Protecting Public Health and the Environment.

Wastewater System Classifications

A public wastewater system is any publicly or privately owned collection system or treatment system that generates, collects, treats, or disposes of 2,500 gallons or more of wastewater per day. Systems that meet this definition are required to comply with Idaho's Wastewater Rules (IDAPA 58.01.16) and the Rules of the Board of Drinking Water and Wastewater Professionals (IDAPA 24.05.01).

The following systems are not considered public wastewater systems and are not subject to the wastewater operator licensure requirements:

  • Any wastewater treatment system operated and maintained exclusively by a single-family residence
  • Any wastewater system consisting solely of a gravity flow, nonmechanical septic tank and subsurface treatment and distribution system
  • Any animal waste system used for agricultural purposes that has been constructed in part or in whole by public funds
  • Industrial wastewater systems under private ownership
  • Any wastewater system with individual septic tanks and individual pump stations that discharge to a common gravity flow subsurface treatment and distribution system, when ownership of each septic tank and pumping station is by individual property owner and ownership of the common system is by a public or private entity

The Rules of the Board of Drinking Water and Wastewater Professionals require that wastewater systems meeting the definition of a public wastewater system be classified based on indicators of potential health risk. Criteria used to determine the potential health risks include the system's complexity, volume, variability in raw waste for treatment systems, and other criteria deemed appropriate. Systems are classified by type (treatment or collection) and class. Classifications range from Very Small Wastewater System to Class I, II, III, or IV. The rules also require that public wastewater systems be staffed by licensed operators based on the system classification.

Determining a System's Classification

Wastewater system owners must calculate the system's classification to ensure its operators, and in particular, the responsible and substitute responsible charge operators, are properly licensed. A worksheet has been developed for both treatment and collection systems to assist in determining system classification.

Based on the information provided in the worksheet, DEQ determines the system's classification.

Note: The Wastewater Rules and Rules of the Board/Idaho Bureau of Occupational Licenses operator (IBOL) application requirements have different deadlines for submittal of wastewater system classification worksheets. The Wastewater Rules require that a system owner submit an initial classification worksheet and every 5 years thereafter. However, the board rules/IBOL application require that the operator applicant include a system classification worksheet for the application to be considered complete. Since the board rules/IBOL deadline is application-specific, the system owner should be prepared with a DEQ-verified and -approved system classification worksheet on file so any unlicensed operator submitting a first-time application or any licensed operator submitting an application to upgrade a license only has to photocopy the DEQ-approved system classification worksheet on file for the wastewater system. Enclosure of a DEQ-verified and -approved classification worksheet allows the board/IBOL to process the license application in a timely manner.  

Current Public Wastewater System Classifications

DEQ maintains and periodically updates a list of wastewater treatment and collection systems that have submitted classification worksheets and received verification of the official system classification.

Note: This list is a snapshot in time according to the date shown on the list.

Wastewater System Name and Address Changes

The wastewater system owner or the owner's designee should report changes to the name of the wastewater system, name of the legal owner of the wastewater system, owner's contact information, and changes to the mailing or physical address. To report the changes, completely fill out the Owner Information Form and submit to the following: 

Idaho Department of Environmental Quality
1410 N. Hilton
Boise, ID  83706
Attention: Adam Bussan

The wastewater system owner is required to report a name change of a responsible charge operator or substitute responsible charge operator to DEQ within 10 days following the change in personnel. To report changes in either a responsible charge operator or a substitute responsible charge operator, fill out a Public Wastewater System Operator Licensure Record Form

Staff Contacts

Water Quality Engineer
Jerimiah Fenton
DEQ State Office
1410 N. Orchard St.
Boise, ID 83706
(208) 373-0551

Water Quality Engineering Manager
Valerie Greear
DEQ Boise Regional Office
1445 N. Orchard St.
Boise, ID 83706
(208) 373-0550

Water Quality Engineering Manager
Matthew Plaisted
DEQ Coeur d'Alene Regional Office
2110 Ironwood Parkway
Coeur d'Alene, ID 83814
(208) 666-4622

Water Quality Engineering Manager
Gregory Eager
DEQ Idaho Falls Regional Office
900 N. Skyline Drive, Suite B
Idaho Falls, ID 83402
(208) 528-2650

Water Quality Engineering Manager
Michael Camin
DEQ Lewiston Regional Office
1118 "F" St.
Lewiston, ID 83501
(208) 799-4370

Drinking Water/Wastewater Manager

Drinking Water/Wastewater Manager
DEQ Twin Falls Regional Office
650 Addison Avenue West, Suite 110
Twin Falls, ID 83301

State Rules

Related Pages

Wastewater Collection and Treatment Systems

Wastewater Disposal Options

Wastewater System Supervision Requirements

Wastewater Operator Resources