Santoro, E. Delaware River Basin Commission, esantoro@drbc.state.nj.us
Sharp, J. College of Marine Studies, University of Delaware, jsharp@cms.udel.edu

 
LONG TERM IMPROVEMENT IN WATER QUALITY IN THE DELAWARE ESTUARY
 
The Delaware River Basin Commission's Boat Run Program is one of the most consistent and oldest water quality programs in the Country. Since 1967 samples have been collected on a consistent frequency along the mainstem of the Delaware River and Bay. Historically, ambient water quality monitoring from this program has served as an indicator of regulatory compliance toward managing urban and industrial pollution inputs. The data show a great improvement in many aspects of water quality. Over a 30-year period from 1967 - 1997 dissolved oxygen levels have increased from minimum (summer) levels of approximately 1 mg/l in the vicinity of Philadelphia, Pennsylvania, prior to 1980, to minimum oxygen levels of 3.5 to 4.0 mg/l after 1989. Since that time, oxygen concentrations, which are often close to atmospheric saturation, remain stable. Fecal coliform and Enterococcus bacteria level over the period 1989-1997 have shown a significant decline. Ammonium nitrogen has also shown a large decline over the period of record, with much of the decline coinciding with increased nitrate nitrogen. The total inorganic nitrogen (ammonium and nitrate) concentration is slightly lower today than in the late 1960s. Total phosphorus declined dramatically in the early 1970s. Concentrations of both nitrogen and phosphorus remain stable today and, although concentrations are high, there is no indication of problems from these nutrients.
 
Day: Tuesday, Feb. 2
Time: Poster
Location: Sweeney Center
 
Code: SS47TU0503S