Septic services explained
Pumping
Removes the settled sludge and floating scum from the tank. Many companies suggest every 3 to 5 years for a typical household, more often for larger households. On aerobic systems, DEQ rules say the trash tank should be pumped before sludge reaches 40% of its depth (DEQ aerobic systems fact sheet).
Inspection (home purchase or problems)
If you buy a house whose aerobic system is still inside the installer's two-year maintenance period, you are covered until that period ends (OSU Extension: Basic Septic System Rules for Oklahoma). Some companies offer a records search of DEQ files plus an on-site inspection with pumping. Ask what is included and whether the tank will be pumped and opened.
Aerobic system maintenance
Aerobic treatment units (common with spray sprinklers in the metro) need regular checks of chlorine, sludge and the pump tank. For a new aerobic system, DEQ rules make the installer maintain it for two years at no extra cost, including a free chlorine test (on spray systems) and a sludge depth check at least every six months. After that, the owner is responsible (DEQ aerobic systems fact sheet). See the aerobic guide.
New installation or replacement
Needs a DEQ Authorization to Construct before work starts, and most system types need a soil test first: either a percolation test or a soil profile description. Lagoons and aerobic systems with spray irrigation do not require a soil test (OSU Extension: Basic Septic System Rules for Oklahoma). Certified installers who self-inspect must send the final inspection to DEQ within 15 days (Oklahoma DEQ sewage treatment page). The system type (conventional lateral field, aerobic with spray or drip, lagoon) depends on soil and lot size (Oklahoma DEQ sewage treatment page).
Repair
Repairs and modifications are also inspected by DEQ unless done by a certified installer who self-inspects. Anyone may install a system, but non-certified installers are limited to one installation per year and their work must pass a DEQ inspection before it is backfilled (OSU Extension: Basic Septic System Rules for Oklahoma).
What to ask any company
- Are you on the DEQ list of active certified installers (for installs and repairs)?
- Is the quote all-in: disposal, digging up lids, mileage?
- Who handles the DEQ paperwork and inspection?
- Written warranty and, for aerobic systems, written maintenance terms.
Newer guides: How often to pump · Aerobic alarm help
Last checked Oct 24, 2026.
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