Open-File Report 2007–1040
U.S. Geological Survey Open-File Report 2007–1040
By Gerard McMahon, Larinda Tervelt, and William Donehoo
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This report describes an approach for estimating annual total nitrogen and total phosphorus loads from point-source dischargers in the southeastern United States. Nutrient load estimates for 2002 were used in the calibration and application of a regional nutrient model, referred to as the SPARROW (SPAtially Referenced Regression On Watershed attributes) watershed model. Loads from dischargers permitted under the National Pollutant Discharge Elimination System were calculated using data from the U.S. Environmental Protection Agency Permit Compliance System database and individual state databases. Site information from both state and U.S. Environmental Protection Agency databases, including latitude and longitude and monitored effluent data, was compiled into a project database. For sites with a complete effluent-monitoring record, effluent-flow and nutrient-concentration data were used to develop estimates of annual point-source nitrogen and phosphorus loads. When flow data were available but nutrient-concentration data were missing or incomplete, typical pollutant-concentration values of total nitrogen and total phosphorus were used to estimate load. In developing typical pollutant-concentration values, the major factors assumed to influence wastewater nutrient-concentration variability were the size of the discharger (the amount of flow), the season during which discharge occurred, and the Standard Industrial Classification code of the discharger. One insight gained from this study is that in order to gain access to flow, concentration, and location data, close communication and collaboration are required with the agencies that collect and manage the data. In addition, the accuracy and usefulness of the load estimates depend on the willingness of the states and the U.S. Environmental Protection Agency to provide guidance and review for at least a subset of the load estimates that may be problematic.
Abstract
Introduction
Purpose and Scope
Use of Point-Source Nutrient Load Estimates in SPARROW
Challenges in Developing Point-Source Nutrient Load Estimates
Acknowledgments
Methods of Investigation
Developing a Site File by Using the Permit Compliance System and State Databases
Retrieving Monitoring Data from the Permit Compliance System and State Databases
Importing Data into a Common Database
Preparing Data for Load Estimation
Estimating Annual Nutrient Load in Wastewater Discharge
Quality Assuring Estimates of Nutrient Load in Wastewater Discharges
Summary
References Cited
Attachment 1: PCS Data Retrieval Routine
Attachment 2: PCS Data Import Program
Attachment 3: North Carolina Data Import Program
Attachment 4: Data Preparation Program
Attachment 5: Typical Pollutant-Concentration Program
Attachment 6: Load Calculation Program
Attachment 7: Load Summary Program
Attachment 8: Flow Magnitude Checking Program
Suggested Citation: McMahon, Gerard, Tervelt, Larinda, and Donehoo, William, 2007, Methods for estimating annual wastewater nutrient loads in the southeastern United States: U.S. Geological Survey Open-File Report 2007–1040, 81 p.
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URL: https://pubsdata.usgs.gov/pubs/of/2007/1040/index.html
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Page Last Modified: Wednesday, 07-Dec-2016 20:10:58 EST
