Denis R LeBlanc
Denis LeBlanc is a Scientist Emeritus with the New England Water Science Center.
Denis presently coordinates a multidisciplinary research effort at the USGS Cape Cod Toxic Substances Hydrology Research site at the Joint Base Cape Cod (JBCC) near Falmouth, Mass. He also provides technical support to Air Force and Army National Guard environmental restoration programs at JBCC and participates 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, where he is a GSA Fellow. He has focused on Cape Cod's freshwater resources since joining the USGS in 1975.
Professional Experience
1975 - present, U.S. Geological Survey - Research Hydrologist
Education and Certifications
M.S. Civil and Environmental Engineering, Massachusetts Institute of Technology
B.S. Hydrology, University of New Hampshire
Science and Products
Filter Total Items: 65
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 Shapiro, Denis LeBlanc, Peter Schlosser, Andrea Ludin
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 McCobb, Denis LeBlanc, Roy Socolow
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 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 Walter, Denis 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 Rudolph, R. Kachanoski, Michael Celia, Denis LeBlanc, Jonathon 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 LeBlanc, Stephen Garabedian, Kathryn Hess, Lynn Gelhar, Richard Quadri, Kenneth 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 Barber, M.P. Schroeder, E. Thurman, Denis 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. Morin, Denis LeBlanc, W.E. Teasdale
Ground-water resources of Cape Cod, Massachusetts Ground-water resources of Cape Cod, Massachusetts
No abstract available.
Authors
Denis 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 Guswa, Denis LeBlanc
Sewage plume in a sand and gravel aquifer, Cape Cod, Massachusetts Sewage plume in a sand and gravel aquifer, Cape Cod, Massachusetts
Secondarily treated domestic sewage has been disposed of on surface sand beds at the sewage treatment facility at Otis Air Force Base, Massachusetts, since 1936. Infiltration of the sewage through the sand beds into the underlying unconfined sand and gravel aquifer has resulted in a plume of sewage-contaminated ground water that is 2,500 to 3,500 feet wide, 75 feet thick, and more than...
Authors
Denis LeBlanc
Movement and fate of solutes in a plume of sewage-contaminated ground water, Cape Cod, Massachusetts: U.S. Geological Survey toxic waste ground-water contamination program Movement and fate of solutes in a plume of sewage-contaminated ground water, Cape Cod, Massachusetts: U.S. Geological Survey toxic waste ground-water contamination program
The U.S. Geological Survey (USGS) has begun a nationwide program to study the fate of toxic wastes in groundwater. Several sites where groundwater is known to be contaminated are being studied by interdisciplinary teams of geohydrologists, chemists, and microbiologists. The objective of these studies is to obtain a thorough quantitative understanding of the physical, chemical, and...
Filter Total Items: 21
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...
Science and Products
Filter Total Items: 65
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 Shapiro, Denis LeBlanc, Peter Schlosser, Andrea Ludin
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 McCobb, Denis LeBlanc, Roy Socolow
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 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 Walter, Denis 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 Rudolph, R. Kachanoski, Michael Celia, Denis LeBlanc, Jonathon 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 LeBlanc, Stephen Garabedian, Kathryn Hess, Lynn Gelhar, Richard Quadri, Kenneth 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 Barber, M.P. Schroeder, E. Thurman, Denis 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. Morin, Denis LeBlanc, W.E. Teasdale
Ground-water resources of Cape Cod, Massachusetts Ground-water resources of Cape Cod, Massachusetts
No abstract available.
Authors
Denis 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 Guswa, Denis LeBlanc
Sewage plume in a sand and gravel aquifer, Cape Cod, Massachusetts Sewage plume in a sand and gravel aquifer, Cape Cod, Massachusetts
Secondarily treated domestic sewage has been disposed of on surface sand beds at the sewage treatment facility at Otis Air Force Base, Massachusetts, since 1936. Infiltration of the sewage through the sand beds into the underlying unconfined sand and gravel aquifer has resulted in a plume of sewage-contaminated ground water that is 2,500 to 3,500 feet wide, 75 feet thick, and more than...
Authors
Denis LeBlanc
Movement and fate of solutes in a plume of sewage-contaminated ground water, Cape Cod, Massachusetts: U.S. Geological Survey toxic waste ground-water contamination program Movement and fate of solutes in a plume of sewage-contaminated ground water, Cape Cod, Massachusetts: U.S. Geological Survey toxic waste ground-water contamination program
The U.S. Geological Survey (USGS) has begun a nationwide program to study the fate of toxic wastes in groundwater. Several sites where groundwater is known to be contaminated are being studied by interdisciplinary teams of geohydrologists, chemists, and microbiologists. The objective of these studies is to obtain a thorough quantitative understanding of the physical, chemical, and...
Filter Total Items: 21
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...