Electronic Reporting
NPDES E-Reporting Rule

Phase 1: Electronic DMR Submission

All NPDES-permitted facilities must submit Discharge Monitoring Reports electronically through EPA’s NetDMR system or an equivalent state electronic reporting system. This applies to both major and minor individual permit holders, as well as general permit holders required to submit monitoring data. Paper DMR forms are no longer accepted.

Phase 2: Expanded Electronic Reporting

Phase 2 extends electronic reporting requirements beyond DMRs to additional NPDES program areas:

• General permit reports — Notices of intent (NOIs), notices of termination (NOTs), and no-exposure certifications
• Biosolids and sewage sludge reports — Annual reports under 40 CFR Part 503
• Sewer overflow and bypass reports — SSO and CSO event notifications
• Pretreatment program reports — Pretreatment annual reports from POTWs
• CAFO annual reports — Concentrated animal feeding operation monitoring data

NetDMR Account Setup

Facilities must register for NetDMR, establish authorized signatories (the person legally responsible for the accuracy of submitted data), and complete the subscriber agreement process. Each signatory must obtain a CDX (Central Data Exchange) account with identity verification.

Data Formatting Requirements

NetDMR requires data in a specific structure: parameter codes, monitoring location codes, statistical base codes, and value/qualifier pairs that match the permit’s monitoring requirements. Manually entering this data into the NetDMR web interface is time-consuming and error-prone, especially for permits with many outfalls and parameters.

Calculation Standardization

Electronic submission makes calculation errors more visible. DMR values are validated by NetDMR against permit limits, and discrepancies trigger warning flags. Facilities that previously relied on ad-hoc spreadsheet formulas may discover inconsistencies in their calculation methods when subjected to automated validation.

Automated DMR Preparation

Software imports validated lab data, calculates all required DMR statistics (monthly averages, daily maximums, loading rates, geometric means), and formats the results in the structure required by NetDMR. This eliminates manual calculation and formatting entirely.

Electronic Export Files

Generate export files that can be uploaded directly to NetDMR or state electronic reporting systems rather than manually entering values into web forms. This reduces data entry time from hours to minutes and eliminates transcription errors during the submission process.

Pre-Submission Validation

Software validates DMR data against permit limits before export, identifying exceedances, missing data, and calculation anomalies. This catches issues before submission rather than after NetDMR flags errors, reducing rejected submissions and revision cycles.

Submission Audit Trail

Maintain a complete record of what was submitted, when, and by whom. If questions arise about historical DMR data, you have a traceable record from the original lab result through validation, calculation, review, and submission.