![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Pollutant Loading Data Dictionary
Visit EPA's Pollutant Loading Tool information page to learn more about the Pollutant Loading Tool and how to integrate loadings data into your search results.
Definition of Pollutant Loading Data Fields
Pollutant columns that are integrated into the search results will always be pulled from the most recent year of Loading data available. To view earlier years of data, visit the Detailed Pollutant Loading Report.
Reporting Year - The year the discharge was reported. Data is available for the years 2007 through 2011.
Total Pounds Discharged - Annual mass discharge of pollutants to a receiving stream (in units of pounds) calculated using the methodology described in Section 3.3 of the Technical Users Background Document for the DMR Pollutant Loading Tool.
Total Pounds Discharged - Metals - Annual mass discharge of metals pollutants to a receiving stream (in units of pounds) calculated using the methodology described in Section 3.3 of the Technical Users Background Document for the DMR Pollutant Loading Tool.
Total Pounds Discharged - Nitrogen - Annual mass discharge of nitrogen pollutants to a receiving stream (in units of pounds) calculated using the methodology described in Section 3.3 of the Technical Users Background Document for the DMR Pollutant Loading Tool.
Total Pounds Discharged - Organic Enrichment - Annual mass discharge of organic enrichment pollutants to a receiving stream (in units of pounds) calculated using the methodology described in Section 3.3 of the Technical Users Background Document for the DMR Pollutant Loading Tool.
Total Pounds Discharged - Phosphorus - Annual mass discharge of phosphorus pollutants to a receiving stream (in units of pounds) calculated using the methodology described in Section 3.3 of the Technical Users Background Document for the DMR Pollutant Loading Tool.
Total Pounds Discharged - Priority Pollutants - Annual mass discharge of priority pollutants to a receiving stream (in units of pounds) calculated using the methodology described in Section 3.3 of the Technical Users Background Document for the DMR Pollutant Loading Tool.
Total Pounds Discharged - Solids - Annual mass discharge of solids pollutants to a receiving stream (in units of pounds) calculated using the methodology described in Section 3.3 of the Technical Users Background Document for the DMR Pollutant Loading Tool.
Total TWPE Discharged - The relative toxicities of different pollutant discharges (in units of TWPE) to a receiving stream in a year. TWPE is calculated by multiplying the pollutant mass (in pounds) by its toxic weighting factor. This value is not a measure of risk or potential for human health impacts but is a relative measure of the potential toxicity between pollutant discharges.
Total TWPE Discharged - Metals - The relative toxicities of different metals pollutant discharges (in units of TWPE) to a receiving stream in a year. TWPE is calculated by multiplying the pollutant mass (in pounds) by its toxic weighting factor. This value is not a measure of risk or potential for human health impacts but is a relative measure of the potential toxicity between pollutant discharges.
Total TWPE Discharged - Priority Pollutants - The relative toxicities of priority pollutant discharges (in units of TWPE) to a receiving stream in a year. TWPE is calculated by multiplying the pollutant mass (in pounds) by its toxic weighting factor. This value is not a measure of risk or potential for human health impacts but is a relative measure of the potential toxicity between pollutant discharges.
Pathogen Indicators Average Concentration - The average pathogen indicators concentration for a calendar year calculated as the arithmetic average of the average pollutant concentrations for all monitoring periods in the calendar year (in units of count/100mL).
Pathogen Indicators Max Concentration - The maximum of the average monitoring period concentrations for pathogen indicators in a reporting year (in units of count/100mL). For example, if a facility reports monthly average discharge concentrations, the maximum facility concentration is the maximum of the reported monthly average concentrations.
Average Temperature - The average of monitoring period wastewater temperatures in a reporting year (in degrees Fahrenheit). For example, if a facility reports monthly average temperatures, the annual average facility temperature is the arithmetic average of the reported monthly average temperatures.
Max Temperature - The maximum of the average monitoring period wastewater temperatures in a reporting year (in degrees Fahrenheit). For example, if a facility reports monthly average temperatures, the maximum facility temperature is the maximum of the reported monthly average temperatures.
Average Daily Wastewater Flow - The average of monitoring period flows in a reporting year (in units of millions of gallons per day). For example, if a facility reports monthly wastewater flows, the facility average flow is the arithmetic average of the reported monthly wastewater flows.
Total Annual Wastewater Flow - The total annual wastewater volume (in units of millions of gallons) in a reporting year.
Top Pollutant by Pounds - The name used in ICIS-NPDES to identify the substance with the highest discharge by pounds for this facility in the reporting period.
Pounds Discharged by Top Pollutant by Pounds - The highest annual mass discharge of pollutants to a receiving stream for this facility (in units of pounds) calculated using the methodology described in Section 3.3 of the Technical Users Background Document for the DMR Pollutant Loading Tool.
Top Pollutant by TWPE - The name used in ICIS-NPDES to identify the substance with the highest discharge by TWPE for this facility in the reporting period.
TWPE Discharged by Top Pollutant by TWPE - The highest relative toxicity of different pollutant discharges (in units of TWPE) to a receiving stream for this facility in the reporting period. TWPE is calculated by multiplying the pollutant mass (in pounds) by its toxic weighting factor. This value is not a measure of risk or potential for human health impacts but is a relative measure of the potential toxicity between pollutant discharges.