Point Source Atlas
- Published:
- August 1, 1988
- Originator:
- Chesapeake Bay Program
- Categorized in:
- Report
A computerized data base of Chesapeake Bay point source discharges has been developed to document information on point source pollutant input to the Bay. Installed on the Chesapekae Bay Program computer and available to registered users, the Chesapeake Bay point source data base (Atlas 85) provides a central repository for locational and administrative data on almost 6,000 point source dischargers located in the commonwealths of Virginia and Pennsylvania, the states of Maryland, New York, West Virginia and Delaware and the District of Columbia.
Point sources of pollution are defined as municipal and industrial plants that discharge waste to a water body from a discrete pipe or ditch. Municipal Point sources are wastewater treatment plants that receive and treat both domestic wastewater and wastewater generated by local commercial and industrial activities. These wastewaters contain large amounts of organic matter, including nutrients such as phosphorus and nitrogen, that man cause significant depletion of dissolved oxygen (DO) in the receiving stream. Heavy metals, chlorinated hydrocarbons and other toxic substances may also be present.
Industrial point sources are commercial and industrial plants that carry out diverse and complex manufacturing processes which require solvents, catalysts, and other chemicals that contaminate discharged wastewater. These wastewaters may also contain large amounts of oxygen-demanding substances. In the Bay watershed, there are 461 different types of industrial activity, including coal mining, iron and steel production, electric power generation, seafood processing, inorganic and organic chemical manufacturing, concrete manufacturing and petroleum refining.
The point source data base contains information on 1345 municipal dischargers and 4651 industrial dischargers. Of these, 205 municipal and 192 industrial dischargers have been designated as major dischargers. The location and distribution of major dischargers are displayed in Figure 1. It is important to note that this point source map shows only the general location of sources and is intended primarily to illustrate the number and geographic distribution of selected categories of point sources.
The point source data base provides 1985 wastewater characteristics for more than 500 municipal dischargers and estimates nutrient and toxicant wastewater concentrations for 93 different types of industrial activities with the potential to generate and discharge these pollutants.
The information in the point source date base was initially compiled from federal data bases such as the Environmental Protection Agency (EPA) Needs Survey and Permit Compliance System; it was then refined and expanded with state and facility data. A more complete description of date sources may be found in the data base documentation file available from the Chesapeake Bay Liaision Office.
All effluent data are annual averages for the calendar year 1985. As such, the information in the data base serves as the baseline from which progress towards meeting the Bay Agreement commitment to reduce nutrient loads, reduce toxic discharges and control conventional pollutants can be measured. Importantly, municipal wastewater characteristics and industrial niutrient loads are consistent with state estimates presented in state nutrient reduction strategies (April 1988). These estimates include industrial nutrient sources not available during preparation of the report, A Commitment Renewed (Implementation Committee, February 1988). As a result, industrial nutrient loads (and percentages of point source total) are slightly higher than those cited in the earlier report.