What Should Happen on an Aerobic Septic Service Visit

You pay for service visits. Most owners could not say what is supposed to happen during one.

That is not carelessness. It is because nobody tells you. The contract says “routine maintenance.” The provider arrives, spends twenty minutes at the tank, and leaves. Whether that was a thorough visit or a drive-by is almost impossible to judge from the driveway, and the invoice looks the same either way.

There is no single national standard for what a visit must include. But there are three places where the content of a visit is actually defined, and between them you can tell whether you are getting what you paid for.

The three documents that define your visit

Your manufacturer’s instructions. Model-specific, and they govern. They name the components, the intervals and the tolerances for your unit, and no article can substitute for them.

Your state’s rule. Some states specify the tasks in the regulation itself. Oklahoma names four measurements outright, which makes it a clear worked example.

Your contract. What the provider has actually agreed to do, as distinct from what you assumed. Our guide to what to check in a maintenance contract covers getting that in writing before you sign.

If they appear to conflict, ask the provider and permitting authority to reconcile the requirements in writing; a contract cannot authorize a procedure that conflicts with the permit or applicable rules.

The measurements a rule actually names

Oklahoma’s rule is worth reading even if you live elsewhere, because it is unusually specific about what maintaining an aerobic system means. Under OAC 252:641-10-3, during the installer’s two-year obligation, these are to be done at least once every six months:

• Free chlorine residual of the effluent in the pump tank, tested and recorded, where spray dispersal is used.
• Depth of sludge in the trash tank, measured and recorded.
• Volume of sludge in forced-air aerobic treatment units, measured and recorded.
• Where a pump tank is used, a clarity test, with the result recorded as passing or failing.

Alongside that, the installer is responsible for repairing, adjusting or replacing broken or malfunctioning parts.

Notice the word that appears after every one of those: recorded. A measurement that was taken and not written down is, for every practical purpose, a measurement that was not taken. You cannot audit it, a buyer’s inspector cannot read it, and a regulator cannot see it. Oklahoma’s rule goes further: the installer must notify the owner in writing of all maintenance provided at each visit and keep the records for three years (OAC 252:641-10-3(a)(6)–(7)).

These are the provider’s tasks, not yours. We are setting them out so you know what to look for on the report, not so you can do them: sludge measurement and effluent sampling mean working at an open tank containing untreated and partially treated wastewater, and that is exactly the work this site tells you to leave to someone qualified.

How often, by state

The cadence is set in different ways depending on where you are, which is why owners comparing notes across state lines confuse each other.

The federal baseline is lower and broader. EPA advises that alternative systems with electrical float switches, pumps or mechanical components should be inspected more often than conventional systems, generally once a year, and that a service contract matters precisely because these systems have mechanized parts.

This is general federal guidance, not a universal service interval. The permit, local rules and manufacturer may require more frequent visits. Our state-by-state comparison sets out the rest of what each one requires.

What a useful visit report contains

This is the practical test, and it needs no technical knowledge to apply. A report you can use has:

1. The date, and the name of the person who attended. Not just the company.
2. Their licence, certification or permit number, where the state issues one. In Texas that is a TCEQ-licensed Maintenance Provider, and our guide to verifying a provider’s licence shows how to check it in two minutes.
3. Numbers, not adjectives. “Chlorine residual acceptable” is an opinion. A figure is a measurement. Same for sludge depth.
4. The condition of the aerator, and whether the air filter was cleaned or replaced. Its expected operating cycle depends on the model; ask the provider to document changes from normal operation.
5. Anything replaced or adjusted, named, with the reason.
6. What was not done, and why. A component that could not be reached, a lid that could not be lifted, a reading that could not be taken. Honest reports say this. It also tells you what to clear before the next visit.
7. What to expect next, and when.

Keep every one of them. The printable records give you somewhere to file them, and the reason to bother is not tidiness: a buyer’s inspector reads your maintenance records before they look at your tank, as our guide to selling a home with an aerobic system explains. A thick file is worth money and a thin one costs it.

What is not the provider’s job

A lot of friction between owners and providers comes from this boundary being unstated.

Things that are usually yours, not theirs, unless the contract says otherwise: keeping the lids and control panel accessible, not parking or building over any part of the system, managing how much water goes through the house, keeping what harms the biology out of the drains, and watching the dispersal area between visits. Oklahoma’s rule puts it starkly, listing the circumstances where the installer is not responsible: careless damage, excessive water usage, and the introduction of harmful items into the system.

What falls to you between visits is a separate exercise, and we have written it up on its own: our maintenance schedule covers the monthly and quarterly owner routine and what to ask after a professional visit. This page covers what the professional should be doing during it.

If the visits do not match any of this

Three steps, in order, and none of them involve confrontation.

Ask for the records. Not a verbal summary, the written reports. If they exist, you have your answer. If they do not, you have a different and more useful answer.

Read your contract against this page. You may be paying for an inspection contract and expecting a maintenance one. Those are different products, and the difference is usually in a clause rather than a conversation.

Check with your permitting authority. In some states the provider files reports with the regulator, so your authority may hold records you have never seen. In Texas, where the system is under a maintenance contract, the provider reports to the permitting authority and the owner; in Florida a copy of the maintenance agreement goes to the regulator; in Louisiana the owner is required to supply the health unit with a copy of the contract. Your permitting authority can tell you what is on file for your property.

If what you find is that the equipment has been neglected rather than the paperwork, that becomes a different decision, and repair or replacement covers how to approach it. Age alone is rarely the answer: how long an aerobic system lasts explains what actually predicts it.

Scope and safety

Educational information only, and not a diagnosis of your system or an assessment of your provider. The tasks and intervals described here are drawn from published state rules and federal guidance and are set out so that you can read your own service reports and contract with more confidence; they are not a specification for your system, and they are not instructions for you to perform. Your manufacturer’s documentation, your permit, your contract and your permitting authority govern what is required on your property, and where they differ from anything here, they win. The measurements described are performed by qualified providers at open tanks containing wastewater. This site does not encourage tank entry, electrical work, contact with untreated wastewater, effluent sampling, chemical handling outside label instructions, or unqualified repairs. The hazards associated with these systems include disease-causing microorganisms, electrical shock, poisonous or explosive gases, and confined space entry.

Sources

• Oklahoma Administrative Code, OAC 252:641-10-3, Responsibility for maintenance, for the four six-monthly measurements, the obligation to repair, adjust or replace malfunctioning parts, the written notice and three-year record keeping, and the circumstances excluded from the installer’s responsibility.
• U.S. Environmental Protection Agency, How to Care for Your Septic System, for the guidance that alternative systems with electrical float switches, pumps or mechanical components should generally be inspected once a year and that a service contract is important because such systems have mechanized parts.
• Texas Commission on Environmental Quality, OSSF maintenance guidance, for the reporting cadence to the permitting authority and the owner under a maintenance contract (30 TAC §285.90(3) is the sample report form).
• Florida Administrative Code, Rule 62-6.012, for the maintenance entity’s obligation to inspect or service at least twice each year, the inspection reports it furnishes to the Department, and the copy of the agreement provided to the regulator.
• Louisiana Department of Health, Office of Public Health, plan review material for mechanical treatment plants, for the six-month service intervals and the owner’s duty to supply a copy of the contract.
• Texas A&M AgriLife Extension, B-6234, “Living with an Aerobic Treatment Unit and Spray Field”, for the hazards associated with servicing these systems.

If your state specifies visit contents and we have not covered it, tell us through our contact page and we will add it.

Last reviewed: October 28, 2026.