If you’re buying a rural property in the Hastings region, had a slow drain or odour issue, or simply can’t remember when the septic was last looked at, a septic inspection gives you a clear picture of what you’ve got, and what it needs. Many homeowners have never seen one done and don’t know what to expect. This guide walks through exactly what a licensed contractor does during a standard septic inspection.
Quick answer (BLUF)
A septic inspection typically takes 1-3 hours and involves locating the tank and system components, inspecting tank interior condition (walls, baffles, inlet and outlet), measuring sludge and scum levels, assessing the absorption area condition, checking pump and alarm function (for AWTS), and issuing a written report. An inspection alone doesn’t include a pump-out; you may be advised to schedule one immediately based on findings.
Before the inspection: what to prepare
A good contractor will ask you for:
- Approved system documentation: Your PMHC OSSM approval, which specifies the system type, tank size, and approved absorption area. If you don’t have a copy, the contractor may be able to source it or advise what records PMHC holds.
- Last pump-out date: Or an estimate, if known.
- Known issues: Any recent slow drains, odours, wet patches, or alarm activations.
- Property age and usage: This informs the inspection scope, a 1950s concrete tank on a Comboyne Plateau property that’s never been pumped is a different inspection to a 2018 AWTS on a Port Macquarie coastal estate.
Step 1: Locating system components
The inspector starts by locating the tank lid(s), inspection riser, and absorption area. On properties where lids are buried (common on older systems), the contractor may use a soil probe or metal detector to find the lid before excavating.
On older Hastings hinterland properties, it’s not uncommon to find unlabelled tanks in surprising locations, buried deep under garden beds, under decking, or at the end of very long runs from the house. Knowing the property’s layout from the approval drawings helps; if these aren’t available, this locating step can take time.
For AWTS systems, the control panel, air pump housing, and alarm are also located and visually inspected.
Step 2: Opening the inspection lids
Tank inspection is done with the lids open. Safety note: Septic tanks produce hydrogen sulphide and methane. A licensed contractor has the training and equipment (at minimum, gas detection) to work safely at open tanks. Never lean over an open septic tank, hydrogen sulphide at high concentrations is colourless, odourless and can cause immediate incapacitation.
Most modern systems have accessible inspection risers that bring the lid to ground level. Older concrete tanks in the Hastings region often have flush-with-ground lids that may be cracked, broken, or covered with soil.
Step 3: Visual inspection of tank interior
With the lid open, the inspector visually assesses:
Tank walls and floor: Cracks, spalling concrete, corrosion, root intrusion. Hairline cracks may not be immediately critical; large cracks or structural failure require urgent attention.
Inlet baffle/pipe: The inlet should be submerged below the liquid surface (to prevent disturbance of the settled sludge) and free of obstruction.
Outlet baffle/T-pipe: Critical component. The outlet baffle prevents floating scum from exiting to the absorption area. A broken or missing baffle means solids have likely been reaching the trenches. Replacement is a relatively simple fix.
Scum layer: The floating mat on the surface. The inspector estimates its depth. A scum layer more than 100 mm deep is approaching pump-out threshold. Thick scum over a T-pipe outlet is a warning sign.
Sludge layer depth: Using a sludge depth probe (a perforated tube that captures sludge), the contractor measures the settled solids layer at the tank base. When combined sludge and scum depths occupy more than one-third of the tank volume, pump-out is recommended.
Liquid level: Should be at the outlet invert level. Liquid above the outlet indicates the absorption area or outlet pipe is not draining correctly.
Step 4: Outlet pipe and distribution box inspection
Where accessible, the contractor inspects the outlet pipe condition and the distribution box (which splits flow between multiple trenches). Blocked distribution can mean one trench is overloaded while others sit unused.
A drain camera may be used where there’s suspicion of a blockage or root intrusion in the outlet line, this is an additional service, not standard in every inspection.
Step 5: Absorption area assessment
The inspector walks the absorption area looking for:
- Surface ponding or wet patches, particularly important during dry weather when natural moisture levels are low
- Unusual green growth over trench lines (suggesting surfacing effluent fertilising the grass)
- Subsidence over trenches (indicating the gravel has collapsed or settled)
- Odours over the drain field
On properties with AWTS drip irrigation, the drip lines are visually inspected for emitter blockage and line integrity.
Step 6: AWTS-specific checks
For AWTS systems, additional checks include:
- Air pump running condition (listening for correct operation, checking pressure)
- Aeration chamber dissolved oxygen level (using a DO meter)
- Treatment quality visual assessment (colour and clarity of treated effluent in the clarification chamber)
- UV lamp condition (if installed)
- Alarm test, activating the alarm to confirm it functions
- Service log review, the service contractor’s log records previous findings and maintenance actions
Step 7: The inspection report
After the inspection, you receive a written report covering:
- System type, age (estimated), and tank capacity
- Sludge and scum depths with pump-out recommendation
- Tank structural condition (with rating: satisfactory, monitor, action required)
- Outlet baffle condition
- Absorption area condition (satisfactory, monitor, failing)
- AWTS components condition (if applicable)
- Compliance notes, any departure from the PMHC approval or identified non-compliance issues
- Recommended actions with priority (urgent, recommended, noted)
For pre-purchase inspections, this report is typically provided in a format suitable for inclusion in conveyancing due diligence.
FAQs
How long does a septic inspection take?
A standard residential inspection takes 1.5-3 hours depending on system complexity, how easily components are located, and whether any follow-up investigation (drain camera, dye testing) is required. A simple AWTS inspection on a known modern system may be completed in under an hour; a complex older system on a rural hinterland property with buried lids may take longer.
Does a septic inspection include a pump-out?
Not automatically. An inspection assesses the system condition; a pump-out is a separate service. However, if the inspection finds that sludge and scum levels warrant immediate pump-out, a combined inspection-and-pump-out can usually be arranged in the same visit. Confirm this when booking.
Who can legally conduct a septic inspection in NSW?
Inspections for condition assessment and PMHC compliance purposes are conducted by licensed plumbers (drainage licence) with septic inspection experience. For OSSM compliance and technical system assessment, a licensed plumber with septic expertise is recommended.
How much does a septic inspection cost in the Hastings region?
A standalone inspection typically costs $250 to $500 depending on travel to the site and system complexity. Combined with a pump-out, the total service ranges from $450 to $900+. Remote properties (Comboyne, upper Wauchope) may attract travel surcharges. Contact Hastings Septic Co for a current quote.