Source check: 2026-10-04. Shared WPI courses are linked only where the standardized exam and class match are confirmed. Local grades may not equal WPI class numbers. Your authority's current documents control.
Exam route under review
Program authority: Idaho Board of Drinking Water and Wastewater Professionals, Division of Occupational and Professional Licenses (DOPL)
Local levels: Drinking Water Treatment Operator: Operator-In-Training; Class I Restricted; Class I; Class II; Class III; Class IV. Very Small Drinking Water Systems is a separate drinking-water system credential, not a numbered treatment class.
Idaho-specific treatment exams numbered 1–4 are listed by the state-designated administrator. Neither that list nor the linked bulletin explicitly identifies them as WPI/ABC standardized rather than customized exams. No local-to-WPI class equivalence is verified; Operator-In-Training and Class I Restricted exam correspondence is also unverified.
No state-matched course is linked for this stream yet.
Rule 100.01, dated 7-1-26, lists Drinking Water Treatment Operator classifications: ‘Operator-In-Training, Class I Restricted, Class I, II, III, or IV.’
Lists ‘Idaho Water Treatment Class 1’ through ‘Idaho Water Treatment Class 4’; does not label them standardized or customized.
Bulletin updated 10/1/2024 states examinations are delivered at PSI Test Centers and ‘ABC’s standard formula sheet’ is provided. A standard formula sheet is not evidence of a standardized exam.
Exam route under review
Program authority: Idaho Board of Drinking Water and Wastewater Professionals, Division of Occupational and Professional Licenses (DOPL)
Local levels: Wastewater Treatment Operator: Operator-In-Training; Class I Restricted; Class I; Class II; Class III; Class IV; Land Application. Separate credential: Very Small Wastewater Systems. The current operative classification table does not separately list Lagoon.
Wastewater-treatment exams numbered 1–4 are directly documented, independently of drinking-water evidence. PSI also lists Land Application and Small Wastewater System/Lagoon exams. No opened authority/administrator source establishes standardized WPI scope, customized ABC identity, or a state-written exam. The Lagoon terminology discrepancy requires clarification.
No state-matched course is linked for this stream yet.
Rule 100.01 lists treatment classifications ‘Operator-In-Training, Class I Restricted, Class I, II, III, IV, or Land Application’ plus separate ‘Very Small Wastewater Systems.’ Rule 100.03.i requires Land Application operators to maintain an active Wastewater Treatment Operator license.
Lists ‘Idaho Wastewater Treatment Class 1’ through ‘Class 4,’ ‘Idaho Land Application,’ and ‘Idaho Small Wastewater System/Lagoon.’
Exam route under review
Program authority: Idaho Board of Drinking Water and Wastewater Professionals, Division of Occupational and Professional Licenses (DOPL)
Local levels: Drinking Water Distribution Operator: Operator-In-Training; Class I Restricted; Class I; Class II; Class III; Class IV. Separate credential: Very Small Drinking Water Systems.
The administrator lists distribution exams numbered 1–4 and a separate Very Small Water System exam. Their standardized, customized ABC, or state-specific identity is not established. Very Small, Operator-In-Training, and Class I Restricted must not be automatically mapped to WPI Class I.
No state-matched course is linked for this stream yet.
Rule 100.01 lists Drinking Water Distribution Operator as ‘Operator-In-Training, Class I Restricted, Class I, II, III, or IV’ and separately lists ‘Very Small Drinking Water Systems.’ Rule 100.03.b requires twelve hours of chlorination and drinking-water distribution courses for Very Small Drinking Water.
Lists ‘Idaho Water Distribution Class 1’ through ‘Class 4’ and ‘Idaho Very Small Water System’; no standardized/customized designation is given.
Exam route under review
Program authority: Idaho Board of Drinking Water and Wastewater Professionals, Division of Occupational and Professional Licenses (DOPL)
Local levels: Wastewater Collections Operator: Operator-In-Training; Class I Restricted; Class I; Class II; Class III; Class IV. Very Small Wastewater Systems is a separate combined-system credential, not a numbered collection class.
Collection licensing and exams numbered 1–4 are independently confirmed. Explicit standardized WPI/ABC scope and local-to-WPI correspondence are absent from the opened sources. The Very Small Wastewater definition includes collection, but that does not establish a separate collection exam or WPI class mapping.
No state-matched course is linked for this stream yet.
Rule 100.01 uses ‘Wastewater Collections Operator’ with ‘Operator-In-Training, Class I Restricted, Class I, II, III, or IV.’ Rule 002.02 defines Very Small Public Wastewater System as including a collection system and specified limited treatment processes.
Explicitly lists ‘Idaho Wastewater Collection Class 1’ through ‘Idaho Wastewater Collection Class 4.’
Dedicated prep is not available or being sold yet.