As part of DEQ’s responsibility to protect Idaho’s water resources, permits are required for the disposal of wastewater. There are two main permitting programs depending on how a facility wishes to dispose of the treated effluent. If a facility intends to discharge to a surface water body—a river, lake, reservoir, or stream—the facility should apply for an Idaho Pollutant Discharge Elimination System permit. If the facility wishes to use the treated effluent as recycled water to apply to crops or other beneficial uses, the facility should apply for a reuse permit.
In some instances (e.g., federally licensed dams or dredge and fill permits) DEQ reviews the application the entity submits and determines whether or not a federal agency (e.g., the Federal Energy Regulatory Commission or the US Army Corps of Engineers) can issue a permit that would comply with Idaho’s water quality standards. This authority stems from section 401 of the Clean Water Act, and these are often referred to as Section 401 Certifications.
The Idaho Pollutant Discharge Elimination System (IPDES) Bureau develops permits authorizing effluent discharges and fact sheets describing how permit conditions are developed. IPDES permits are written to comply with the state water quality standards and limit the amount of pollution that point sources may discharge into surface waters.
An IPDES permit authorizes a permittee to discharge pollutants from point sources into waters of the United States in Idaho, except on tribal land. DEQ requires those classes or sectors of discharges required by EPA to have a National Pollutant Discharge Elimination System (NPDES) permit to obtain an IPDES permit, but will not expand required coverage beyond federal regulatory requirements.
Our IPDES staff are available to answer any questions users may have related to a permit application, compliance, monitoring, reporting, inspection, and the IPDES E-Permitting System.
We update the Permit Issuance Plan (PIP) annually. The PIP is DEQ’s plan for drafting and issuing permits and covers a two-year time frame.
Our online system for accepting information from permittees and applicants allows users to register accounts, associate the accounts with facilities, submit information, and track progress on draft permits. The IPDES E-Permitting System is the main route for permittees to provide required information and materials to DEQ. Depending on the permit class or sector, we may require permittees to continuing using NetDMR or NeT to comply with EPA’s electronic reporting rule.
IPDES individual municipal permits are issued to publicly and privately-owned treatment works (POTW) that provide services for municipalities, sewer districts, and communities across Idaho. These services include treatment of domestic sewage, storm water drainage, and sewage sludge disposal.
Additionally, some municipal drinking water treatment plants discharge filter backwash to surface waters, which requires an IPDES permit. When a municipal system accepts waste from a categorical industrial user or a significant industrial user, that municipality may need to develop a pretreatment program.
DEQ assesses an annual fee for municipal wastewater dischargers. This annual fee is based on information that permittees provide annually through the IPDES E-Permitting System, identifying the population served by the treatment works and average household size. This information accessed through the U.S. Census Bureau Factfinder.
We developed a User’s Guide to Permitting and Compliance, Volume 2 – POTWs to help municipal users apply for and understand an IPDES permit.
DEQ gained authorization to issue surface water discharge permits for non-POTWs on July 1, 2019.
IPDES individual industrial permits are issued for non-POTW point source dischargers that are not appropriately covered by an IPDES general permit. Examples of activities that need industrial permit coverage for their discharge to surface waters include mining, silviculture, food processing, aquaculture, and concentrated animal feeding operations.
We developed a User’s Guide to Permitting and Compliance, Volume 3 – Non-POTWs to help industrial users apply for and understand an IPDES permit.
DEQ gained authorization to issue general discharge permits excluding storm water permits on July 1, 2020.
IPDES general permits cover multiple permittees with similar discharges that are located in similar geographic areas. A general permit applies similar conditions to all covered dischargers. In Idaho, there are currently six non storm water general permit types:
- Concentrated Animal Feeding Operations (CAFO)
- Concentrated Aquatic Animal Production (CAAP) Facilities:
- Drinking Water Facilities
- Groundwater Remediation Facilities
- Small Suction Dredge Placer Miners
- Pesticide Applications
Idaho encourages reuse, the practice of using recycled water for irrigation, ground water recharge, landscape impoundments, toilet flushing in commercial buildings, dust control, and other beneficial uses. To protect public health and prevent pollution of surface and ground waters, Idaho's Recycled Water Rules (IDAPA 58.01.17) require anyone wishing to construct, modify, or operate a reuse facility in the state to first obtain a permit from DEQ. Two types of reuse permits are issued—industrial and municipal. Industrial permits regulate reuse from operations such as food processing facilities. Municipal permits regulate reuse containing treated sewage. Idaho does not currently permit recycled water systems for individual residential applications.
Obtaining a reuse permit may take six months or longer depending on the complexity of the project as well as the submittal and review timelines. Regulations regarding reuse in the State are contained in IDAPA 58.01.17, the Recycled Water Rules”. All reuse permits specify both standard and site-specific conditions. Additional requirements apply to municipal permits.
The reuse permit application process begins with the applicant scheduling a pre-application meeting with DEQ at which application requirements are discussed. Applicants are then required to submit to DEQ an application including site-specific information, facility and topographic maps, and reuse-specific information.
Upon receipt of the application, DEQ reviews the applicant's information and, if all requirements have been met, issues a completeness determination within 30 days. If the application is determined to be complete, DEQ will then set the effective date of the application. Within 30 days following the effective date of the application, DEQ will issue a preliminary decision to prepare a draft permit or deny the application. Following a decision to prepare a draft permit, DEQ will prepare the draft permit within 60 days. The public is then notified that a draft permit has been issued and is given an opportunity to comment. The effective date of the final permit is generally 60 days after the draft permit has been issued.
Municipal recycled water is classified based on use and is often used to irrigate farmlands, orchards and vineyards, golf courses, cemeteries, parks, playgrounds, schoolyards, and other areas. Because of the nature of this recycled water and its potential exposure to humans and animals, certain specific treatment requirements apply to municipal reuse. For example, monitoring requirements include mandatory bacterial sampling. Other specific measurable criteria also must be met, depending on whether the recycled water may come into contact with edible or inedible portions of raw food crops, fruit, fodder, seed, and processed food crops. Irrigation may be allowed only during periods of non-use, and public access may be restricted.
Industrial wastewater characteristics can vary greatly with changing production rates, schedules, and industry type. Constituents of industrial wastewater are typically different from municipal wastewater and can contain toxic substances such as metals. Possible concerns with the reuse of high-strength industrial recycled water include odor and overloading of the site with constituents in the recycled water. Industrial reuse systems typically require additional pretreatment and special site management to ensure the practice is protective of public health and the environment.
Section 401 of the federal Clean Water Act requires state certification for any permit or license issued by a federal agency for an activity that may result in a discharge into waters of the US. Water quality certifications ensure projects comply with state water quality standards and any other water quality requirements under state law.
Visit our Water Quality Certifications web page for additional information.