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Effluent Limit Exceedance Search Criteria Help

The Effluent Limit Exceedances Search identifies instances where discharge monitoring self reporting data indicates there was an exceedance of the NPDES permit effluent limit. The four search boxes provide search options to help you determine where discharges are occurring (Location or Watershed Box), what pollutants are discharged (Pollutant Box), and who the dischargers of interest are (Industry and Facility Boxes). Change the criteria in one or more of the boxes and click the Search button to retrieve DMR effluent limit exceedances information.

Search criteria are organized by the order they appear in each search box. The hyperlinks below to allow you to quickly find the search term of interest.

Select Year Range

Select the calendar year(s) for the discharge monitoring report (DMR) data.

By default, the year range is set to the most recent complete 5 year range of data. Select a year from the Start Year dropdown to change the year range. The End Year will dynamically update depending on what you selected as the Start Year. Up to five years of data will be available from the selected start year.

Search Considerations: The Loading Tool extracts the year from the monitoring period dates associated with DMR measurements in Integrated Compliance Information System-National Pollutant Discharge Elimination System (ICIS-NPDES). Dates are included for all DMR measurements. See About the Data for information about DMR data completeness.

Location or Watershed

Search for facilities with effluent exceedances across the U.S., without restrictions on location or watershed.
Search by Location
Search for facilities with effluent exceedances based on their location in the Facility Registry Service (FRS). If the location is not populated in FRS, location information in ICIS-NPDES is used. Narrow search results based on ZIP Code, EPA Region, State, City, and County.
ZIP Code
The 5-digit mail code for the facility address. This field is not required to be populated in the source database.
Search Considerations: The search will produce results if the specified ZIP code matches the first five digits of any facility's ZIP code in FRS or ICIS-NPDES. ZIP codes are not required in FRS or ICIS-NPDES. If a facility's ZIP code is blank in the Loading Tool database, then the ZIP code search will exclude the facility.
EPA Region
The EPA designated area that U.S. states, territories, and tribes are assigned to. There are 10 EPA regions.
The U.S. state the facility is located in.
The city name for the facility location.
Search Considerations: City names can be blank in FRS and ICIS-NPDES. If the city name is not provided for a facility, then the city name search will produce no results for that facility.
The county name for the facility location.
Search Considerations: County names can be blank in FRS and ICIS-NPDES. If the county name is not provided for a facility, then the county name search will produce no results for that facility.
Search by Watershed
Search for facilities based on watershed. Narrow search results based on ZIP code, Watershed ID (HUC), and Major U.S. Watersheds.
ZIP Code
The 5-digit mail code for the facility address in FRS. If the ZIP code is not populated in FRS, then the ZIP code in ICIS-NPDES is used. This field is not required to be populated in the source database.
To identify discharges in watersheds that overlap with the specified ZIP code's geographic boundaries. For this type of search, the search will produce results if:
  1. The specified ZIP code overlaps with a Hydrologic Unit Code (HUC) in the Watershed Boundary Database
  2. The corresponding HUC is connected with a NPDES ID in the Watershed Boundary Dataset;
  3. The corresponding NPDES ID is in ICIS-NPDES; and
  4. The NPDES ID has DMR measurements in ICIS-NPDES.
Watershed ID (2-Digit to 12-Digit HUC)
The code assigned by the U.S. Geological Survey to classify watersheds in the United States and the Caribbean. Code 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), Cataloging unit (fourth-level, 8-digit HUC), Watershed (fifth-level, 10-digit HUC), and Subwatershed (sixth-level, 12-digit HUC). This field is not required to be populated in the source database.
Search Considerations: The Loading Tool links facility discharges with hydrologic unit codes (HUC-12) using a WATERS web service. Searching on HUC-12 will produce results if the WATERS web service returns NPDES IDs that correspond to the specified HUC-12. For more information see Overview of Watershed Data.
Major U.S. Watersheds
This menu includes 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.
This menu also provides options to search watershed boundaries defined by:
USGS: The U.S. Geological Survey classifies watersheds in the U.S. and the Caribbean into 21 regions, represented by 2-digit Hydrologic Unit Codes (HUCs).
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.
Only include facilities that discharge:
To impaired water bodies: Under section 303(d) of the Clean Water Act, states, territories, and authorized tribes are required to develop lists of impaired waters. Impaired water bodies are waters that are too polluted or otherwise degraded to meet the water quality standards set by states, territories, or authorized tribes. The law requires that these jurisdictions establish priority rankings for waters on the lists and develop TMDLs for these waters. A Total Maximum Daily Load (TMDL) is a calculation of the maximum amount of a pollutant that a water body can receive and still safely meet water quality standards.
Pollutants contributing to a water body impairment: Search for all pollutants discharged by the facility that are potentially contributing to the impairment of local water bodies.
To counties or watersheds with ESA-listed aquatic species: Endangered Species Act (ESA)-listed aquatic species are a group of organisms that live in the water for most or all of its life and are designated as threatened or endangered under the ESA. The purpose of the ESA is to protect and recover imperiled species and the ecosystems upon which they depend on. It is administered by the U.S. Fish and Wildlife Service and the Commerce Department's National Marine Fisheries Service (NMFS).

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All Pollutants
This default selection does not restrict results based on pollutant discharges.
Specify Pollutant
Search for facilities with effluent exceedances based on specific pollutant discharges. Narrow search results based on Pollutant name or Chemical Abstract Service number (CAS).
Pollutant Name(s)
Select the name used in ICIS-NPDES to identify the substance discharged.
Search Considerations: A pollutant name is provided for each DMR measurement in ICIS-NPDES. See About the Loading Tool Data for more information about DMR data completeness.
Chemical Abstract Service (CAS) Number
A number assigned by the American Chemical Society that uniquely identifies a chemical.
Search Considerations: CAS numbers are not available for bulk parameters (e.g., biochemical oxygen demand). Therefore, this search field cannot be used to find loadings for bulk parameters.
Pollutant Categories
Categories of different types of pollutants, as identified in the NPDES parameter to pollutant category crosswalk.
  • Nitrogen: All parameters for total nitrogen, organic nitrogen, total Kjeldahl nitrogen, nitrite, nitrate, and ammonia are included.
  • Phosphorus: All phosphorus and phosphate pollutant parameters.
  • Organic Enrichment: All biochemical oxygen demand (BOD) and chemical oxygen demand (COD) pollutant parameters.
  • Solids: All parameters for suspended and settable solids. This category does not include chemical-specific solids, such as suspended copper.
  • Metals: All metals parameters. 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.
  • Clean Water Act Priority Pollutants: All 126 pollutants that EPA currently defines as priority pollutants.
  • CERCLA Hazardous Substances: Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) hazardous substances are substances that are considered severely harmful to human health and the environment. Many are commonly used substances which are harmless in their normal uses, but are quite dangerous when released. They are defined in terms of those substances either specifically designated as hazardous under the Superfund law, or those substances identified under other laws. Superfund's definition of a hazardous substance includes the following:
    • Any element, compound, mixture, solution, or substance designated as hazardous under section 102 of CERCLA.
    • Any hazardous substance designated under section 311(b)(2)(a) of the Clean Water Act (CWA), or any toxic pollutant listed under section 307(a) of the CWA. There are over 400 substances designated as either hazardous or toxic under the CWA.
    • Any hazardous waste having the characteristics identified or listed under section 3001 of the Resource Conservation and Recovery Act. Any hazardous air pollutant listed under section 112 of the Clean Air Act, as amended. There are over 200 substances listed as hazardous air pollutants under the Clean Air Act (CAA).
    • Any imminently hazardous chemical substance or mixture which the EPA Administrator has "taken action under" section 7 of the Toxic Substances Control Act.
  • TRI Chemicals: All pollutants that are associated with chemicals that are reported to EPA's Toxics Release Inventory (TRI) Program.
  • Per- and Polyfluoroalkyl Substances (PFAS): PFAS are a group of man-made chemicals that includes Perfluorooctanoic acid (PFOA),  Perfluorooctane Sulfonate (PFOS), GenX, and many other chemicals. PFAS have been manufactured and used in a variety of industries around the globe, including in the United States since the 1940s. PFOA and PFOS have been the most extensively produced and studied of these chemicals. Both chemicals are very persistent in the environment and in the human body – meaning they don’t break down and they can accumulate over time. There is evidence that exposure to PFAS can lead to adverse human health effects.
  • Pathogen Indicators: All parameters for total coliform, streptococci, and enteric.
  • Temperature: All wastewater temperature parameters for measuring wastewater temperature in degrees Fahrenheit and Celsius. The Loading Tool presents all measurements in degrees Fahrenheit.
  • Wastewater Flow: All wastewater flow parameters for measuring wastewater flows in millions of gallons per day, gallons per day, and gallons per minute. The Loading Tool presents all flows in millions of gallons per day and millions of gallons per year.
  • General Radioactivity: All parameters for measuring radioactivity not specific to a particular isotope, such as gross alpha and gross beta radiation. Annual loadings cannot be calculated for these parameters.
  • Color: All parameters measuring color in wastewater. Color measurements may be reported using a variety of units, such as Platinum Cobalt (Pt-Co) units or pound/ton produced. The Loading Tool presents the measurements in the units reported on DMRs, and does not convert the measurements into standard units.
  • Whole Effluent Toxicity: All parameters measuring Whole Effluent Toxicity (WET) in wastewater. WET refers to the aggregate toxic effect to aquatic organisms from all pollutants contained in a facility’s wastewater. WET tests measure wastewater's effects on specific test organisms' ability to survive, grow and reproduce. WET measurements may be reported using a variety of units, such as percentages or pass/fail. The Loading Tool presents the measurements in the units reported on DMRs, and does not convert the measurements into standard units.
Only Include Facilities with
Any Exceedance or SNC/Category I Exceedances: Search for all exceedances (default) or only exceedances in which the permit is considered in Significant Noncompliance (SNC) for major permits or Category I noncompliance for non-major permits. 
Minimum number of exceedances: Enter a whole number greater than zero to limit the search to a minimum number of effluent exceedances over the selected year range.
A facility can have one or more permitted discharge points or outfalls Search for a minimum number of exceedances across the entire facility (default) or at a single facility outfall.
Note on the terminology of significant violations: The national program database (ICIS-NPDES) calculates the severity of violations according to the Clean Water Act regulations, which have specific criteria specifying the duration, severity, and type of violations that rise to the level of SNC. SNC can occur at major facilities. The calculation of "Category I" violations is equivalent to the SNC calculations, but because the violations occur at smaller dischargers (non-major), EPA does not classify the violations as "SNC". Whether a violation is "SNC" or "Category I" has some bearing on the government response used to address the violation(s). Repeat SNC occurrences normally are addressed through formal enforcement actions, while Category I violations are often addressed via informal processes.
Only Include Facilities with Specific Limit Exceedances
Further restrict your search to exceedances above a selected threshold. Enter a whole number greater than zero in one of the three options: percent over limit (%), pounds over limit (lb), or toxic pounds over limit (TWPE).
Toxic Weighted Pounds Equivalent (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 toxic weighting factor (TWF).
Note: EPA developed TWFs for use in its Effluent Limitations Guidelines and Standards (ELGs) development program to allow comparison of pollutants with varying toxicities. See Technical Support Documents for more information on TWF values and methodology.
Limit Pollutant Loadings Based on Data Quality Flags
Use the dropdown to search for exceedances that include or exclude data that have been flagged as potential outliers or data errors (as indicated by a blue flag). This will not exclude facility records, but rather only pollutant loading records identified as potential outliers.
To identify and report a potential data error to EPA, see How to Report an Error.

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All Point Sources
This selection will return all industry classifications, including Publicly Owned Treatment Works (POTWs) and industrial dischargers (non-POTWs).
Publicly Owned Treatment Works (POTWs) Only
A POTW is a sewage treatment plant that is owned and usually operated by a government agency. POTWs are typically owned by local government agencies and are usually designed to treat domestic sewage.
Search Considerations: The Loading Tool identifies POTWs using the Facility Type Indicator Code in ICIS-NPDES. This field is required to be populated in the source database.
Industrial Point Sources (non-POTW)
This selection will return all Industrial Point Sources that are not classified as POTWs and are often referred to as "non-municipals" or "industrials." Industrial point sources may include privately owned treatment works, water treatment plants, concentrated animal feeding operations (CAFOs), or any manufacturing or commercial activity.
Point Source Category
Specific industry categories that facilities are grouped in based on the release of pollutants from discrete point sources. Each point source category is subject to effluent guidelines under the CWA. However, the Drinking Water Treatment category is not a regulated category under the effluent guidelines, but is included to provide the capability to easily search for this industrial sector.
Search Considerations: Point source category classification is based on a facility's primary SIC code in ICIS-NPDES. SIC codes are not required to be reported in ICIS-NPDES. Searching on point source category will only return records for facilities that 1) have a primary SIC code in ICIS-NPDES, and 2) have a SIC code that maps to a point source category.
Industrial Sector ID (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. Choose a two-digit code from the dropdown menu or enter a four-digit code. Use the lookup feature to search for an SIC code. See the U.S. Department of Labor website for more information.
Search Considerations: For SIC code searches, the Loading Tool identifies matching facilities based on their primary SIC code in ICIS-NPDES. SIC codes are not required to be reported in ICIS-NPDES. Searching by SIC code will only return records for facilities that have a primary SIC code in ICIS-NPDES that matches the specified SIC code for the search.
North American Industry Classification System (NAICS) Code
The first two-digits of the six-digit code represents the industry sector, in which there exist 20 broad sectors. These sectors are provided by name in the dropdown. See the U.S. Census website for more information. This field is not required to be populated in the source database.
Search Considerations: Searching on this field will only return results for facilities that have NAICS codes in ICIS-NPDES.

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Facility Name
Permit holder name, as maintained in ICIS-NPDES.
Facility ID
Search for effluent limit exceedances by facility identifiers. Separate multiple IDs with a comma or carriage return. The search form allows for up to 1,500 IDs to be entered at once.
NPDES ID - A unique 9-character ID assigned for each permit within the National Pollutant Discharge Elimination System (NPDES) program. The ID may contain both letters and numbers and often begins with the two-letter abbreviation for the state in which the facility is permitted.
FRS ID - A 12-digit code used to uniquely identify a facility site within the EPA FRS database. FRS uniquely identifies a facility by assigning an identification number (FRS ID) and uses this FRS ID to link together all regulatory program database records (such as for permit IDs and facility IDs that facilities use in reporting to EPA).
TRI ID - A unique 15-character ID assigned to each facility within the Toxics Release Inventory (TRI) program. The format is ZZZZZNNNNNSSSSS, where ZZZZZ = ZIP code, NNNNN = the first 5 consonants of the name, and SSSSS = the first 5 non-blank non-special characters in the street address.
CWNS ID - A unique identifier for a facility in the Clean Watershed Needs Survey. Most facilities identified are publicly owned treatment works (POTWs). Every four years, EPA and states conduct the survey to determine the capital needs for municipal wastewater treatment facilities to meet the goals in the Clean Water Act.
Permit Type
Search for a facility or permit by permit classification. Permit classifications include:
  • NPDES Individual Permit - An individual NPDES permit is unique to each facility. The limitations and other conditions in an individual permit are based on the facility's operations, type and amount of discharge, and receiving stream, among other factors.
  • NPDES Master General Permit - A NPDES permit that covers multiple facilities that have similar discharges and are located in a specific geographic area. A general permit applies the same or similar conditions to all dischargers covered under the general permit. This is the record for the general permit that is issued by the permitting authority. It sets the conditions with which permittees will be required to comply. The Master General Permit contains no facility-specific data, and compliance and enforcement data are associated with a Master General Permit (rather any data would be associated with the General Permit Covered Facility).
  • NPDES General Permit Covered Facility - A NPDES facility that is covered under a Master General Permit.
Major/Non-Major Indicator
A facility classification from the NPDES permitting authorities based on toxic pollutant potential, ratio of discharge flow/stream flow volume, conventional pollutant loading, public health impact, water quality factors, and proximity to coastal waters. EPA places greater priority on major facilities and requires authorized states to provide more information about the compliance status of these dischargers. For more information, refer to About the Data.
Compare DMR to TRI
The Water Pollutant Loading Tool presents data from ICIS-NPDES and Toxics Release Inventory (TRI). This feature provides criteria for restricting results based on inclusion in ICIS-NPDES. Facilities may be linked at the facility, industry, and pollutant level. For further information about how facilities are linked, please refer to Linking DMR and TRI Data in the Water Pollutant Loading Tool.
Only include facilities that link to TRI ID(s): This selection will return facilities in ICIS-NPDES that link to TRI ID(s). The Loading Tool uses Facility Registry System (FRS) identification numbers to link NPDES permit numbers to TRI facility IDs. A TRI ID is a number used to uniquely identify facilities in EPA's TRI database.
Report TRI releases to surface waters: This selection will return facilities that report direct discharges to receiving streams or water bodies to TRI based on a facility and pollutant linkage.
DO NOT report TRI releases to surface waters: This selection will return facilities that DO NOT report direct discharges to receiving streams or water bodies to TRI.
Only include facilities that DO NOT link to TRI ID(s): This selection will return facilities in ICIS-NPDES that DO NOT link to TRI ID(s).
Clear selection: Clears the current selection for the compare feature.


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