Cesspit vs Septic Tank: What the Words Mean in NSW and Which One You Have

A cesspit is a pit or chamber that stores raw sewage without treating it. A septic tank treats sewage: solids settle and break down inside it, and the liquid runs out to an absorption trench where the soil finishes the job. So the short answer to cesspit vs septic tank is that one only stores and the other treats.

The confusion comes from the word itself. The NSW guidelines treat a cesspit as a pit toilet and say it is not a sound way to manage sewage. In England a cesspit (or cesspool) usually means a sealed tank with no outlet that a tanker empties, which NSW calls a holding tank, a pump-out system or a collection well. And on an older Hunter property, “the old cesspit” can mean a brick-lined pit left over from before septic tanks. This guide sorts out the names and tells you what to do if you find one.

What a cesspit actually is

A cesspit, in the original sense, is a hole in the ground that takes human waste and holds it, often lined with brick or stone. Few were fully watertight, so sewage seeped into the surrounding ground and could pollute nearby wells. There was no treatment stage at all.

The Hunter had them too. An archaeological report on the NeW Space site at the corner of Hunter and Auckland Streets in Newcastle records that by 1900 only 330 properties in the town were sending sewage through the council’s stormwater pipes into the harbour, 1,570 were still on the pan system, and 175 had cesspits. The Newcastle sewerage scheme started in 1903. The same dig uncovered a large brick and stone lined cess pit from the second half of the 1800s.

Town sewerage schemes never reached most rural blocks, and plenty of Hunter properties are still unsewered today. That is why an old pit, a brick chamber or a buried vessel that nobody can explain can still turn up when people renovate, extend or sell an older house in Maitland, Cessnock, Singleton or Dungog.

NSW law still names the cesspit. The Local Government Act 1993 lists it as a type of “human waste storage facility”, alongside septic closets, chemical closets and others, and the Local Government (General) Regulation 2021 carries performance standards for cesspits. But the NSW Office of Local Government’s Onsite Wastewater Management Guidelines (2025) are blunt: cesspits, “otherwise known as pit toilets”, are not considered sound for environmental or human health reasons and are not recommended as an on-site system. The same guidelines suggest councils list pit toilets among the systems that are unacceptable in their area.

Cesspit vs cesspool, and the words NSW uses instead

If you have been reading UK websites, you will have seen cesspit and cesspool used as the same thing. England’s drainage guidance for the building regulations, Approved Document H, defines a cesspool as a watertight underground tank for storing sewage, with no treatment involved. It should have no openings except the inlet, access for emptying and ventilation, and it is only acceptable where no other option is feasible. The minimum size gives you a sense of how much a sealed tank has to hold: 18,000 litres for two users, plus 6,800 litres for each extra person.

NSW has the same kind of system, it just uses different names:

• Holding tank. The general term for a sealed tank that stores wastewater until a truck removes it. The Easy Septic Guide uses it for the storage tank in a pump-out system.
• Pump-out system. The domestic version. The OLG guidelines describe it as wastewater treated to a primary standard onsite, then displaced into a collection well that is emptied by a liquid waste contractor’s tanker.
• Collection well. The storage vessel in a pump-out system, usually with a standpipe near the boundary that the tanker hose connects to.

So a Hunter owner asking for their “cesspit” to be pumped most likely has a pump-out system or an ordinary septic tank. Our holding tank pumping page covers pump-out systems and commercial tanks in detail.

Cesspit, holding tank, septic tank and AWTS side by side

The pump-out frequencies for a pump-out system and a septic tank with trenches both come from the NSW Easy Septic Guide. If you are weighing up a septic tank against an AWTS for a new or replacement system, we compare them properly in septic tank vs AWTS.

How a septic tank is different from a cesspit

As the NSW Easy Septic Guide explains, sewage entering a septic tank separates into three layers: scum on top, sludge on the bottom, and clearer effluent in between. As new wastewater comes in, the same volume of effluent flows out to an absorption trench, where the soil carries on the treatment.

That is the key difference. A cesspit hands raw waste straight to the ground. A septic tank holds back the solids and sends only partly treated liquid on, to a trench designed for it. Because the tank keeps only solids, it can go years between pump-outs: the OLG guidelines size a domestic tank for a five-year cycle.

Why a holding tank fills so fast

A holding tank keeps everything. Every shower, flush and load of washing stays in the collection well until the tanker comes. That is why pump-out systems run on weekly or fortnightly visits rather than the 3 to 5 years a septic tank manages.

The OLG guidelines show the gap clearly. They work out a house’s design occupancy from its bedrooms: 3 people for the first bedroom and 1 for each extra bedroom, so a three-bedroom house is designed for 5 people. For a house on tank water, they allow 120 litres of wastewater per person per day (150 litres on town or bore water).

For that three-bedroom house:

• The minimum septic tank is 2,750 litres, sized to hold a day’s flow plus five years of sludge.
• The minimum collection well for a weekly pump-out is seven days of flow plus two days of emergency storage. At 600 litres a day, that is 5,400 litres, and it still needs emptying every week.

The Easy Septic Guide says a pump-out system in full-time use should be pumped every 1 to 2 weeks depending on the number of people, inspected every 1 to 2 years, and never allowed to get more than two-thirds full. It also says every collection well should have a dipstick with a “full” mark on it.

Wells built to the current guidelines also carry a high water alarm with a buzzer and a light, set to go off when less than 48 hours of storage is left. If you mute it, it must turn itself back on after 24 hours. Treat the alarm as a two-day warning, not a crisis, and ring that day.

Guests, a leaking cistern and back-to-back washing loads all shorten the interval, because every extra litre has to go out on the truck.

When Hunter councils still allow a pump-out system

Rarely, for new homes. The OLG guidelines say domestic pump-out systems “should only be considered as a last resort”, and only where an existing system is failing and a sewer connection is not possible. A new development that relies on one should be treated as over-development of the site and not approved. The guidelines add that many councils do not accept pump-out systems at all, and that councils which do should inspect them at frequent intervals and investigate any property recording no pump-outs.

The concern is cost. The guidelines note that high running costs invite misuse, and they ask councils to guard against deliberate illegal discharges, which carry a high health risk.

Existing pump-out systems still operate legally across the Hunter where the council approved them. Like any on-site system, they need an approval to operate from council under section 68 of the Local Government Act 1993. The model approval conditions in the OLG guidelines include a working audible and visual high water alarm, a graduated dipstick, and pump-outs only by a liquid waste collection contractor before the well is full. Keep every disposal docket, as councils ask owners to hold on to them as evidence of maintenance.

Getting off a pump-out system usually starts with a site and soil assessment to see whether the block can take an AWTS with a designed irrigation area. We handle the assessment and section 68 paperwork support; the installation is carried out by licensed plumbing and drainage contractors we work with; their NSW licence number appears on every quote.

Found an old brick cesspit on your property? What to do

Renovations, landscaping and building inspections on older Hunter houses sometimes turn up a brick-lined pit or a buried vessel.

Stay out of it and keep the lid on. SafeWork NSW lists tanks, pits and wet or dry wells among confined spaces, where contaminants in the air and a lack of oxygen can kill, and it warns the hazards are not always obvious. Never lean in or climb in. Old brickwork and unreinforced lids can also give way, so fence off the area and keep vehicles and mowers clear.

Work out what it is. It might be an old cesspit, a disused septic tank, a collection well, or even an old well or soakage pit. A septic inspection with a written report tells you what is there, whether it is connected to anything, and whether it still holds liquid or sludge. That matters if you are buying or selling: see buying a property with a septic tank in NSW.

Ask your council what it wants. NSW Health’s Advisory Note 3 (revised January 2017) sets out how redundant septic tanks and collection wells should be demolished, reused or removed, and the OLG guidelines tell councils to apply it when a system is no longer needed. An old cesspit is not strictly a septic tank, so ask your council’s environmental health team which steps it expects. If the house is heritage-listed, also ask whether heritage approval applies before the pit is disturbed.

Empty it before anything else. Advisory Note 3 says the contents of a tank being demolished must be removed by a method the council accepts, such as tanker removal to an authorised site, and must never be spread or discharged above ground. That part we do. The waste is transported and disposed of under NSW EPA waste rules at a licensed treatment facility, and a disposal docket is provided for every load.

Then demolish or fill it properly. For a septic tank or collection well being demolished on site, Advisory Note 3 describes hosing down the surfaces as the waste is removed, spreading builders’ (hydrated) lime over them, punching or drilling holes in the base, collapsing the lid and upper walls into the tank, and filling it with clean soil or rubble topped with clean soil so no void is left to collapse later. The excavation and demolition are carried out by licensed plumbing and drainage contractors we work with; their NSW licence number appears on every quote. Our full guide to decommissioning a septic tank in NSW walks through the paperwork.

Do not reuse an old cesspit or tank for anything inside the house. Advisory Note 3 is clear that septic tanks and collection wells must never be reused to hold drinking water or water for any internal household purpose.

What it costs

Our septic tank pump-outs are priced by tank capacity:

Emergency or after-hours dispatch adds $150 to $300. A lid buried deeper than 300 mm adds $75 to $150, a hose run beyond 45 metres $50 to $120, and hardened sludge $75 to $150, always quoted before we start. For a collection well, ask us to quote for your well size and pump-out interval. There is no travel surcharge across the Maitland, Cessnock, Singleton or Port Stephens corridors.

A pre-purchase septic inspection with a written report is $250 to $500. Most routine pump-outs are scheduled within 48 hours; see septic tank pumping to book, or call 0468 278 123 and tell us what you have found.

Frequently Asked Questions

What is the difference between a cesspit and a septic tank?

A cesspit only stores raw sewage, and in its traditional form lets the liquid seep untreated into the surrounding soil. A septic tank separates and partly treats sewage, holding back solids and sending the clearer effluent to an absorption trench designed for it. That is why a septic tank goes 3 to 5 years between pump-outs.

Is a cesspit the same as a cesspool?

In the UK the two words are used for the same thing: a sealed underground tank with no outlet that a tanker empties. In NSW that kind of system is called a holding tank, a pump-out system or a collection well. The NSW guidelines use cesspit to mean a pit toilet, which they do not recommend.

Are cesspits still allowed in NSW?

The NSW Office of Local Government guidelines say cesspits, also known as pit toilets, are not considered sound for environmental or human health reasons and are not recommended as an on-site system. Councils can list them as unacceptable in their area. If you have one, ask your council what it expects you to do with it.

How often does a holding tank need to be pumped out?

The NSW Easy Septic Guide says a domestic pump-out system in full-time use should be pumped every 1 to 2 weeks, depending on how many people live there. It should never be allowed past two-thirds full. A dipstick in the collection well shows when it is ready.

Can I get a new pump-out system approved in the Hunter?

It is unlikely for a new home. The OLG guidelines say domestic pump-out systems should only be a last resort where an existing system is failing and sewer is not available, and many councils do not accept them. Talk to your council before applying for anything.

What should I do if I find an old brick cesspit on my property?

Keep everyone out and keep the lid on, because an old pit is a confined space and old lids can collapse. Get it identified, ask your council what it requires, and have it pumped out before any demolition or filling. The demolition and backfill are done by licensed plumbing and drainage contractors, following the steps council sets.

Sources and further reading

• NSW Office of Local Government, Onsite Wastewater Management Guidelines (2025): cesspits described as pit toilets and not recommended (section 5.3.4), the human waste storage facility definition, pump-out systems as a last resort (section 5.8.2), design occupancy and flow allowances (Tables 6-1 and 6-2), minimum septic tank capacity (Table 6-3), collection well sizing and alarm rules (section 6.2.1), collection well approval conditions, and the requirement to decommission under NSW Health Advisory Note 3.
• NSW Office of Local Government, The Easy Septic Guide: how a septic tank separates sewage into layers, desludging every 3 to 5 years for a tank with absorption trenches, and the pump-out system routine (every 1 to 2 weeks, no more than two-thirds full, dipstick in the collection well).
• NSW Health, Advisory Note 3: Destruction, Removal or Reuse of Septic Tanks, Collection Wells, AWTS and other SMF (revised January 2017), hosted by Muswellbrook Shire Council: removing contents, lime, holes in the base, collapsing and filling, and the ban on reuse for drinking or household water.
• Old Treasury Building Melbourne, The Nightman: brick-lined cesspits, few of them watertight, seeping sewage and polluting wells, and the pan system that replaced them.
• HM Government, Approved Document H: Drainage and waste disposal (2015 edition, England): the UK definition of a cesspool (paragraph 1.13), when one is acceptable (1.14), and its openings and minimum capacity (1.61 and 1.62).
• SafeWork NSW, Confined spaces: tanks, pits and wells as confined spaces, and the risks of airborne contaminants and oxygen deficiency.
• Archaeological Management & Consulting Group, NeW Space Final Archaeological Report, Vol. 1 (2018), via Hunter Living Histories: Newcastle’s 1900 figures for pan system and cesspit properties, the 1903 sewerage scheme, and the brick and stone lined cess pit found on site.