Septic System Inspection When Buying A House [Tank Evaluation Checklist]

Do you need a septic test for mortgage or property purchase? What is involved in a standard septic tank inspection?

Here is a complete checklist, procedure, and safety consideration when examing a real estate septic system.

What is a septic inspection?

This is a systematic process of checking for pests and examining the septic structure of a property.

The condition of septic tanks is vital to how well sewage is treated and properly disposed of.

Septic tank inspection is one action that needs to be done as frequently as necessary.

Real Estate Septic System Inspection Process

Our discussion will border on the frequency of inspection, the inspection process, and how it should be carried out.

Also, we’ll be providing safety warnings to help avoid accidents. Can septic tank inspection be done by you? We’ll find out soon enough.

If you feel you aren’t cut out for this, there’s still a solution. In a nutshell, there’s something for everyone and we’ll ensure every second of your time is worth it.

Is a Septic Inspection Necessary When Buying A House?

Although septic inspections are not compulsory, it is recommended.

This is because it exposed defects in your system early, saving you from increased costs on septic system repairs.

A lot of homeowners do not bother inspecting their septic tanks unless requested by lenders, which mostly happens due to a flag in the appraiser’s report.

Who Can Conduct A Septic System Inspection?

A lot of people will rather have a septic company carry out the unpleasant job of inspection than have to deal with such themselves.

On the other hand, some other people won’t mind getting the job done themselves. In the case of the latter, there needs to be an understanding of how it works.

Knowledge is necessary and we’ve taken the time to provide you with the information you need to get it done. The easiest way out is by calling the experts.

These are septic companies with the right training and skill to conduct a thorough inspection.

The responsibility for septic tank inspection depends on what works best for you.

Septic Inspection Frequency

How frequently should a septic tank be inspected?

It depends on the type of septic tank you have. Those having mechanical components or electrical float switches will need to be inspected more frequently (once a year).

These types of septic systems are known as alternative systems.

Other types of septic systems such as household systems should be inspected at least every three years. If you can’t handle getting the job done yourself, septic companies are just a call away.

These companies are well equipped to perform a thorough job.

You will be needing the services of septic companies more often for alternative systems. For this category of septic systems, it’s best to enter into a contract for scheduled inspections.

This helps a lot to keep such systems functioning optimally.

How To Call For Real Estate Septic Inspection

It is one thing to identify the need for septic tank inspection when buying a house and another to contact an inspector or septic company to provide the service.

Luckily, it doesn’t take a whole lot to find a service professional within your locality.

You only need to use the online directory provided by the National Onsite Wastewater Recycling Association (NOWRA) to get started.

Septic Tank Inspection Checklist For Home Sale

To get the best septic system inspection service, it’s necessary to take some responsibility.

Your role, though restricted is essential to ensure a thorough inspection. While the septic service provider inspects your septic system, it is important to keep a record.

Record of what exactly? A maintenance record of work carried out on your septic system helps a great deal during the next inspection.

Here is how to pass a septic inspection.


  • Authenticate System Information: Check previous reports and validate them. Check the age of the system, date of the last inspection, pumping, and if any repair work has been done lately.
  • Assess the model and type of septic system and note any information that may affect the accuracy of your inspection report, e.g. the number of rooms and duration of occupancy.
  • Study the as-built drawing of the system and note the location of the tanks, lids, and pipes. You can also bring the tank onsite for a more thorough inspection process.


  • Protect your hands with rubber gloves and eyes with a mask. PPEs prevent exposure to risks and injuries from bacteria and toxic fumes.
  • Ensure you are careful with septic holes. Keep them in front of you, never back them, and don’t leave them open for long to prevent injuries for accidental falls.
  • Use a standard checklist for the inspection. Follow each step and document your findings and attach relevant photos.


  • There is a need to dispose of waste off properly. Also, minimize or avoid the use of chemicals during septic cleaning.
  • Clean and sanitize your hands and tools properly.
  • Fix defects by pumping tanks after you identify them visually.
  • Keep an updated record of inspection and repair activities done on the system.

What Happens During Septic System Inspection?

The word inspection when focused on gives a sense of finding out if the system needs some maintenance or not.

However, it goes beyond that. Septic system inspection also includes finding out the scum and sludge layers.

This seeks to ensure they don’t exceed acceptable levels.

  • Visual And Full Inspection

Septic system inspection is categorized under two main types; visual inspection and full inspection. These have different approaches and fit specific needs.

To better understand what each of these translates to, we’ll discuss them briefly as follows;

i. Visual Septic System Inspection

Visual septic system inspection by its nature is quite limited. It is limited in the sense that little or nothing is done to carry out a thorough job.

In most cases, the septic tank may not be opened at all. Instead, it is flushed with water to find out if there’s free flow and also to help identify blockages if any.

There’s an absorption area where water isn’t supposed to surface over. When the opposite happens, a visual inspection should identify the problem easily. Outside of this, little is done to check the entire septic system.

As such, this comes at a disadvantage to the client.

It comes at a disadvantage in the sense that several problems may result. Such include backflow, tank size, leaving accumulated sludge behind, and a leaking septic tank.

Other problems associated with visual inspections include an overfull tank, corrosion, and more. These aren’t easily identified during visual septic system inspection.

Although the visual inspection isn’t as thorough as it may be needed, it can be taken further. This is done through a method known as the dye test. What this means is that dye is added or introduced via a faucet into the plumbing.

This is done with one aim; to find out if the dye surfaces anywhere around the yard. When this is noticed, it shows that the septic system needs replacement or maintenance.

The cost for visual inspection too is much lower when compared to full septic system inspection. The reasons are obvious; the job isn’t as thorough. Why then should anyone need visual inspection when the job isn’t thorough?

People have different reasons for asking for specific services. Anyway, here are the average quotes for most inspections.

ii. Full Septic System Inspection

As the name suggests, this is quite thorough and involves a whole lot of processes.

With full inspection, the septic tank is opened and the liquid level checked. Why is this necessary? It is because leakages do occur. An inspection helps identify if there are any to fix them.

Also, the full opening of the septic tank during full inspection seeks to find out if it is overfull. When it’s discovered to be, immediate action is taken to evacuate its content.

However, when it isn’t (not overfull) water is introduced into the system.

The purpose of introducing such water is to help find out if it flows unhindered into the septic tank and from there to the absorption area. A septic system in good working condition should not have water rising in the tank. There shouldn’t be surfacing water either.

An examination of the house plumbing is also carried out to ensure the identification of blockages if any. This is followed by immediate repairs. All connections are thoroughly checked and fixed when found to be defective.

Full septic system inspection also involves pumping out the contents of the tank when needed.

On average, a septic tank should be pumped out every 3 to 5 years. However, this is more frequent (yearly) for alternative systems (those with mechanical components or float switches).

When an inspector comes around, you should be able to provide satisfactory answers to all questions raised. Recall that we earlier mentioned the need to get involved by keeping a detailed record of all inspection, repair, and maintenance of your septic system.

Doing so helps make the work more accurate and detailed.

How Long Does it Take to Inspect a Septic Tank?

An inspector will generally take between 1 – 3 hours for a complete evaluation depending on the type of septic system, its complexity, and accessibility, as well as on-site discoveries.

Safety Procedures During Septic Inspection

When inspecting a septic system, certain precautionary measures need to be followed to avoid putting yourself in harm’s way. The following are ways to help avoid such accidents from happening;

  • Never Work Alone

When inspecting your septic tank, ensure you never do so alone. Why is this important? First, methane gas is released from such tanks. This can affect you. Also, falling into one (septic tank) can be fatal if nobody is there to help.

  • Never Step Into The Tank Without Protection

Apart from the knowledge required to fix a faulty septic tank, you also need to wear the right protective gear to get the job done. Such protective gear should include a self-contained breathing apparatus.

  • How To Help

Accidents may happen during a septic system inspection.

An inspector might fall into the septic tank. When this happens, avoid getting in to help without a self-contained breathing apparatus. Only do so when you have one.

If you don’t, quickly call in emergency services to help out.

  • Flames Should Be Far Removed

Septic tanks produce highly flammable methane gas. Having flames close by is likely to cause an explosion. This is an experience you’d rather do without.

  • Only Work In Well Ventilated Areas

During septic system inspection, good ventilation is of the essence especially when it comes to opening the septic tank.

Apart from an explosion that is likely to result from exposure to flame and sparks, sewer gas is also toxic to humans. A well-ventilated area should help reduce the risk significantly.

  • Allow The Pros Handle The Job

Sometimes, clients try to avoid the cost of inspecting septic systems by doing it themselves.

Doing so with limited knowledge will only be counterproductive. Not knowing what exactly needs to be done will only help perpetuate the problem. Plus, you will be exposing yourself to risks such as those mentioned above.

The professionals know exactly where to look when it comes to inspection. The time taken to get the job done is also reduced significantly.

Septic system inspection as discussed here has touched on key areas that need to be considered by anyone seeking to perform a thorough job. For your septic system to function properly, it must be inspected as frequently as necessary.

That way, you can increase the lifespan.