Water-Quality Trends From Lake Cores Active
Sediment cores let us look back in time at the contaminant history of a watershed. Learn about what lake and reservoir sediment cores tell us about trends in metals, organochlorine pesticides, polycyclic aromatic hydrocarbons, and other sediment-related contaminants.
Water-quality trends can provide an assessment of the effectiveness of regulatory actions aimed at improving water quality, a warning of water-quality degradation, and an improved understanding of how human activities affect water quality.
Sediment cores—long tubes of mud—are collected from a lake or reservoir and sliced into thin intervals. Each slice represents an interval of time. By analyzing the sediments in each slice for the contaminants of interest, changes in the occurrence of contaminants and their use in the watershed can be reconstructed. The approximate date corresponding to deposition of the sediment in each slice is determined by analysis of radionuclides (cesium-137 and lead-210).
USGS studies of reconstructed trends in metals and hydrophobic organic contaminants have shed light on the effectiveness of restrictions on the use of leaded gasoline, DDT, and PCBs, and the effectiveness of the Clean Air Act in reducing concentrations of some heavy metals. The studies also have identified some contaminants, like polycyclic aromatic hydrocarbons (PAHs), whose concentrations are increasing in urban areas, spurring efforts to identify the source or sources of these upward trends.
Find out more about coal-tar-based sealcoat, a potent source of PAHs to lake and streambed sediment, and related environmental health issues.
NATIONAL SUMMARIES
- Increased mercury fallout near major U.S. cities (Environ. Pollution, 2012)
- Coal-tar sealcoat largest PAH source to U.S. lakes (Sci. Total Env., 2010)
- PAH in coal tar sealcoat a national problem (Env. Sci. & Tech., 2009)
- National-scale trends in organics (Env. Sci. & Tech., 2005)
- National-scale trends in metals (Env. Tox. & Chem., 2006) associated Data Report
- Methods and age dating of cores (USGS SIR 2004-5184)
- Urban trends in PAHs (Env. Sci. & Tech., 2000)
- Rates of decrease in DDT and PCBs (Env. Sci. & Tech., 1998)
- Trends in organochlorine compounds (Env. Sci. & Tech., 1997)
TOPICAL FINDINGS
- Evaluating mercury and 210Pb atmospheric fallout and focusing to lakes (Env. Sci. & Tech., 2009)
- Effects of Hurricanes Katrina and Rita on Lake Pontchartrain sediments (Env. Sci. & Tech., 2006)
- Parking lot sealcoat: an urban source of PAHs (Env. Sci. & Tech., 2005) associated fact sheet, data report
- Chemical response to urbanization, New England, USA (Chalmers et al. 2007)
- Contaminant trends in the Mississippi River Basin (Van Metre and Horowitz 2013)
- Reservoir cores versus stream suspended sediments (Env. Sci. & Tech., 2004)
- Monitoring suspended sediment chemistry (Arch. Env. Contam. & Tox., 2003)
- Metal diagenesis in reservoir cores (J. Paleolimnology, 2000)
LOCAL RESULTS
- PAHs decline after ban on coal-tar sealcoat, Austin, TX (Env. Sci. Technol., 2014)
- Chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England (Contam. Hydro., 2007)
- Lead and zinc in greater Atlanta, Georgia (Env. Sci. & Tech., 2000)
- Trends in White Rock Lake, Texas (J. Paleolimnology, 1997)
Read about additional science related to sediment-associated contaminants and water-quality trends by following the links to web pages below.
Learn more about water quality trends as recorded in sediment cores at the publications below.
Trends in hydrophobic organic contaminants in urban and reference lake sediments across the United States, 1970-2001
Similar rates of decrease of persistent, hydrophobic and particle-reactive contaminants in riverine systems
Water-quality trends in the Rio Grande/Rio Bravo Basin using sediment cores from reservoirs
Water-quality trends in White Rock Creek Basin from 1912-1994 identified using sediment cores from White Rock Lake Reservoir, Dallas, Texas
Organochlorine compounds in a sediment core from Coralville reservoir, Iowa
Historical trends in organochlorine compounds in river basins identified using sediment cores from reservoirs
Water-quality trends using sediment cores from White Rock Lake, Dallas, Texas
- Overview
Sediment cores let us look back in time at the contaminant history of a watershed. Learn about what lake and reservoir sediment cores tell us about trends in metals, organochlorine pesticides, polycyclic aromatic hydrocarbons, and other sediment-related contaminants.
Water-quality trends can provide an assessment of the effectiveness of regulatory actions aimed at improving water quality, a warning of water-quality degradation, and an improved understanding of how human activities affect water quality.
Sediment cores—long tubes of mud—are collected from a lake or reservoir and sliced into thin intervals. Each slice represents an interval of time. By analyzing the sediments in each slice for the contaminants of interest, changes in the occurrence of contaminants and their use in the watershed can be reconstructed. The approximate date corresponding to deposition of the sediment in each slice is determined by analysis of radionuclides (cesium-137 and lead-210).
USGS studies of reconstructed trends in metals and hydrophobic organic contaminants have shed light on the effectiveness of restrictions on the use of leaded gasoline, DDT, and PCBs, and the effectiveness of the Clean Air Act in reducing concentrations of some heavy metals. The studies also have identified some contaminants, like polycyclic aromatic hydrocarbons (PAHs), whose concentrations are increasing in urban areas, spurring efforts to identify the source or sources of these upward trends.
Find out more about coal-tar-based sealcoat, a potent source of PAHs to lake and streambed sediment, and related environmental health issues.
NATIONAL SUMMARIES
- Increased mercury fallout near major U.S. cities (Environ. Pollution, 2012)
- Coal-tar sealcoat largest PAH source to U.S. lakes (Sci. Total Env., 2010)
- PAH in coal tar sealcoat a national problem (Env. Sci. & Tech., 2009)
- National-scale trends in organics (Env. Sci. & Tech., 2005)
- National-scale trends in metals (Env. Tox. & Chem., 2006) associated Data Report
- Methods and age dating of cores (USGS SIR 2004-5184)
- Urban trends in PAHs (Env. Sci. & Tech., 2000)
- Rates of decrease in DDT and PCBs (Env. Sci. & Tech., 1998)
- Trends in organochlorine compounds (Env. Sci. & Tech., 1997)
TOPICAL FINDINGS
- Evaluating mercury and 210Pb atmospheric fallout and focusing to lakes (Env. Sci. & Tech., 2009)
- Effects of Hurricanes Katrina and Rita on Lake Pontchartrain sediments (Env. Sci. & Tech., 2006)
- Parking lot sealcoat: an urban source of PAHs (Env. Sci. & Tech., 2005) associated fact sheet, data report
- Chemical response to urbanization, New England, USA (Chalmers et al. 2007)
- Contaminant trends in the Mississippi River Basin (Van Metre and Horowitz 2013)
- Reservoir cores versus stream suspended sediments (Env. Sci. & Tech., 2004)
- Monitoring suspended sediment chemistry (Arch. Env. Contam. & Tox., 2003)
- Metal diagenesis in reservoir cores (J. Paleolimnology, 2000)
LOCAL RESULTS
- PAHs decline after ban on coal-tar sealcoat, Austin, TX (Env. Sci. Technol., 2014)
- Chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England (Contam. Hydro., 2007)
- Lead and zinc in greater Atlanta, Georgia (Env. Sci. & Tech., 2000)
- Trends in White Rock Lake, Texas (J. Paleolimnology, 1997)
- Science
Read about additional science related to sediment-associated contaminants and water-quality trends by following the links to web pages below.
- Publications
Learn more about water quality trends as recorded in sediment cores at the publications below.
Trends in hydrophobic organic contaminants in urban and reference lake sediments across the United States, 1970-2001
A shift in national policy toward stronger environmental protection began in the United States in about 1970. Conversely, urban land use, population, energy consumption, and vehicle use have increased greatly since then. To assess the effects of these changes on water quality, the U.S. Geological Survey used sediment cores to reconstruct water-quality histories for38 urban and reference lakes acroAuthorsP. C. Van Metre, B.J. MahlerFilter Total Items: 42Similar rates of decrease of persistent, hydrophobic and particle-reactive contaminants in riverine systems
Although it is well-known that concentrations of anthropogenic radionuclides and organochlorine compounds in aquatic systems have decreased since their widespread release has stopped in the United States, the magnitude and variability of rates of decrease are not well-known. Paleolimnological studies of reservoirs provide a tool for evaluating these long-term trends in riverine systems. Rates of dAuthorsPeter C. Van Metre, Jennifer T. Wilson, Edward Callender, Christopher C. FullerWater-quality trends in the Rio Grande/Rio Bravo Basin using sediment cores from reservoirs
Water-quality trends reflect the relation between water quality and human activities, chronicling changes in concentrations of environmental contaminants, introduction of new contaminants, and successful efforts in environmental pollution remediation. Historical data available for analyzing trends often have severe limitations, from questionable accuracy to unknown sampling and analytic methodologAuthorsPeter C. Van Metre, B.J. Mahler, Edward C. CallenderWater-quality trends in White Rock Creek Basin from 1912-1994 identified using sediment cores from White Rock Lake Reservoir, Dallas, Texas
Historical trends in selected water-quality variables from 1912 to 1994 in White Rock Creek Basin were identified by dated sediment cores from White Rock Lake. White Rock Lake is a 4.4-km2 reservoir filled in 1912 and located on the north side of Dallas, Texas, with a drainage area of 259 km2. Agriculture dominated land use in White Rock Creek Basin before about 1950. By 1990, 72% of the basin wasAuthorsP. C. Van Metre, E. CallenderOrganochlorine compounds in a sediment core from Coralville reservoir, Iowa
No abstract available.AuthorsS. J. Kalkhoff, Peter C. Van MetreHistorical trends in organochlorine compounds in river basins identified using sediment cores from reservoirs
This study used chemical analyses of dated sediment cores from reservoirs to define historical trends in water quality in the influent river basins. This work applies techniques from paleolimnology to reservoirs, and in the process, highlights differences between sediment-core interpretations for reservoirs and natural lakes. Sediment cores were collected from six reservoirs in the central and souAuthorsP. C. Van Metre, E. Callender, C. C. FullerWater-quality trends using sediment cores from White Rock Lake, Dallas, Texas
The U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program has three objectives, one of which is "to define trends (or lack of trends) in water quality" (Leahy and others, 1990). Water-quality trends are of interest for at least three reasons: First, trends can improve our understanding of the influence of human activities on water-quality conditions; second, trends can indicateAuthorsPeter C. Van Metre, Larry F. Land, C.L. Braun