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IPDES Permits

Idaho Pollutant Discharge Elimination System (IPDES) permits authorize the discharge of pollutants into Waters of the United States in Idaho (except on tribal land) per IDAPA 58.01.25. IPDES permits are written to comply with state water quality standards and limit the amount of pollution that permitted facilities may discharge into surface waters.

Contact EPA Region 10 at (206) 553-1200 for projects on tribal lands. DEQ does not issue IPDES permits for facilities within tribal lands.

Quick Actions

Apply and Pay

  1. Contact your DEQ Regional Office to discuss your individual permit or if you are unsure what type of general permit you need.
  2. Apply through the IPDES E-Permitting System.
    • Aquaculture and Pesticide Permitting: Apply via EPA Central Data Exchange.
    • CAFO Permitting: Contact DEQ for application instructions. 
  3. Pay any applicable fees through the IPDES E-Permitting System.

Submit Compliance Reports

Reports are due by the dates specified in your permit.

Report a Permit Violation

  • Report public health emergencies immediately by calling the 24-hour Idaho Emergency Medical Services Communications Center at (800) 632-8000.
  • Give verbal notice to DEQ within 24 hours by calling (833) IPDES24 or (833) 473-3724.
  • For violations reported within 24 hours, follow up with a written report to DEQ via the IPDES E-Permitting System within five days.

Types of IPDES Permits

Individual IPDES Permits

An individual IPDES permit is issued to a specific facility or discharge and is tailored to the unique characteristics of that operation. Applicants must submit a comprehensive permit application. DEQ will conduct a full technical review before developing permit conditions specific to the discharge. Learn more about the different types of individual IPDES permits in the dropdowns below.

Publicly Owned Treatment Works (POTWs) and Private Domestic Treatment Works (PDTWs) discharging to Idaho surface waters must hold an individual municipal IPDES permit. Permits are issued for five-year terms and must comply with IDAPA 58.01.02 and IDAPA 58.01.25. 

Key Permit Conditions 

  • Compliance Schedules — If a reissued permit includes new or more stringent limits and immediate compliance is not feasible, the permit may include a compliance schedule.
  • Effluent Limits — Common parameters include BOD₅, TSS, pH, E. coli, ammonia, and nutrients. 
  • Monitoring and Reporting — May include collecting samples at required locations, testing using approved methods, and submitting results electronically in regular reports. 
  • Pretreatment — Requirements are included directly in the permit. No separate pretreatment permit is issued in Idaho. 
  • Sludge and Biosolids — Prepare and submit a Sludge Disposal Plan, also known as a Biosolids Management Plan.
  • Standard and Special Conditions — May include WET testing, thermal impact studies, and compliance schedules. 

Apply

Via the IPDES E-Permitting System

Guidance

Individual industrial permits are issued to point-source dischargers that are not POTWs and are not appropriately covered by an IPDES general permit. Activities requiring industrial permit coverage for their discharge to surface waters include mining, silviculture, and food processing. 

Apply

Via the IPDES E-Permitting System

Guidance

General IPDES Permits

A general IPDES permit is issued by DEQ to cover multiple facilities or activities with similar discharge characteristics under one standardized set of requirements. Learn more about the different types of general IPDES permits in the dropdowns below.

Fish processing and concentrated aquatic animal production (CAAP) facilities are defined in IDAPA 58.01.25.010 as a “hatchery, fish farm, or other facility which meets the criteria in Appendix C of 40 CFR Part 122, or which the Department designates under 40 CFR 122.24(c).”

Facilities eligible for coverage under these general permits must discharge pollutants to surface Waters of the United States during at least 30 days per year. The facility must contain, grow, or hold fish in raceways, ponds, or other similar structures and meet at least one of the following criteria: 

  • For cold water aquatic species, the facility must produce 20,000 pounds or more of cold-water aquatic species per year and feed at least 5,000 pounds of food in any one calendar month.
  • For warm water aquatic species, the facility must produce more than 100,000 pounds of warm water aquatic species per year.

Aquaculture Facilities Designated as CAAP on a Case-by-Case Basis under 40 CFR 122.24(c)

A facility not meeting the above requirements may still need to seek coverage if, after an on-site visit, DEQ determines the facility is a significant contributor of pollutants based on: 

  • Location and quality of the receiving water 
  • Holding, feeding, and production capacities of the facility 
  • Quantity and nature of the pollutants discharged 
  • Other relevant factors, such as TMDL determinations for the watershed 

Apply

Submit a Notice of Intent (NOI) via the EPA Central Data Exchange (CDX) — NeT-AQUA

Guidance

Permit Documents

A CAFO is a facility where animals have been, are, or will be stabled or confined and fed or maintained for a total of 45 days or more in any 12-month period and where vegetation is not sustained in the confinement area during the normal growing season.

Any CAFO that meets specific animal thresholds and discharges to a water of the US must obtain coverage under the CAFO general permit.

Coverage Thresholds for Concentrated Animal Feeding Operations:

AnimalMinimum # for Coverage Requirement
Mature Dairy Cattle (milked or not) 200
Veal Calves 300
Cattle other than Mature Dairy Cattle 300
Swine weighing 55 lbs or more 750
Swine weighing less than 55 lbs 3,000
Horses 150
Sheep or Lambs 3,000
Turkeys 16,500
Laying Hens (with liquid manure handling) 9,000
Chickens (other than laying hens) 37,500
Laying Hens (with non-liquid manure handling) 25,000
Ducks (with non-liquid manure handling) 10,000
Ducks (with liquid manure handling) 1,500

Permit Requirements 

  • Nutrient Management Plan (NMP) — Permitted CAFOs must develop and implement an NMP addressing manure and wastewater handling and storage, land application rates, site-specific nutrient management controls, and recordkeeping. 
  • Manure and Wastewater Storage Structures — Permitted CAFOs must prevent discharge except as allowed under the permit and agricultural stormwater provisions. 

Coordination with Idaho State Department of Agriculture 

The Idaho State Department of Agriculture (ISDA) regulates AFOs, CAFOs, and dairy farms pursuant to the Beef Cattle Environmental Control Act, the Dairy Environmental Control Act, the Poultry Environmental Act, and rules adopted under the authority of these Acts. DEQ and ISDA have a Memorandum of Understanding addressing how the two agencies coordinate permitting and inspecting CAFOs. 

Apply

Contact your DEQ Regional Office for application instructions.

Guidance

The drinking water treatment facility general permit provides coverage for facilities that discharge treated wastewater from water treatment filtration processes (e.g., filter backwash, sedimentation/presedimentation wash-down, sedimentation/clarification, filter to waste) and their delivery systems to surface Waters of the United States.

Apply

Submit a Notice of Intent (NOI) via the IPDES E-Permitting System

Guidance

Permit Documents

Owners and operators of facilities that pump and treat groundwater and discharge to Waters of the United States are eligible for coverage under the groundwater remediation general permit.

Operators of construction/excavation dewatering activities, building dewatering, and aquifer pump testing that occur at designated or known contaminated sites are also eligible for coverage.

Apply

Submit a Notice of Intent (NOI) via the IPDES E-Permitting System

Guidance

Permit Documents

The pesticide general permit (PGP) covers the application of biological or chemical pesticides that leave a residue. These pesticides may enter surface water when applied for mosquito and other flying insect pest control, weed and algae pest control, animal pest control, or forest canopy pest control use. Operators must seek coverage under the PGP under specified conditions.

Apply

Submit a Notice of Intent (NOI) via EPA Central Data Exchange (CDX) — NeT-PGP

Guidance 

Permit Documents

The small suction dredge mining general permit (SSDMGP) covers recreational suction dredging for waters open to mining, and it specifies limits on maximum nozzle size and cumulative horsepower rating.

Apply

Three permit authorizations are required before dredging:

  1. SSDMGP approval from DEQ
    • Submit a Notice of Intent (NOI) through the IPDES E-Permitting System at least 60 days before you plan to start dredging
    • Once received, post the permit certificate at the dredging site
    • If permit coverage was authorized the previous year, permit coverage authorization is dependent on the submittal of the annual report for the previous year
  2. Idaho Department of Water Resources (IDWR) small-scale mining approval
  3. Federal land manager approval from one of the following:

Do not begin dredging until all three permit authorizations are received.

*Instructions for accessing the correct USFS contact: Select the State and the forest/grassland of interest and select “GO.” Then select the “Topics” tab and select “Geology.”

NOI Submittal Windows for Special Areas

NOIs must be submitted at least 60 days prior to dredging, however, special areas have specific timeframes for submittals. 

Special AreaNOI WindowAllocation Method
GEM CreeksJanuary 1 – April 1 each yearAllocated hours; number of permits limited
McCoy CreekJanuary 1 – May 1 each yearFirst come, first served; number of permits limited
Lolo CreekJanuary 1 – May 1 each yearFirst come, first served; number of permits limited
Moose CreekJanuary 1 – May 1 each yearFirst come, first served; number of permits limited
French & Orogrande CreeksJanuary 1 – May 1 each yearFirst come, first served; number of permits limited
South Fork Clearwater River (SFCW)January 1 – March 1 each yearFirst 15 dredgers with all permits via interagency coordination
Middle Fork Boise River and South Fork Payette RiverUSFS Boise National Forest eligibility approval firstUSFS Eligibility Approval Letter must be obtained and uploaded when submitting the DEQ NOI. If the document is missing, the NOI will be denied and will need to be resubmitted once obtained.

Closed Waters 

Any water closed by the permit, regardless of IDWR’s open/closed status, will not be granted coverage under general permit. The waters closed by the permit include: 

  • Nationally protected areas 
  • Tribal reservations 
  • National wild and scenic rivers 
  • Endangered species habitat areas 
  • Withdrawn river segments by Idaho Department of Lands 
  • State protected rivers 
  • Mercury or sediment-impaired streams without a waste load allocation for suction dredging 

Nationally protected and designated critical habitat areas may be open under the general permit only if a federal agency has completed Endangered Species Act section 7 consultation.

Guidance 

Permit Documents

DEQ Staff Contact

Construction projects that disturb one or more acres and discharge stormwater must be permitted under the stormwater construction general permit. Sites under one acre that are part of a larger common plan of development or sale are also covered.

Key Requirements

  • Submit a Notice of Intent before earth disturbance begins
  • Develop and maintain a Stormwater Pollution Prevention Plan (SWPPP) onsite
  • Install and maintain best management practices (BMPs)
  • Conduct regular inspections

Projects that disturb less than 5 acres and have a Rainfall Erosivity Factor (R factor) of less than 5 may qualify for a low erosivity waiver (LEW). Calculate R factor using the EPA Erosivity Calculator.

SWPPP Requirements 

A SWPPP is required under the CGP (IDR100000) and MSGP (IDR050000). It must be completed before submitting a Notice of Intent.

The SWPPP must include:

  • Identification of potential pollution sources
  • Description of control measures (BMPs)
  • Site map showing drainage and discharge points
  • Inspection and maintenance procedures
  • Corrective action procedures

Apply

  1. Develop a SWPPP
  2. Submit a Notice of Intent (NOI) via the IPDES E-Permitting System
  3. Associated fees must be paid for DEQ to initiate NOI review
  4. The 14-day external agency review begins when the NOI is deemed complete

Guidance

Permit Documents

Facilities with industrial activities or materials exposed to stormwater must seek coverage under the multi-sector general permit (MSGP). Coverage is based on the facility’s standard industrial classification (SIC) code. Facilities required to obtain coverage based on their SIC code are listed in Appendix B of the MSGP.

Facilities commonly covered in Idaho include mines, airports, and junkyards, as well as facilities that process food, cement products, wood products, and metal products.

Key Requirements

  • Develop and maintain a Stormwater Pollution Prevention Plan (SWPPP) onsite
  • Implement best management practices (BMPs) and conduct routine inspections
  • Perform monitoring and submit required reports

Facilities that would otherwise require MSGP coverage based on their SIC code may qualify for a no exposure certification (NEC) if industrial activities and materials are not exposed to stormwater, as outlined in Appendix H of the MSGP.

SWPPP Requirements 

A SWPPP is required under the CGP (IDR100000) and MSGP (IDR050000). It must be completed before submitting a Notice of Intent.

A SWPPP must include:

  • Identification of potential pollution sources
  • Description of control measures (BMPs)
  • Site map showing drainage and discharge points
  • Inspection and maintenance procedures
  • Corrective action procedures

Apply

Develop a SWPPP and then submit a Notice of Intent (NOI) via the IPDES E-Permitting System

Guidance

Permit Documents

Municipalities meeting certain population criteria must seek coverage under a municipal separate storm sewer system permit (MS4). MS4 permits cover public entities discharging stormwater, including cities, counties, the Idaho Transportation Department, state universities, local colleges, and local highway districts. 

MS4s are regulated as large/medium (Phase I) or small (Phase II) systems.

  • Phase I systems are defined as cities or certain counties with populations of 100,000 or more.
  • Phase II systems are in Census-designated urban areas with a population of 50,000 or more.

Urbanized areas owned by separate municipalities may be covered under one permit.

All permitted MS4s are required to implement six minimum control measures:  

  • Public education and outreach 
  • Public involvement 
  • Illicit discharge detection and elimination 
  • Construction site runoff control
  • Post-construction stormwater management
  • Municipal operations controls 

Apply

Apply via the IPDES E-Permitting System

Guidance

Apply or Renew

Individual Permits

Before you apply:

How to apply:

After you apply:

  • DEQ reviews your application and may request additional information.
  • The permit is added to the development queue on the Permit Issuance Plan.
  • DEQ develops a draft permit when the permit is up for development in the queue.
  • 10-day errors and omissions review.
  • 30-day public comment period.
  • Final permit issuance.
  • 28-day appeal period.

Renew

  • Renewal applications must be submitted through the IPDES E-Permitting System at least 180 days before the permit expires.
    Note: Many Idaho IPDES permits are listed as “Admin. cont.” in the Permit Issuance Plan or on DEQ’s website, indicating the permit term is expired but the permit is still in effect because a timely renewal was filed.

General Permits

Before you apply:

  • If you are unsure of the permit type needed for your project, contact your DEQ Regional Office to determine the appropriate permit type.
  • Stormwater Construction General Permit (CGP) and Multi-Sector General Permit (MSGP): complete a Stormwater Pollution Prevention Plan (SWPPP) before submitting a Notice of Intent (NOI)

How to apply:

  1. Submit an NOI via the IPDES E-Permitting System.
  2. Pay applicable fees. DEQ will not initiate review of your Notice of Intent (NOI) until applicable fees are paid.

After you apply:

  • DEQ reviews the NOI and obtains agency partner review if required.
  • DEQ authorizes or denies coverage under the general permit.

Renew

  • Reference the specific general permit language for renewal timeline information.
  • To renew general permit coverage, submit an NOI via the IPDES E-Permitting System.

Modify, Transfer, or Terminate a Permit

Permit Modifications

Modifications may be initiated by DEQ or by request of an interested person, including the permittee. Requests must be submitted through the IPDES E-Permitting System in writing and contain facts or reasons supporting the request. 

  • General Permits: To modify general permit coverage, submit a Change Notice of Intent (NOI) through the IPDES E-Permitting System.
  • Individual Permits: To modify an individual permit, contact the DEQ IPDES program at (833) IPDES24 or (833) 473-3724.
    • Minor permit modifications are administrative and do not require public notice.
    • Major permit modifications require a 30-day public notice period.

Permit Transfers

  • Submit a signed transfer agreement from both parties through the IPDES E-Permitting System at least 30 days before the proposed transfer.
  • DEQ will review the transfer agreement and may issue a notice of intent to modify or may revoke and reissue the permit. A modification to incorporate a permit transfer is considered a minor modification.
  • If DEQ does not issue any notice, the transfer is effective on the date specified in the agreement. 
  • Some general permits (i.e. MSGP and CGP) do not allow permit transfers, and instead require the new operator submit their own NOI.

Permit Terminations

Terminations may be initiated by DEQ or by request of an interested person, including the permittee. Permit terminations must meet the eligibility requirements in IDAPA 58.01.25.203.

  • Permittees requesting termination must submit a Notice of Termination (NOT) signed by the Certifying Official through the IPDES E-Permitting System.
  • Aquaculture and pesticide general permit NOTs must be submitted through EPA Central Data Exchange (CDX).
  • Permit coverage remains active until DEQ approves the NOT and notifies the permittee of the termination date.

Fees and Payments

IPDES fees are established under IDAPA 58.01.14.170. Annual fees are assessed October 1 and are due by December 30. Annual fees may be prorated when coverage is issued or terminated during the fee year.

Fees vary based on permit type:

Permit TypeApplication FeeAnnual Fee
Individual Permits
Individual Permit Municipal$0$1.74 per EDU
Individual Permit Industrial — Major$0$13,000
Individual Permit Industrial — Minor$0$4,000
Construction General Permit (CGP) — IDR100000
>0–10 acres$200$0
>10–50 acres$400$75
>50–100 acres$750$100
>100–500 acres$1,000$400
>500 acres$1,250$400
Low Erosivity Waiver$125$0
Multi-Sector General Permit (MSGP) — IDR050000
Industrial MSGP$1,500$1,000
Certificate of No Exposure$250$100
Other General Permits
Other General Permits$0$0

How to Pay

IMPORTANT: Notices of Intent (NOIs) will not be reviewed until the applicable fee is paid. To avoid delays in the processing of general permits, DEQ strongly recommends paying fees online. Mailed checks are allowed but may result in delayed permit application processing and approval.   

  • Online (Preferred)
  • By Mail (May result in delayed permit application approval)
    • Make checks payable to: DEQ
    • Memo: invoice number
    • Mail to:
      Idaho DEQ Financial Office
      1410 N. Hilton St.
      Boise, ID 83706

Compliance Requirements

IPDES permits require permittees to conduct periodic evaluations of compliance with established effluent limits and report these to DEQ. IPDES permits specify what must be monitored, how often monitoring must occur, and how results must be reported.

Submitting Reports

Reports are due by the dates specified in your permit. Submit reports using the appropriate system:

Report a Permit Violation

  • Report public health emergencies immediately by calling the 24-hour Idaho Emergency Medical Services Communications Center at (800) 632-8000.
  • Give verbal notice to DEQ within 24 hours by calling (833) IPDES24 or (833) 473-3724.
  • For violations reported within 24 hours, follow up with a written report to DEQ via the IPDES E-Permitting System within five days.

Compliance Inspections

TypeDescriptionConducted By
Compliance Evaluation (CEI) Full facility, records, outfall review Regional or State IPDES Compliance Officer
Reconnaissance Visual survey, no advance notice Regional IPDES Compliance Officer
Performance Audit In-depth treatment & sampling review State IPDES Compliance Officer
Construction Site Best Management Practice (BMP), Stormwater Pollution Prevention Plan (SWPPP) verification Regional IPDES Compliance Officer
Follow-Up Corrective action verification Regional or State IPDES Compliance Officer

Staff Contacts

IPDES E-Permitting Support
(833) IPDES24 / (833) 473-3724
IPDESe-permitting@deq.idaho.gov

Enforcement Questions
Main enforcement line: (208) 373-0182 
wwenforcement@deq.idaho.gov

Individual Permits (Municipal & Industrial)
Matthew Stutzman
(208) 373-0247
Matthew.Stutzman@deq.idaho.gov

Stormwater Construction General Permit,
Drinking Water General Permit
Rebecca Garcia
(208) 373-0423
Rebecca.Garcia@deq.idaho.gov

Industrial Stormwater General Permit,
Small Suction Dredge Mining
David Hotz
(208) 373-0178
David.Hotz@deq.idaho.gov

Municipal CWA Programs – Pretreatment, Biosolids, Municipal Separate Storm Sewer System (MS4)
Vacant
(833) 473-3724
IPDESe-permitting@deq.idaho.gov

Aquaculture,
CAFOs,
Groundwater Remediation,
Pesticide General Permits

Patrick Gillis
(208) 373-0498
Patrick.Gillis@deq.idaho.gov

EPA Platforms (CDX, NeT-DMR, NeT-PGP, NeT-AQUA, ECHO, ICIS)
Brynn Lacabanne
(208) 373-0289
Brynn.Lacabanne@deq.idaho.gov

Other General Permit Questions
Angela Anderson
(208) 373-0560
Angela.Anderson@deq.idaho.gov

Resources

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