Oklahoma septic rules, in plain English

Septic pumping, aerobic service and repair help across Oklahoma, Cleveland and Canadian counties(405) 546-2064

Oklahoma regulates home septic systems at the state level through the Department of Environmental Quality. Two chapters of the Oklahoma Administrative Code do most of the work: Chapter 641 covers designing, building and running on-site systems, and Chapter 645 covers the companies that pump and haul what comes out of them. Here is what each means for someone who owns a house in Oklahoma, Cleveland or Canadian County.

Chapter 641: the system itself

OAC 252:641 applies to anyone who owns, designs, builds, modifies, repairs or operates an on-site system. For owners, the key parts are:

You're responsible for operation. Sewage can't surface, pool, run across the ground or reach a creek. Tanks, lift stations and aerobic units can't leak or overflow. Lids, manhole covers and any required fences have to stay secure.
A failure needs prompt action. The owner must repair a malfunctioning system, prevent further violations and clean up the site.
Changes need authorization. New systems and modifications (expanding or relocating any part) need DEQ authorization before work starts and an inspection before backfill.
Aerobic systems have a built-in service period. The installer maintains a new aerobic system for two years at no added cost; then it's on the owner.
The rules are minimums. The chapter itself says its standards don't guarantee a system will perform.

Chapter 645: the pump truck

OAC 252:645 applies to anyone who pumps, hauls, stores, treats, land-applies or disposes of septage. The business needs an annual DEQ license, which expires January 31. To get one, the applicant completes two hours of DEQ training and passes an exam with at least 70 percent; renewals need two more hours of approved training each year. Drivers working for a licensed company must be certified within 45 days of being hired. Other duties:

Pump the tank empty, leaving no more than five percent of its volume.
Give the owner a written statement of the volume removed.
Keep a daily log of each truck's loads, where they were pumped and where they went.
Register and pass inspection on every truck each year and paint its DEQ number, four inches high, on both sides of the tank.
Post a $25,000 surety bond that DEQ can draw on to clean up a spill.

Grease trap waste and car wash mud trap waste don't count as domestic septage under the rule (DEQ pumper page).

Ring this number and we put you through to a DEQ-licensed septic outfit that works your part of the metro. (405) 546-2064

Checking a company

If they...	Ask for	Where to check
Pump or haul septage	Their DEQ license number	DEQ licensed pumper list, with the county where each business is based
Install, modify or repair systems	Their certification categories	DEQ certified installer search
Do soil profiles	Their soil profiler certification	DEQ's list of certified soil profilers

The pumper list is statewide. The version DEQ published in November 2025 showed 232 active licensees, of which 14 were based in Oklahoma County, 7 in Canadian County and 5 in Cleveland County. Plenty of companies based in neighboring counties also work the metro, so a company's home county isn't the whole story.

Records worth asking for

The local DEQ office can provide a copy of a system's original inspection report, which shows where the tank and field are (DEQ guide). DEQ also performs existing-system evaluations on request for a set fee; see the cost guide. If you're buying a house, combine those records with a pump-out so someone actually sees inside the tank.

Questions about a specific property go to DEQ's Environmental Complaints and Local Services division at (405) 702-6100 or your local DEQ office.

Frequently asked

Does Oklahoma license septic pumpers?

Yes. DEQ issues an annual license to businesses that pump, haul or dispose of septage, and each truck must be registered and display its DEQ number.

Does Oklahoma require aerobic systems to have a maintenance contract?

The rule requires the installer to maintain a new aerobic system for its first two years. After that, the owner is responsible for keeping it maintained, either personally or by hiring someone.

Who do I call about a bootlegged septic system?

DEQ takes reports of unpermitted systems at 1-800-522-0206. Reports can be anonymous but need specifics such as the location and dates.

Talk to a septic contractor who covers your road

This line routes to independent local septic businesses, not to us doing the work. The contractor quotes and does the job. Toilets backing up or sewage in the yard? Quit using water in the house and phone now.