Surface Water Discharge Permitting (MPDES)

DEQ develops the limits and requirements for an Individual Permit based on a facility's operations, type and amount of discharge, and the nature of the receiving stream, among other factors.

All forms are provided using FACTS. Log in or create an account in FACTS to apply or renew online using the FACTS button.

 

The General Permit for Stormwater Discharges Associated with Construction Activity (SWC) regulates the discharge of stormwater from construction sites. Authorization under the SWC is required for construction activities that disturb one or more acres of land. Disturbance is defined as clearing, excavating, grading, grubbing, or placement/removal of earthen material.

SWC General Permit

• General Permit (Effective January 1, 2023)
• Fact Sheet 
• Response to Comments 
• Environmental Assessment

Forms

Applications

To apply for an authorization under the SWC, submit a complete NOI package to DEQ through DEQ’s e-permitting system, FACTS. A complete NOI package includes a NOI with map, SWPPP (see form below) with map(s), Sage Grouse Program consultation letter (if applicable), and appropriate fee. NOI packages are to be submitted through FACTS before the proposed construction start date. A permittee is authorized to discharge under the SWC after DEQ receives a complete Notice of Intent (NOI) package.

• Sage Grouse Program website
• Public Sign FAQs

Other Documents

• Attachment A- Delegation of Authority Form
• Attachment B- Self-Inspection Report Form

Transfers

Use the Permit Transfer Notification (PTN) form in FACTS to request a transfer an authorization under the SWC to a new owner or operator or to change the name of a legal entity that holds an authorization.

Terminations

Projects which have reached final stabilization and meet additional termination requirements in the SWC may terminate permit coverage.

• Notice of Termination (NOT)

Rainfall Erosivity Waiver

To be eligible for a Rainfall Erosivity Waiver, a project must:

• Have a disturbance area of less than 5 acres,
• Begin construction after March 30 ^th and achieve final stabilization before November 30 ^th of the same calendar year,
• Have a rainfall erosivity factor of less than 5. The rainfall erosivity factor may be calculated using the EPA online calculator.

A Rainfall Erosivity Waiver does not remove the requirement to implement appropriate erosion and sediment controls, nor does it allow for the violation of water quality standards. The Rainfall Erosivity Waiver can be found in the FACTs permitting system.

Recently Terminated and Currently Effective SWC Authorizations

Spreadsheets are updated monthly and reflect all current authorizations under the SWC and terminations that have occurred in the last 6 months.

• Effective SWC Authorizations by County (PDF)
• Effective SWC Authorizations by County (Excel)
• Recently Terminated SWC Authorizations by County (PDF)
• Recently Terminated SWC Authorizations by County (Excel)

Contacts

• Applications, Terminations, Transfers, and FACTS: Wendy Simons (406) 444-0574
• Rainfall Erosivity Waivers: Tyler Halligan (406) 444-2897

Authorization under the Multi-Sector General Permit for Storm Water Discharges Associated with Industrial Activity (also called the Multi-Sector General Permit or MSGP) is required for a wide range of industrial facilities based upon the standard industrial classification code of the facility.

Multi-Sector General Permit

• General Permit (effective February 1, 2023)
• Fact Sheet
• Response to Comments
• Environmental Assessment

Forms

Applications

To apply for an authorization under the Multi-Sector General Permit, submit a complete NOI package to DEQ through DEQ’s e-permitting system, FACTS. A complete NOI package includes a NOI with map, SWPPP with map(s), Sage Grouse Program consultation letter (if applicable), and appropriate fee.

• Sage Grouse Program Website

Annual Report

All permittees authorized to discharge storm water under the MSGP must submit an annual report each year to DEQ.

Transfers

Use the Permit Transfer Notification form in FACTS to request a transfer an authorization under the MSGP to a new owner or operator or to change the name of a legal entity that holds an authorization.

Terminations

Facilities which cease operation, no longer discharge to state surface waters, and meet additional termination requirements in the MSGP may apply for termination of permit coverage using the NOT form in FACTS.

No Exposure Certification

Industrial facilities that are required to obtain permit coverage under the MSGP may be excluded from those requirements if they can demonstrate and certify that all industrial materials and processes are protected by a storm-resistant shelter from rain, snowmelt, and runoff. An Industrial No-Exposure certification must be recertified every five years.

• Industrial No Exposure Certification Form
• Industrial No Exposure Certification Instructions

Contact

• Tyler Halligan (406) 444-2897

Fees

The General Permit for Storm Water Discharges Associated with Small Municipal Separate Storm Sewer Systems (MS4) is required for urbanized areas within the state of Montana.

MS4 General Permit

• General Permit (Effective April 1, 2022)
• Fact Sheet
• Fact Sheet (Modification)
• Response to Comments
• Environmental Assessment
• MS4-Annual Report Form (2023-2026)

Contact

• Tyler Halligan (406) 444-2897

The General Permit for Concentrated Animal Feeding Operations regulates discharge of manure, process wastewater, and other wastes to state waters from CAFOs. A CAFO is an Animal Feeding Operation that meets certain additional regulatory criteria, primarily based on number of animals in the confined production area. A CAFO may be designated as Large or Medium, depending on thresholds outlined in the General Permit, or by the determination of DEQ on the basis of potential to contribute pollution to state waters.

CAFO General Permit

• General Permit (Effective November 1, 2023)
• Fact Sheet
• Response to Comment
• Environmental Assessment

Forms

• Notice of Intent (NOI) and Nutrient Management Plan (NMP)
• Instructions for Notice of Intent (NOI) and Nutrient Management Plan (NMP)
• Annual Report (AR2) Form 
• Instructions for Annual Report Form (AR2) 
• Discharge Event Form (CD)
• Technical Standards for CAFO
• Montana Phosphorus Risk Assessment Agronomy Technical Note

Fees

• New Permit Fee (Includes Initial Annual Fee): $1,200
• Renewal Fee: $600
• Annual Fee: $600

Contact

• Hannah New (406) 444-3441

The General Permit for Construction Dewatering regulates the discharge of construction dewatering to state surface waters. Construction dewatering is the action of pumping or actively removing ground water and/or surface water from a construction site and includes well pump tests and/or well development. Effluent limitations, monitoring requirements, and other conditions are set forth in the General Permit.

Construction Dewatering General Permit

• 2025 General Permit (Effective May 1, 2025)
• 2025 Fact Sheet
• 2025 Environmental Assessment
• 2025 Response to Comment
• 2025 NOI-07
• 2025 NOI-07 Instructions
• 2025 GIS Contamination Links and Contacts
• Daily Log
• CDGP Info Sheet

Fees

• New Permit Fee (Includes Initial Annual Fee): $900 - per billable outfall
• Renewal Fee: $400 - per billable outfall
• Annual Fee: $450 - per billable outfall

Contacts

• Christine Weaver (406) 444-3927

The General Permit for Disinfected Water and Hydrostatic Testing regulates discharges into state waters after treatment resulting from hydrostatic testing or disinfecting with water containing chlorine. Effluent limitations, monitoring requirements, and other conditions are set forth in the General Permit.

Disinfected Water & Hydrostatic Testing General Permit

• General Permit (Effective January 01, 2021)
• Fact Sheet
• Response to Comments
• Environmental Assessment

Fees

• New Permit Fee (Includes Initial Annual Fee): $1,200
• Renewal Fee: $800
• Annual Fee: $750

Contacts

• Kristeen Wofford (406) 444-5341

There are two General Permit for Domestic Sewage Treatment Lagoons 1) for Batch and Non-Discharging Facilities and 2) for Continuous Dischargers. These General Permits regulate the discharge of treated wastewater from eligible public and private domestic lagoons to state surface waters. The General Permits includes effluent limitations, monitoring requirements, and other conditions.

To be eligible for authorization under one of the General Permits, a facility must:

• Be a facultative or aerated sewage treatment lagoon
• Be classified as a minor discharger (i.e. have an average daily design flow of less than 1.0 million gallons per day);
• Have no pretreatment program;
• Not accept discharge from categorical industrial users (CIU) or significant industrial users (SIU); and
• Not discharge to Outstanding Resource Waters, National Parks, or waterbodies classified as A-1 or A-Closed

Domestic lagoon facilities that do not meet eligibility requirements in the General Permits may need coverage under an Individual Permit using  MPDES Form 2A.

Batch & Non-Discharging Facilities – MTG580000

Batch & Non-Discharging Facilities General Permit (2023)

In order to maintain permit coverage for a batch or non-discharging domestic lagoon wastewater discharge, you need to submit a complete renewal package by no later than October 31 ^st. To reapply, please use DEQ’s online application system, FACTS.

The Fish Farm General Permit regulates discharge wastewater effluent to state surface waters from fish farms and hatcheries. Effluent limitations, monitoring requirements, and other conditions are set forth in the General Permit. All facilities must develop and implement a waste management plan to minimize waste discharges into state waters.

Fish Farms General Permit

• General Permit (Effective July 1, 2016)
• Fact Sheet
• Response to Comments
• Environmental Assessment

Fees

• New Permit Fee (Includes Initial Annual Fee): $1,200
• Renewal Fee: $600
• Annual Fee: $450

Contacts

• Matthew Nichols (406) 444-5326

The General Permit for Pesticides regulates the discharge of certain pesticides (due to application into, over, or near state surface waters) into state surface waters. This is not a pesticide applicator license.

Applicants will be classified as Tier I or Tier II facilities, depending on their pesticide use pattern and total annual treatment area. If a permittee’s application area is less than the thresholds designated for their use pattern, they are considered Tier I facilities and are subject to universal requirements. Tier II facilities are subject to additional requirements, including the development of a Pesticide Discharge Management Plan.

Pesticides General Permit

• General Permit (Effective November 1, 2021)
• Fact Sheet 
• Response to Comment
• Environmental Assessment

Contact

• Hannah New (406) 444-3441

The General Permit for Petroleum Cleanup regulates discharge to state surface waters of wastewater from petroleum-related, contaminated water treatment facilities. Effluent limitations, monitoring requirements, and other conditions are set forth in the General Permit.

Petroleum Cleanup General Permit

• General Permit (Effective September 1, 2025)
• Fact Sheet
• Response to Comments
• Environmental Assessment

Instructions and Forms

• Notice of Intent (NOI-79)
• Notice of Termination (NOT)

Fees

• New Permit Fee (Includes Initial Annual Fee): $1,200
• Renewal Fee: $800
• Annual Fee: $750

Contacts

• Alanna Shaw (406) 444-3967

The General Permit for Produced Water regulates discharge wastewater from oil and natural gas production wells to ephemeral (seasonal) drainage ways or holding ponds for the purpose of the prescribed beneficial use. Effluent limitations, monitoring requirements, and other conditions are set forth in the General Permit.

Produced Water General Permit

• General Permit (Effective December 1, 2021)
• Fact Sheet
• Fact Sheet (includes minor modification)
• Response to Comments
• Environmental Assessment

Fees

• New Permit Fee (Includes Initial Annual Fee): $1,200
• Renewal Fee: $900
• Annual Fee: $750

Contacts

• Amelia Flanery Staats (406) 444-2856

The General Permit for Sand and Gravel Operations regulates the discharge of wash water, transport water, scrubber water, and pit dewatering or other process water associated with mineral mining and processing to state surface waters. Effluent limitations, monitoring requirements and other conditions are set forth in the General Permit. Other operational discharges may require an Individual Permit and a separate application form.

Sand and Gravel Permit

• General Permit (Effective March 1, 2025)
• Fact Sheet
• Response to Comments
• Environmental Assessment
• Daily Log

Fees

• New Permit Fee (Includes Initial Annual Fee): $1,200
• Renewal Fee: $900
• Annual Fee: $750

Contacts

• Amelia Flanery Staats (406) 444-2856

The General Permit for Portable Suction Dredging regulates discharge wash water from portable recreational suction dredge operations into state surface waters. Effluent limitations, monitoring requirements, and other conditions are set forth in the General Permit.

New applicants must secure area seasonal stream restrictions from the Montana Department of Fish, Wildlife & Parks biologist. Both new and renewal applicants must complete a Notice of Intent (Form NOI37), which is filed with DEQ. The fee structure is included on the NOI37 form. All applicants must secure a no-cost Section 310 Permit from the local Conservation District.

Suction Dredges General Permit

• General Permit (Effective August 1, 2024)
• Fact Sheet
• Environmental Assessment
• Suction Dredging Info Sheet

Contacts

• Matthew Nichols (406) 444-5326

• Permit Transfer Notification (PTN): Use this form to request a transfer or change in name of a legal entity that holds a MPDES General Permit authorization (excluding stormwater).
• Notice of Termination (NOT): Use this form to request termination of a MPDES General Permit authorization (excluding stormwater).