Watershed Statistics Help

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Instructions

Select a reporting year and watershed criteria to download data about facilities and wastewater discharges located within a watershed(s). This search is particularly useful for watershed modelers and mapping applications. Select a "Download" button to generate a comma-separated values (CSV) file.

  • Download Watershed File: facility counts and loadings for the selected watershed(s).
  • Download Facility File: facility attribute information (e.g., facility name, unique identifiers, address) for the selected watershed(s).

Facilities are aggregated to the Facility Registry Service (FRS) ID. FRS identifies a facility by assigning an identification number (FRS ID), and uses this ID to link together EPA regulatory program database records. Note that FRS IDs may link to one or more NPDES IDs or TRIFIDs. As a result, the counts displayed in the Watershed Statistics downloads may not match counts in the results of a Water Pollution Search , as the Water Pollution Search identify facilities by NPDES ID or TRIFID.

Search Criteria

Search criteria are organized by the order they appear on the page.

Select Reporting Year
The calendar year for the pollutant loadings.
Search Considerations: The Loading Tool extracts the year from the monitoring period dates associated with DMR measurements in ICIS-NPDES. Dates are included for all DMR measurements. See About Loading Tool Data for information about DMR data completeness.
Watershed
Nationwide
Search for all watershed loadings or facilities across the Unites States., without restrictions on location.
Search by Watershed
Search for watershed loadings or facilities for specific watersheds. The Loading Tool offers searching for watersheds by several boundary classifications, as described below.
HUC Region
Select a region 2-digit Hydrologic Unit Code (HUC) from the dropdown menu. Two-digit HUCs classify the United States into 21 major geographic areas, or regions. These geographic areas contain either the drainage area of a major river, or the combined drainage areas of a series of rivers. For more information, see Hydrologic Unit Maps. To learn more about how the Loading Tool obtains watershed information for facilities, see Watershed Data and Maps.
Watershed ID (2-Digit to 12-Digit HUC)
Enter one or more 2- to 12-digit HUCs. Separate multiple codes by a comma or carriage return.
For more information about HUCs and how the Loading Tool obtains watershed information, see Watershed Data and Maps.
Major U.S. Watersheds
Search watershed boundaries defined by several programs. Select a watershed boundary group from the first dropdown, then select a specific watershed of interest in the second dropdown.
Major Watersheds: the Albemarle and Pamlico Sounds, Chesapeake Bay, Columbia River Basin, Delaware Bay, Delaware River Basin, Great Lakes, Long Island Sound, Lower Columbia River Basin, Mississippi-Atchafalaya River Basin, Mobile Bay, Puget Sound, San Francisco Bay, and Tampa Bay. Many of these watersheds consist of several HUC-12 codes. Maps of these watersheds are available from HUC Maps and Codes for Major U.S. Watersheds.
USGS Watersheds: The U.S. Geological Survey classifies watersheds in the U.S. and Caribbean into 21 regions, represented by a 2-digit Hydrologic Unit Code (HUC).
Large Aquatic Ecosystems (LAEs) Program: EPA's Office of Wetlands, Oceans & Watersheds classifies LAEs to include multiple small watersheds and water resources within a large geographic area that provides significant resources or services, such as food supply, recreation and tourism, groundwater recharge, flood management, air purification, nutrient cycling, and wildlife habitat.
National Estuaries Program (NEP): The NEP identifies nationally significant estuaries of the U.S. for protection and restoration. EPA administers the NEP, but program decisions and activities are carried out by committees of local government officials, private citizens, and representatives from other federal agencies, academic institutions, industry, and estuary user-groups. Estuaries are selected for inclusion in the program through a nomination process. There are currently 28 estuary programs implemented in the U.S.

Download File Field Descriptions

Watershed File
Field Name Description
Year The calendar year for the pollutant loadings.
HUC 12 Code Hydrologic Unit Code (HUC) assigned by the US Geological Survey used to classify watersheds in the United States and the Caribbean. Code consists of twelve digits based on six levels of classification: Region (first-level, 2-digit HUC), Subregion (second-level, 4-digit HUC), Accounting unit (third-level, 6-digit HUC), Cataloguing unit (fourth-level, 8-digit HUC), Watershed (fifth-level, 10-digit HUC), and Subwatershed (sixth-level, 12-digit HUC).
Watershed Name The name of the 12-digit HUC.
Number of DMR Dischargers The number of facilities located in the watershed with pollutant loadings, based on DMR data in ICIS-NPDES.
Number of TRI Dischargers The number of facilities located in the watershed reporting water pollutant releases to EPA’s Toxic Release Inventory (TRI) program.
Total DMR Discharges (lb/yr) The total amount of DMR pollutant loadings for all parameters, in pounds.
Total TRI Discharges (lb/yr) The total amount of surface water discharges reported to TRI, in pounds.
Total DMR TWPE (lb-eq/yr) The total amount of DMR discharges, expressed as toxic-weighted pound-equivalents.

TWPE is the mass of a pollutant or chemical discharged that accounts for its relative toxicity. To convert pollutant loadings into TWPE, EPA multiplies the pollutant mass (in pounds) by its pollutant specific toxic weighting factor (TWF). Not all pollutants have a toxic weighting factor(for example, Total Suspended Solids), which means that these pollutants do not have a toxicity score(i.e., TWPE = 0). See Technical Reference Documents for more information about TWFs.
Total TRI TWPE (lb-eq/yr) The total amount of TRI surface water releases, expressed as toxic-weighted pound-equivalents.
DMR Metals Discharges (lb/yr) The total amount of DMR pollutant loadings for metals parameters, in pounds. Hexavalent or trivalent metals and metals in ionic form (e.g., hexavalent chromium and aluminum, ion) are included, but metal compounds (e.g., calcium chloride) are not included.
TRI Metals Discharges (lb/yr) The total amount of metal releases to surface waters reported to TRI, in pounds.
DMR Metals TWPE (lb-eq/yr) The total amount of DMR pollutant loadings for metals parameters, expressed as toxic-weighted pound-equivalents.
TRI Metals TWPE (lb-eq/yr) The total amount of TRI surface water releases for metals parameters, expressed as toxic-weighted pound-equivalents.
DMR Priority Pollutants Discharges (lb/yr) The total amount of DMR pollutant loadings for priority pollutants, in pounds. Includes the 126 pollutants that EPA currently defines as priority pollutants.
TRI Priority Pollutants Discharges (lb/yr) The total amount of TRI surface water releases for priority pollutants, in pounds.
DMR Priority Pollutants Discharges TWPE (lb-eq/yr) The total amount of DMR pollutant loadings for priority pollutants, expressed as toxic-weighted pound-equivalents.
TRI Priority Pollutants Discharges TWPE (lb-eq/yr) The total amount of TRI surface water releases for priority pollutants, expressed as toxic-weighted pound-equivalents.
DMR Solids Discharges (lb/yr) The total amount of solids discharges, in pounds. Includes all parameters for suspended and settleable solids. This category does not include chemical-specific solids, such as suspended copper.
DMR Organic Enrichment Discharges (lb/yr) The total amount of pollutant discharges from biochemical oxygen demand (BOD) and chemical oxygen demand (COD) parameters in ICIS-NPDES, in pounds.
Total DMR Nitrogen Discharges (lb/yr) The total amount of aggregated nitrogen discharges reported to ICIS-NPDES for a given year, in pounds. This includes all parameters for total nitrogen, organic nitrogen, total Kjeldahl nitrogen, nitrite, nitrate, and ammonia are included.
DMR Nitrogen Discharges from POTWs (lb/yr) The total amount of aggregated nitrogen discharges from publicly-owned treatment works (POTWs) (i.e., Facility Type Indicator = POTW) reported to ICIS-NPDES for a given year, in pounds. All parameters for total nitrogen, organic nitrogen, total Kjeldahl nitrogen, nitrite, nitrate, and ammonia are included.
Total DMR Phosphorus Discharges (lb/yr) The total amount of aggregated phosphorus discharges reported to ICIS-NPDES for a given year, in pounds. All phosphorus and phosphate pollutant parameters are included.
DMR Phosphorus Discharges from POTWs (lb/yr) The total amount of aggregated phosphorus discharges from publicly-owned treatment works (i.e., Facility Type Indicator = POTW) reported to ICIS-NPDES for a given year, in pounds. All phosphorus and phosphate pollutant parameters are included.
DMR Nitrogen Discharges from Non-POTWs (lb/yr) The total amount of aggregated nitrogen discharges from industrial sources reported to ICIS-NPDES, in pounds. All parameters for total nitrogen, organic nitrogen, total Kjeldahl nitrogen, nitrite, nitrate, and ammonia are included.
DMR Phosphorus Discharges from Non-POTWs (lb/yr) The total amount of aggregated phosphorus discharges from industrial sources reported to ICIS-NPDES, in pounds. All phosphorus and phosphate pollutant parameters are included.
DMR Avg Pathogen Indicators Discharges (cfu/100mL) The average discharge amount of all parameters for total coliform, streptococci, E. coli, and enteric viruses reported to ICIS-NPDES in colony-forming units per 100 milliliters. These parameters are reported in units that cannot be expressed as a mass discharge, and thus are not included as total load calculations.
DMR Max Pathogen Indicators Discharges (cfu/100mL) The maximum discharge amount of all parameters for total coliform, streptococci, E. coli, and enteric viruses reported to ICIS-NPDES in colony-forming units per 100 milliliters. These parameters are reported in units that cannot be expressed as a mass discharge, and thus are not included as total load calculations.
DMR Avg Temperature Discharges (DegF) The average temperature of wastewater discharges. All parameters measuring wastewater temperature in degrees Fahrenheit and Celsius are included. The Loading Tool presents all measurements in degrees Fahrenheit.
DMR Max Temperature Discharges (DegF) The maximum temperature of wastewater discharges. All parameters measuring wastewater temperature in degrees Fahrenheit and Celsius are included. The Loading Tool presents all measurements in degrees Fahrenheit.
DMR Avg Daily Flow (MGD) The average daily flow of wastewater discharges for the selected year. All parameters in ICIS-NPDES for measuring wastewater flows in units of millions of gallons per day, gallons per day, and gallons per minute are included. The Loading Tool presents flows in millions of gallons per day and millions of gallons per year.
DMR Total Annual Flow (Mgal/yr) The total flow of wastewater discharges for the selected year. All parameters in ICIS-NPDES for measuring wastewater flows in units of millions of gallons per day, gallons per day, and gallons per minute are included. The Loading Tool presents flows in millions of gallons per day and millions of gallons per year.
Number of CSOs The total number of combined sewer overflow (CSO) events at POTWs located in the watershed. CSO event counts are from ICIS-NPDES.

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Facility File
Field Name Description
Year The calendar year for the pollutant loadings.
FRS ID The 12-character code used to uniquely identify a facility site within the EPA Facility Registry System (FRS) database. The code is also known as the UIN (Unique Identification Number). The FRS ID links together programs records across EPA data systems, such as linking NPDES permits to TRI Facility IDs.
NPDES IDs A nine-character code used to uniquely identify a permitted NPDES facility. The NPDES permit program regulates the direct discharge of pollutants into US waters.
TRI Facility ID(s) A code used to uniquely identify facilities in EPA's TRI database. This ID is also known as the Toxics Release Inventory Facility Identification Number (TRIFID).
Facility Name The primary name used to identify a facility in FRS.
Address Street address where facility is located, as maintained in FRS.
City The city name for the facility location. City names can be blank in FRS and ICSI-NPDES.
State The two-character state abbreviation for the facility location.
ZIP Code The 5-digit mail code for the facility address. Zip codes are not required in FRS or ICIS-NPDES.
Latitude The horizontal position coordinate for the facility location in units of decimal degrees.
Longitude The vertical position coordinate for the facility location in units of decimal degrees.
HUC 12 Code Code used to classify watersheds in the United States and the Caribbean. It consists of twelve digits which correspond to six levels of classification: Region (first-level, 2-digit HUC), Subregion (second-level, 4- digit HUC), Accounting unit (third-level, 6-digit HUC), Cataloguing unit (fourth-level, 8-digit HUC), Watershed (fifth-level, 10-digit HUC), and Subwatershed (sixth-level, 12-digit HUC).

The Loading Tool links facilities with hydrologic unit codes (HUC-12s) using a WATERS web service. Not all NPDES IDs have a matching HUC-12 in the Watershed Boundary Dataset. For more information see Watershed Data and Maps.
Watershed Name The name of the 12-digit HUC.
SIC Code Code that describes the primary activity of the facility. The two-digit code defines a major business sector, the four-digit code contains two additional numbers that denote a facility's specialty within the major sector. See the U.S. Department of Labor website for more information.
SIC Description A description of the primary activity of the facility.
NAICS Code A six-digit code that identifies NAICS industries and has replaced the U.S. Standard Industrial Classification (SIC) system. The first two-digits represent the industry sector, in which there exist 20 broad sectors. The third digit represents the industry subsector, the fourth digit represents the industry group, the fifth digit represents the industry, and the sixth digit specifies the country (i.e., U.S., Canada, or Mexico). See the U.S. Census website for more information.
NAICS Description A description of the primary activity of the facility.
Facility Type Indicator Facility ownership classification derived from codes in ICIS-NPDES. Facilities can be classified as publicly-owned treatment works (POTW), non-POTW, federal, or state.

Facility Type Indicator is a system-generated classification in ICIS-NPDES, based on the NPDES permit component and Facility Type of Ownership.

 

  • Facility Type = POTW if the permit has a POTW component and Facility Type of Ownership is one of the following:
    • County Government
    • City Government
    • GOCO (Government Owned/Contractor Operated)
    • Municipal or Water District
    • Mixed Ownership (e.g., Public/Private)
    • School District
    • State Government
    • Tribal Government
  • Facility Type = Federal if the Facility Type of Ownership is a Federal Facility (U.S. Government)
  • Facility Type = Non-POTW in all other cases
Major/Minor A facility classification in ICIS-NPDES from the NPDES permitting authorities, which is based on considerations such as toxic pollutant potential, ratio of discharge flow/stream flow volume, conventional pollutant loading, public health impact, water quality factors, and proximity to coastal waters.
Discharges in ICIS Only "Y" indicates the facility has pollutant loadings from DMR data only, during the reporting year.
Discharges in TRI Only "Y" indicates the facility reported surface water discharges to TRI, but not on DMRs, during the reporting year.
Discharges in both ICIS and TRI "Y" indicates the facility has pollutant loadings from DMR and TRI surface water releases during the reporting year.

 

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