Figure 6 - uploaded by Peter Schlosser
Content may be subject to copyright.
![(a) Map of Wright-Patterson Air Force Base and Mad River well field area showing well locations along cross sections E-E and F-F. Potentiometric contours are based on water-level data for wells at depths less than or equal to 15 m reported by Schalk [1992], Yost [1995], and this study. (b) Cross sections E-E and F-F showing 3 H-3 He age (in years), 3 H concentration (in TU), and [ 3 H] [ 3 He trit ] concentration (in TU). Also shown are water levels at time of sampling and lithology of aquifer sediments at the location of each well or well cluster.](profile/Peter-Schlosser/publication/240489313/figure/fig6/AS:349459281137665@1460328993074/a-Map-of-Wright-Patterson-Air-Force-Base-and-Mad-River-well-field-area-showing-well.png)
(a) Map of Wright-Patterson Air Force Base and Mad River well field area showing well locations along cross sections E-E and F-F. Potentiometric contours are based on water-level data for wells at depths less than or equal to 15 m reported by Schalk [1992], Yost [1995], and this study. (b) Cross sections E-E and F-F showing 3 H-3 He age (in years), 3 H concentration (in TU), and [ 3 H] [ 3 He trit ] concentration (in TU). Also shown are water levels at time of sampling and lithology of aquifer sediments at the location of each well or well cluster.
Source publication
![Figure 3. The [ 3 H] [ 3 He trit ] versus 3 H-3 He recharge year (a) by...](profile/Peter-Schlosser/publication/240489313/figure/fig3/AS:349459276943362@1460328992754/The-3-H-3-He-trit-versus-3-H-3-He-recharge-year-a-by-subgroup-locations-and-b_Q320.jpg)
The 3H-3He dating method is applied in a buried-valley aquifer near Dayton, Ohio. The study area is large, not all sampling locations lie along well-defined flow paths, and existing wells with variable screen lengths and diameters are used. Reliable use of the method at this site requires addressing several complications: (1) The flow system is dis...
Similar publications
Tritium presents a natural radioactive isotope which can be used as a tracer in hydrology. This paper presents the usage of tritium in hydrogeological research of the Zagreb aquifer, which presents the country`s strategic water reserves and is protected by the Republic of Croatia. In the research area, higher tritium content in surface water and gr...
Limpopo Province has the highest number of geothermal springs, which were classified according to the residing mountains: Soutpansberg, Waterberg and Drakensberg. Mphephu, Sagole, Siloam and Tshipise geothermal springs fell within the Soutpansberg. This study was aimed at using the geochemical and isotopic compositions to understand the origin, age...
Ljubljansko polje and Ljubljansko Barje aquifers are the main groundwater resources for the needs of Ljubljana, the capital of Slovenia. Carbonate chemistry and isotope analysis of the groundwater were performed to acquire new hydrogeological data, which should serve as a base for improvement of hydrogeological conceptual models of both aquifers. A...
The Palaeozoic age Natal Group Sandstone (NGS) that outcrops from Hlabisa (in the north) to Port Shepstone (in the south) and Greytown (to the west) to Stanger (to the east) in KwaZulu-Natal Province, South Africa, is investigated in terms of its hydrogeological characteristics. The NGS, which consists of a Lower Durban Formation and an Upper Maria...
![Figure 2. Hydrogeological cross sections (modified after [24]). Legend,...](publication/375564085/figure/fig1/AS:11431281204318373@1699706337455/Hydrogeological-cross-sections-modified-after-24-Legend-from-left-to-right-1-upp_Q320.jpg)
In this study, we present the hydrogeological, hydrogeochemical and isotopic characterisation and monitoring activity of a closed landfill located in the northern sector of the Phlegrean Fields groundwater body in the Campania Region (Southern Italy). The aim of the study is to distinguish between natural enrichments (e.g., geogenic sources) and an...
Citations
... Groundwater dating studies first focused on porous and relatively homogeneous aquifers in steady-state conditions (Smethie et al. 1992;Szabo et al. 1996;Cook and Solomon 1997;Corcho-Alvarado et al. 2007). More recently, the investigation of fractured aquifers under transient conditions induced by intensive pumping became a research focus because of the issues related to the vulnerability of groundwater linked with anthropogenic activities and climate change (Dunkle- Shapiro et al. 1998;Shapiro 2001;USGS 2005;Visser et al. 2013;Kolbe et al. 2016;Jurgens et al. 2016;Jasechko et al. 2017). ...
Information about the age distribution of groundwater provides unique and particularly relevant insights about groundwater flow and mixing conditions, as well as about the vulnerability and sustainability of the resource. Constraining flow paths in heterogeneous and fractured aquifers requires spatially distributed and depth-related observations. Where multiple wellbores are not available, depth-specific samples from individual long open-borehole wells may provide useful information. In this study, results from depth-specific sampling of environmental tracers (3H, 85Kr, SF6, CFC-12, noble gases, 13C, 14C) are reported from seven long open-borehole wells (depths ≤100 m below the surface) in the area of the St Lawrence Lowlands (Quebec, Canada). The multitracing approach allowed for the determination of the groundwater mixing conditions within the fractured-rock aquifers. The results indicate that fracture networks induce complex groundwater mixing patterns, without any evidence that the residence times significantly increase with the depth. Under unstressed conditions, the investigated aquifers contain 20–50% “modern” water (less than 60 years old) and 50–80% “old” water with residence times of ~4–11,000 years. The observed groundwater bi-modal age distribution is caused by fast flows through interconnected fractures and slow flows through poorly connected fractures or the primary porosity of the rock. Within the catchment of the wellfields, the pumped groundwater becomes essentially “modern” because of the preferential draining of productive fractures, while the water within the less transmissive volumes cannot be leaked out as fast. Thus, groundwater abstraction increases the aquifer’s intrinsic vulnerability to anthropogenic pollution.
... Tritium-helium dating was also applied for the first time in the Philippines through this study. Tritium-helium dating has been applied in several hydrological studies to determine groundwater age (Hinkle 2009;McMahon et al. 2011;Shapiro et al. 1998;Solomon and Sudicky 1991;Solomon et al. 1995;Szabo et al. 1996). While classical techniques are still important in hydrological studies, we demonstrate in this study that isotope data provide important supplemental information for studying groundwater recharge processes and residence time. ...
A groundwater study was conducted in Cagayan de Oro City (CDO) located in the north-central part of Mindanao, the Philippines using isotopic techniques. The study identifies the recharge sources of the groundwater in the city and estimates the groundwater age and groundwater recharge rate. Monthly integrated samplings of rainfall were conducted in three locations of varying altitudes from October 2012 to March 2015. Groundwater samples from production wells and shallow wells were also collected within the same period at least twice, during the dry and the wet seasons. The samples were analyzed for their stable isotopic compositions and groundwater in selected deep wells was dated using tritium-helium dating. A meteoric water line of δD = (8.26 ± 0.21) δ18O + (11.56
± 1.88) was calculated using the precipitation-weighted reduced major axis (PWRMA) method. Isotopic compositions of groundwater show that local precipitation recharges the shallow aquifer. An interaction exists between the shallow and deep aquifer possibly due to the absence of a well-defined multilayer aquifer based on available lithological profiles. Coastal shallow wells appear to be recharged from 35–80 meters above sea level (masl), while deep wells appear to be recharged from 200–300 masl. A recharge rate of 380 mm/yr was estimated, which is more than 20% of the average annual rainfall and twice the estimated recharge using the precipitation-based method.
... The ratio of the concentrations 3 H and 3 He has been used for dating of groundwaters since the 1980's (Poreda et al., 1988;Schlosser et al., 1988Schlosser et al., , 1989. This technique was later applied in various groundwater studies to calculate recharge rates and groundwater velocities (Solomon and Sudicky, 1991;Ekwurzel et al., 1994;Reilly et al., 1994;Cook et al., 1996;Shapiro et al., 1998), to improve the validity of numerical models (Solomon et al., 1992;Ekwurzel et al., 1994;Szabo et al., 1996;Sheets et al., 1998) and to understand the timing of contaminant release to the subsurface (Solomon et al., 1995;Bohlke and Uhlířská catchment, using noble gases, 2 H, 18 O, 3 H and CFCs. Investigation of apparent groundwater ages at different depths is combined with synoptic lumped-parameter multi-tracer assessment of groundwater mean residence times. ...
Groundwater recharge amounts and residence times were estimated in the quaternary aquifer of the Jizera Mountains, Czech Republic, using noble gases, ²H, ¹⁸O, ³H and CFCs. Tracer ages from years to decades were determined for water in a shallow sedimentary aquifer (three boreholes of 10, 20 and 30 m depth). Approximately 90–180 mm of precipitation (7–14% of annual precipitation) infiltrates to deep percolation. A mean percolation velocity of 0.6 m/y in the sedimentary Uhlířská aquifer was estimated based on an apparent groundwater age of 40 years at 30 m depth. A lumped parameter approach was used to calculate groundwater residence times based on synoptic evaluation of ³H/³He, ³H and CFCs. Groundwater apparent ages in the shallowest borehole (10 m depth) determined by ³H/³He are younger than those determined by CFCs. This discrepancy is caused by partial re-equilibration of water with modern air, and by admixing of water that has zero age. The pronounced variations of δ¹⁸O values in the borehole may be ascribed to a young component quickly recharged from the air-exchanged stream water or through preferential flowpaths.
... In fractured rocks, heterogeneous water flow paths and channelling effects have been demonstrated. At a regional scale, heterogeneity has been investigated in relation with regional flow paths, discharge, geology, or agricultural practices (Chen, Tang, Sakura, Kondoh, Yu, Shi-madaet al., 2004;Grassi and Cortecci, 2005;Shapiro, Rowe, Schlosser, Ludin, and Stute, 1998;Weissmann, Zhang, La Bolle, Fogg, 2002). ...
Hydrochemical patterns has been mapped and correlated with groundwater flow systems to varying degrees using hydrochemical facies. Reliable broad relationship between chemical composition and the flow distribution of groundwater were established in the process. This study examines the water quality and groundwater flow patterns present in the crystalline basement aquifer of Part of Minna in North Central Nigeria for environmental purpose. Sixteen water samples were collected from wells and analyzed for various parameters including pH, total dissolved solids (TDS), electrical conductivity (Ec), K+, Na+, Ca+, Mg+, Cl-, HCO3- and SO4- using standard procedures of water analysis. The analytical results present the abundance of both physical and chemical parameters in the following order: pH (5.8 – 7.6), Ec (116.7 - 1562µs/m), TDS (128.6 – 1046.5 mg/l), Na+ (25.3 – 144.8 mg/l), K+ (1.1 – 39.5 mg/l), Mg+2 (5.6 – 30.7 mg/l), Cl- (20.4 – 276.5 mg/l), HCO3- (10.0 – 21.0 mg/l), SO4- (8.0 – 180 mg/l). Piper trilinear for the study area shows that there is a mixture of two types of water with variable concentrations of major ions. These are Na+ , K– ,Cl– , SO4+2 water type and Ca+ , Mg+2 , Cl –, SO4 +2, water types. This means that groundwater in the area is mainly made up of mixtures of the alkaline and alkaline earth metals and predominantly Cl- - SO4+2 water type. Comparison made from the geochemical maps indicate that high total dissolve solids occur at the discharge area and relatively the groundwater at various discharge point is older in age and has high residence time to that of recharge area. Hydrochemical data analysis revealed four sources of solutes. The processes responsible for their enrichment include: chemical weathering, leaching of the overlying sediments, domestic activities, climatic condition and the flow pattern of the aquifer. These factors have contributed to the changes of the groundwater chemistry. From the static well level measurement plot, it was revealed that the dominant trend for the groundwater movement is in the N-S, NW-SE and NE-SW directions which shows that the groundwater of the area is structurally controlled.
... is often plotted against the 3 H/ 3 He age, as in Figure 1, and compared to the local 3 H precipitation record. This comparison is used as a consistency check on the data (22,28,42) and to estimate the extent of mixing or dispersion (6,8,22). ...
... Frequently, the comparison reveals samples with young 3 H/ 3 He ages and high concentrations of tritium and helium-3 that do not match the 3 H precipitation record, or a [ 3 H + 3 He] peak with a younger than expected age (17,22,42). This discrepancy has been explained by tritium contamination from a local landfill (42), degassing of water samples (22), and transport through the unsaturated zone (17). ...
... Frequently, the comparison reveals samples with young 3 H/ 3 He ages and high concentrations of tritium and helium-3 that do not match the 3 H precipitation record, or a [ 3 H + 3 He] peak with a younger than expected age (17,22,42). This discrepancy has been explained by tritium contamination from a local landfill (42), degassing of water samples (22), and transport through the unsaturated zone (17). ...
... However, only DM with the lowest dispersion parameter can account for higher 3 H values if 3 He was significantly degassed, which is not plausible considering the relatively long-screened interval of the wells (Fig. 9). Also, other wells in anaerobic conditions including MW-5, GW-11, and GW-19 did not have higher 3 H values. Shapiro et al. (1998) found a group of groundwater samples had 3 H values much higher than those expected from local precipitation in a buried-valley aquifer and suggested the elevated 3 H values could have resulted from the incinerator/landfill facility in the area. Manning et al. ...
Stable isotopes of water and 3H-3He were used to delineate recharge patterns and contaminant transport for a granitic regolith aquifer in an industrial complex in Wonju, South Korea, that has historically been contaminated with chlorinated solvents including trichloroethene (TCE) and carbon tetrachloride (CT). Groundwater recharge mainly occurred in upgradient forested areas while little recharge occurred in the downgradient industrial areas covered with extensive sections of impermeable pavement and paddy fields. δ18O and δD data indicated that groundwater was mainly derived from summer precipitation. The apparent groundwater ages using 3H-3He ranged from 1 to 4 yrs in the upgradient area and from 9 to 10 yrs in the downgradient area. Comparison of groundwater flow velocities based on Darcy's law and those calculated with simple mass balance models and groundwater age supported the presence of preferential pathways for TCE movement in the study area. Measureable TCE was observed in groundwater irrespective of groundwater age. Considering the 3-yr duration of the TCE spill, 14 yrs before sampling, this indicates that TCE plumes were continuously fed from sources in the unsaturated zone after the spill ended and moved downgradient without significant degradation in the aquifer.
... The ratio of the two concentrations can be used to calculate the time since the tritiated water entered the water table (the "age of the groundwater"), with no need to know the highly variable tritium input function. This technique has been applied in various groundwater studies to calculate recharge rates and groundwater velocities (Solomon and Sudicky 1991;Ekwurzel et al. 1994;Reilly et al. 1994;Cook et al. 1996;Shapiro et al. 1998), to improve the validity of numerical models ( Solomon et al. 1992;Ekwurzel et al. 1994;Szabo et al. 1996;Sheets et al. 1998), and to understand the timing of contaminant release to the subsurface ( Solomon et al. 1995;Bohlke and Denver 1995;Shapiro et al. 1999). 3 H-3 He groundwater ages are thus a valuable measurement than can be used to infer the properties of an aquifer system independently of physical measurements such as hydraulic conductivity and hydraulic head. ...
... To evaluate the validity of 3 H-3 He Valcartier groundwater ages, their consistency can be checked against historical tritium input from atmospheric precipitation that recharged the groundwater system. For this purpose, the present tritium ( 3 H pre ) and tritiogenic 3 He ( 3 He tri ) concentrations found in groundwater and the calculated groundwater ages obtained from these concentrations, which provide the date of recharge, were used to reconstruct the initial concentration of tritium ( 3 H ini ) in precipitation for Valcartier ( Shapiro et al. 1998). In Fig. 3 ...
... (Fig. 4). This could be related to the effects of nearby pumping wells, which can affect the 3 He dissolved in groundwater and change the groundwater age distribution even after operation has ceased ( Shapiro et al. 1998;Zinn and Konikow 2007). A production well that is currently inactive is located up gradient of PO-152-153, which may have impacted the groundwater age distribution resulting in low 3 H-3 He ages nearby at PO-152-153. ...
Tritium-helium groundwater dating was carried out in a trichloroethylene (TCE)-contaminated valley-fill aquifer system in Quebec, Canada, where a numerical groundwater flow model was developed. Forty seven discrete groundwater and dissolved gas samples were obtained along two flow paths originating from known TCE source zones whose related plumes converge down gradient to form a single plume. Sampling points in monitoring wells were projected onto vertical sections showing particle tracks along the two flow paths. At these points, simulated advective ages obtained from particle tracking were matched to tritium-helium ages using different porosity values; the best match was 0.35. Ages were also obtained above and below a prodeltaic silty aquitard in a portion of the aquifer where some source zones are located, which provide groundwater and TCE transit times through the aquitard as well as a mean vertical hydraulic conductivity that agrees with previous estimates used in the model. In certain locations, anomalously old ages associated with high terrigenic 4He indicate areas where groundwater from the underlying proglacial unit flows upward into the deltaic sand aquifer through aquitard windows. Upflow locations correspond with increased TCE concentrations, suggesting significant TCE provenance through the proglacial unit originating from a previously unrecognized TCE source zone.
... Contamination, in the strict sense, is commonly associated with waste disposal or industrial effluents. Contamination originating from landfills or local industrial activity has been observed for tritium [18,58]. While tritium contamination prevents dating based on the tritium input history, it did not strongly affect 3 H- 3 He dating in these studies, as the contamination occurred near the beginning of the flow path. ...
Many problems related to groundwater supply and quality, as well as groundwater-dependent ecosystems require some understanding of the timescales of flow and transport. For example, increased concern about the vulnerabilities of 'young' groundwaters (less than ~1000 years) to overexploitation, contamination, and land use/climate change effects are driving the need to understand flow and transport processes that occur over decadal, annual, or shorter timescales. Over the last few decades, a powerful suite of environmental tracers has emerged that can be used to interrogate a wide variety of young groundwater systems and provide information about groundwater ages/residence times appropriate to the timescales over which these systems respond. These tracer methods have distinct advantages over traditional approaches providing information about groundwater systems that would likely not be obtainable otherwise. The objective of this paper is to discuss how environmental tracers are used to characterise young groundwater systems so that more researchers, water managers, and policy-makers are aware of the value of environmental tracer approaches and can apply them in appropriate ways. We also discuss areas where additional research is required to improve ease of use and extend quantitative interpretations of tracer results.
... The environmental tracer tritium and the combined tritium/ helium-3 system have been used extensively in groundwater studies to evaluate recharge rates, flow paths, flow velocities, and to ascertain the extent of contaminant plumes Beyerle et al. 1999; Carmi and Gat 1994; Clark et al. 2004; Ekwurzel et al. 1994; Robertson and Cherry 1989; Shapiro et al. 1998; Solomon et al. 1993; 1995. The activity of tritium, a radioactive isotope of hydrogen , greatly exceeded natural levels due to above-ground nuclear weapons testing in the 1950s and early 1960s. ...
As issues of source water protection of drinking water supplies have come to the forefront, the methodology to effectively manage semiconfined aquifers is still unclear. Commonly, the area around the wellhead is considered the most risk sensitive area, but in semiconfined settings the most sensitive areas may be located some distance away from the wellhead. This research employed the use of age-distribution modeling in concert with environmental tracers tritium/helium-3, geochemical, and other hydrogeologic data. A synthetic test case was developed to determine the suitability of the technique for identifying localized areas of recharge to a wellhead in aquifers where evidence of modern water infiltration exists. Results of the model runs based on the synthetic test case indicate that the technique presented herein is capable of identifying localized areas of recharge contributing to a wellhead, in a semiconfined aquifer setting, with only a limited amount of required data. These results and the relative ease of application make this technique a valuable tool for obtaining a greater understanding of the flow regime at a wellhead, which in turn provides more information for risk assessment of public water supplies.
... is often plotted against the 3 H/ 3 He age, as in Figure 1, and compared to the local 3 H precipitation record. This comparison is used as a consistency check on the data (22,28,42) and to estimate the extent of mixing or dispersion (6,8,22). ...
... Frequently, the comparison reveals samples with young 3 H/ 3 He ages and high concentrations of tritium and helium-3 that do not match the 3 H precipitation record, or a [ 3 H + 3 He] peak with a younger than expected age (17,22,42). This discrepancy has been explained by tritium contamination from a local landfill (42), degassing of water samples (22), and transport through the unsaturated zone (17). ...
... Frequently, the comparison reveals samples with young 3 H/ 3 He ages and high concentrations of tritium and helium-3 that do not match the 3 H precipitation record, or a [ 3 H + 3 He] peak with a younger than expected age (17,22,42). This discrepancy has been explained by tritium contamination from a local landfill (42), degassing of water samples (22), and transport through the unsaturated zone (17). ...
Diffusion of tritiated water (referred to as tritium) and helium-3 between mobile and immobile regions in aquifers (mass transfer) can affect tritium and helium-3 concentrations and hence tritium-helium-3 (3H/3He) ages that are used to estimate aquifer recharge and groundwater residence times. Tritium and helium-3 chromatographically separate during transport because their molecular diffusion coefficients differ. Simulations of tritium and helium-3 transport and diffusive mass transfer along stream tubes show that mass transfer can shift the 3H/3He age of the tritium and helium-3 concentration ([3H + 3He]) peak to dates much younger than the 1963 peak in atmospheric tritium. Furthermore, diffusive mass-transfer can cause the 3H/3He age to become younger downstream along a stream tube, even as the mean water-age must increase. Simulated patterns of [3H + 3He] versus 3H/3He age using a mass transfer model appear consistent with a variety of field data. These results suggest that diffusive mass transfer should be considered, especially when the [3H + 3He] peak is not well defined or appears younger than the atmospheric peak. 3H/3He data provide information about upstream mass-transfer processes that could be used to constrain mass-transfer models; however, uncritical acceptance of 3H/3He dates from aquifers with immobile regions could be misleading.
