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: 22
Microbial Community and N-cycling gene abundance from Ponds and Groundwater on Cape Cod, MA (2015 - 2018) Microbial Community and N-cycling gene abundance from Ponds and Groundwater on Cape Cod, MA (2015 - 2018)
Surface water, pore water, pond bottom sediments, and groundwater were sampled within and downgradient from five groundwater flow-through ponds that ranged from oligotrophic to eutrophic in Cape Cod, Massachusetts during different seasons from 2015 – 2018. The sampled ponds included Ashumet, Santuit, Snake, Shubael, and Longs. Pore water was collected between 15 to 100 cm below the pond...
Target-Chemical Concentration Results of Mixed-Organic/Inorganic Chemical Exposures in Cape Cod, Massachusetts Tapwater, 2018 Target-Chemical Concentration Results of Mixed-Organic/Inorganic Chemical Exposures in Cape Cod, Massachusetts Tapwater, 2018
This dataset provides the water-quality results for organic and inorganic concentrations analyzed from samples collected at residential tapwater faucets, sourced from private drinking water wells in Cape Cod, Massachusetts. Samples were collected in July and August, 2018 from 20 locations. Samples were analyzed at various U.S. Geological Survey laboratories: the National Water Quality...
Transient Electromagnetics, Passive Seismic, and Borehole Electromagnetics, Gamma, and Nuclear Magnetic Resonance Methods to Characterize an Unconsolidated Aquifer on Cape Cod, Massachusetts Transient Electromagnetics, Passive Seismic, and Borehole Electromagnetics, Gamma, and Nuclear Magnetic Resonance Methods to Characterize an Unconsolidated Aquifer on Cape Cod, Massachusetts
Reserved for CDJ. Transient Electromagnetics, Passive Seismic, and Borehole Electromagnetics, Gamma, and Nuclear Magnetic Resonance Methods to Characterize an Unconsolidated Aquifer on Cape Cod, Massachusetts Johnson, White, Phillips, Pappas, Hull, LeBlanc, and Lane
Determination of the effect of temperature (Q10) on rates of oxygen consumption in surface sediments collected from Ashumet Pond on Cape Cod, MA (2016) Determination of the effect of temperature (Q10) on rates of oxygen consumption in surface sediments collected from Ashumet Pond on Cape Cod, MA (2016)
This data release presents results from a laboratory study designed to measure the effect of temperature on rates of oxygen consumption within lake-bottom surface sediments at 0- to 5-cm depth. Sediment and lake water samples were collected June 8, 2016 from the South site in Ashumet Pond, Cape Cod, MA, where lake water recharges to the aquifer. Samples were shipped to Boulder, CO for...
Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed
The U.S. Geological Survey Toxic Substances Hydrology Program at Cape Cod has been investigating the fate and transport of a treated-wastewater, groundwater contaminant plume. A portion of the contaminated groundwater discharges into Ashumet Pond, a kettle hole, freshwater lake. A study was conducted from June 2013 to June 2015 to document transport, transformation, and discharge of...
Data Release for Lake Shadow Seepage Calculations from Ashumet Pond, Cape Cod, MA, 2016 - 2018 Data Release for Lake Shadow Seepage Calculations from Ashumet Pond, Cape Cod, MA, 2016 - 2018
Hydrologic data were collected in the nearshore lake-bottom sediments of five lakes on western Cape Cod, Massachusetts: Ashumet (Falmouth), Long (Centerville), Santuit (Mashpee), Shubael (Barnstable), and Snake (Sandwich) Ponds. Water budgets of flow-through glacial kettle lakes are commonly dominated by groundwater flow into and surface-water seepage out of the lake, and inputs and...
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: 66
Characterizing the diverse hydrogeology underlying rivers and estuaries using new floating transient electromagnetic methodology Characterizing the diverse hydrogeology underlying rivers and estuaries using new floating transient electromagnetic methodology
The hydrogeology below large surface water features such as rivers and estuaries is universally under-informed at the long reach to basin scales (tens of km+). This challenge inhibits the accurate modeling of fresh/saline groundwater interfaces and groundwater/surface water exchange patterns at management-relevant spatial extents. Here we introduce a towed, floating transient...
Authors
John W. Lane, Martin A. Briggs, PK Maurya, Eric A. White, JB Pedersen, Esben Auken, Neil Terry, Burke J. Minsley, Wade Kress, Denis R. LeBlanc, Ryan F. Adams, Carole D. Johnson
Hillslope groundwater discharges provide localized ecosystem buffers from regional PFAS contamination in a gaining coastal stream Hillslope groundwater discharges provide localized ecosystem buffers from regional PFAS contamination in a gaining coastal stream
Emerging groundwater contaminants such as per- and polyfluoroalkyl substances (PFAS) may impact surface-water quality and groundwater-dependent ecosystems of gaining streams. Although complex near-surface hydrogeology of stream corridors challenges sampling efforts, recent advances in heat tracing of discharge zones enable efficient and informed data collection. For this study we used a
Authors
Martin A. Briggs, Andrea K. Tokranov, Robert B. Hull, Denis R. LeBlanc, A. Haynes, John W. Lane
Simulated water-table and pond-level responses to proposed public water-supply withdrawals in the Hyannis Ponds Wildlife Management Area, Barnstable, Massachusetts Simulated water-table and pond-level responses to proposed public water-supply withdrawals in the Hyannis Ponds Wildlife Management Area, Barnstable, Massachusetts
The glacial kettle ponds in the Hyannis Ponds Wildlife Management Area in Barnstable, Massachusetts, support a community of rare and endangered plants. The ponds are hydraulically connected to the unconfined aquifer that underlies Cape Cod. The plants are adapted to the rise and fall of water levels in the ponds as the water table fluctuates in response to seasonal and year-to-year...
Authors
Denis R. LeBlanc, Timothy D. McCobb, Jeffrey R. Barbaro
Lithostratigraphic, geophysical, and hydrogeologic observations from a boring drilled to bedrock in glacial sediments near Nantucket Sound in East Falmouth, Massachusetts Lithostratigraphic, geophysical, and hydrogeologic observations from a boring drilled to bedrock in glacial sediments near Nantucket Sound in East Falmouth, Massachusetts
In spring 2016, a 310-foot-deep boring (named MA–FSW 750) was drilled by the U.S. Geological Survey near Nantucket Sound in East Falmouth, Massachusetts, to investigate the hydrogeology of the southern coast of western Cape Cod. Few borings that are drilled to bedrock exist in the area, and the study area was selected to fill a gap between comprehensive geologic datasets inland to the...
Authors
Robert B. Hull, Carole D. Johnson, Byron D. Stone, Denis R. LeBlanc, Timothy D. McCobb, Stephanie N. Phillips, Katherine L. Pappas, John W. Lane
Hydrologic site assessment for passive treatment of groundwater nitrogen with permeable reactive barriers, Cape Cod, Massachusetts Hydrologic site assessment for passive treatment of groundwater nitrogen with permeable reactive barriers, Cape Cod, Massachusetts
Wastewater disposal associated with rapid population growth and development on Cape Cod, Massachusetts, during the past several decades has resulted in widespread contamination of groundwater with nitrogen. As a result, water quality in many of the streams, lakes, and coastal embayments on Cape Cod is impaired by excess nitrogen. To reduce nitrogen loads to these impaired water bodies...
Authors
Jeffrey R. Barbaro, Marcel Belaval, Danna B. Truslow, Denis R. LeBlanc, Thomas C. Cambareri, Scott C. Michaud
Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed
Groundwater discharge delivering anthropogenic N from surrounding watersheds can impact lake nutrient budgets. However, upgradient groundwater processes and changing dynamics in N biogeochemistry at the groundwater-lake interface are complex and difficult to resolve. In this study, hydrograph variations in a groundwater flow-through lake altered discharge patterns of a wastewater-derived
Authors
Richard L. Smith, Deborah A. Repert, Deborah Stoliker, Douglas B. Kent, Bongkeun Song, Denis R. LeBlanc, Timothy D. McCobb, J.K. Bohlke, Sung Pil Hyun, Hee Sun Moon
Science and Products
Filter Total Items: 22
Microbial Community and N-cycling gene abundance from Ponds and Groundwater on Cape Cod, MA (2015 - 2018) Microbial Community and N-cycling gene abundance from Ponds and Groundwater on Cape Cod, MA (2015 - 2018)
Surface water, pore water, pond bottom sediments, and groundwater were sampled within and downgradient from five groundwater flow-through ponds that ranged from oligotrophic to eutrophic in Cape Cod, Massachusetts during different seasons from 2015 – 2018. The sampled ponds included Ashumet, Santuit, Snake, Shubael, and Longs. Pore water was collected between 15 to 100 cm below the pond...
Target-Chemical Concentration Results of Mixed-Organic/Inorganic Chemical Exposures in Cape Cod, Massachusetts Tapwater, 2018 Target-Chemical Concentration Results of Mixed-Organic/Inorganic Chemical Exposures in Cape Cod, Massachusetts Tapwater, 2018
This dataset provides the water-quality results for organic and inorganic concentrations analyzed from samples collected at residential tapwater faucets, sourced from private drinking water wells in Cape Cod, Massachusetts. Samples were collected in July and August, 2018 from 20 locations. Samples were analyzed at various U.S. Geological Survey laboratories: the National Water Quality...
Transient Electromagnetics, Passive Seismic, and Borehole Electromagnetics, Gamma, and Nuclear Magnetic Resonance Methods to Characterize an Unconsolidated Aquifer on Cape Cod, Massachusetts Transient Electromagnetics, Passive Seismic, and Borehole Electromagnetics, Gamma, and Nuclear Magnetic Resonance Methods to Characterize an Unconsolidated Aquifer on Cape Cod, Massachusetts
Reserved for CDJ. Transient Electromagnetics, Passive Seismic, and Borehole Electromagnetics, Gamma, and Nuclear Magnetic Resonance Methods to Characterize an Unconsolidated Aquifer on Cape Cod, Massachusetts Johnson, White, Phillips, Pappas, Hull, LeBlanc, and Lane
Determination of the effect of temperature (Q10) on rates of oxygen consumption in surface sediments collected from Ashumet Pond on Cape Cod, MA (2016) Determination of the effect of temperature (Q10) on rates of oxygen consumption in surface sediments collected from Ashumet Pond on Cape Cod, MA (2016)
This data release presents results from a laboratory study designed to measure the effect of temperature on rates of oxygen consumption within lake-bottom surface sediments at 0- to 5-cm depth. Sediment and lake water samples were collected June 8, 2016 from the South site in Ashumet Pond, Cape Cod, MA, where lake water recharges to the aquifer. Samples were shipped to Boulder, CO for...
Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed
The U.S. Geological Survey Toxic Substances Hydrology Program at Cape Cod has been investigating the fate and transport of a treated-wastewater, groundwater contaminant plume. A portion of the contaminated groundwater discharges into Ashumet Pond, a kettle hole, freshwater lake. A study was conducted from June 2013 to June 2015 to document transport, transformation, and discharge of...
Data Release for Lake Shadow Seepage Calculations from Ashumet Pond, Cape Cod, MA, 2016 - 2018 Data Release for Lake Shadow Seepage Calculations from Ashumet Pond, Cape Cod, MA, 2016 - 2018
Hydrologic data were collected in the nearshore lake-bottom sediments of five lakes on western Cape Cod, Massachusetts: Ashumet (Falmouth), Long (Centerville), Santuit (Mashpee), Shubael (Barnstable), and Snake (Sandwich) Ponds. Water budgets of flow-through glacial kettle lakes are commonly dominated by groundwater flow into and surface-water seepage out of the lake, and inputs and...
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: 66
Characterizing the diverse hydrogeology underlying rivers and estuaries using new floating transient electromagnetic methodology Characterizing the diverse hydrogeology underlying rivers and estuaries using new floating transient electromagnetic methodology
The hydrogeology below large surface water features such as rivers and estuaries is universally under-informed at the long reach to basin scales (tens of km+). This challenge inhibits the accurate modeling of fresh/saline groundwater interfaces and groundwater/surface water exchange patterns at management-relevant spatial extents. Here we introduce a towed, floating transient...
Authors
John W. Lane, Martin A. Briggs, PK Maurya, Eric A. White, JB Pedersen, Esben Auken, Neil Terry, Burke J. Minsley, Wade Kress, Denis R. LeBlanc, Ryan F. Adams, Carole D. Johnson
Hillslope groundwater discharges provide localized ecosystem buffers from regional PFAS contamination in a gaining coastal stream Hillslope groundwater discharges provide localized ecosystem buffers from regional PFAS contamination in a gaining coastal stream
Emerging groundwater contaminants such as per- and polyfluoroalkyl substances (PFAS) may impact surface-water quality and groundwater-dependent ecosystems of gaining streams. Although complex near-surface hydrogeology of stream corridors challenges sampling efforts, recent advances in heat tracing of discharge zones enable efficient and informed data collection. For this study we used a
Authors
Martin A. Briggs, Andrea K. Tokranov, Robert B. Hull, Denis R. LeBlanc, A. Haynes, John W. Lane
Simulated water-table and pond-level responses to proposed public water-supply withdrawals in the Hyannis Ponds Wildlife Management Area, Barnstable, Massachusetts Simulated water-table and pond-level responses to proposed public water-supply withdrawals in the Hyannis Ponds Wildlife Management Area, Barnstable, Massachusetts
The glacial kettle ponds in the Hyannis Ponds Wildlife Management Area in Barnstable, Massachusetts, support a community of rare and endangered plants. The ponds are hydraulically connected to the unconfined aquifer that underlies Cape Cod. The plants are adapted to the rise and fall of water levels in the ponds as the water table fluctuates in response to seasonal and year-to-year...
Authors
Denis R. LeBlanc, Timothy D. McCobb, Jeffrey R. Barbaro
Lithostratigraphic, geophysical, and hydrogeologic observations from a boring drilled to bedrock in glacial sediments near Nantucket Sound in East Falmouth, Massachusetts Lithostratigraphic, geophysical, and hydrogeologic observations from a boring drilled to bedrock in glacial sediments near Nantucket Sound in East Falmouth, Massachusetts
In spring 2016, a 310-foot-deep boring (named MA–FSW 750) was drilled by the U.S. Geological Survey near Nantucket Sound in East Falmouth, Massachusetts, to investigate the hydrogeology of the southern coast of western Cape Cod. Few borings that are drilled to bedrock exist in the area, and the study area was selected to fill a gap between comprehensive geologic datasets inland to the...
Authors
Robert B. Hull, Carole D. Johnson, Byron D. Stone, Denis R. LeBlanc, Timothy D. McCobb, Stephanie N. Phillips, Katherine L. Pappas, John W. Lane
Hydrologic site assessment for passive treatment of groundwater nitrogen with permeable reactive barriers, Cape Cod, Massachusetts Hydrologic site assessment for passive treatment of groundwater nitrogen with permeable reactive barriers, Cape Cod, Massachusetts
Wastewater disposal associated with rapid population growth and development on Cape Cod, Massachusetts, during the past several decades has resulted in widespread contamination of groundwater with nitrogen. As a result, water quality in many of the streams, lakes, and coastal embayments on Cape Cod is impaired by excess nitrogen. To reduce nitrogen loads to these impaired water bodies...
Authors
Jeffrey R. Barbaro, Marcel Belaval, Danna B. Truslow, Denis R. LeBlanc, Thomas C. Cambareri, Scott C. Michaud
Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed Seasonal and spatial variation in the location and reactivity of a nitrate-contaminated groundwater discharge zone in a lakebed
Groundwater discharge delivering anthropogenic N from surrounding watersheds can impact lake nutrient budgets. However, upgradient groundwater processes and changing dynamics in N biogeochemistry at the groundwater-lake interface are complex and difficult to resolve. In this study, hydrograph variations in a groundwater flow-through lake altered discharge patterns of a wastewater-derived
Authors
Richard L. Smith, Deborah A. Repert, Deborah Stoliker, Douglas B. Kent, Bongkeun Song, Denis R. LeBlanc, Timothy D. McCobb, J.K. Bohlke, Sung Pil Hyun, Hee Sun Moon