New septic system installation in the Oklahoma City area

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

Building on acreage outside the sewer mains, or replacing a system that's past saving, follows a fixed state process in Oklahoma. It runs through DEQ, not the county, and the paperwork has specific names. Knowing them makes the conversation with an installer a lot shorter.

Step 1: The 581 report

DEQ Form 641-581, the "Report for On-Site Sewage," decides which system types your property can use and the minimum dispersal area based on the size of the house (DEQ sewage treatment). It's built on one of three things:

Soil profile test. At least three holes or pits dug in the proposed dispersal area and described for texture. Only DEQ or a DEQ-certified soil profiler can do it. It can qualify a lot for a conventional system, aerobic spray or drip, or a lagoon.
Percolation test. At least three holes kept filled to a minimum of twelve inches of water for 24 hours before measuring. It can only be used for conventional lateral lines, and not in a water body protection area.
Design only. No digging; the design assumes Group 5 soil, the heaviest clay. Allowed only for aerobic spray or lagoon systems.

Step 2: Authorization to construct

Before a new system goes in, or an existing one is expanded or moved, the installer buys an Authorization to Construct from DEQ, which is assigned to the local Environmental Specialist. DEQ reviews the 581 report before issuing it. Anything that departs from the standard rules is an "alternative system" and needs its own individual permit and plan review (OAC 252:641-1-2.1).

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

Step 3: Inspection

The system must be inspected and approved before it's covered and used. A certified installer can self-inspect within the categories they hold; everyone else gets a DEQ inspection. Final inspections go on DEQ Form 641-576, which records every component, its location and its separation distances. Keep a copy; it's the map the next pumper or buyer will want.

Rules that shape the design

Tank size. At least 1,000 gallons for a home with up to four bedrooms, plus 250 gallons for each bedroom beyond that.
Design flow. 200 gallons a day for two bedrooms or fewer, plus 66 gallons for each additional bedroom. Field size comes from that number.
Lot size. Minimums are set in the rule's Appendix A. Lots in plats recorded before January 1, 1974, are exempt from the minimum but not from the construction rules.
Fill dirt. More than six inches of fill or any digging over a tested site means calling the local DEQ office about a new test; tests aren't allowed at all in major fill areas.
Lakes and streams. Within 300 feet of a listed reservoir's normal pool or a stream bed (Zone 1), a dispersal field needs an NSF/ANSI 245 nitrogen-reduction unit ahead of it.
Your own land. Every tank, pump and field must sit on the owner's property or a recorded easement.

Choosing an installer

Since November 1, 2025, someone without DEQ certification can install just one system per calendar year, and DEQ must inspect it with the installer present (DEQ FAQ). DEQ certifies installers in four categories: conventional/shallow extended/ET-A, lagoon, aerobic with spray, and aerobic with drip (DEQ certified installers). Ask which categories a company holds and check them on DEQ's installer search. A system put in without authorization is a "bootlegged" system, and DEQ can require it be permitted and inspected after the fact.

State fees for each step are in the septic cost guide. If you're going aerobic, read aerobic system service first so the upkeep isn't a surprise.

Frequently asked

Can I install my own septic system in Oklahoma?

An uncertified person can install one system per calendar year. It still needs the 581 report, an Authorization to Construct, and a DEQ inspection with the installer present before it's covered.

Why was my lot only approved for an aerobic system?

The soil test or design-only route decides the allowed types. Heavy clay, shallow rock, wet soil or a small dispersal area can rule out conventional lateral lines.

Does the county issue septic permits here?

No. In Oklahoma the authorization comes from DEQ, with the local DEQ Environmental Specialist handling review and inspection.

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.