Evaluation of groundwater flow patterns around a dual-screened groundwater circulation well

“…The depth intervals in which injection and extraction occur are inverted in adjacent wells to create a circulation cell between screens in the adjacent wells. This approach is generally more robust, and produces a better capture zone, than trying to induce vertical flow between screens on an individual well (Johnson and Simon, 2007 Tratnyek et al (2001) showed that essentially all of the degradation products become completely sequestered on the iron, a process which can be sustained for thousands of pore volumes, even at very high flow rates and contaminant loadings. Similar performance is expected in the field, although site-specific geochemical conditions may have some impact on both performance and longevity.…”

Section: Technology Descriptionmentioning

confidence: 99%

Remediation of Explosives in Groundwater Using Zero-Valent Iron In Situ Treatment Wells

Johnson¹,

Tratnyek²

2008

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Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER REPORT DATE MAR 20082 PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)Oregon Health and Science University 8. PERFORMING ORGANIZATION REPORT NUMBER SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S) SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release, distribution unlimited SUPPLEMENTARY NOTESThe original document contains color images. IMPLEMENTATION ISSUES ........................................................................................ ....................................................................................................................... 39 9. POINTS OF CONTACT ................................................................................................... Demonstration DesignThis report evaluates an approach in which granular iron was placed outside of the well screens in a pair of dual-screened wells. The wells were installed inside a large diameter temporary casing such that the iron adjacent to the upper and lower screens could be isolated from one another in a manner which would promote groundwater circulation between the pair of dualscreened wells. Summary of ResultsThe groundwater hydrology of the well pair was evaluated, and met design expectations. A primary concern in the methodology was that water entering the treatment zone would contain materials (e.g., sulfate) that would plug the treatment zone over time. Based on our calculations for the site, this was not expected to be a problem, which turned out to be the case. Unfortunately, an unanticipated problem arose in which water moving out of the upper screen (which was located near the water table) became oxygenated and plugged the treatment zone. An additional problem with oxygen arose because of regionally-decreasing water table elevations in the area of the demonstration. This exposed a portion of the iron adjacent to the upper screen and, together with drawdown during pumping, led to a loss of permeability in the well in which water was extracted from the upper screen. These problems could have been avoided if the screened interval was below the water table, and if a pac...

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“…Huang and Goltz [20] developed a three-dimensional analytical solution to map the spatial extent of capture zone resulting from operation of a tandem circulation wells. Based on comprehensive data set and numerical model, Johnson and Simon [21] defined the time-dependent recirculation zone and capture zone for a real VCW site. Chen et al [22] developed a mathematical model for describing reagent transport in a VCW flow field, which is the first attempt to delineate the spatial distribution of the solute.…”

Section: Introductionmentioning

confidence: 99%

Visualizing hydraulic zones of a vertical circulation well in presence of ambient flow

Qiang¹,

Zhang²,

Xu³

et al. 2019

Desalination and Water Treatment

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a b s t r a c tAlthough vertical circulation well (VCW) has been widely applied for aquifer remediation and hydrogeological parameter estimation for three decades, few studies have focused on the hydraulic zone visualization, and the spatial scale of hydraulic zones as functions of VCW parameters. This study provided a numerical method to visualize 3D steady-state flow field induced by VCW in a confined aquifer in presence of an ambient flow. Mathematical model for velocity field is established based on the superposition principle, and the fourth-order Runge-Kutta method is adopted to perform particle tracking. Visualization results illustrate that 3D flow regime can be divided into Recirculation, Capture, and Discharge zones. An integrated dimensionless parameter Q D is introduced to account for the relative strength of VCW flow against ambient flow. Comparison is performed through simulations by different Q D -d D combinations, where d D is the dimensionless distance between injection and extraction screens. Results demonstrate that: (1) a Q D -d D breakthrough line can be established to mark the occurrence of circulatory flow; (2) the effect of Q D on the size of recirculation zone is significant when Q D is smaller than 3.5, while d D becomes more influential if Q D is larger; (3) the extent of capture and discharge zone enlarges as Q D and/or d D increases.

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Evaluation of groundwater flow patterns around a dual-screened groundwater circulation well

Cited by 31 publications

References 23 publications

Estimation of water velocities in boreholes using a new passive flowmeter

Estimation of water velocities in boreholes using a new passive flowmeter

Remediation of Explosives in Groundwater Using Zero-Valent Iron In Situ Treatment Wells

Visualizing hydraulic zones of a vertical circulation well in presence of ambient flow

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