Development of Nutrient TMDLs for the Raritan River Basin

The Raritan River Basin Nutrient TMDL study is being performed by TRC Omni Environmental Corporation on behalf of the Rutgers University New Jersey EcoComplex.  The project is designed to help New Jersey Department of Environmental Protection address phosphorus and other conventional impairments in the Raritan River Basin, namely total suspended solids, pH, temperature, and dissolved oxygen.  Extensive data collection was performed during this study, the purpose of which was to provide data necessary to evaluate nutrient chemistry and use impairment, as well as provide data necessary for the modeling work that is currently underway.  Sampling was performed at 88 stream, lake, and sewage treatment plant locations throughout the Raritan River basin.  Sampling events included high-flow, low-flow, diurnal monitoring, periphyton, and stormwater.  TRC Omni began the sampling phase of this project in May 2004 and completed the final low-flow sampling event on August 4-5, 2005.

Results from this study indicate that nonpoint sources associated with various land uses exert a profound impact on stream quality through both stormwater and baseflow in the Raritan River watershed.  In addition, the data clearly show the impact of streambank erosion on suspended solids in the streams.  Many sections of the North and South Branch Raritan River experience extreme streambank erosion, as seen in the photograph below of the North Branch Raritan River in Bridgewater.