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Chemistry of Wet and Dry Fall to Lower Chesapeake Bay |
The Chemistry of Wet and Dry Fall to Lower Chesapeake Bay study, and its companion Maryland project, evaluated the importance of atmospheric sources of nutrients, acids, and toxic substances to the Chesapeake Bay. The study's objectives were to determine concentrations of nutrients, acids and selected toxic substances in wet deposition in order to evaluate seasonal variability, and estimate total annual inputs of these constituents to the Lower Chesapeake Bay.
Four sampling stations were established to provide representative spatial coverage of the lower Chesapeake Bay. Stations, all of which were located in Virginia, were located in Norfolk, Gloucester Point, Kilmarnock (on the western side of the Chesapeake) and Cedar View (on the Eastern Shore of the Chesapeake). The report provides landuse information about the monitoring locations, which includes the following:
- The Norfolk Station was located at Old Dominion University approximately 20 m off the ground. The area around Old Dominion is urban and includes several major industries that may contribute to the pollution burden of the Tidewater area. This station was selected to represent an urban environment.
- The Gloucester Point Station was located at the Virginia Institute of Marine Science on the North Shore of the York River. Samplers were located approximately 10 m above the ground and may have been effected by both regional and local sources of hydrocarbons, including an electric generating station and an oil refinery. There was also an oil boiler located on the far end of the building from where the samplers were positioned, however, the study reports that this did not appeare to have a significant impact.
- The Kilmarnock Station was located in a small town in an area that is dominated by agriculture and fishing. The samplers were located on a 20-m tower near the center of the town.
- The Cedar View Station was located on the banks of the Nandua Creek in an area that did not appear to have any sources of combustion-related contamination. Agriculture and fishing are the dominant occupations in this area.
Precipitation monitoring occurred at these stations for approximately 54 weeks, or slightly more than a year between December 1981 and January 1982. A total of 152 samples were collected, however some lacked sufficient sample volume to analyze, thus 129 samples were included in this analysis. Samples were analyzed for pH, major anions, metals (Na, K, Mg, Ca, Fe, Mn, Be, Cd, Cr, Cu, Ni, Pb, Zn), nutrients (NO2, NO3, NH4, PO4, SiO2), acidity, and total organic carbon. Specifics about sampler construction are not provided in this document, and it is stated that samples were analyzed by standard methods. Quality assurance procedures were undertaken for analysis methods. Analytical methods and QA results are presented in tables in this report.