A proper septic inspection covers twelve things: the permit file, locating the system, pumping the tank so it can be seen, sludge and scum measurements, both baffles, the effluent filter, the tank walls and lid, the inlet and outlet lines, the distribution box, the leaching bed, any pump and alarm, and a written report. If an inspection skips one, the report should say which and why.
Our guide to what a septic inspection is explains the different types. This page is the list you hand to whoever you hire, item by item, with what a pass looks like and what a red flag looks like.
How to Use the Checklist
Use it twice: before you book, to ask what is included, and after, to check the report. Every item ends as checked and fine, checked and flagged, or not checked. Watch the third. An inspector who could not open the second lid, or could not see the bed under snow, should write that down. A report that says nothing about an item has not passed it.
Inspections run $150 to $500 depending on the type (septic inspection cost guide). A visual-only inspection cannot tick most of this list, so ask a low quote which items it leaves out.
1. Records and the Permit File
Before anyone digs, somebody should know what is supposed to be in the ground.
| Check | Pass | Red flag |
|---|---|---|
| Permit record from the municipality | A permit on file, with a drawing or approval | No record at all |
| Design versus reality | Tank size, location and bed match the file | A different tank, a moved bed, or an addition the file never mentions |
| Service history | Pump-out receipts every few years | No receipts, or a claim it never needed pumping |
| System type | Conventional, filter bed or tertiary unit, clearly stated | Nobody can say what the system is |
In the City of Kawartha Lakes, sewage system records sit with the City’s Building and Septic Division (705-324-9411), not the health unit, and they go back to 1974. If a system went in after that and the City has nothing on file, it was almost certainly never permitted. Our post on requesting your septic records in Kawartha Lakes walks through the request.
2. Finding and Opening the Tank
Locating the system
Pass: the inspector finds the tank, the distribution box and the bed, and marks them on a sketch or photo in the report. Red flag: “tank not located” with no follow-up, or a bed location that is only a guess.
How to find your septic tank covers the usual clues if you want a head start.
Lids and risers
Pass: lids that are intact, sit tight, and cannot be lifted by a child. Risers bring the lids to grade. Red flag: a cracked or rotted lid, a lid held down by nothing, or plywood over the opening.
The current Code calls for risers when a new tank’s lid sits more than 300 mm below grade; many older tanks have none. Without one, a digging fee of $100 to $200 is normal, which is the case for septic tank risers. A lid replacement runs $100 to $300.
Stay well back from an open tank while it is being worked on. The gases inside can overcome a person quickly, and nobody should lean over the opening.
3. Inside the Tank
Measure first, then pump
This is the item most often done in the wrong order. Sludge and scum must be measured before the tank is pumped, and the liquid level noted, because pumping erases all three.
Pass: two numbers in the report, sludge depth and scum thickness, plus the liquid level against the outlet pipe. Red flag: “tank pumped, looks good” with no measurements.
The US EPA says to pump when the bottom of the scum is within six inches (about 150 mm) of the outlet, the top of the sludge is within 12 inches (about 300 mm) of it, or sludge and scum together fill more than 25 percent of the liquid depth (EPA septic care guidance). A simpler one-third rule is also common. Either way, you want the numbers in the report, not just the verdict.
Liquid level normally sits at the bottom of the outlet pipe. Well above it means water is not leaving, which points at the filter, the outlet line or the bed. Well below it can mean the tank leaks.
Pump so the tank can be seen
Pumping makes the walls, floor, baffles and any partition wall visible. Without it, the next three checks are mostly guesses.
Both baffles
Pass: an inlet baffle and an outlet baffle, both present, attached and turning flow downward. Red flag: a missing outlet baffle, a baffle hanging loose, or concrete baffles eroded to stubs.
The outlet baffle protects the bed: when it fails, scum and solids go straight out to it. Our guide to inlet versus outlet baffles explains which does what. Outlet baffles typically last 15 to 20 years and a replacement runs $200 to $500, a cheap fix next to what it protects.
Effluent filter
Not every tank has one. If yours does:
Pass: found, pulled, cleaned and put back in its housing, with a note on how clogged it was. Red flag: a filter packed so tight it is holding water back, or an empty housing where a filter used to be.
A clogged filter is maintenance, not failure. Cleaning the effluent filter is routine, and a replacement is $50 to $150.
Walls, floor and lid
Pass: sound concrete or plastic, tight joints, and no water trickling in once the tank is empty. Red flag:
- cracks you can see through, or a wall that has shifted
- concrete softened or crumbling above the liquid line
- rust holes in a steel tank
- groundwater running in through joints or pipe openings after pumping
That last one is easy to miss: water coming into an empty tank means it is not watertight, and in a high water table extra water is heading for the bed. Concrete tanks typically last 30 to 40 years, plastic or fibreglass 20 to 30, steel 15 to 20.
4. Inlet and Outlet Lines
Pass: water run inside the house reaches the tank promptly, and the outlet line carries it away without backing up. Red flag: slow arrival, gurgling, standing water in the inlet, roots at the pipe openings, or a sag where the line has settled.
A standard inspection sees only the ends of each line. If they look wrong, a camera run is the next step, usually priced as an add-on.
5. Distribution Box and Leaching Bed
Distribution box
Pass: found, opened, level, with effluent splitting evenly between the outlets and no solids in the box. Red flag: a tilted box sending everything down one run, sludge in the box, or a box nobody could find.
Solids in the box have already left the tank, which points back at the outlet baffle. Distribution boxes typically last 20 to 30 years, and our post on distribution box problems covers the usual faults.
Walking and probing the bed
Pass: firm, dry ground over the bed, even grass, no odour, and a probe that finds the runs without hitting saturated soil near the surface. Red flag:
- wet or spongy ground, or standing water, in dry weather
- lush green stripes over the runs
- sewage odour near the bed
- a driveway, parking spot, shed or deck built over it
- trees or large shrubs growing on it
Leaching beds typically last 15 to 25 years, so the install date from the permit file matters here. The inspector should also note the distance to the well. The Code minimum for a leaching bed is 15 m from a drilled well with a watertight casing at least 6 m deep, and 30 m from a dug well or any other well. The tank needs 15 m from any well.
If the bed is failing, the report should say whether the cause could be upstream, such as a failed baffle, before anyone prices a new bed. For what a buyer can spot on a showing, see our septic red flags when house hunting.
6. Pump, Alarm and Treatment Unit (If Present)
Plenty of systems here are gravity only, and this section does not apply to them. If the property has a pump chamber, a raised bed fed by a pump, or a tertiary treatment unit, it does.
| Check | Pass | Red flag |
|---|---|---|
| Effluent pump | Starts when the float lifts, stops when it drops | Runs constantly, hums without pumping, or never starts |
| Float switches | Move freely, set at the right heights | Tangled, tied up, or missing |
| High-water alarm | Sounds when tested, panel lights work | Disconnected, unplugged or silenced |
| Treatment unit | Service records, unit running as designed | No service history, blower or pump not running |
A silenced alarm is one of the worst findings here, because it hides everything else in the pump chamber. If yours has been sounding, what to do when a septic alarm is going off runs through the likely causes. Effluent pumps typically last 7 to 10 years and a replacement runs $600 to $1,500, so the pump’s age belongs in the report. The EPA suggests systems with mechanical parts be looked at about once a year, so ask for a treatment unit’s service records by name.
7. The Written Report
The report is the part you keep, and our guide to reading a septic inspection report explains the terms. Against this checklist, it should contain:
- the date, the address, and who did the inspection
- whether the tank was pumped, and by whom
- sludge and scum measurements, and the liquid level before pumping
- a finding for every item above, including “not inspected” with a reason
- photos of the baffles, the tank interior and the bed
- recommendations ranked by urgency, repairs listed before replacement
Red flag: a one-page pass/fail letter with no measurements, no photos, and nothing marked as not inspected. That letter proves someone visited, and not much else.
On a purchase, it also has to land inside your condition window: see septic inspection before buying a house in Ontario for timing and our real estate septic inspection page for what the file usually needs.
Some items cannot be finished for reasons unrelated to the system: snow over the bed, frozen ground, a tank under a deck. That is acceptable if the report says so and a purchase agreement leaves room for a follow-up visit. Septic inspections in winter covers what can be checked in the cold months.
The rules behind all of this sit in Part 8 of the Ontario Building Code, currently the 2024 Code (O. Reg. 163/24). The City’s own sewage system inspections page explains its maintenance inspection program, which covers only properties near the City’s wellheads and water intakes and is not a condition report for a buyer.
Frequently Asked Questions
What does a septic inspection include?
A full septic inspection includes a records check, locating the system, measuring sludge and scum, pumping the tank, and checking both baffles, the effluent filter, the tank walls, the inlet and outlet lines, the distribution box and the leaching bed. If there is a pump or alarm, those get tested too. It ends with a written report that covers every item, including anything that could not be inspected.
Should the tank be pumped during a septic inspection?
For a full inspection, yes, but only after the sludge, scum and liquid level have been measured. Pumping lets the inspector see the walls, floor and baffles, which cannot be judged through a tank full of liquid. A visual inspection without pumping costs less but leaves most of the tank unseen.
What is the biggest red flag on a septic inspection?
A failing leaching bed is the most expensive finding, because the bed is the costliest part to replace. A missing outlet baffle is the most common serious one, because it lets solids reach the bed. A disconnected high-water alarm also deserves attention, since it can hide a pump problem until sewage backs up.
Can a septic system pass inspection if the tank was just pumped?
The empty tank can still be examined, but the inspector cannot measure how much sludge and scum had built up or see whether liquid was sitting above the outlet. The report should state that the tank had already been pumped and by whom. If you are buying, ask the seller for the pump-out receipt and any notes the pumper made.
Book an Inspection That Covers the Whole List
We measure before we pump, check both baffles and the filter, walk the bed, and write down anything we could not get to. Our septic inspection page has the details. If the report turns up a baffle, lid or filter problem, we diagnose before we replace, and septic tank repair covers those fixes.
Call (705) 702-5526 or book an inspection, and we call back within 24 hours during business hours. There is no travel surcharge anywhere in the City of Kawartha Lakes. For Peterborough County, Durham, Belleville and Haliburton, the price is quoted up front before we book.