The Research Triangle area, located within the upper Cape Fear and Neuse River basins, is one of the most rapidly developing areas in the Nation. Growth has increased demand for water from public suppliers, the majority of which draw water from streams and lakes in the region. Growth also brings the threat of greater loads of contaminants and new contaminant sources that, if not properly managed, could adversely affect water quality.
In 1988, several local governments, with assistance from Triangle J Council of Governments (TJCOG), formed the Triangle Area Water Supply Monitoring Project. With cooperative assistance from the U.S. Geological Survey (USGS), the Project has tracked water-quality conditions and trends in many of the area's water-supply reservoirs, rivers, and selected tributaries since October 1988.
The project recently received a 2017 National Association of Development Organizations (NADO) Innovation Award, which honors creative approaches to advancing regional community and economic development and improved quality of life. (2017 NADO Innovation Award Winners)
Background:
Concerns about lake eutrophication and contaminants that affect drinking-water quality have remained priorities since the Project began. Additional concerns have been addressed as they arose. Pesticides and PCBs, pharmaceuticals and other emerging contaminants, disinfection by-products, microbial pathogens such as Cryptosporidium and Giardia, mercury, and cyanotoxins also have been investigated during previous phases, and a series of USGS reports have been published. The sustainability of water supplies depends on water availability as well as water quality; therefore, 10 streamflow-gaging stations are also supported by the Project.
New public health concerns have recently emerged in the Triangle area related to probable carcinogens in drinking water. From 2014-2016, high levels of bromide and 1,4-dioxane were reported in portions of the Cape Fear River basin; however, information is lacking for many of the water-supply sources in the Triangle area. Bromide supports the formation of brominated trihalomethanes. 1,4-dioxane is an organic solvent that is a probable human carcinogen. No Triangle area data are available for hexavalent chromium, another constituent of concern. Water suppliers need additional information for these constituents; therefore, the USGS is investigating their occurrence and distribution in Triangle area water supplies while continuing the long-term monitoring program for conventional water-quality constituents.
Objective:
The project currently is in Phase VIII, which spans the period July 2017-June 2022. Water-quality and hydrologic monitoring from Phase VII will continue, with the addition of constituents of current concern to municipal water suppliers. Specific objectives for Phase VIII are to:
- Continue monitoring major ions, nutrients, suspended sediment, and chlorophyll a to document water-quality conditions throughout the study area and to provide data that can be used in the future to evaluate loads to reservoirs and water-quality trends.
- Investigate additional constituents of concern to local water suppliers, including bromide, chromium (hexavalent, trivalent, and total), and 1,4-dioxane.
- Operate a network of 10 continuous-streamflow stations and make the data available in real time at https://waterdata.usgs.gov/nc/nwis/rt.
Approach:

The USGS samples 9 lake sites and 4 stream sites six times per year. Dissolved oxygen, pH, water temperature, specific conductance, turbidity, nutrients, major ions (including bromide), chromium fractions, and 1,4-dioxane are sampled at all sites. In addition, suspended sediment is monitored at stream sites. Chlorophyll, water clarity, iron, and manganese are measured at lake sites. Eight additional streams in the study area are sampled by the North Carolina Department of Environmental Quality (DEQ) as part of their Ambient Monitoring System. The USGS samples these sites during selected storm events on a rotational basis. As part of this project, the USGS also operates continuous-record streamflow gaging stations at 10 stream sites.
Quality-assurance measures include the use of clean sampling techniques, collection of numerous quality-control samples, and extensive data review. Samples are analyzed by the USGS National Water Quality Laboratory in Denver, Colorado, the USGS Eastern Region Sediment Laboratory in Louisville, Kentucky, and the USGS Redox Chemistry Laboratory in Boulder, Colorado. All data are permanently stored and made available to the public online through the USGS National Water Information System.
Long-term water-quality trends in the study area are currently being evaluated and will be published in a USGS Scientific Investigations Report. Water-quality constituents that will be analyzed for trends include nitrogen and phosphorus species, suspended sediment, chlorophyll, and selected major ions .
Below are publications associated with this project.
Occurrence and distribution of mercury in streams and reservoirs in the Triangle Area of North Carolina, July 2007–June 2009
Triangle Area Water Supply Monitoring Project, North Carolina—Summary of monitoring activities, quality assurance, and data, October 2017–September 2019
Triangle area water supply monitoring project, North Carolina-Summary of monitoring activities, quality assurance, and data, October 2015–September 2017
Trends in water quality of selected streams and reservoirs used for water supply in the Triangle area of North Carolina, 1989–2013
Triangle Area Water Supply Monitoring Project, North Carolina—Summary of monitoring activities, quality assurance, and data, October 2013–September 2015
Quality of surface-water supplies in the Triangle Area of North Carolina, water years 2012–13
Quality of surface-water supplies in the Triangle area of North Carolina, water years 2010-11
Quality of surface-water supplies in the Triangle area of North Carolina, water year 2009
Quality of surface-water supplies in the Triangle area of North Carolina, water year 2008
Occurrence of Organic Wastewater Compounds in Selected Surface-Water Supplies, Triangle Area of North Carolina, 2002-2005
Triangle area water supply monitoring project, October 1988 through September 2001, North Carolina -- description of the water-quality network, sampling and analysis methods, and quality-assurance practices
Water-quality trends for streams and reservoirs in the Research Triangle area of North Carolina, 1983-95
Below is a map and data links associated with this project.
Below are partners associated with this project.
- Overview
The Research Triangle area, located within the upper Cape Fear and Neuse River basins, is one of the most rapidly developing areas in the Nation. Growth has increased demand for water from public suppliers, the majority of which draw water from streams and lakes in the region. Growth also brings the threat of greater loads of contaminants and new contaminant sources that, if not properly managed, could adversely affect water quality.
In 1988, several local governments, with assistance from Triangle J Council of Governments (TJCOG), formed the Triangle Area Water Supply Monitoring Project. With cooperative assistance from the U.S. Geological Survey (USGS), the Project has tracked water-quality conditions and trends in many of the area's water-supply reservoirs, rivers, and selected tributaries since October 1988.
The project recently received a 2017 National Association of Development Organizations (NADO) Innovation Award, which honors creative approaches to advancing regional community and economic development and improved quality of life. (2017 NADO Innovation Award Winners)
Background:
Jessica Cain and Ryan Rasmussen, Hydrologic Technicians, measure water quality at Jordan Lake, 2016. (Public domain.) Concerns about lake eutrophication and contaminants that affect drinking-water quality have remained priorities since the Project began. Additional concerns have been addressed as they arose. Pesticides and PCBs, pharmaceuticals and other emerging contaminants, disinfection by-products, microbial pathogens such as Cryptosporidium and Giardia, mercury, and cyanotoxins also have been investigated during previous phases, and a series of USGS reports have been published. The sustainability of water supplies depends on water availability as well as water quality; therefore, 10 streamflow-gaging stations are also supported by the Project.
Cane Creek Reservoir, Orange County, NC, 2003(Public domain.) New public health concerns have recently emerged in the Triangle area related to probable carcinogens in drinking water. From 2014-2016, high levels of bromide and 1,4-dioxane were reported in portions of the Cape Fear River basin; however, information is lacking for many of the water-supply sources in the Triangle area. Bromide supports the formation of brominated trihalomethanes. 1,4-dioxane is an organic solvent that is a probable human carcinogen. No Triangle area data are available for hexavalent chromium, another constituent of concern. Water suppliers need additional information for these constituents; therefore, the USGS is investigating their occurrence and distribution in Triangle area water supplies while continuing the long-term monitoring program for conventional water-quality constituents.
Objective:
The project currently is in Phase VIII, which spans the period July 2017-June 2022. Water-quality and hydrologic monitoring from Phase VII will continue, with the addition of constituents of current concern to municipal water suppliers. Specific objectives for Phase VIII are to:
Jason Fine, Hydrologist, collects storm-runoff samples at Flat River, 2003.(Public domain.) - Continue monitoring major ions, nutrients, suspended sediment, and chlorophyll a to document water-quality conditions throughout the study area and to provide data that can be used in the future to evaluate loads to reservoirs and water-quality trends.
- Investigate additional constituents of concern to local water suppliers, including bromide, chromium (hexavalent, trivalent, and total), and 1,4-dioxane.
- Operate a network of 10 continuous-streamflow stations and make the data available in real time at https://waterdata.usgs.gov/nc/nwis/rt.
Approach:
Sources/Usage: Public Domain. Visit Media to see details.Ryan Rasmussen and Cassandra Pfeifle, Hydrologic Technicians, collect samples at Little River Reservoir, 2009. (Public domain.) The USGS samples 9 lake sites and 4 stream sites six times per year. Dissolved oxygen, pH, water temperature, specific conductance, turbidity, nutrients, major ions (including bromide), chromium fractions, and 1,4-dioxane are sampled at all sites. In addition, suspended sediment is monitored at stream sites. Chlorophyll, water clarity, iron, and manganese are measured at lake sites. Eight additional streams in the study area are sampled by the North Carolina Department of Environmental Quality (DEQ) as part of their Ambient Monitoring System. The USGS samples these sites during selected storm events on a rotational basis. As part of this project, the USGS also operates continuous-record streamflow gaging stations at 10 stream sites.
Quality-assurance measures include the use of clean sampling techniques, collection of numerous quality-control samples, and extensive data review. Samples are analyzed by the USGS National Water Quality Laboratory in Denver, Colorado, the USGS Eastern Region Sediment Laboratory in Louisville, Kentucky, and the USGS Redox Chemistry Laboratory in Boulder, Colorado. All data are permanently stored and made available to the public online through the USGS National Water Information System.
Long-term water-quality trends in the study area are currently being evaluated and will be published in a USGS Scientific Investigations Report. Water-quality constituents that will be analyzed for trends include nitrogen and phosphorus species, suspended sediment, chlorophyll, and selected major ions .
- Publications
Below are publications associated with this project.
Filter Total Items: 16Occurrence and distribution of mercury in streams and reservoirs in the Triangle Area of North Carolina, July 2007–June 2009
During the time period 2001–2006, the U.S. Geological Survey reported mercury-concentration measurements that exceeded the North Carolina water-quality criterion (NCWQC) of 0.012 microgram per liter for total recoverable mercury in streams and reservoirs across the Triangle Area of North Carolina. Mercury data were sparse, however, generally consisting of only one or two water samples per year. AdAuthorsAnna M. McKee, Sharon Fitzgerald, Mary J. GiorginoTriangle Area Water Supply Monitoring Project, North Carolina—Summary of monitoring activities, quality assurance, and data, October 2017–September 2019
Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of local governments have tracked water-quality conditions and trends in several of the area’s water-supply lakes and streams. This report summarizes data collAuthorsCassandra A. Pfeifle, Jessica L. Cain, Ryan B. RasmussenTriangle area water supply monitoring project, North Carolina-Summary of monitoring activities, quality assurance, and data, October 2015–September 2017
Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of local governments have tracked water-quality conditions and trends in several of the area’s water-supply lakes and streams. This report summarizes data collAuthorsCassandra A. Pfeifle, Jessica L. Cain, Ryan B. RasmussenTrends in water quality of selected streams and reservoirs used for water supply in the Triangle area of North Carolina, 1989–2013
As the population of the Triangle area in central North Carolina increases, the demand for good quality drinking water from streams and lakes within the upper Neuse and upper Cape Fear River Basins also increases. The Triangle area includes Raleigh, Cary, Research Triangle Park, Durham, Chapel Hill, and the surrounding communities. The U.S. Geological Survey examined temporal trends in water qualiAuthorsMary J. Giorgino, Thomas F. Cuffney, Stephen L. Harden, Toby D. FeasterTriangle Area Water Supply Monitoring Project, North Carolina—Summary of monitoring activities, quality assurance, and data, October 2013–September 2015
Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of local governments have tracked water-quality conditions and trends in several of the area’s water-supply lakes and streams. This report summarizes data collAuthorsC.A. Pfeifle, J.L. Cain, R.B. RasmussenQuality of surface-water supplies in the Triangle Area of North Carolina, water years 2012–13
Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of local governments have tracked water-quality conditions and trends in several of the area’s water-supply lakes and streams. This report summarizes data collAuthorsC.A. Pfeifle, J.L. Cain, R.B. RasmussenQuality of surface-water supplies in the Triangle area of North Carolina, water years 2010-11
Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of local governments have tracked water-quality conditions and trends in several of the area’s water-supply lakes and streams. This report summarizes data collAuthorsC.A. Pfeifle, J.L. Cain, R.B. RasmussenQuality of surface-water supplies in the Triangle area of North Carolina, water year 2009
Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of governments have tracked water-quality conditions and trends in several of the area’s water-supply lakes and streams. This report summarizes data collectedAuthorsC. A. Pfeifle, M. J. Giorgino, R. B. RasmussenQuality of surface-water supplies in the Triangle area of North Carolina, water year 2008
Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of governments have tracked water-quality conditions and trends in several of the area's water-supply lakes and streams. This report summarizes data collectedAuthorsM. J. Giorgino, R.B. Rasmussen, C.A. PfeifleOccurrence of Organic Wastewater Compounds in Selected Surface-Water Supplies, Triangle Area of North Carolina, 2002-2005
Selected organic wastewater compounds, such as household, industrial, and agricultural-use compounds, sterols, pharmaceuticals, and antibiotics, were measured at eight sites classified as drinking-water supplies in the Triangle Area of North Carolina. From October 2002 through July 2005, seven of the sites were sampled twice, and one site was sampled 28 times, for a total of 42 sets of environmentAuthorsM. J. Giorgino, R.B. Rasmussen, C.M . PfeifleTriangle area water supply monitoring project, October 1988 through September 2001, North Carolina -- description of the water-quality network, sampling and analysis methods, and quality-assurance practices
The Triangle Area Water Supply Monitoring Project was initiated in October 1988 to provide long-term water-quality data for six area water-supply reservoirs and their tributaries. In addition, the project provides data that can be used to determine the effectiveness of large-scale changes in water-resource management practices, document differences in water quality among water-supply types (largeAuthorsCarolyn J. OblingerWater-quality trends for streams and reservoirs in the Research Triangle area of North Carolina, 1983-95
Water-quality and streamflow monitoring data, collected from 1983 to 1995, were analyzed for 34 stream and reservoir sites in a seven- county region within the upper Neuse and upper Cape Fear River Basins. Early data (1983-88) were compiled from U.S. Geological Survey water- quality studies and from the ambient water-quality monitoring network of the North Carolina Department of Environment, HealtAuthorsC.J. Childress, Neeti Bathala - Web Tools
Below is a map and data links associated with this project.
- Partners
Below are partners associated with this project.