Abstract Simulating groundwater flow in a water‐table (unconfined) aquifer can be difficult because the saturated thickness available for depends on model‐calculated hydraulic heads. It is often possible to realize substantial time savings and still obtain accurate head solutions by specifying an approximate priori, thus linearizing this aspect of model. This specified‐thickness approximation relies use “confined” option numerical models, which has led confusion criticism method. article...

Combined use of the tritium/helium 3 ( H/ He) dating technique and particle‐tracking analysis can improve flow‐model calibration. As shown at two sites in Great Miami buried‐valley aquifer southwestern Ohio, combined He age particle tracking led to a lower mean absolute error between measured heads simulated than original calibrated models and/or travel times ages. Apparent groundwater ages were obtained for water samples collected from 44 wells locations where previously constructed finite...

This report presents the results of first known integrated study long-term average ground-water recharge to shallow aquifers (generally less than 100 feet deep) in United States and Canada for Great Lakes, upper St. Lawrence, Ottawa River Basins. The approach used was consistent throughout area allows direct comparison rates disparate parts area. Estimates are based on base-flow estimates streams Lakes Basin assumption that base flow a given stream is equal amount surrounding watershed,...

Abstract Velocity fields computed from simulated flows a steady–state, three–dimensional numerical model of glacialdrift/carbonate–bedrock aquifer system were used in conjunction with particle–tracking program to delineate traveltimerelated capture areas municipal wellfield and compute flow paths advective traveltimes hypothetical spill sites located along interstate highways heavily traveled State routes. Results indicate the wells operated by City Columbus, Ohio, certain highway segments...

Three geophysical profiling methods were tested to help characterize subsurface materials at selected transects along the Great Miami River, in southwestern Ohio. The used continuous seismic (CSP), resistivity (CRP), and electromagnetic (CEP). Data collected with global positioning systems spatially locate data river. depth flow conditions of River limited amount quality that could be CSP CRP methods. from generally poor because shallow reflections (less than 5 meters) mostly obscured by...

Source-tracking tools were used to identify potential sources of fecal contamination at two Lake Erie bathing beaches: an urban beach (Edgewater in Cleveland, Ohio) and a small city (Lakeshore Ashtabula, Ohio). These included identifying spatial patterns Escherichia coli (E. coli) concentrations each area, determining weather that caused elevated E. coli, applying microbial source tracking (MST) techniques specific sites. Three MST methods during this study: multiple antibiotic resistance...

Hydrogeologic data from Regional Aquifer System Analyses (RASA) studies by the U.S. Geological Survey in Great Lakes Basin, United States, during 1978-95, were compiled and used to estimate total volume of water that is stored many aquifers basin. These focused on six regional aquifer systems: Cambrian-Ordovician system Wisconsin, Illinois, Indiana; Silurian- Devonian Michigan, Indiana, Ohio; surficial (aquifers alluvial glacial origin) found throughout Basin; Pennsylvanian sandstone...

To determine specific storage and porosity, areally limited time-consuming aquifer tests are frequently done. Hydrogeologic studies often do not have the resources to collect such data rely on existing sources for properties. An alternative tool determining these properties is analysis of earth tides. The objective this study was whether water-level barometric-pressure could be used properties, as porosity storage, a regional scale. In study, national databases from Great Lakes Region were...

The Great Miami River Buried Valley Aquifer System is one of the most productive sources potable water in Midwest, yielding as much 3,000 gallons per minute to wells. Many water-supply wells tapping this aquifer system are purposely placed near rivers take advantage induced infiltration from rivers. City Hamilton's North Well Field consists 10 River, all completed lower System. A well-drilling program and a multiple-well test were done investigate ground-water flow directions estimate...

Agreements between United States governors and Canadian territorial premiers establish water-management principles a framework for protecting Great Lakes waters, including ground water, from diversion consumptive uses. The issue of ground-water diversions out the Basin by large-scale pumping near divides has been raised. Two scenario models, in which regional flow models represent major aquifers region, were used to assess effect divides. carbonate aquifer model was generalized representing...

A compilation of regional ground-water divides for the five principal aquifers corresponding to Great Lakes Basin within United States is presented. The (or aquifer systems) are Cambrian-Ordovician system, Silurian-Devonian aquifers, Mississippian Pennsylvanian and surficial system. mark boundary between flow that discharges or their tributaries other major surface-water bodies, such as Mississippi River. Multicounty multistate (regional) hydrologic studies were reviewed determine whether...

First posted April 20, 2018 For additional information, contact: Director, Upper Midwest Water Science Center U.S. Geological Survey 8505 Research Way Middleton, WI 53562 The collection of high-frequency (in other words, “continuous”) water data has been made easier over the years because advances in technologies to measure, transmit, store, and query large, temporally dense datasets. Commercially available, in-situ sensors data-collection platforms—together with new techniques for...

In 1988, the U.S. Geological Survey's Ohio-Indiana Carbonate-Bedrock and Glacial Regional Aquifer-System Analysis began to examine hydrogeologic framework, flow system, water chemistry, withdrawal response of aquifers in western Ohio eastern Indiana.The initial phase this project involved collection essential hydrologic geologic data for glacial carbonate units within study area.This report describes collected Ohio.Wells completed material bedrock were chosen from paper files drillers' logs,...