CCTV Drain Inspection for Septic Systems: What the Camera Finds and When You Need One

A CCTV drain inspection on a septic property means pushing a small waterproof camera through the pipes and recording what’s inside them: the drain from the house to the tank, and the line from the tank out to the distribution box and trench. It finds the physical faults behind slow drains and repeat blockages, mainly tree roots, sagging sections that hold water, cracked or collapsed pipe, and joints that have pulled apart or dropped out of line.

You usually need one in three situations: you’re buying a property, the same drain keeps blocking, or you’re about to spend real money on the trench and want to know the pipes feeding it are sound. A camera can’t tell you how full the tank is or whether the soil under the trench still absorbs. Those need a sludge measurement and a trench probe, which is why a camera check makes most sense as part of a full inspection.

What a camera inspection of a septic system looks at

A problem in any of these runs looks much the same from inside the house. The camera’s job is to work out which run it’s in.

The house drain, from the dwelling to the tank inlet. The gravity drain that carries everything from the toilets, showers, kitchen and laundry, and where roots, fat, wipes and settled pipe often cause slow drains. Where this drain is longer than 60 metres, the OLG’s Onsite Wastewater Management Guidelines double the minimum grade and call for inspection ports at least every 30 metres or at any change of direction or grade. Those openings are also where a camera goes in.

The tank inlet. A blocked septic tank inlet looks exactly like a blocked house drain from inside, but the fix is different. With the lid off and the tank pumped down, the inlet can be seen directly and the camera pushed back up the line from the tank.

The tank outlet to the distribution box and trenches. Effluent leaves the tank through the outlet tee, runs to a distribution box on multi-trench systems, and spreads out along the trench lines. A camera down these lines shows whether they are open, crushed, root-bound or silted. The OLG guideline says a distribution box must sit on a stable surface to minimise uneven settlement, and that its adjustable outlets should be checked and adjusted regularly. A box that has tilted can send most of the flow down one line.

AWTS lines. The house drain and inlet on an aerated system are cameraed the same way. The irrigation side is different. The OLG guidelines say the pressure pipe from the treatment unit to surface or subsurface irrigation must be lilac, and that subsurface drip line is typically 16 mm, which is too narrow for a standard drain camera head. Irrigation lines are checked by flushing, pressure and a look over the irrigation area, not by camera.

What the camera finds

The Water Services Association of Australia’s Conduit Inspection Reporting Code (WSA 05) is the national code utilities use to describe what a CCTV survey sees in sewers and sanitary drains. It gives separate codes for roots, cracking, deformation, collapse, displaced joints, obstructions, infiltration and water level in the pipe. Private septic lines show the same set of faults on a smaller scale.

Roots are what most people expect. The OLG guidelines say roots can interfere with treatment systems, plumbing pipework, subsurface irrigation and soil absorption systems. The older Easy Septic Guide says small trees should be planted at least 5 metres from the trench and large trees more than 20 metres away, “if not the roots will harm the trench”; the current OLG guidelines say to plant large trees back from the effluent area by their expected height. The Easy Septic Guide also warns that driving or parking on the area may break the pipework and crush the trench domes.

A sag is the fault owners are least likely to have heard of. The OLG guideline’s pipe table, adapted from AS/NZS 3500.2, lists a minimum grade of 1:60 for a 100 mm drain, with a lower minimum (1 per cent) allowed for drains leaving a septic tank. That isn’t much fall, so a section that settles a few centimetres can hold water permanently, and solids drop out there with every flush. On camera it shows as the lens going under water partway along the line.

Why Hunter lines fail the way they do

Many Hunter blocks sit on reactive clay that swells when wet and shrinks when dry, and a rigid pipe laid in moving ground gets pushed around. Building Commission NSW’s plumbing note on drains in “other than stable ground” says flexible joints must be used where a drain is laid in filled, unstable or water-charged ground, or in highly reactive soil classes (H1, H2 or E), and a recognised expert thinks the ground is likely to move enough to damage it. When a rigid line in moving ground does shift, the result on camera is joints that have opened or stepped, and sections that have dropped.

The other pattern is a line nobody knew ran under a driveway, a horse yard or a gum that was a sapling when the tank went in. The OLG guideline sets a minimum 500 mm of cover over most pipe in areas subject to vehicle traffic, against 300 mm elsewhere. A line laid under open paddock may not have that once a driveway goes over it, and a crushed pipe shows up clearly on camera.

When you need one

Buying a property. A building and pest inspection doesn’t usually include a drain camera, so ask your inspector. Ours is part of the pre-purchase septic inspection, along with the tank assessment, trench probe and written report. The camera tells you whether the slow shower drain the vendor mentioned is a small repair or a line that needs relaying. The wider checklist for buyers is in buying a property with a septic tank in NSW.

The same drain keeps blocking. The same toilet or floor waste backing up every few months often points to a fault in the pipe: a root intrusion that regrows after clearing, a sag that collects solids, or an offset joint that catches paper. Clearing it again treats the symptom. The camera finds the cause.

Before trench rejuvenation or a trench rebuild. Jetting and biomat rejuvenation of an existing trench can bring a sealed trench back, but it’s wasted money if the line from the tank is crushed or the distribution box has dropped. Our absorption trench rejuvenation cost guide explains how the diagnostic step, camera included, decides which of those two jobs you’re actually paying for.

After a vehicle, an excavator or a flood has been over the lines. A new shed pad, a truck on the trench or floodwater sitting over the area can all move pipe. If drains have been slower since, look before it turns into a backup.

If sewage is coming up right now, the camera can wait. Stop water use and read what to do if your septic is backing up, which explains how the overflow relief gully tells you whether the blockage is in the house drain or at the tank.

How it’s done on the day

The camera needs a way in: an inspection opening on the house drain, and on the outlet side the tank, the distribution box, or the inspection port the OLG guideline says should sit at the end of each trench. Where there is no opening, the tank inlet with the lid off is often the only access.

A flooded line is just murky water on a screen, so if the tank is full to the inlet, nothing useful shows until the level drops. That’s why the camera is usually paired with a pump-out: pump the tank down, look at the fittings with the tank empty, then camera lines that are draining again.

Many drain cameras carry a small transmitter in the head. A locator on the surface picks up the signal to mark where a fault sits and roughly how deep, so a repair crew can dig in the right spot.

The findings go into the written inspection report: which runs were checked, where each fault is, and which items are licensed plumbing and drainage work.

What a camera cannot show

A camera shows the inside of a pipe. It doesn’t show:

• How full the tank is. Sludge and scum depth is measured with a sampling tube through the lid, not seen through a pipe.
• Whether the trench soil still absorbs. A trench line can look perfectly open on camera and still sit in saturated gravel because the soil beneath has sealed. A probe along the trench and a look at where the effluent level sits in the inspection ports answer that.
• Small leaks through a dry joint. A joint can look closed and still let water out, or groundwater in, when the ground is wet.
• The outside of the pipe. A camera sees the bedding only where a pipe has broken open. It can’t tell you whether the pipe has support under it until it has already sagged.
• Past a blockage. If the line is plugged solid, the camera stops there until it’s cleared, and clearing a house drain is licensed drainage work.
• AWTS mechanical faults. A blower, pump or float switch fault is found on an AWTS service, not with a camera.

What it costs and who does the repair

We don’t publish a separate price for the camera. The CCTV line check is part of our septic inspection: a pre-purchase real estate septic inspection is $250 to $500 and includes a CCTV line check, tank structural assessment, trench absorption probe and a written report. A pre-purchase or council compliance inspection bundled with a pump-out adds $100 to $200 to the pump-out price, which is $350 to $500 for a tank up to 3,000 litres. There’s no travel surcharge across the Maitland, Cessnock, Singleton or Port Stephens LGA service corridors.

The repair is often a different business, and the law decides that. NSW Government licensing guidance defines draining work as including the repair, flushing or cleansing of a sanitary drain, and says it “includes work on a house drain connected to an onsite wastewater management system”. Draining work needs a licence. So clearing, jetting or relaying the drain from your house to the tank is carried out by licensed plumbing and drainage contractors we work with; their NSW licence number appears on every quote. A baffle or pipe repair is typically $250 to $650. On the other side of the tank, jetting and biomat rejuvenation of an existing trench runs $1,500 to $4,500, and a new absorption trench is $8,000 to $14,000, built by a licensed drainage contractor.

One thing the Easy Septic Guide is clear on while you wait: don’t pour caustic soda or chemical drain cleaners into a septic system.

If a drain keeps blocking or you’re weighing up a purchase, call 0468 278 123 and we’ll tell you which runs are worth looking at first.

Frequently Asked Questions

What is a CCTV drain inspection?

A small waterproof camera is pushed through a drain and records the inside of the pipe. On a septic property it covers the drain from the house to the tank and the line from the tank to the trenches. It shows roots, sags, cracks, collapsed pipe, offset joints and blockages, and where they are.

How do I know if my septic tank inlet is blocked?

Drains throughout the house run slowly or back up, but the liquid in the tank, seen with the lid off, is not above the outlet. That combination points to a blockage in the house drain or at the inlet rather than a full tank. Pumping the tank down and looking at the inlet fitting, then running a camera up the line, confirms which it is.

Can a drain camera see inside a septic tank?

That isn’t how a tank is assessed. Its condition, fittings and sludge depth are checked with the lid off, using a sampling tube for the sludge, and the tank pumped down to see the walls. The camera is for the pipes running in and out, which you can’t see from the lid.

Does a CCTV inspection check the absorption trench?

It checks the pipe in the trench, not the soil around it. A camera can show a crushed line, roots or a silted distribution box, but a trench can look open on camera and still fail because the soil beneath has sealed. A trench probe and the effluent level in the inspection ports show whether the trench still absorbs.

Is a drain camera included in a pre-purchase septic inspection?

Ours includes one. Our pre-purchase inspection, $250 to $500, includes a CCTV line check alongside the tank structural assessment, trench absorption probe and written report. A standard building and pest inspection doesn’t usually camera the drain, so check what yours covers.

Who fixes the problem a drain camera finds?

It depends where the fault is. Work on the house drain, including clearing and flushing it, is licensed drainage work in NSW, carried out by licensed plumbing and drainage contractors whose NSW licence number appears on the quote. Pump-outs, effluent filter work and rejuvenation of an existing trench are septic service work that we do ourselves.

Sources and further reading

• NSW Office of Local Government, Onsite Wastewater Management Guidelines (April 2025): inspection ports on long drains, pipe grade and cover tables, distribution boxes, trench inspection ports, lilac pipe, drip line size, roots and tree distances.
• NSW Office of Local Government, The Easy Septic Guide: tree distances, vehicles breaking pipework, and the caustic soda warning.
• NSW Government, Plumbing, draining and gasfitting licences: draining work includes a house drain connected to an onsite system.
• NSW Government, Drains in other than stable ground (plumbing note 1/2023): flexible joints in ground likely to move.
• Water Services Association of Australia, Conduit Inspection Reporting Code of Australia WSA 05 (extract, v4.2): the national CCTV defect codes for sewers and sanitary drains.