Skip to Main Content

DEQ Title, click to go to DEQ home page

photo of a septage pumper truck

Listing of Certified Installers

Septic tanks should be pumped out every three to five years. Click here to be directed to a listing of licensed Septage Pumpers and Transporters.



All on-site systems have a septic tank. According to the Environmental Protection Agency, the septic tank is a buried, watertight container typically made of concrete, fiberglass, or polyethylene. It holds the wastewater long enough to allow solids to settle out (forming sludge) and oil and grease to float to the surface (as scum). It also allows partial decomposition of the solid materials. Newer tanks generally have risers with lids at the ground surface to allow easy location, inspection, and pumping of the tank.

Under average conditions, you should have your septic tank pumped every three to five years. However, a number of factors impact the frequency of pumping. You may contact a
professional to inspect your tank or you can check it yourself. If you or a professional cannot check the tank, tank-pumping frequency can be estimated on the number of people using the
system. The following chart may be used as a guideline and should not take the place of a professional inspection or actual measuring of the sludge.

1000 gallon capacity septic tank
number of people using the system 1 2 4 6 8
years between each pumping 12 6 3 2 1

Septage Pumpers and Transporters

Periodic pumping of the septic tank is essential to the long-term operation of the on-site wastewater treatment system.

Oklahoma law requires a license for anyone engaged in the business of pumping, hauling or disposing of domestic wastewater (septage) from septic tanks, holding tanks, chemical toilets, or any other similar wastewater holding tanks. The pumping of the tank and the disposal of the waste shall be in accordance with DEQ rules and regulations pertaining to septage pumpers and haulers. Click here to be directed to a listing of licensed Septage Pumpers and Transporters.

Septic Tank Maintenance

  • Mark the location of your septic tank. This will help prevent activities that may damage the tank, like someone driving a vehicle over the tank.

  • The use of septic tank additives is not recommended. More than enough bacteria are naturally present in your system to provide the necessary treatment. Some products kill the beneficial bacteria and no product eliminates the need for periodic pumping.

  • Minimize or eliminate the use of a garbage disposal. Food waste fills a tank quickly, causing the tank to require more frequent pumping.

  • Do not flush harmful substances such as pesticides, disinfectants, medicines, varnishes, etc.

  • Minimize the use of bleach and drain cleaners. These substances can kill the naturally occuring microorganisms in your system that are essential to proper function.

Water DropOn-site treatment systems are designed to treat and disperse a set number of gallons of wastewater a day. If the amount of wastewater is exceeded, then your on-site system may malfunction. It is recommended that water-conserving fixtures be installed in residences. Please contact your local DEQ office for additional information concerning maintenance of your on-site system.