Pump Out Tank vs Septic Tank: What's the Difference?

The main difference between a pump out tank and a septic tank is that a septic tank partly treats wastewater and sends the liquid into the soil, while a pump out tank just holds all of it until a vacuum truck takes it away. Plenty of Southern Highlands properties outside town sewer use one or the other, and the type you have affects how often the truck needs to visit and what you need to keep an eye on. At Anderson Waste Services, we service both types on properties across the Highlands, and this guide explains how each one works.

Key Takeaways

• A pump out tank, also called a holding tank, stores all household wastewater until it's removed by a vacuum truck. A septic tank treats wastewater on-site and sends effluent to a drain field.
• Because nothing leaves a pump out tank between services, it needs emptying much more often than a septic tank.
• On-site sewage systems in the Wingecarribee Shire are regulated by council, and council decides what type of system a property can have.
• Our vacuum truck services both conventional septic tanks and pump out tanks, from residential blocks to acreage and hobby farms.

Introduction: Why Pump-Out Tank vs Septic Tank Matters in the Southern Highlands

Knowing whether your property has a pump out tank or a septic tank tells you how your wastewater is handled and how often it needs servicing. Many homes and rural properties around Moss Vale, Bowral, Robertson, Bundanoon and Exeter aren't connected to town sewer, so they rely on an on-site sewage management system. In most cases that means a septic tank or a pump out tank. In this guide, Anderson Waste Services covers how each system works, why a property might have one rather than the other, and what that means for maintenance.

What Is a Septic Tank and How Does a Septic System Work?

A septic tank is the first stage of a septic system that treats household wastewater on your property. It's more than a storage tank.

• Wastewater from toilets, showers, sinks and the laundry flows into the tank.
• Solids settle to the bottom as sludge, and fats, oils and grease float to the top as a scum layer.
• Bacteria in the tank break down some of the organic matter.
• The clearer liquid in the middle, called effluent, flows out to a land application area such as absorption trenches, where the soil keeps treating it.

Because the liquid leaves the tank, only the sludge and scum build up over time. That's why a septic tank only needs a pump out every few years. As a general guide, most residential septic tanks in the Southern Highlands are pumped out every three to five years. How well a septic system works depends a lot on having suitable soil and enough room for the drain field, which is why it isn't the right fit for every block.

What Is a Pump-Out Tank (Holding Tank)?

A pump out tank is a sealed holding tank that collects and stores household wastewater without treating it or releasing it into the ground. There's no outlet to trenches or a drain field. Everything from the toilets, showers, sinks and laundry stays in the tank until a licensed operator empties it with a vacuum truck.

Pump out tanks are usually used where releasing effluent into the soil isn't suitable or allowed. That might be because of the block size, the soil, the slope or nearby waterways. Because the tank holds everything, it fills much faster than a septic tank and needs regular emptying. How often depends on the tank size and how much water the household uses.

At Anderson Waste Services, we empty pump out tanks across the Southern Highlands and transport the waste in our licensed vehicles to an EPA-approved facility.

Key Differences: Pump-Out Tank vs Septic Tank

The key difference is treatment. A septic system treats wastewater on-site, while a pump out tank stores it for removal. Here's how they compare:

• Treatment: a septic tank partly treats wastewater and the soil finishes the job. A pump out tank doesn't treat anything.
• Where the liquid goes: septic effluent flows to a drain field or absorption trenches. A pump out tank has no outlet, so everything is removed by truck.
• How often it's emptied: a septic tank needs a pump out every few years. A pump out tank needs emptying far more often.
• Running costs: more frequent servicing usually means higher ongoing costs for a pump out tank.
• Land needed: a septic system needs room for a drain field with suitable soil. A pump out tank doesn't.
• Day-to-day care: pump out tank owners need to watch their water use closely, because every litre fills the tank.

When Council Requires a Septic Tank vs When a Pump-Out Tank Is Used

In the Wingecarribee Shire, council decides what type of on-site sewage system a property can have, under the Local Government Act and the NSW on-site sewage management guidelines. Things like lot size, soil conditions, slope and distance from waterways all come into it.

In general terms, a conventional septic system suits properties with enough suitable land for a drain field. A pump out tank tends to be used where that isn't possible, for example on small or constrained blocks, difficult soils, or sites close to sensitive waterways.

If you're buying a property, ask what type of system it has and check its approval status with Wingecarribee Shire Council. For your obligations as an owner, contact council directly.

Choosing the Right System for Southern Highlands Residential Properties

For most owners, the choice is made by council and by the property's soil, size and layout. Still, understanding the trade-offs helps with planning and budgeting.

• Septic tanks mean fewer truck visits and can work quietly for years when they're well designed and looked after.
• Pump out tanks work on sites where a drain field isn't an option, but they need more frequent servicing and careful water use.

Property size, soil, truck access, household size and water use all matter. Speak with a licensed plumber or wastewater designer, and confirm any new or upgraded system with Wingecarribee Shire Council before work starts.

How Often Do Septic Tanks and Pump-Out Tanks Need Pumping?

A septic tank usually needs pumping every few years, while a pump out tank needs emptying much more often because it stores all of the household's wastewater.

For septic tanks, a general guide for most Southern Highlands homes is every three to five years. Smaller tanks, larger households or heavily used systems may need it sooner. For pump out tanks, the right schedule depends on the tank's capacity and how much water goes into it. We're happy to help you work out a realistic routine based on how your household uses water.

For more on how our service works, see our page on septic tank pump out in the Southern Highlands.

How Anderson Waste Services Helps with Both System Types

At Anderson Waste Services, our vacuum truck services both conventional septic tanks and pump out tanks on properties of all sizes, from standard residential blocks to acreage and hobby farms. All the waste we collect is transported in our licensed vehicles and disposed of at an EPA-approved facility in line with NSW environmental regulations.

We're a family-owned business based in Moss Vale, and we work across Bowral, Mittagong, Bundanoon, Berrima, Robertson, Exeter and the wider Wingecarribee Shire. If you notice wet patches, bad smells, overflowing or slow drains, call us on 02 4869 4260. We can also give you documentation of the service for your records or for council.

Practical Tips Before Your Tank Is Pumped Out

A little preparation makes any pump out quicker and easier.

• Make sure tank lids and inspection points can be reached. Trim back plants and avoid building decks or paving over them.
• On acreage and hobby farms, mark where the tank is so the truck can park in the right spot.
• Check there's safe access for the truck. Tell us about narrow driveways, low branches, steep slopes or soft ground.
• Let us know whether you have a septic tank or a pump out tank so we can plan the job.

FAQ: Common Questions About Pump-Out Tanks and Septic Tanks

Is a pump out tank the same as a septic tank?

No. A septic tank is part of a system that treats wastewater and sends effluent into the soil. A pump out tank simply stores all wastewater until a vacuum truck removes it. They work differently and need servicing on very different schedules.

Can I change from a pump out tank to a septic system?

Possibly, if the property has enough suitable land and the right soil, but any change needs Wingecarribee Shire Council approval and a proper design by qualified professionals. Talk to council first.

How do I know what type of system my property has?

Check council records, the original plumbing plans or your property purchase documents. If you're still not sure, a licensed plumber or wastewater operator can inspect the system and tell you what's installed.

What happens to the waste after my tank is pumped?

We transport all septic waste in licensed vehicles to an EPA-approved facility, where it's handled in line with NSW environmental regulations.

Who should I contact about my legal obligations?

Contact Wingecarribee Shire Council about approvals and your obligations as an owner. For practical help with pump outs and looking after your system, contact Anderson Waste Services.