Ein neues integrales Verfahren zur Quantifizierung der Grundwasserimmission, Teil II: Numerische Lösung und Anwendung in Eppelheim

Ptak, Thomas; Schwarz, Rainer; Holder, Thomas M.; Teutsch, Georg

doi:10.1007/s767-000-8369-4

Cited by 26 publications

(5 citation statements)

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“…The issue of heterogeneity of the contaminant distribution in the subsurface is addressed by using the integral pumping test method (Schwarz et al, 1998;Teutsch et al, 2000;Ptak et al, 2000;Bauer et al, 2004;. This method consists of one or more pumping wells along a control plane perpendicular to the mean groundwater flow direction.…”

Section: Integral Pumping Testsmentioning

confidence: 99%

Measuring methods for groundwater – surface water interactions: a review

Kalbus

Reinstorf

Schirmer

2006

Hydrol. Earth Syst. Sci.

638

349

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Abstract.Interactions between groundwater and surface water play a fundamental role in the functioning of riparian ecosystems. In the context of sustainable river basin management it is crucial to understand and quantify exchange processes between groundwater and surface water. Numerous well-known methods exist for parameter estimation and process identification in aquifers and surface waters. Only in recent years has the transition zone become a subject of major research interest; thus, the need has evolved for appropriate methods applicable in this zone. This article provides an overview of the methods that are currently applied and described in the literature for estimating fluxes at the groundwater -surface water interface. Considerations for choosing appropriate methods are given including spatial and temporal scales, uncertainties, and limitations in application. It is concluded that a multi-scale approach combining multiple measuring methods may considerably constrain estimates of fluxes between groundwater and surface water.

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Section: Integral Pumping Testsmentioning

confidence: 99%

Measuring methods for groundwater – surface water interactions: a review

Kalbus

Reinstorf

Schirmer

2006

Hydrol. Earth Syst. Sci.

638

349

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“…The IPT method has been applied to megasites, targeting multiple contaminants from different sources [e.g., Ptak et al , 2000; UW Umweltwirtschaft , 2003; Bayer‐Raich et al , 2004; Jarsjö et al , 2005; Zeru and Schäfer , 2005; Kalbus et al , 2007]. In particular, results show that estimates of average concentrations, total mass flows over control planes (CPs), and degradation rates λ are robust even if the spatial concentration variability is considerable transverse to the flow direction [e.g., Bockelmann et al , 2001; Peter et al , 2004; Bayer‐Raich et al , 2006]; however, if mass loss is large along the flow direction due to biodegradation, it is conceivable that mass flows can change considerably over the IPT measurement scale (the well capture zone) and potentially lead to biased interpretations.…”

Section: Statement Of the Problemmentioning

confidence: 99%

“…Of particular concern is the possibility that aquifer heterogeneity and irregular source zone extent may lead to a spatially complex pattern of contamination, thereby introducing uncertainty into estimates of mass flow. In the present study, we investigate methodology‐related errors in such mass flow estimates and show how these errors can propagate into estimates of mass loss and degradation rates, considering both traditional point measurements and relatively novel integral pumping test (IPT) measurements [e.g., Teutsch et al , 2000; Ptak et al , 2000; Bockelmann et al , 2001].…”

Section: Introductionmentioning

confidence: 99%

Estimating plume degradation rates in aquifers: Effect of propagating measurement and methodological errors

Jarsjö

Bayer‐Raich

2008

Water Resources Research

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[1] Field estimates of plume degradation rates l [T À1 ] in aquifers provide a basis for assessing the possible impact of (toxic) organic pollutants on downstream environments; however, difficulties with measurement and methodology mean that estimated site-specific rates potentially involve considerable uncertainty. Here, we specifically show that if mass flow or average concentration measurements are associated with errors of $20% (or even less), the errors may in many cases propagate, magnify, and cause order-ofmagnitude errors in estimates of l. We also investigate uncertainties in the integral pumping test method, in which average concentrations are determined based on concentrations measured from pumping wells. In this method, the small-scale variability that may bias the results of point measurements can be favorably averaged out when pumping; however, the novelty of the approach means that questions remain regarding its application. For example, the magnitude of methodological errors, such as those associated with the assumption of constant concentration along the flow direction within the extent of the well capture zone, remain poorly understood. This assumption can be violated by the biodegradation of contaminants, thereby leading to a bias in subsequent interpretations. We provide an analytical expression from which the prediction error due to attenuating concentrations can be evaluated and show its dependence on the degradation rate, the degradation function, and the extent of the well capture zone. Even for considerable first-order degradation, the mass flow error generally remains small and is not magnified in estimates of l.Citation: Jarsjö, J., and M. Bayer-Raich (2008), Estimating plume degradation rates in aquifers: Effect of propagating measurement and methodological errors, Water Resour. Res., 44, W02501,

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“…The basic concept of the IPT method, which is further developed here, was first described by Teutsch et al [2000]. It was first applied in the field for measurement of mass flows over, and average concentrations along, CPs at sites contaminated by Tetrachloroethylene (PCE) and Trichloroethylene (TCE) by Ptak et al [2000], using analytical solutions developed by Schwarz [2002]. Bockelmann et al [2001, 2003] used the IPT method at two CPs to estimate Natural Attenuation (NA) rates of benzene, toluene, ethylbenzene, and xylenes (BTEX), chlorinated hydrocarbons and polyaromatic hydrocarbons.…”

Section: Introduction and Statement Of The Problemmentioning

confidence: 99%

Breakthrough of attenuating contaminant plumes in pumping wells: Analytical model and implications for integral pumping tests

Bayer‐Raich

Jarsjö

Teutsch

2009

Water Resources Research

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[1] Monitoring of contaminant plumes and predicting their future fate are essential for effective management of groundwater contaminants. Solute breakthrough curves from operating pumping wells can provide information on the water quality in relatively large aquifer regions, which may be unavailable to instrumentation and direct measurement for practical and/or economical reasons. Relations between spatially varying aquifer concentrations C 0 (x, y) initially surrounding a well and temporally varying concentrations of subsequently extracted well water, C p (t), then need to be quantified. However, limited applicability of analytical expressions and numerical inaccuracies related to solving transport equations for converging flow fields hamper such quantifications even in homogeneous aquifers. We use a stream-tube approach and provide a general problem formulation that accounts for first-order degradation and linear, instantaneous, sorption/retardation in heterogeneous aquifers. An analytical expression is obtained for homogeneous aquifer conditions (in the well vicinity), relating any given initial C 0 (x, y) function and the subsequent contaminant breakthrough C p (t) in the well. Results for wide plumes subject to first-order degradation show that concentrations at the extraction well will increase as a function of pumping time. This increase is despite the fact that late-time data reflect longer transport paths (to the well), along which mass is removed through degradation. We also derive unique solutions for the inverse problem, in particular considering how the average contaminant concentration C av (averaged along a control plane through the well within its capture zone, perpendicular to the mean groundwater flow direction) depends on the measurable C p (t). The solutions demonstrate that the longer the pumping time, the more sensitive the solutions for C av become to degradation rate constants, which if needed can be determined in situ using multiple control planes.

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Ein neues integrales Verfahren zur Quantifizierung der Grundwasserimmission, Teil II: Numerische Lösung und Anwendung in Eppelheim

Cited by 26 publications

References 0 publications

Measuring methods for groundwater – surface water interactions: a review

Measuring methods for groundwater – surface water interactions: a review

Estimating plume degradation rates in aquifers: Effect of propagating measurement and methodological errors

Breakthrough of attenuating contaminant plumes in pumping wells: Analytical model and implications for integral pumping tests

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