Discharge Monitoring Report (DMR) Pollutant Loading Tool

Conventional Pollutants Category

All parameters for 5-day biochemical oxygen demand (BOD5), total suspended solids (TSS), and oil and grease (O&G). Although EPA includes fecal coliform in this category, they are excluded from the Loading Tool because they are not measured in units that can be expressed as a mass discharge. Section 3.3.2 of the Technical Users Background Document for the DMR Pollutant Loading Tool describes how the Loading Tool identifies conventional pollutant parameters and calculates the total conventional pollutants load.

Search Considerations: The Loading Tool selects pollutant loadings for the Conventional Pollutants category if the loadings are associated with parameter codes in ICIS-NPDES and PCS that are on the conventional pollutants list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

The 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 or PCS.

City

The city name for the facility location.

Search Considerations: City names can be blank in FRS, ICIS-NPDES, and PCS. If the city name is not provided for a facility, then the city name search will produce no results for that facility.

County

The county name for the facility location.

Search Considerations: County names can be blank in FRS, ICIS-NPDES, and PCS. If the county name is not provided for a facility, then the county name search will produce no results for that facility.

EPA Region

The EPA designated area that U.S. States, territories, and tribes are assigned to. There are 10 EPA regions.

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 DMR 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 and PCS 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 DMR Pollutant Loading Tool.

Facility Latitude

The horizontal position coordinate 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, or PCS. Searching on coordinates will only return results for facilities that have latitude and longitude data in FRS, ICIS-NPDES, or PCS.

Facility Longitude

The vertical position coordinate 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, or PCS. Searching on coordinates will only return results for facilities that have latitude and longitude data in FRS, ICIS-NPDES, or PCS.

Facility Name

The primary name used to identify a facility in FRS or PCS/ICIS-NPDES.

Facility Type

Facility ownership classification derived from codes in ICIS-NPDES and PCS. Facilities can be classified as publicly-owned treatment works (POTW), non-POTW, federal, or state.

Facility Registry System (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.

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.

Limit Set Designator

A single-character code in ICIS-NDPES and PCS 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 Data for more information about DMR data completeness.

Major/Minor 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 costal waters.

Search Considerations: The Loading Tool identifies major facilities by searching for an ”M“ in the Major/Minor Status Code field from ICIS-NPDES and PCS. If this field is blank, then the Loading Tool assumes the facility is a minor.

Major U.S. Watersheds

The EZ search menu of major U.S. watersheds. This menu includes the Albemarle and Pamlico Sounds, Columbia River Basin, Delaware Bay, Great Lakes, Long Island Sound, Lower Columbia River Basin, Mobile Bay, Ohio River Basin, Puget Sound, San Francisco Bay, and Tampa Bay. Many of these watersheds consist of several HUC-12 codes. Appendix D of the Technical Users Background Document for the DMR Pollutant Loading Tool lists the HUC-12 codes included in each watershed and presents a map of the watershed boundaries.

Search Considerations: The Loading Tool links facility discharges with hydrologic unit codes (HUC-12) using a WATERS web service. Searching on Major U.S. Watershed will produce results if the WATERS web service returns NPDES IDs that correspond to the HUC-12’s for the specified watershed. For more information see Overview of Watershed Data.

Metals Pollutant Category

All metals parameters. Hexavelent 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 DMR 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 and PCS that are on the metals list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

Monitoring Location Code

A single-character code in ICIS-NPDES and PCS 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 Data for more information about DMR data completeness.

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 Data for more information about DMR data completeness.

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 Data for more information about DMR data completeness.

The 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 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 available for facilities that have data stored in PCS, and 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.

Nitrogen Pollutant Category

All parameters for total nitrogen, organic nitrogen, total kjedahl nitrogen, nitrite, nitrate, and ammonia are included. Section 3.1.3 of the Technical Users Background Document for the DMR 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 and PCS that are on the nitrogen list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

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 &lquo;not dected” to zero, to ½ the detection limit, or to the detection limit. Section 3.1.3 of the Technical Users Background Document for the DMR 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 and PCS. If these qualifiers are missing due to a data-entry error, then the Loading Tool will not identify the measurement as a non-detect.

The 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.

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 DMR 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 and PCS that are on the nitrogen and phosphorus lists. These lists are available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

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 DMR 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 and PCS that are on the organic enrichment list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

Parameter Code

A five-character code in ICIS-NDPES and PCS 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 Data for more information about the universe of pollutant parameters in ICIS-NPDES and PCS 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 DMR 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 PCS 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 DMR Pollutant Loading Tool.

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 DMR 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 and PCS that are on the pathogen indicators list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

Permit Feature ID (outfall/pipe number)

A three-character code in ICIS-NPDES and PCS 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 and PCS. See About the Data for more information about DMR data completeness.

Permit Feature Latitude

The horizontal position coordinate 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 or PCS. Searching on coordinates will only return results for permit features that have latitude and longitude data in ICIS-NPDES or PCS.

Permit Feature Longitude

The vertical position coordinate 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 or PCS. Searching on coordinates will only return results for permit features that have latitude and longitude data in ICIS-NPDES or PCS.

Permit Type

The permit classification in the DMR Pollutant Loading Tool. These classifications include the following NPDES Individual Permit (NPD), NPDES Master General Permit (NGP), General Permit Covered Facility (GPC), State Issued Master General Permit (SNN), Individual IU Permit (IUU), Individual State Issued Permit (SIN).

Phosphorus Pollutant Category

All phosphorus and phosphate pollutant parameters. Section 3.1.3 of the Technical Users Background Document for the DMR 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 and PCS that are on the phosphorus list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

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 and PCS. SIC codes are not required to be reported in ICIS-NPDES and PCS. Searching on point source category will only return records for facilities that 1) have a primary SIC code in ICIS-NPDES and PCS, 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. 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 point source categories and NAICS codes to 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 and NAICS codes link to a point source category. See Overview of Industry Look-up Table (PDF) (2 pp, 551K) for more information.

Pollutant Categories

Categories of different types of pollutants that can be viewed as aggregated loads with the EZ Search tool. These categories include Conventional Pollutants, 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 DMR 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 and PCS that are on the specified pollutant category list. These lists are available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

Pollutant Name

The name used in PCS or ICIS-NPDES to identify the substance discharged.

Search Considerations: A pollutant name is provided for each DMR measurement in ICIS-NPDES and PCS. See About the 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 DMR 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 and PCS that are on the priority pollutants list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

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 Indicator Code in ICIS-NPDES (Ownership Type in PCS).

The 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 primary SIC code in ICIS-NPDES or PCS. SIC codes are not required to be reported in ICIS-NPDES and PCS. Searching on SIC code will only return records for facilities that have a primary SIC code in ICIS-NPDES or PCS that matches the specified SIC code for the search.

State

The two-character state abbreviation for the facility location.

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 DMR 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 and PCS that are on the solids list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

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 DMR 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 and PCS that are on the temperature list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

The Toxic Release Inventory Identification Number (TRI ID)

Number used to uniquely identify facilities in EPA’s TRI database. 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 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 or PCS.

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 DMR 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 and PCS that are on the wastewater flow list. This list is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.

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 and PCS. Dates are included for all DMR measurements. See About the 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/PCS. Zip codes are not required in FRS, ICIS-NPDES, or PCS. 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 or PCS; and 4) The NPDES ID has DMR measurements in ICIS-NPDES or PCS.
   
   For more information see:
   • Overview of Watershed Lookup (2 pp, 43K)
   • Overview of Watershed Data (5 pp, 51K)