Principal Investigator Harold Hemond
Many coastal waters are currently being degraded by anthropogenic nitrogen inputs, with loss of fishes and shellfish being one direct result. While the Chesapeake Bay is a well-known example, similar losses are occurring in the coastal waters of Cape Cod. The sources of nitrogen include septic discharge and lawn fertilizer associated with development, and acidic deposition. Some of this nitrogen is transmitted to the coastal waters via groundwater flow.
In this project, we seek to determine the efficiency with which transmission of nitrogen via groundwater occurs, and in particular the extent to which denitrification lessens the nitrogen burden of groundwater as it moves shoreward. The research approach focuses the nitrogen in septic leachate, using N-15 measurements and NZ-Ar ratios to infer the magnitude of denitrification.