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Title: Delineation of a wellhead protection zone and determination of flowpaths from potential groundwater contaminant source areas at Camp Ripley, Little Falls, Minnesota.

Abstract

Groundwater at Camp Ripley, Minnesota, is recharged both on post and off site and discharged to rivers, wetlands, and pumping wells. The subsurface geologic materials have a wide range of permeabilities and are arranged in a complex fashion as a result of the region's multiple glacial advances. Correlation of individual glacial geologic units is difficult, even between nearby boreholes, because of the heterogeneities in the subsurface. This report documents the creation of a numerical model of groundwater flow for Camp Ripley and hydrologically related areas to the west and southwest. The model relies on a hydrogeological conceptual model built on the findings of a University of Minnesota-Duluth drilling and sampling program conducted in 2001. Because of the site's stratigraphic complexity, a geostatistical approach was taken to handle the uncertainty of the subsurface correlation. The U.S. Geological Survey's MODFLOW code was used to create the steady-state model, which includes input data from a variety of sources and is calibrated to water levels in monitoring wells across much of the site. This model was used for several applications. Wellhead protection zones were delineated for on-site production wells H, L, and N. The zones were determined on the basis of a probabilistic assessmentmore » of the groundwater captured by these wells; the assessment, in turn, had been based on multiple realizations of the study area's stratigraphy and groundwater flowfield. An additional application of the model was for estimating flowpaths and times of travel for groundwater at Camp Ripley's range areas and waste management facilities.« less

Authors:
;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOD
OSTI Identifier:
925332
Report Number(s):
ANL/EVS/TM/06-6
TRN: US200809%%665
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Technical Report
Country of Publication:
United States
Language:
ENGLISH
Subject:
54 ENVIRONMENTAL SCIENCES; MILITARY FACILITIES; MINNESOTA; GROUND WATER; FLOW MODELS; HYDROLOGY; M CODES; WATER WELLS; MONITORING; SAMPLING; WASTE MANAGEMENT; POLLUTION CONTROL

Citation Formats

Quinn, J. J., and Environmental Science Division. Delineation of a wellhead protection zone and determination of flowpaths from potential groundwater contaminant source areas at Camp Ripley, Little Falls, Minnesota.. United States: N. p., 2006. Web. doi:10.2172/925332.
Quinn, J. J., & Environmental Science Division. Delineation of a wellhead protection zone and determination of flowpaths from potential groundwater contaminant source areas at Camp Ripley, Little Falls, Minnesota.. United States. doi:10.2172/925332.
Quinn, J. J., and Environmental Science Division. Fri . "Delineation of a wellhead protection zone and determination of flowpaths from potential groundwater contaminant source areas at Camp Ripley, Little Falls, Minnesota.". United States. doi:10.2172/925332. https://www.osti.gov/servlets/purl/925332.
@article{osti_925332,
title = {Delineation of a wellhead protection zone and determination of flowpaths from potential groundwater contaminant source areas at Camp Ripley, Little Falls, Minnesota.},
author = {Quinn, J. J. and Environmental Science Division},
abstractNote = {Groundwater at Camp Ripley, Minnesota, is recharged both on post and off site and discharged to rivers, wetlands, and pumping wells. The subsurface geologic materials have a wide range of permeabilities and are arranged in a complex fashion as a result of the region's multiple glacial advances. Correlation of individual glacial geologic units is difficult, even between nearby boreholes, because of the heterogeneities in the subsurface. This report documents the creation of a numerical model of groundwater flow for Camp Ripley and hydrologically related areas to the west and southwest. The model relies on a hydrogeological conceptual model built on the findings of a University of Minnesota-Duluth drilling and sampling program conducted in 2001. Because of the site's stratigraphic complexity, a geostatistical approach was taken to handle the uncertainty of the subsurface correlation. The U.S. Geological Survey's MODFLOW code was used to create the steady-state model, which includes input data from a variety of sources and is calibrated to water levels in monitoring wells across much of the site. This model was used for several applications. Wellhead protection zones were delineated for on-site production wells H, L, and N. The zones were determined on the basis of a probabilistic assessment of the groundwater captured by these wells; the assessment, in turn, had been based on multiple realizations of the study area's stratigraphy and groundwater flowfield. An additional application of the model was for estimating flowpaths and times of travel for groundwater at Camp Ripley's range areas and waste management facilities.},
doi = {10.2172/925332},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Dec 22 00:00:00 EST 2006},
month = {Fri Dec 22 00:00:00 EST 2006}
}

Technical Report:

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  • In 1989, the Wisconsin Geological and Natural History Survey prepared the report under an agreement with the Environmental Protection Agency to evaluate methods for wellhead protection area (WHPA) delineation in unconfined fractured-rock aquifers. Two fractured-rock settings were selected for the study: Precambrian crystalline rocks in central Wisconsin and Silurian dolomite in northeastern Wisconsin. The methods tested ranged from simple approaches to complex computer models. Four WHPA delineation approaches are suggested for unconfined fractured-rock aquifers that do not behave as porous media.
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