Denis R LeBlanc
Denis LeBlanc is a Scientist Emeritus with the New England Water Science Center.
Denis conducts research on the hydrology of shallow, unconfined groundwater/surface-water systems and the fate and transport of contaminants.
He joined the USGS in 1975 and, until 1983, participated in and led investigations of Cape Cod's hydrologic system.
From 1983 until his retirement in 2023, he conducted and coordinated multidisciplinary research at the USGS Cape Cod Toxic Substances Hydrology Research site at the Joint Base Cape Cod (JBCC) near Falmouth, Mass. He also led the team that provided technical support to Air Force and Army National Guard environmental restoration programs at JBCC and participated in several projects with the U.S Environmental Protection Agency on nitrogen and other wastewater contaminants in Cape Cod's groundwater.
Denis received his B.S. in Hydrology from the University of New Hampshire and his M.S. in Civil and Environmental Engineering from the Massachusetts Institute of Technology.
He is a member of the National Ground Water Association and the Geological Society of America.
Professional Experience
Scientist Emeritus, U.S. Geological Survey, New England Water Science Center, 2023 to Present
Research Hydrologist, U.S. Geological Survey, New England Water Science Center, Cape Cod Toxic Substances Hydrology projects, 1983 to 2023
Hydrologist, U.S. Geological Survey, New England Water Science Center, Cape Cod Hydrology projects, 1975 to 1983
Oceanographic Field Assistant, Normandeau Associates, 1973 to 1975
Education and Certifications
M.S. Civil and Environmental Engineering, Massachusetts Institute of Technology, 2001
B.S. Hydrology, University of New Hampshire, 1975
Affiliations and Memberships*
Geological Society of America 1997, to Present
National Groundwater Association, 1977 to Present
Honors and Awards
Eugene M. Shoemaker Award for Lifetime Achievement in Communications, U.S. Geological Survey, 2020
Distinguished Service Award, Dept. of the Interior, 2016
Fellow, Geological Society of America, 2013
Meritorious Service Award, Dept. of the Interior, 1995
Science and Products
Filter Total Items: 22
No Result Found
40 Years Presenting Cape Cod Hydrology
USGS has studied the hydrology of Cape Cod and the Islands and demonstrated our science to the public for more than four decades. Many visitor groups from government agencies, universities, nonprofit organizations, and local communities have learned about our groundwater and surface water research in southeastern Massachusetts. USGS Research Hydrologist Emeritus Denis Leblanc has been a pillar in...
Filter Total Items: 67
Estimation of hydraulic parameters from an unconfined aquifer test conducted in a glacial outwash deposit, Cape Cod, Massachusetts Estimation of hydraulic parameters from an unconfined aquifer test conducted in a glacial outwash deposit, Cape Cod, Massachusetts
An aquifer test conducted in a sand and gravel, glacial outwash deposit on Cape Cod, Massachusetts was analyzed by means of a model for flow to a partially penetrating well in a homogeneous, anisotropic unconfined aquifer. The model is designed to account for all significant mechanisms expected to influence drawdown in observation piezometers and in the pumped well. In addition to the...
Authors
Allen F. Moench, Stephen P. Garabedian, Denis R. LeBlanc
Estimation of hydraulic parameters from an unconfined aquifer test conducted in a glacial outwash deposit, Cape Cod, Massachusetts Estimation of hydraulic parameters from an unconfined aquifer test conducted in a glacial outwash deposit, Cape Cod, Massachusetts
An aquifer test conducted in a sand and gravel, glacial outwash deposit on Cape Cod, Massachusetts was analyzed by means of a model for flow to a partially penetrating well in a homogeneous, anisotropic unconfined aquifer. The model is designed to account for all significant mechanisms expected to influence drawdown in observation piezometers and in the pumped well. In addition to the...
Authors
A.F. Moench, Stephen P. Garabedian, Denis R. LeBlanc
A siphon gage for monitoring surface-water levels A siphon gage for monitoring surface-water levels
A device that uses a siphon tube to establish a hydraulic connection between the bottom of an onshore standpipe and a point at the bottom of a water body was designed and tested for monitoring surface-water levels. Water is added to the standpipe to a level sufficient to drive a complete slug of water through the siphoning tube and to flush all air out of the system. The water levels in...
Authors
Timothy D. McCobb, Denis R. LeBlanc, Roy S. Socolow
Characterizing a sewage plume using the 3H-3He dating technique Characterizing a sewage plume using the 3H-3He dating technique
An extensive 3H-3He study was performed to determine detailed characteristics of a regional flow system and a sewage plume over a distance of 4 km in a sand and gravel aquifer at Otis Air Base in Falmouth, Massachusetts. 3H-3He ages increase with depth in individual piezometer clusters and with distance along flowpaths. However, the age gradient with depth (Δt/Δz) is smaller in the plume...
Authors
Stephanie Dunkle Shapiro, Denis LeBlanc, Peter Schlosser, Andrea Ludin
Water-quality data and methods of analysis for samples collected near a plume of sewage-contaminated ground water, Ashumet Valley, Cape Cod, Massachusetts, 1993-94 Water-quality data and methods of analysis for samples collected near a plume of sewage-contaminated ground water, Ashumet Valley, Cape Cod, Massachusetts, 1993-94
No abstract available.
Authors
Jennifer G. Savoie, Denis R. LeBlanc
Delineation of contributing areas to selected public-supply wells, western Cape Cod, Massachusetts Delineation of contributing areas to selected public-supply wells, western Cape Cod, Massachusetts
No abstract available.
Authors
John P. Masterson, Donald A. Walter, Denis R. LeBlanc
Infiltration and solute transport experiments in unsaturated sand and gravel, Cape Cod, Massachusetts: Experimental design and overview of results Infiltration and solute transport experiments in unsaturated sand and gravel, Cape Cod, Massachusetts: Experimental design and overview of results
A series of infiltration and tracer experiments was conducted in unsaturated sand and gravel deposits on Cape Cod, Massachusetts. A network of 112 porous cup lysimeters and 168 time domain reflectometry (TDR) probes was deployed at depths from 0.25 to 2.0 m below ground surface along the centerline of a 2-m by 10-m test plot. The test plot was irrigated at rates ranging from 7.9 to 37.0...
Authors
David L. Rudolph, R. Gary Kachanoski, Michael A. Celia, Denis R. LeBlanc, Jonathon H. Stevens
Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 1. Experimental design and observed tracer movement Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 1. Experimental design and observed tracer movement
A large-scale natural gradient tracer experiment was conducted on Cape Cod, Massachusetts, to examine the transport and dispersion of solutes in a sand and gravel aquifer. The nonreactive tracer, bromide, and the reactive tracers, lithium and molybdate, were injected as a pulse in July 1985 and monitored in three dimensions as they moved as far as 280 m down-gradient through an array of...
Authors
Denis R. LeBlanc, Stephen P. Garabedian, Kathryn M. Hess, Lynn W. Gelhar, Richard D. Quadri, Kenneth G. Stollenwerk, Warren W. Wood
Long-term fate of organic micropollutants in sewage-contaminated groundwater Long-term fate of organic micropollutants in sewage-contaminated groundwater
No abstract available.
Authors
Larry B. Barber, M.P. Schroeder, E. Michael Thurman, Denis R. LeBlanc
A statistical evaluation of formation disturbance produced by well- casing installation methods A statistical evaluation of formation disturbance produced by well- casing installation methods
Water-resources investigations concerned with contaminant transport through aquifers comprised of very loose, unconsolidated sediments have shown that small-scale variations in aquifer characteristics can significantly affect solute transport and dispersion. Commonly, measurement accuracy and resolution have been limited by a borehole environment consisting of an annulus of disturbed...
Authors
R. H. Morin, Denis R. LeBlanc, W.E. Teasdale
Ground-water resources of Cape Cod, Massachusetts Ground-water resources of Cape Cod, Massachusetts
No abstract available.
Authors
Denis R. LeBlanc, J.H. Guswa, M. H. Frimpter, C.J. Londquist
Digital models of ground-water flow in the Cape Cod aquifer system, Massachusetts Digital models of ground-water flow in the Cape Cod aquifer system, Massachusetts
The Cape Cod aquifer system was simulated with three-dimensional finite-difference ground-water-flow models. Five areas were modeled to provide tools that can be used to evaluate the hydrologic impacts of regional water development and waste disposal. The model boundaries were selected to represent the natural hydrologic boundaries of the aquifer. The boundary between fresh and saline...
Authors
John H. Guswa, Denis R. LeBlanc
Science and Products
Filter Total Items: 22
No Result Found
40 Years Presenting Cape Cod Hydrology
USGS has studied the hydrology of Cape Cod and the Islands and demonstrated our science to the public for more than four decades. Many visitor groups from government agencies, universities, nonprofit organizations, and local communities have learned about our groundwater and surface water research in southeastern Massachusetts. USGS Research Hydrologist Emeritus Denis Leblanc has been a pillar in...
Filter Total Items: 67
Estimation of hydraulic parameters from an unconfined aquifer test conducted in a glacial outwash deposit, Cape Cod, Massachusetts Estimation of hydraulic parameters from an unconfined aquifer test conducted in a glacial outwash deposit, Cape Cod, Massachusetts
An aquifer test conducted in a sand and gravel, glacial outwash deposit on Cape Cod, Massachusetts was analyzed by means of a model for flow to a partially penetrating well in a homogeneous, anisotropic unconfined aquifer. The model is designed to account for all significant mechanisms expected to influence drawdown in observation piezometers and in the pumped well. In addition to the...
Authors
Allen F. Moench, Stephen P. Garabedian, Denis R. LeBlanc
Estimation of hydraulic parameters from an unconfined aquifer test conducted in a glacial outwash deposit, Cape Cod, Massachusetts Estimation of hydraulic parameters from an unconfined aquifer test conducted in a glacial outwash deposit, Cape Cod, Massachusetts
An aquifer test conducted in a sand and gravel, glacial outwash deposit on Cape Cod, Massachusetts was analyzed by means of a model for flow to a partially penetrating well in a homogeneous, anisotropic unconfined aquifer. The model is designed to account for all significant mechanisms expected to influence drawdown in observation piezometers and in the pumped well. In addition to the...
Authors
A.F. Moench, Stephen P. Garabedian, Denis R. LeBlanc
A siphon gage for monitoring surface-water levels A siphon gage for monitoring surface-water levels
A device that uses a siphon tube to establish a hydraulic connection between the bottom of an onshore standpipe and a point at the bottom of a water body was designed and tested for monitoring surface-water levels. Water is added to the standpipe to a level sufficient to drive a complete slug of water through the siphoning tube and to flush all air out of the system. The water levels in...
Authors
Timothy D. McCobb, Denis R. LeBlanc, Roy S. Socolow
Characterizing a sewage plume using the 3H-3He dating technique Characterizing a sewage plume using the 3H-3He dating technique
An extensive 3H-3He study was performed to determine detailed characteristics of a regional flow system and a sewage plume over a distance of 4 km in a sand and gravel aquifer at Otis Air Base in Falmouth, Massachusetts. 3H-3He ages increase with depth in individual piezometer clusters and with distance along flowpaths. However, the age gradient with depth (Δt/Δz) is smaller in the plume...
Authors
Stephanie Dunkle Shapiro, Denis LeBlanc, Peter Schlosser, Andrea Ludin
Water-quality data and methods of analysis for samples collected near a plume of sewage-contaminated ground water, Ashumet Valley, Cape Cod, Massachusetts, 1993-94 Water-quality data and methods of analysis for samples collected near a plume of sewage-contaminated ground water, Ashumet Valley, Cape Cod, Massachusetts, 1993-94
No abstract available.
Authors
Jennifer G. Savoie, Denis R. LeBlanc
Delineation of contributing areas to selected public-supply wells, western Cape Cod, Massachusetts Delineation of contributing areas to selected public-supply wells, western Cape Cod, Massachusetts
No abstract available.
Authors
John P. Masterson, Donald A. Walter, Denis R. LeBlanc
Infiltration and solute transport experiments in unsaturated sand and gravel, Cape Cod, Massachusetts: Experimental design and overview of results Infiltration and solute transport experiments in unsaturated sand and gravel, Cape Cod, Massachusetts: Experimental design and overview of results
A series of infiltration and tracer experiments was conducted in unsaturated sand and gravel deposits on Cape Cod, Massachusetts. A network of 112 porous cup lysimeters and 168 time domain reflectometry (TDR) probes was deployed at depths from 0.25 to 2.0 m below ground surface along the centerline of a 2-m by 10-m test plot. The test plot was irrigated at rates ranging from 7.9 to 37.0...
Authors
David L. Rudolph, R. Gary Kachanoski, Michael A. Celia, Denis R. LeBlanc, Jonathon H. Stevens
Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 1. Experimental design and observed tracer movement Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 1. Experimental design and observed tracer movement
A large-scale natural gradient tracer experiment was conducted on Cape Cod, Massachusetts, to examine the transport and dispersion of solutes in a sand and gravel aquifer. The nonreactive tracer, bromide, and the reactive tracers, lithium and molybdate, were injected as a pulse in July 1985 and monitored in three dimensions as they moved as far as 280 m down-gradient through an array of...
Authors
Denis R. LeBlanc, Stephen P. Garabedian, Kathryn M. Hess, Lynn W. Gelhar, Richard D. Quadri, Kenneth G. Stollenwerk, Warren W. Wood
Long-term fate of organic micropollutants in sewage-contaminated groundwater Long-term fate of organic micropollutants in sewage-contaminated groundwater
No abstract available.
Authors
Larry B. Barber, M.P. Schroeder, E. Michael Thurman, Denis R. LeBlanc
A statistical evaluation of formation disturbance produced by well- casing installation methods A statistical evaluation of formation disturbance produced by well- casing installation methods
Water-resources investigations concerned with contaminant transport through aquifers comprised of very loose, unconsolidated sediments have shown that small-scale variations in aquifer characteristics can significantly affect solute transport and dispersion. Commonly, measurement accuracy and resolution have been limited by a borehole environment consisting of an annulus of disturbed...
Authors
R. H. Morin, Denis R. LeBlanc, W.E. Teasdale
Ground-water resources of Cape Cod, Massachusetts Ground-water resources of Cape Cod, Massachusetts
No abstract available.
Authors
Denis R. LeBlanc, J.H. Guswa, M. H. Frimpter, C.J. Londquist
Digital models of ground-water flow in the Cape Cod aquifer system, Massachusetts Digital models of ground-water flow in the Cape Cod aquifer system, Massachusetts
The Cape Cod aquifer system was simulated with three-dimensional finite-difference ground-water-flow models. Five areas were modeled to provide tools that can be used to evaluate the hydrologic impacts of regional water development and waste disposal. The model boundaries were selected to represent the natural hydrologic boundaries of the aquifer. The boundary between fresh and saline...
Authors
John H. Guswa, Denis R. LeBlanc
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government