River-borne nutrients, especially nitrogen, contribute to water-quality degradation in Long Island Sound. The Connecticut River is the largest tributary to the Sound, and quantification of nutrient loads from the three upper States in the watershed, as well as the State of Connecticut, is essential for prioritizing efforts to improve the Sound’s water quality.
In order to distinguish the combined nutrient load from the upper watershed States (New Hampshire, Vermont, and Massachusetts) from the State of Connecticut load, a new USGS monitoring station has been established for continuous streamflow measurement and weekly nutrient sampling at the Connecticut River at Northfield, MA, near the MA/NH/VT border. Sampling is also continuing at the MA/CT State line, at the existing Connecticut River at Thompsonville, CT station. The specific project objectives are to:
- Install, operate, and maintain a side-looking acoustic Doppler velocity meter (ADVM) at the Northfield, MA site, for measurement of streamflow.
- Collect weekly cross-sectional, composite water-quality samples for total and dissolved nitrogen and phosphorus constituents and standard field parameters. Document weather conditions for the 48 hours prior to sample collection.
- Increase sampling frequency at the Thompsonville, CT station to weekly, to match that of the Northfield station. Collect Thompsonville samples 24 to 30 hours after the Northfield samples, to account for the average travel time of a parcel of water between the two sites.
- Develop a workplan for continued monitoring for a total of five years of data collection. Prepare an interpretative report describing nutrient loads at the Northfield site after three years of data collection.
Below are publications associated with this project.
Nutrient, organic carbon, and chloride concentrations and loads in selected Long Island Sound tributaries—Four decades of change following the passage of the Federal Clean Water Act
Below are partners associated with this project.
- Overview
River-borne nutrients, especially nitrogen, contribute to water-quality degradation in Long Island Sound. The Connecticut River is the largest tributary to the Sound, and quantification of nutrient loads from the three upper States in the watershed, as well as the State of Connecticut, is essential for prioritizing efforts to improve the Sound’s water quality.
In order to distinguish the combined nutrient load from the upper watershed States (New Hampshire, Vermont, and Massachusetts) from the State of Connecticut load, a new USGS monitoring station has been established for continuous streamflow measurement and weekly nutrient sampling at the Connecticut River at Northfield, MA, near the MA/NH/VT border. Sampling is also continuing at the MA/CT State line, at the existing Connecticut River at Thompsonville, CT station. The specific project objectives are to:
- Install, operate, and maintain a side-looking acoustic Doppler velocity meter (ADVM) at the Northfield, MA site, for measurement of streamflow.
- Collect weekly cross-sectional, composite water-quality samples for total and dissolved nitrogen and phosphorus constituents and standard field parameters. Document weather conditions for the 48 hours prior to sample collection.
- Increase sampling frequency at the Thompsonville, CT station to weekly, to match that of the Northfield station. Collect Thompsonville samples 24 to 30 hours after the Northfield samples, to account for the average travel time of a parcel of water between the two sites.
- Develop a workplan for continued monitoring for a total of five years of data collection. Prepare an interpretative report describing nutrient loads at the Northfield site after three years of data collection.
- Install, operate, and maintain a side-looking acoustic Doppler velocity meter (ADVM) at the Northfield, MA site, for measurement of streamflow.
- Publications
Below are publications associated with this project.
Nutrient, organic carbon, and chloride concentrations and loads in selected Long Island Sound tributaries—Four decades of change following the passage of the Federal Clean Water Act
Trends in long-term water-quality and streamflow data from 14 water-quality monitoring sites in Connecticut were evaluated for water years 1974–2013 and 2001–13, coinciding with implementation of the Clean Water Act of 1972 and the Connecticut Nitrogen Credit Exchange program, as part of an assessment of nutrient and chloride concentrations and loads discharged to Long Island Sound. In this study, - Partners
Below are partners associated with this project.