Matthew K Landon
Matthew Landon has been a Hydrologist with the U.S. Geological Survey since 1990.
He received a M.S. in Geology from the University of Minnesota in 1993 and a B.S. in Geology from the University of Kansas in 1987. He has conducted studies of groundwater hydrology and geochemistry in Minnesota, Nebraska, California, and Southeast Asia. He has been with the USGS California Water Science Center in San Diego since 2005, serving as Program Chief for the Groundwater and Geochemistry Projects Group from 2012-2016 and the California Oil, Gas, and Groundwater Projects Group since 2016.
Science and Products
Filter Total Items: 90
Accuracy of travel time distribution (TTD) models as affected by TTD complexity, observation errors, and model and tracer selection
Analytical models of the travel time distribution (TTD) from a source area to a sample location are often used to estimate groundwater ages and solute concentration trends. The accuracies of these models are not well known for geologically complex aquifers. In this study, synthetic datasets were used to quantify the accuracy of four analytical TTD models as affected by TTD complexity, observation
Authors
Christopher T. Green, Yong Zhang, Bryant C. Jurgens, J. Jeffrey Starn, Matthew K. Landon
Characterization of potential transport pathways and implications for groundwater management near an anticline in the Central Basin area, Los Angeles County, California
The Central Groundwater Basin (Central Basin) of southern Los Angeles County includes ~280 mi2 of the Los Angeles Coastal Plain and serves as the primary source of water for more than two million residents. In the Santa Fe Springs–Whittier–Norwalk area, located in the northeastern part of the basin, several sources of volatile organic compounds have been identified. The volatile organic compunds a
Authors
Daniel J. Ponti, Brian J. Wagner, Michael Land, Matthew K. Landon
Statistical evaluation of variables affecting occurrence of hydrocarbons in aquifers used for public supply, California
The variables affecting the occurrence of hydrocarbons in aquifers used for public supply in California were assessed based on statistical evaluation of three large statewide datasets; gasoline oxygenates also were analyzed for comparison with hydrocarbons. Benzene is the most frequently detected (1.7%) compound among 17 hydrocarbons analyzed at generally low concentrations (median detected concen
Authors
Matthew K. Landon, Carmen A. Burton, Tracy A. Davis, Kenneth Belitz, Tyler D. Johnson
Trends in concentrations of nitrate and total dissolved solids in public supply wells of the Bunker Hill, Lytle, Rialto, and Colton groundwater subbasins, San Bernardino County, California: Influence of legacy land use
Concentrations and temporal changes in concentrations of nitrate and total dissolved solids (TDS) in groundwater of the Bunker Hill, Lytle, Rialto, and Colton groundwater subbasins of the Upper Santa Ana Valley Groundwater Basin were evaluated to identify trends and factors that may be affecting trends. One hundred, thirty-one public-supply wells were selected for analysis based on the availabilit
Authors
Robert Kent, Matthew K. Landon
Modeling the long-term fate of agricultural nitrate in groundwater in the San Joaquin Valley, California
Nitrate contamination of groundwater systems used for human water supplies is a major environmental problem in many parts of the world. Fertilizers containing a variety of reduced nitrogen compounds are commonly added to soils to increase agricultural yields. But the amount of nitrogen added during fertilization typically exceeds the amount of nitrogen taken up by crops. Oxidation of reduced nitro
Authors
Francis H. Chapelle, Bruce G. Campbell, Mark A. Widdowson, Mathew K. Landon
Groundwater-quality data in the Western San Joaquin Valley study unit, 2010 - Results from the California GAMA Program
Groundwater quality in the approximately 2,170-square-mile Western San Joaquin Valley (WSJV) study unit was investigated by the U.S. Geological Survey (USGS) from March to July 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program's Priority Basin Project (PBP). The GAMA-PBP was developed in response to the Californ
Authors
Timothy M. Mathany, Matthew K. Landon, Jennifer L. Shelton, Kenneth Belitz
Geogenic sources of benzene in aquifers used for public supply, California
Statistical evaluation of two large statewide data sets from the California State Water Board's Groundwater Ambient Monitoring and Assessment Program (1973 wells) and the California Department of Public Health (12417 wells) reveals that benzene occurs infrequently (1.7%) and at generally low concentrations (median detected concentration of 0.024 μg/L) in groundwater used for public supply in Calif
Authors
Matthew K. Landon, Kenneth Belitz
Modeling the potential impact of seasonal and inactive multi-aquifer wells on contaminant movement to public water-supply wells
Wells screened across multiple aquifers can provide pathways for the movement of surprisingly large volumes of groundwater to confined aquifers used for public water supply (PWS). Using a simple numerical model, we examine the impact of several pumping scenarios on leakage from an unconfined aquifer to a confined aquifer and conclude that a single inactive multi-aquifer well can contribute nearly
Authors
R.L. Johnson, B.R. Clark, M.K. Landon, L. J. Kauffman, S. M. Eberts
Status and understanding of groundwater quality in the Santa Clara River Valley, 2007-California GAMA Priority Basin Project
Groundwater quality in the approximately 460-square-mile Santa Clara River Valley study unit was investigated from April through June 2007 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project is conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board
Authors
Carmen A. Burton, Joseph Montrella, Matthew K. Landon, Kenneth Belitz
Groundwater quality in the Santa Clara River Valley, California
The Santa Clara River Valley (SCRV) study unit is located in Los Angeles and Ventura Counties, California, and is bounded by the Santa Monica, San Gabriel, Topatopa, and Santa Ynez Mountains, and the Pacific Ocean. The 460-square-mile study unit includes eight groundwater basins: Ojai Valley, Upper Ojai Valley, Ventura River Valley, Santa Clara River Valley, Pleasant Valley, Arroyo Santa Rosa Vall
Authors
Carmen A. Burton, Matthew K. Landon, Kenneth Belitz
Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA
In a 2,700-km 2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO 3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO 3 and
Authors
Matthew K. Landon, Christopher T. Green, Kenneth Belitz, Michael J. Singleton, Bradley K. Esser
Status and understanding of groundwater quality in the North San Francisco Bay groundwater basins, 2004: California GAMA Priority Basin Project
Groundwater quality in the approximately 1,000-square-mile (2,590-square-kilometer) North San Francisco Bay study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in northern California in Marin, Napa, and Sonoma Counties. The GAMA Priority Basin Project is being conducted by the California St
Authors
Justin T. Kulongoski, Kenneth Belitz, Matthew K. Landon, Christopher Farrar
Science and Products
Filter Total Items: 90
Accuracy of travel time distribution (TTD) models as affected by TTD complexity, observation errors, and model and tracer selection
Analytical models of the travel time distribution (TTD) from a source area to a sample location are often used to estimate groundwater ages and solute concentration trends. The accuracies of these models are not well known for geologically complex aquifers. In this study, synthetic datasets were used to quantify the accuracy of four analytical TTD models as affected by TTD complexity, observation
Authors
Christopher T. Green, Yong Zhang, Bryant C. Jurgens, J. Jeffrey Starn, Matthew K. Landon
Characterization of potential transport pathways and implications for groundwater management near an anticline in the Central Basin area, Los Angeles County, California
The Central Groundwater Basin (Central Basin) of southern Los Angeles County includes ~280 mi2 of the Los Angeles Coastal Plain and serves as the primary source of water for more than two million residents. In the Santa Fe Springs–Whittier–Norwalk area, located in the northeastern part of the basin, several sources of volatile organic compounds have been identified. The volatile organic compunds a
Authors
Daniel J. Ponti, Brian J. Wagner, Michael Land, Matthew K. Landon
Statistical evaluation of variables affecting occurrence of hydrocarbons in aquifers used for public supply, California
The variables affecting the occurrence of hydrocarbons in aquifers used for public supply in California were assessed based on statistical evaluation of three large statewide datasets; gasoline oxygenates also were analyzed for comparison with hydrocarbons. Benzene is the most frequently detected (1.7%) compound among 17 hydrocarbons analyzed at generally low concentrations (median detected concen
Authors
Matthew K. Landon, Carmen A. Burton, Tracy A. Davis, Kenneth Belitz, Tyler D. Johnson
Trends in concentrations of nitrate and total dissolved solids in public supply wells of the Bunker Hill, Lytle, Rialto, and Colton groundwater subbasins, San Bernardino County, California: Influence of legacy land use
Concentrations and temporal changes in concentrations of nitrate and total dissolved solids (TDS) in groundwater of the Bunker Hill, Lytle, Rialto, and Colton groundwater subbasins of the Upper Santa Ana Valley Groundwater Basin were evaluated to identify trends and factors that may be affecting trends. One hundred, thirty-one public-supply wells were selected for analysis based on the availabilit
Authors
Robert Kent, Matthew K. Landon
Modeling the long-term fate of agricultural nitrate in groundwater in the San Joaquin Valley, California
Nitrate contamination of groundwater systems used for human water supplies is a major environmental problem in many parts of the world. Fertilizers containing a variety of reduced nitrogen compounds are commonly added to soils to increase agricultural yields. But the amount of nitrogen added during fertilization typically exceeds the amount of nitrogen taken up by crops. Oxidation of reduced nitro
Authors
Francis H. Chapelle, Bruce G. Campbell, Mark A. Widdowson, Mathew K. Landon
Groundwater-quality data in the Western San Joaquin Valley study unit, 2010 - Results from the California GAMA Program
Groundwater quality in the approximately 2,170-square-mile Western San Joaquin Valley (WSJV) study unit was investigated by the U.S. Geological Survey (USGS) from March to July 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program's Priority Basin Project (PBP). The GAMA-PBP was developed in response to the Californ
Authors
Timothy M. Mathany, Matthew K. Landon, Jennifer L. Shelton, Kenneth Belitz
Geogenic sources of benzene in aquifers used for public supply, California
Statistical evaluation of two large statewide data sets from the California State Water Board's Groundwater Ambient Monitoring and Assessment Program (1973 wells) and the California Department of Public Health (12417 wells) reveals that benzene occurs infrequently (1.7%) and at generally low concentrations (median detected concentration of 0.024 μg/L) in groundwater used for public supply in Calif
Authors
Matthew K. Landon, Kenneth Belitz
Modeling the potential impact of seasonal and inactive multi-aquifer wells on contaminant movement to public water-supply wells
Wells screened across multiple aquifers can provide pathways for the movement of surprisingly large volumes of groundwater to confined aquifers used for public water supply (PWS). Using a simple numerical model, we examine the impact of several pumping scenarios on leakage from an unconfined aquifer to a confined aquifer and conclude that a single inactive multi-aquifer well can contribute nearly
Authors
R.L. Johnson, B.R. Clark, M.K. Landon, L. J. Kauffman, S. M. Eberts
Status and understanding of groundwater quality in the Santa Clara River Valley, 2007-California GAMA Priority Basin Project
Groundwater quality in the approximately 460-square-mile Santa Clara River Valley study unit was investigated from April through June 2007 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project is conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board
Authors
Carmen A. Burton, Joseph Montrella, Matthew K. Landon, Kenneth Belitz
Groundwater quality in the Santa Clara River Valley, California
The Santa Clara River Valley (SCRV) study unit is located in Los Angeles and Ventura Counties, California, and is bounded by the Santa Monica, San Gabriel, Topatopa, and Santa Ynez Mountains, and the Pacific Ocean. The 460-square-mile study unit includes eight groundwater basins: Ojai Valley, Upper Ojai Valley, Ventura River Valley, Santa Clara River Valley, Pleasant Valley, Arroyo Santa Rosa Vall
Authors
Carmen A. Burton, Matthew K. Landon, Kenneth Belitz
Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA
In a 2,700-km 2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO 3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO 3 and
Authors
Matthew K. Landon, Christopher T. Green, Kenneth Belitz, Michael J. Singleton, Bradley K. Esser
Status and understanding of groundwater quality in the North San Francisco Bay groundwater basins, 2004: California GAMA Priority Basin Project
Groundwater quality in the approximately 1,000-square-mile (2,590-square-kilometer) North San Francisco Bay study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in northern California in Marin, Napa, and Sonoma Counties. The GAMA Priority Basin Project is being conducted by the California St
Authors
Justin T. Kulongoski, Kenneth Belitz, Matthew K. Landon, Christopher Farrar