Glossary of Frequent Terms in the Loading Tool


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Search Terms

 Abandoned, Inactive, or Uncontrolled Hazardous Waste Sites
Hazardous waste facilities identified through the U.S. EPA CERCLIS Database as abandoned, inactive or uncontrolled. The CERCLIS Database stores information from the Superfund program. Superfund is a program administered by EPA to locate, investigate, and clean up the worst hazardous waste sites throughout the United States. These data are from Envirofacts
 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. These data are from ICIS-NPDES
 CERCLA Priority Pollutants Pollutant Category
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.
These data are from CERCLIS.
 CERCLIS (Comprehensive Environmental Response, Compensation and Liability Information System)
CERCLIS (Comprehensive Environmental Response, Compensation and Liability Information System) is a database maintained by EPA that contains information such as the current status of cleanup efforts, cleanup milestones reached, and amounts of liquid and solid media treated at sites on the National Priorities List (NPL) or under consideration for the NPL. These data are from CERCLIS
 City
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. These data are from FRS and ICIS-NPDES.
 Clean Watersheds Needs Survey (CWNS) ID
A unique identifier for a facility. Most facilities identified are publicly owned treatment works (POTWs). Every four years the 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.
Search Considerations: The Loading Tool pulls CWNS IDs from the CWNS 2008 database. Searching on this field will produce results if 1) the CWNS ID is in the CWNS 2008 database; and 2) the CWNS 2008 database links the CWNS ID to a NPDES ID that is in either ICIS-NPDES. These data are from CWNS.
 Combined Sewer Overflow (CSO)
A combined sewer system (CSS) is a wastewater collection system owned by a municipality which conveys sanitary wastewater (domestic, commercial, and industrial) and stormwater through a single pipe system to a publicly owned treatment works. A combined sewer overflow (CSO) is the discharge from a CSS at a point prior to the treatment plant. CSOs are point sources subject to NPDES permit requirements including both technology-based and water quality-based requirements of the Clean Water Act. These data are from ICIS-NPDES.
 County
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. These data are from FRS and ICIS-NPDES.
 Color Pollutant Category
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.
Search Considerations: The Loading Tool selects pollutant measurements for the color category if the measurements are associated with parameter codes in ICIS-NPDES that are on the color list. This list is available in the Technical Support Documentation. These data are from ICIS-NPDES.
 OIL Database
EPA's OIL database contains information on Spill Prevention, Control and Countermeasure (SPCC) and Facility Response Plan (FRP) subject facilities to prevent and respond to oil spills.

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 EPA Region
The EPA designated area that U.S. States, territories, and tribes are assigned to. There are 10 EPA regions. These data are from ICIS-NPDES.
 ESA-listed Aquatic Species
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 Endangered Species Act (ESA). The purpose of the ESA is to protect and recover imperiled species and the ecosystems upon which they depend. It is administered by the U.S. Fish and Wildlife Service and the Commerce Department's National Marine Fisheries Service (NMFS). These data are from ICIS-NPDES.
 Estimation Function
A function that estimates loads when monitoring data are not reported for one or more monitoring periods in a reporting year. The Loading Tool applies an estimation factor to extrapolate the annual loads to account for a full 12 months of discharges. The estimation factor is calculated by dividing 12 by the sum of the number of months with DMR data and the number of months with no discharge. Section 3.2.4 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool uses the function.
Search Considerations: This calculation feature uses data from the "No Data Indicator" and "Number of Report" fields in ICIS-NPDES to determine if the reported measurements account for a full 12 months of discharges. Information about this calculation option is provided in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Facility Latitude and Longitude
The horizontal position coordinate (latitude) and the vertical position coordinate (longitude) for the facility location in units of decimal degrees.
Search Considerations:Latitude and longitude coordinates are not required to be entered into FRS, ICIS-NPDES. Searching on coordinates will only return results for facilities that have latitude and longitude data in FRS or ICIS-NPDES.
 Facility Name
The primary name used to identify a facility in FRS/ICIS-NPDES.
 Facility Type
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 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
These data are from ICIS-NPDES.
 Facility Registry Service (FRS) ID
A 12 character code used to uniquely identify a facility site within the EPA FRS database.
 Hydrologic Unit Code (HUC)-12 Code
Code assigned by the US Geological Survey used 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), Cataloguing unit (fourth-level, 8-digit HUC), Watershed (fifth-level, 10-digit HUC), and Subwatershed (sixth-level, 12-digit HUC).

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.
These data are from WATERS.
 HUC Region
The first level of classification for watersheds and is represented by a 2-digit HUC. The United States and the Caribbean are divided into 21 regions. (See HUC-12 Code).
Search Considerations:The Loading Tool links facility discharges with hydrologic unit codes (HUC-12) using a WATERS web service. Searching on HUC Region will produce results if the WATERS web service returns NPDES IDs that correspond to the HUC-12’s for the specified HUC Region. For more information see Overview of Watershed Data.
These data are from WATERS.
 Impaired Water Body
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. These data are from ICIS-NPDES.
Search Considerations:The Loading Tool links facilities to impaired water bodies using a WATERS web service. See Overview of Watershed Data.
 Intermittent Discharges
Facilities may have one or more outfalls that do not continuously discharge wastewater for one or more months. Some facilities may only discharge in emergency situations.
Search Considerations:ICIS-NPDES has reporting parameters for discharge duration. However, not all permits require reporting of this information. If this information is not provided on a facility's DMR then the loading tool must assume the discharge occurred continuously for the entire monitoring period. Consequently, the tool may overestimate pollutant discharges for intermittent dischargers that only discharge in emergency situations (i.e., facilities with unscheduled limit sets). EPA will work with states to improve pollutant discharge calculations for these intermittent dischargers.
These data are from ICIS-NPDES.

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 Limit Set Designator
A single-character code in ICIS-NPDES that groups limits that are set on a similar basis (e.g., monthly vs. annual limits, seasonal limits).
Search Considerations: A limit set designator code is provided for each DMR measurement and limit. See About the Loading Tool Data for more information about DMR data completeness. These data are from ICIS-NPDES.
 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.
Search Considerations: The Loading Tool identifies major facilities by searching for an M in the Major/Non-Major Status Code field from ICIS-NPDES. If this field is blank, then the Loading Tool assumes the facility is a non-major facility.
 Major U.S. Watersheds
This menu includes major watersheds: Albemarle and Pamlico Sounds, Apalachicola-Chattahoochee-Flint River Basin, 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 on About the Loading Tool Data.
The Loading Tool also provides options to search watershed boundaries (in WATERS) defined by the following classifications:
  • USGS: The US Geological Survey classifies watersheds in the US 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 US 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.
 Metals Pollutant Category
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. Section 3.3.2 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies metals parameters and calculates the total metals load.
Search Considerations:The Loading Tool selects pollutant loadings for the Metals category if the loadings are associated with parameter codes in ICIS-NPDES that are on the metals list. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool.
 Monitoring Location Code
A single-character code in ICIS-NPDES that indicates the sampling location for each pollutant measurement. The Loading Tool only includes locations for effluent sampling points. These include:
  • 1 – Effluent gross discharge
  • 2 – Effluent net discharge
  • A – After Disinfection
  • B – Before Disinfection, and
  • SC – See Comments.
Search Considerations: A monitoring location code is provided for each DMR measurement and limit. See About the Loading Tool Data for more information about DMR data completeness. These data are from ICIS-NPDES.
 Monitoring Period Range Start
The end date for the first monitoring period selected for the search.
Search Considerations:A monitoring period end date is provided for each DMR measurement. See About the Loading Tool Data for more information about DMR data completeness. These data are from ICIS-NPDES.
 Monitoring Period Range End
The end date for the last monitoring period selected for the search.
Search Considerations: A monitoring period end date is provided for each DMR measurement. See About the Loading Tool Data for more information about DMR data completeness. These data are from ICIS-NPDES.
 National Pollutant Discharge Elimination System (NPDES) Permit ID
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. These data are from ICIS-NPDES.
 Nitrogen Pollutant Category
All parameters for total nitrogen, organic nitrogen, total Kjeldahl nitrogen, nitrite, nitrate, and ammonia are included. Section 3.1.3 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies nitrogen parameters and aggregates nitrogen loads.
Search Considerations: The Loading Tool selects pollutant loadings for the Nitrogen category if the loadings are associated with parameter codes in ICIS-NPDES that are on the nitrogen list. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool.
These data are from ICIS-NPDES.
 No Data Indicator (NODI)
The unique code indicating why a DMR value was not submitted by the permittee during a monitoring period. These data are from ICIS-NPDES.
No Data Indicator Code
Code Description
1 Wrong Flow
2 Operation Shutdown
3 Special Report Attached
4 Discharge to Lagoon/Groundwater
5 Frozen Conditions
7 No Influent
8 Other (See Comments)
9 Conditional Monitoring - Not Required This Period
A General Permit Exemption
B Below Detection Limit/No Detection
C No Discharge
D Lost Sample/Data Not Available
E Analysis Not Conducted/No Sample
F Insufficient Flow for Sampling
G Sampling Equipment Failure
H Invalid Test
I Land Applied
J Recycled - Water-Closed System
K Natural Disaster
L DMR Received but not Entered
R Administratively Resolved
S Fire Conditions
V Weather Related
W Dry Lysimeter/Well
Q Not Quantifiable
X Parameter/Value Not Reported
M Laboratory Error
N Not Constructed
Z COVID-19

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 Non-Detects
Pollutants that are measured at concentrations below the sample detection limit concentration. The Advanced Search provides users three options for calculating pollutant loads for concentrations reported not detected, setting all concentrations reported not detected to zero, to ½ the detection limit, or to the detection limit. Section 3.1.3 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool calculates pollutant loads for concentrations reported not detected.
Search Considerations: The Loading Tool identifies pollutant measurements that are not detected using data qualifiers in ICIS-NPDES. If these qualifiers are missing due to a data-entry error, then the Loading Tool will not identify the measurement as a non-detect. These data are from ICIS-NPDES.
 North American Industry Classification System (NAICS) Code
A six-digit code that identifies NAICS industries and has replaced the U.S. Standard Industrial Classification (SIC) system. The system was developed to give special attention to developing production-oriented classifications for (a) new and emerging industries, (b) service industries in general, and (c) industries engaged in the production of advanced technologies.
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.
Search Considerations: NAICS codes are not required in ICIS-NPDES. Therefore, searching on this field will only return results for facilities that have NAICS codes in ICIS-NPDES. NAICS codes are required in TRI.
 Nutrient Aggregation Function
A function in the Advanced Search that can calculate aggregated phosphorus and aggregated nitrogen loads. Section 3.1.3 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool performs nutrient aggregation.
Search Considerations: The Loading Tool calculates aggregated nitrogen and phosphorus loadings by selecting pollutant loadings associated with parameter codes in ICIS-NPDES that are on the nitrogen and phosphorus lists. These lists are available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Organic Enrichment Pollutant Category
All biochemical oxygen demand (BOD) and chemical oxygen demand (COD) pollutant parameters. Section 3.3.2 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies organic enrichment parameters and calculates the total organic enrichment load.
Search Considerations: The Loading Tool selects pollutant loadings for the Organic Enrichment category if the loadings are associated with parameter codes in ICIS-NPDES that are on the organic enrichment list. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Parameter Code
A five-character code in ICIS-NPDES that identifies the regulated pollutant parameter in a NPDES permit and specifies both the pollutant name and pollutant form (e.g., dissolved or suspended). Multiple parameters can apply to a single pollutant or CAS number.
Search Considerations: Parameter codes must be reported for all pollutant measurements. See About the Loading Tool Data for more information about the universe of pollutant parameters in ICIS-NPDES and DMR data completeness.
 Parameter Grouping Function
A function that groups parameters that represent the same pollutant, and selects the parameter that best represents the total pollutant load, to avoid double counting in the Loading Tool. Double counting can be contributed to NPDES permits that may require a facility to measure a pollutant in more than one way. For example, a facility may report both total lead and dissolved lead. The function will select the total lead if reported instead of dissolved lead, to calculate the lead load. The EZ Search automatically uses this function, but users can turn it off in the Advanced Search. Section 3.2.2 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool uses the parameter grouping function.
Search Considerations: The Loading Tool uses parameter codes in ICIS-NPDES and a parameter selection hierarchy to group loadings for parameters that represent the same pollutant. The parameter grouping hierarchy is available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES
 Pathogen Indicators Pollutant Category
All parameters for total coliform, streptococci, and enteric. The Pathogen pollutant category query in EZ Search is the only query option for users to view discharges of pathogens. Because these parameters are reported in units that cannot be expressed as a mass discharge (count per 100 mL), they are excluded from all other Loading Tool searches. Section 3.3.2 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies pathogen indicator parameters and calculates the pathogen indicator discharges.
Search Considerations: The Loading Tool selects pollutant measurements for the Pathogen Indicators category if the measurements are associated with parameter codes in ICIS-NPDES that are on the pathogen indicators list. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Feature ID (outfall/pipe number)
A three-character code in ICIS-NPDES that identifies the point of discharge (e.g., outfall) for a facility. A NPDES permit may have multiple points of discharge.
Search Considerations: A permit feature ID is provided for each DMR measurement and limit in ICIS-NPDES. See About the Loading Tool Data for more information about DMR data completeness. These data are from ICIS-NPDES.
 Permit Feature Latitude and Longitude
The horizontal position coordinate (latitude) and vertical position coordinate (longitude) for the point of discharge location in units of decimal degrees.
Search Considerations: Latitude and longitude coordinates are not required to be entered into ICIS-NPDES. Searching on coordinates will only return results for permit features that have latitude and longitude data in ICIS-NPDES. These data are from ICIS-NPDES.

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 Permit Type
The permit classification in the program database, ICIS-NPDES. The Loading Tool calculates pollutant loadings for the following permit types: NPDES Individual Permit (NPD) and General Permit Covered Facility (GPC). All other permit types are excluded from loading calculations: NPDES Master General Permit (NGP), Associated Permit Record (APR), State Issued Master General Permit (SNN), Individual IU Permit (IUU), Individual State Issued Permit (SIN), Unpermitted Facility (UFT).
 Pesticide-Producing Establishment (FIFRA)
All pesticides used in the U.S. must be registered by EPA through the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Facilities that produce pesticides are recorded in the U.S. EPA Section Seven Tracking System (SSTS). The SSTS records the registration of new establishments and records pesticide production at each establishment. These data are from Envirofacts.
 Per- and Polyfluoroalkyl Substances (PFAS) Pollutant Category
Pollutant loadings associated with individual parameters in ICIS-NPDES, which are identified as PFAS by the Loading Tool. Section 3.3.1.13 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies PFAS parameters, including the list of parameter codes included in the pollutant category.
 Phosphorus Pollutant Category
All phosphorus and phosphate pollutant parameters. Section 3.1.3 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies phosphorus parameters and aggregates phosphorus loads.
Search Considerations: The Loading Tool selects pollutant loadings for the Phosphorus category if the loadings are associated with parameter codes in ICIS-NPDES that are on the phosphorus list. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Point Source Category
Specific industry categories that facilities are grouped in based on the release of pollutants from discrete point sources (i.e., pipes and smokestacks).
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 an SIC code that maps to a point source category.
 Point Source Category Code
A three-digit code that corresponds to an Effluent Limitations Guideline's 40 CFR Part. For example, Point Source Category Code 414 corresponds to Organic, Chemicals, Plastics, and Synthetic Fibers (40 CFR Part 414).
Search Considerations: EPA has developed crosswalks to relate SIC codes to likely point source categories and NAICS codes to likely point source categories. The crosswalks link SIC Codes and NAICS codes to point source categories if EPA determined that the industrial activities described by the SIC and NAICS were covered under the applicability of the effluent limitations guidelines for the point source category. Not all SIC codes or NAICS codes link to a point source category.
 Pollutant Categories
Categories of different types of pollutants that can be viewed as aggregated loads with the EZ Search tool. These categories include Metals, Nitrogen, Organic Enrichment, Pathogen Indicators, Phosphorus, Clean Water Act Priority Pollutants, Solids, Temperature, and Wastewater Flow. Section 3.3.2 of the Technical Users Background Document for the Water Pollutant Loading Tool describes the pollutant categories and how the Loading Tool calculates the pollutant category loads.
Search Considerations: The Loading Tool selects pollutant loadings for each pollutant category if the loadings are associated with parameter codes in ICIS-NPDES that are on the specified pollutant category list. These lists are available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Pollutant Name
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.
 Clean Water Act Priority Pollutants Category
All 126 pollutants that EPA currently defines as priority pollutants. Section 3.3.2 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies and priority pollutant parameters and calculates total priority pollutant loads.
Search Considerations: The Loading Tool selects pollutant loadings for the Priority Pollutants category if the loadings are associated with parameter codes in ICIS-NPDES that are on the priority pollutants list. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Publicly Owned Treatment Works (POTW)
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.
 Section Seven Tracking System (SSTS)
Section Seven Tracking System (SSTS) is one of the major systems that supports the Pesticide Program at EPA. SSTS is the only automated system that EPA uses to track pesticide producing establishments and the amount of pesticides they produce. SSTS records the registration of new establishments and records pesticide production at each establishment. It is a repository for information on the establishments that produce pesticides.

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 Spill Prevention Control and Countermeasure and Facility Response Plan (SPCC/FRP)
The Spill Prevention Control and Countermeasure (SPCC) is a rule to prevent oil discharges to the navigable waters of the U.S. It requires any facility that stores oil and could reasonably be expected to discharge oil into or upon navigable waters to develop and implement a Facility Response Plan (FRP). The FRP demonstrates a facility's preparedness to respond to a worst case oil discharge. The SPCC and FRP are part of the Oil Pollution Prevention regulation (40 CFR 112). These data are from Envirofacts.
 Standard Industrial Classification (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.
Search Considerations: For SIC code searches, the Loading Tool identifies matching facilities based on their permit SIC code in ICIS-NPDES. If the permit SIC code is blank, the Loading Tool uses the primary facility SIC code.
Note that SIC codes are not required to be reported in ICIS-NPDES. Searching on SIC code will only return records for facilities that have either a primary permit or facility SIC code in ICIS-NPDES that matches the specified SIC code for the search. These data are from ICIS-NPDES.
 State
The two-character state abbreviation for the facility location. These data are from ICIS-NPDES.
 Solids Pollutant Category
All parameters for suspended and settable solids. This category does not include chemical-specific solids, such as suspended copper. Section 3.3.2 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies solids parameters and calculates the total solids load.
Search Considerations: The Loading Tool selects pollutant loadings for the Solids category if the loadings are associated with parameter codes in ICIS-NPDES that are on the solids list. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Temperature Pollutant Category
All wastewater temperature parameters for measuring wastewater temperature in degrees Fahrenheit and Celsius. The Loading Tool presents all measurements in degrees Fahrenheit. Section 3.3.2 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies and selects temperature parameters.
Search Considerations: The Loading Tool selects temperature measurements for the Temperature category if the measurements are associated with parameter codes in ICIS-NPDES that are on the temperature list. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Toxics Release Inventory Identification Number (TRI ID)
A unique 15-character ID assigned for 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. This ID is also known as the Toxics Release Inventory Facility Identification Number (TRIFID).
TRI is a database available to the public that includes toxic chemical releases and waste management activities reported annually by industries.
Search Considerations: Searching on TRI ID on the DMR Water Pollution Search will produce results if 1)The specified TRI ID is in FRS; and 2) FRS links the TRI ID to a NPDES ID in ICIS-NPDES. These data are from FRS.
 TRI Chemicals Pollutant Category
All pollutants that are associated with chemicals that are reported to TRI.
Search Considerations: The Loading Tool selects pollutant loadings for the TRI Chemicals category if the DMR pollutants are linked to chemicals that are reported to TRI. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool.
 Wastewater Flow Pollutant Category
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. Section 3.3.2 of the Technical Users Background Document for the Water Pollutant Loading Tool describes how the Loading Tool identifies and selects wastewater flow parameters.
Search Considerations: The Loading Tool selects measurements for the Wastewater Flow category if the measurements are associated with parameter codes in ICIS-NPDES that are on the wastewater flow list. This list is available in the Technical Users Background Document for the Water Pollutant Loading Tool. These data are from ICIS-NPDES.
 Whole Effluent Toxicity (WET) Pollutant Category
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.
Search Considerations: The Loading Tool selects pollutant measurements for the WET category if the measurements are associated with parameter codes in ICIS-NPDES that are on the WET list. This list is available in the Technical Support Documentation.
 Year
The calendar year for the annual pollutant loadings.
Search Considerations: The Loading Tool extracts 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.
 ZIP
The 5-digit mail code for the facility address.
Search Considerations: The Loading Tool searches use ZIP codes in two ways:
  1. To identify discharges from facilities located in the specified ZIP code. For this type of search, 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.
  2. 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.
For more information see Overview of Watershed Data. These data are from FRS and ICIS-NPDES.