorganic (fertilizers) and organic sources, based on nitrogen and oxygen isotope ratios of nitrate. Evidence for denitrification in the Lost River Boil spring includes enriched ??15N and ??18O, excess N2 gas, and low dissolved O2 concentrations (<0.5mg/L). Multiple age-tracer data (SF6, 3H, tritiogenic 3He) for the two uppermost springs (Mammoth East and Mammoth West) indicate a binary mixture dominated by recent recharge water (mean age 6-7 years, and 87-97% young water). Tracer data for the three downstream spring vents (Lost River Boil, Catfish Hotel-1, and Catfish Conventional Hall-1) indicate exponential mixtures with mean ages of 26-35 years. Contamination from non-atmospheric sources of CFCs and SF5CF3 precluded their use as age tracers here. Variations in chemistry were consistent with mean groundwater age, as nitrate-N and dissolved O2 concentrations were higher in younger waters, and the Ca/Mg ratio decreased with increasing mean age. ?? 2010 Springer-Verlag (outside the USA).

Explore related subjects

Hydrogeology Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

L. Knowles, B. G. Katz, D. J. Toth. 2010-11-16. Using multiple chemical indicators to characterize and determine the age of groundwater from selected vents of the silver springs group, Central Florida, USA. https://doi.org/10.1007/s10040-010-0669-y

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Characterization of subsurface groundwater pathways from treated wastewater effluent infiltration along the South Rim of Grand Canyon National Park, Arizona, USA

Recharge of treated wastewater to the environment is increasingly becoming a component of water resources management, especially in water-limited areas such as the Grand Canyon. Treated wastewater from the Grand Canyon South Rim Wastewater Treatment Plant has been discharged to a dry wash located along the surface expression of a fault for decades, but the fate of the wastewater is unclear. Previous research suggested possible connections between the treated wastewater discharge sites and springs along the South Rim of Grand Canyon, particularly Monument spring. Additional investigations presented in this report add further evidence to the connection between the wastewater and Monument spring, utilizing per- and polyfluoroalkyl substances, artificial sweeteners, and stable isotopes of water. A dye trace established the first direct connection between wastewater and Monument spring where the dye added to treated wastewater took about 4–6 months to move through the subsurface and was detectable for 5 months. The persistence of wastewater tracers over time and the timing of dye movement suggests a fast subsurface flow pathway. On the basis of geologic observations of faults and jointing, groundwater flow follows a possible combination of karst and other structural pathways. The dye and wastewater tracers were monitored at other springs along the South Rim of Grand Canyon and the combination of repeated dye detections and multiple wastewater tracers were only found at Monument spring. Multiple lines of evidence provide a robust tracer suite to support evidence of structural/karst controls on preferential flowpaths; faults alone are unlikely to explain the flow pathway.

Arizona↗

USGS2026

Regional and local controls on groundwater salinity in California’s southwestern San Joaquin Valley, United States: Insights from airborne electromagnetic surveys

The San Joaquin Valley is one of the most intensive oil and gas and agricultural production regions of the United States, yet the regional groundwater salinity distribution is not well defined, particularly near the western margin of the valley where salinity is highly variable. Airborne electromagnetic (AEM) surveys were conducted to improve the understanding of the three-dimensional variations in groundwater salinity in the upper 300 m. A salinity mapping approach representing geophysical and interpretational uncertainty was used to predict the probability of the occurrence of three salinity categories commonly used in water resource management (fresh, total dissolved solids (TDS) < 3000 mg/L; brackish, TDS 3000–10,000 mg/L; saline, TDS > 10,000 mg/L). The salinity mapping identifies regions of fresh and brackish groundwater near oil fields, suggests potential gaps in groundwater monitoring, and supports improved fresh and brackish groundwater resource availability estimates. Shallow saline regions are common near historical lake beds and marsh areas, with abrupt transitions between saline and fresh/ brackish groundwater in both historical and modern hydrogeologic contexts. The common occurrence of a shallow saline groundwater inversion implies that reliance on single-depth salinity threshold maps may lead to overestimation of the availability of fresh and brackish groundwater. Some parts of these saline areas can be correlated to chemical indicators of oil-field water, likely resulting from historical surface disposal of produced water.

California↗

USGS2025

Review: The hydrogeology of critical mineral resources relevant to the energy transition

Attaining the goals of the international treaty on climate change (the Paris Agreement) will greatly increase the demand for the critical minerals required to implement clean-energy technologies. This poses both challenges and opportunities to the hydrogeologic community from several perspectives. Here, important insights that the hydrogeological sciences have to offer for mineral exploration, mineral production, and addressing environmental issues related to mining and mine decommissioning are summarized. This study focuses on copper, cobalt, lithium, and rare earths to represent the broad spectrum of critical minerals and illustrate their relevance by referring to projected demands and production rates. The current understanding of the hydrogeologic processes that form major deposits of these minerals are then summarized. Ore is defined as the naturally occurring material from which minerals of economic value can be extracted, where most ore deposits are the products of complex hydrogeologic couplings between fluid flow, heat transport, solute transport, chemical reactions, and mechanical deformation. Exploration models for the discovery of deeper, hidden deposits are potentially informed by hydrogeologic theory and hydrogeochemical processes. Hydrogeologic understanding and methods are also essential to production and recovery. Longstanding challenges are mine dewatering and (conversely) mine water supply, as well as mineral-extraction practices such as spoil heap leaching and in situ mining. New challenges arise from element extraction from subsurface brines. Finally, the quantity of water use and potential environmental impacts of mining on water quality are at the core of ‘social license’: the approval and acceptance of society to mining activities.

Hydrogeology Journal↗