FAQ's for Changes Effective November 1, 2025

Under Oklahoma Statutes- Title 59: Professions and Occupations, Section 1158: Installers of individual sewage disposal systems: Any person, before engaging in the installation of individual sewage disposal systems, shall first obtain certification from the Department of Environmental Quality... the provisions of this subsection shall only apply to persons who install more than one individual sewage disposal system per calendar year.

The Oklahoma On-Site Wastewater Association (OOWA) ran legislation (Senate Bill 111) that moved to amend the statute referenced above. This amendment was approved without the Governor's signature with an effective date of November 1, 2025.

Yes. An individual who is not certified by DEQ may install one on-site sewage system per calendar year. The individual listed as the installer will be held responsible by DEQ to ensure compliance with all provisions set forth in OAC 252:641 Individual and Small Public On-Site Sewage Treatment Systems as well as OS 27A Environment and Natural Resources.

An on-site sewage treatment system installed by a non-certified installer must be inspected by DEQ . The installer must be present at the time of inspection.

Any deficiencies identified during the inspection must be corrected before DEQ will issue the final inspection and before the system may be placed into operation.

Contact our Oklahoma City office at 405-702-6100 and ask to speak to the on-site team. If no authorization is identified under your name, we will assist you with your request. 

Yes. Non-certified ATC's purchased before November 1, 2025 may be installed by you and must be inspected by DEQ. If you achieve certification before the install, you may self-inspect the system.

DEQ will investigate all reports of non-compliance. An on-site sewage system installed without proper authorization or inspection is considered a bootlegged system. DEQ will require the system be properly permitted and inspected, even if it has already been installed.

An individual found to be non-compliant with DEQ’s rules or regulations may face enforcement actions including orders to correct deficiencies and/or administrative penalties enforceable in district court.

To report a bootlegged on-site system, file an Environmental Complaint with DEQ.

To become a certified installer, applicants must install five (5) experience systems and two (2) joint inspections in the category they are seeking certification in. To meet these requirements, applicants will be placed into a “Certified Installer-In Training” status once all other application requirements have been completed. 

All application items, excluding experience installations and joint inspection installations, must be received and processed by DEQ:

• Certified Installer Application
• Affidavit of Citizenship
• Copy of non-expired government issued ID
• A surety bond of $75,000 under the installer's name (not the business) listing Oklahoma Department of Environmental Quality as the obligee
• Payment of all fees
• Attend initial certification training and pass the exam with a 70% score or higher

Once you meet the requirements to become a “Certified Installer-In Training”, you will be provided your certification number. This number may be used on the online application to purchase your authorizations. 

While in an "In Training" status, you will only be able to purchase soil tests and authorizations <=1500 gpd which credit towards your experience installations or joint inspection installations.

Yes. All installations must be inspected by DEQ while in training.

You will have two (2) years after the initial application date to complete all experience systems and joint inspections.

Yes. Any systems installed within two (2) years of your application date may be credited toward achieving certification. These systems must have you listed as the installer of record.  Systems that you assisted in the installation of will not be counted.

Individuals who began the certification process prior to November 1, 2025, will be considered “Certified Installer-In Training”. Your installer number must be entered on the online payments application. 

All other certification items must be provided before certification is achieved.

All installations must be inspected by DEQ until certification is achieved. 

Certified installers may self-inspect on-site sewage systems in the category/categories they are certified in. System category/categories for which you are not certified must be inspected by DEQ and will be charged at the higher, non-certified price.

While in a not-renewed, suspended, or inactive status, you will be treated as a non-certified installer and you may install one (1) on-site sewage treatment system per calendar year until your certification is reinstated.