Why the NPDES Application Package Looks Bigger Than Expected
An NPDES industrial discharge permit application package is built around EPA's eight standardized application forms governed by 40 CFR 122.21. Form 1 (General Information) is required for every industrial applicant except POTWs, and Form 2C (Discharges from Industrial Manufacturing) is the most common partner form for manufacturing facilities. States authorized to run the NPDES program may require EPA's 2023-revised forms, the 2019 forms, or their own state-specific forms; applicants must confirm the correct set with their permitting authority before filing.
The single regulation that ties the whole package together is 40 CFR 122.21. Per the EPA Applications and Forms page, "EPA regulations at 40 CFR 122.21 establish permit application requirements for applicants seeking coverage under individual permits." That regulation was substantively rewritten by the 2019 NPDES Applications and Program Updates Rule, which revised the application requirements and forced the eight-form overhaul every applicant now inherits. On July 31, 2023, the Office of Management and Budget approved modifications to the format and instructions of the EPA NPDES application forms, and applicants in EPA-administered jurisdictions have been required to use the 2023-revised forms from that date forward. The task is not to pick forms from a menu—it is to match your discharge type and jurisdiction to the correct subset of the eight forms, then supply the supporting data each form expects.
Step 1: Confirm Whether Your State or EPA Runs the Permit Program
The permitting authority determines the form set, the revision year, and the submission address. NPDES is a federal program delegated to authorized states; EPA-issued permits are administered directly by an EPA regional office, while state-authorized permits are administered by a state environmental agency approved to run the program in lieu of the federal government. Only the latter appear in the EPA State Program Information list, which is the only reliable way to confirm where your application belongs.
The EPA Applications and Forms page is explicit: "States that are authorized to administer the NPDES program might require use of EPA's 2023 updated application forms, the EPA 2019 application forms or might have developed their own state-specific application forms. If you are located in a jurisdiction in which a state administers the NPDES program, you should contact the state to determine the appropriate application form(s) to submit." The Form 2C instructions point the applicant in the same direction: "Consult Exhibit 1–1 of Form 1's 'General Instructions' to identify your NPDES permitting authority." That single exhibit inside Form 1 is the lookup table every applicant is expected to use before downloading a single PDF.
| Permit Issuer | Form Set Accepted | Where to Confirm | Submission Address |
|---|---|---|---|
| EPA regional office (EPA-issued) | EPA 2023-revised forms (mandatory after July 31, 2023) | EPA Applications and Forms page | Applicable EPA regional office |
| Authorized state agency (state-issued) | EPA 2023 forms, EPA 2019 forms, or state-specific forms — set by the state | Contact the state agency directly; cross-check EPA State Program Information | State environmental agency |
Phone the state agency before downloading forms. The state will tell you the revision year it accepts, whether it requires supplementary state-only attachments, and where the package must be mailed or uploaded. Skipping this call is the most common reason a complete-looking application gets returned unopened.
Step 2: Identify Which of the Eight NPDES Application Forms You Need
Eight standardized application forms cover every NPDES discharge type. Most industrial manufacturers will file exactly two of them; aquaculture, animal feeding, mining, and biosolids applicants each have a dedicated form they must add to Form 1. The table below is the one-glance reference most readers will screenshot and forward to the consultant.
| Form # | Form Name | Who Must File |
|---|---|---|
| Form 1 | General Information | All NPDES applicants except POTWs and other treatment works treating domestic sewage |
| Form 2A | Stormwater Discharges from Industrial Activity | Industrial facilities with regulated stormwater discharges |
| Form 2B | Stormwater Discharges from Municipal Separate Storm Sewer Systems | MS4 operators |
| Form 2C | Discharges from Industrial Manufacturing | Manufacturing facilities discharging process wastewater |
| Form 2D | Aquaculture | Aquaculture facilities |
| Form 2E | Animal Feeding Operations | AFOs and CAFOs |
| Form 2F | Mines | Mining operations |
| Form 2S | Sewage Sludge / Biosolids | Facilities that prepare sewage sludge for land application |
Form 1's mandatory scope is stated verbatim in the Form 1 PDF: "All applicants to the National Pollutant Discharge Elimination System (NPDES) permits program, with the exception of publicly owned treatment works and other treatment works treating domestic sewage, must complete Form 1." For a manufacturing facility discharging process wastewater, Form 1 is paired with Form 2C exactly as the Form 2C filing instructions specify: "Submit your completed application package (Forms 1 and 2C) to your National Pollutant Discharge Elimination System (NPDES) permitting authority." Stormwater-covered industrial sites add Form 2A. POTWs do not file Form 1 at all—they have a separate application track.
Step 3: Assemble the Supporting Documents Behind the Forms
Supporting documents provide the technical evidence required to make the application complete and reject-proof. EPA and authorized states consistently expect the same tier of attachments behind Forms 1 and 2C. For a typical industrial facility, that tier includes: a facility site map with the latitude and longitude of every discharge point, a process flow diagram, a line drawing of the wastewater treatment system with unit operations and design flows, the facility's SIC code and its North American Industry Classification System (NAICS) code, and any existing effluent monitoring data from prior self-monitoring or DMRs.
Effluent characterization data is the data backbone of Form 2C—influent and effluent pollutant concentrations, flow rates measured at each outfall, and the treatment unit that achieves those values. Equipment datasheets and certified laboratory analyses typically supply that data, and it is also the data set a treatment-system vendor generates during pilot or commissioning work. For example, when a plant benchmarks a DAF system or specifies an automatic chemical dosing system for a new pretreatment train, the resulting bench-sheet and pilot data can populate the Form 2C effluent tables directly. Discharge monitoring reports from the previous permit term are usually required as attachments for renewals, and the permit writer will reconcile the new application against those historical values. For facilities dealing with cooling water, the supporting documents also need to account for side streams like cooling tower blowdown, which carries its own characterization profile.
Form 1 and Form 2C: What Each Section Asks For
The Form 1 PDF and its General Instructions define the question set, while the Form 2C instructions define the discharge-data set. Reading them first prevents the common scramble of re-collecting data points that were already available but not identified as requirements.
Form 1 (General Information) asks for: facility identification (legal name, mailing address, facility address), owner and operator information including responsible corporate officer, SIC and NAICS codes, existing environmental permits held by the facility, and the latitude and longitude of each discharge point expressed in decimal degrees. Each of these is a hard field—leaving one blank triggers a rejection rather than a clarification request.
Form 2C (Industrial Manufacturing) asks for: a written description of each discharge, production data expressed in units the permit writer can convert to flow-normalized pollutant loads, effluent characterization for each outfall (pollutant, concentration, sample type, frequency), flow rates in million gallons per day, and a description of the treatment system including unit operations and removal efficiency. The Form 2C instructions require this form to be filed together with Form 1 as a single package, and EPA publishes a "TIPS for Completing Fillable PDF NPDES Permit Application Forms" document (85.36 KB) that walks through the fillable-PDF workflow. Submit the completed Forms 1 and 2C package to the NPDES permitting authority identified in Form 1's Exhibit 1-1.
Pre-Submission QA: Five Items That Trigger Application Rejections
Certain frequent errors lead to immediate application rejections even when the primary forms are complete. Run this list against the package before mailing or uploading.
- Wrong form revision year. Submitting an EPA 2019 PDF in an EPA-administered jurisdiction after July 31, 2023—the cutoff for the 2023-revised forms. Authorized states set their own cutoffs; confirm with the state.
- Unsigned or undated application certification. Form 1's certification block must be signed and dated by the responsible corporate officer defined in the form, not by an EHS manager or consultant.
- Missing latitude and longitude. Every discharge point on Form 1 needs decimal-degree coordinates. "See attached map" is not sufficient.
- Missing or mismatched SIC and NAICS codes. Both codes are typically required, and the codes must describe what the facility actually does—a metal finisher using a food-processing SIC will be flagged.
- Submission to the wrong authority. Filing an EPA-issued package with an authorized state, or a state package with an EPA regional office. Form 1's Exhibit 1-1 lookup exists specifically to prevent this.
Frequently Asked Questions
Which form set do I file if my state runs the NPDES program? It depends on the state. Per the EPA Applications and Forms page, authorized states "might require use of EPA's 2023 updated application forms, the EPA 2019 application forms or might have developed their own state-specific application forms." Contact the state agency before downloading any PDF.
Do I file Form 1 if I am a POTW? No. The Form 1 PDF states that "with the exception of publicly owned treatment works and other treatment works treating domestic sewage," all applicants must complete Form 1. POTWs follow a separate application track.
Where do I send the completed application? To the NPDES permitting authority identified in Form 1's Exhibit 1-1, per the Form 2C filing instructions.
Do I need laboratory effluent data before I file? Yes, for Form 2C. Influent and effluent pollutant concentrations and flow rates at each outfall are required fields; vendor bench-sheets, pilot data, or third-party lab analyses are typical sources.
Is there a fee to apply? Permit application fees are set by the permitting authority—the state agency or the EPA regional office—not by the form itself. Confirm the fee schedule with the permitting authority before submission.
