NPDES Permits and Compliance

Permitting for facilities that discharge directly to a surface water.

Any facility that discharges directly to a surface water is required to obtain a federal permit, called a National Pollutant Discharge Elimination System (NPDES) permit. The EPA administers this program. The state of New Hampshire is one of three states not delegated by EPA to administer this program. However, NHDES must certify that the limitations and conditions contained in the NPDES permit will ensure that the proposed discharge will not violate any state law or regulation.

NPDES permits include individual and general permits. Individual NPDES permits are issued to reflect site-specific conditions of a single discharger and is unique to that discharger. General NPDES permits are issued to cover multiple dischargers with similar operations and types of discharges.

Facilities covered under individual NPDES permits must submit individual applications available through EPA. Facilities covered under general permits must file Notice of Intent (NOI) forms in lieu of individual applications.

The general NPDES permits administered by EPA and certified by NHDES include:

  • Publicly Owned Treatment Works General Permit (POTW GP).
  • Potable Water Treatment Facility General Permit (PWTF GP).
  • Multi-Sector General Permit (MSGP).
  • Construction General Permit (CGP).
  • Dewatering General Permit (DGP).
  • Remediation General Permit (RGP).
  • Noncontact Cooling Water General Permit (NCCWGP).
  • Hydroelectric Generating Facilities General Permit (HYDROGP).
  • Pesticide General Permit (PGP).
  • Vessel General Permit (VGP).
  • Small Vessel General Permit (sVGP).

NHDES has developed a fact sheet that provides more information about the individual and general NPDES permits certified by the state of New Hampshire.

Dewatering and Remediation General Permit

The Dewatering and Remediation General Permit (DRGP) is now available for use. This permit combined the two former separate permits.

    NHDES Compliance Program

    After EPA issues a federal NPDES permit, NHDES may adopt it as a state permit. For NPDES permits adopted as State Surface Water Discharge Permits, NHDES:


    Permit compliance is a self-monitoring program supported by inspections and required permittee reporting. The NPDES inspection program identifies and documents noncompliance, supports the enforcement process, monitors compliance with enforcement orders and decrees, establishes presence in the regulated community, deters noncompliance, and supports the permitting process.

    Routine NPDES compliance inspections are performed in a manner designed to:

    • Determine compliance with NPDES permit.
    • Verify the accuracy of information submitted by permittees.
    • Evaluate in-house laboratory procedures conducted for NPDES reportable parameters.
    • Verify the adequacy of sampling and monitoring conducted by the permittee.

    NHDES NPDES staff incorporate inspection checklists as a tool to promote consistency among inspectors in evaluating compliance from site to site. Much of the existing checklist framework is based on federal guidance.

    NPDES Compliance Inspection Checklists

    Reporting Requirements for NPDES Permittees

    Reporting Non-Compliance Events

    Reportable events may include daily maximum permit parameter violations, unauthorized discharges such as Sanitary Sewer Overflows (SSOs), and other noncompliance which may endanger health or the environment. NPDES permit Part II Standard Conditions (April 2018) (January 2007) includes reporting requirements. Specific permits may have additional reporting stipulations. Permittees must adhere to non compliance reporting deadlines.

    Information submitted with each non-compliance report should contain:

    • A description of the non-compliance, including the amount discharged.
    • The cause of the non-compliance.
    • The period of discharge, including the exact start and end dates and times.
    • How the non-compliance was corrected. If the non-compliance has not been corrected, the anticipated time it is expected to continue. And steps taken or planned to reduce, eliminate, and prevent reoccurrence of the non-compliance.

    EPA Electronic Reporting

    Facilities may be required to submit Discharge Monitoring Report (DMR) data to EPA as part of their NPDES permit. All facilities required to provide DMR data must do so electronically using NetDMR. The database is maintained by EPA with assistance available through the NetDMR Support Portal.

    Typically, the DMR must be completed and electronically submitted by the 15th of the month following the monitoring period. This is a compliance deadline. Monthly Operating Reports (MORs) for municipal wastewater facilities are a state specific requirement in permits and are to be attached in NetDMR with the relevant monitoring period.

    There are many other program services available through the CDX platform. NeT is the NPDES eReporting Tool developed to facilitate electronic submittal of data (other than DMRs) by the regulated community. Program services under NeT include, but are not limited to, the EPA Biosolids Annual Program Report and Notices of Intent (NOI) for coverage under the Multi-Sector General Permit and Construction General Permit.

    Electronic Reporting

    NetDMR is a web-based application that allows NPDES permittee users to enter and electronically submit Discharge Monitoring Report (DMR) data through the Central Data Exchange (CDX) to EPA.