A power outage is inconvenient in any home, but if your property relies on an Aerated Wastewater Treatment System, commonly known as an AWTS, you may also wonder what the blackout means for your wastewater system.

Can you still flush the toilet? Can you shower? Will the system overflow? Does the AWTS need to be restarted? And how long can the power stay off before there is a problem?

The good news is that a short power outage does not automatically mean your wastewater system will fail. However, an AWTS relies on electrical components to treat and distribute wastewater, so it is important to understand what happens when those components temporarily stop operating.

Knowing what to do during a blackout can help protect your system, reduce the risk of an alarm or overflow and prevent unnecessary damage.

What Is an AWTS?

An Aerated Wastewater Treatment System is an on-site wastewater system designed to treat household wastewater before the treated effluent is dispersed or reused on the property.

Unlike a basic septic tank, an AWTS uses a combination of treatment processes that may include primary settling, aeration, clarification, disinfection and irrigation.

Eco Septic systems use biological treatment processes in which naturally occurring microorganisms help break down organic matter in household wastewater. Air is introduced into the aeration chamber by an air blower, creating the oxygen-rich environment needed by aerobic bacteria. Once treated, wastewater is moved through the system and ultimately pumped to the approved land application or irrigation area.

These processes depend on electrical equipment.

That means a blackout does not stop wastewater entering the tank, but it can temporarily stop some of the processes responsible for aeration, pumping and irrigation.

What Stops Working During a Power Outage?

The exact components depend on the wastewater system installed at your property, but in a typical AWTS, a power outage can affect equipment such as:

• the air blower

• the irrigation or effluent pump

• the control panel

• alarm systems

• timers or float controls

• other electrical treatment equipment

Eco Septic systems use an air blower to introduce oxygen into the treatment process and an automatic submersible pump to deliver treated wastewater to the irrigation system.

During a blackout, wastewater from your home can still enter the system when you flush toilets, use sinks, shower, run washing machines or use the dishwasher.

The important difference is that the system may not be able to treat and pump that wastewater at its normal rate.

This is why reducing household water use becomes important during an extended outage.

Can I Still Flush the Toilet?

Generally, yes.

A short blackout does not normally mean you must immediately stop using every toilet or tap in the house.

However, once the power is off for an extended period, water use should be kept to a minimum.

If the power has been off for several hours, it is sensible to reduce household water use. Toilets can still be flushed when necessary, but showers should be kept short and non-essential water use should be delayed.

The principle is simple: every litre of water going down a drain eventually becomes wastewater entering the treatment system.

If the irrigation pump is not operating, the system has limited capacity to continue receiving wastewater before water levels rise.

What Should I Avoid During a Longer Blackout?

If the power outage continues, avoid high-volume water use wherever practical.

That means postponing activities such as:

• multiple loads of washing

• long showers

• filling and draining baths

• running the dishwasher repeatedly

• unnecessary toilet flushing

• large amounts of cleaning water

• allowing leaking taps or toilets to continue running

A washing machine can introduce a significant volume of water into an on-site wastewater system in a relatively short period.

Normally this is not a problem because the AWTS is designed to treat normal household flows. During a blackout, however, the pumping and aeration equipment may not be operating.

Spreading your water use across the day rather than creating sudden high-volume loads can reduce pressure on the system.

The safest approach during a prolonged outage is simply to conserve water until power is restored.

What Happens to the Bacteria in the System?

One of the most important parts of an AWTS is something you cannot see: the biological population living inside it.

Aerobic bacteria and other microorganisms help break down organic matter in the wastewater.

The air blower continuously supplies oxygen to support these organisms.

When the electricity fails, the blower stops.

For a short outage, this usually does not mean the biological process immediately collapses. However, the longer aeration is unavailable, the greater the potential impact on biological treatment.

If power remains off for a very long period, the biological activity within the system can be affected and the wastewater may not receive the same level of treatment it normally would.

This is one reason homeowners should contact their wastewater service provider after a prolonged outage rather than assuming everything has returned to normal.

Will My AWTS Overflow During a Blackout?

A short blackout does not automatically cause an overflow.

The system has storage capacity within its chambers, which provides some tolerance for normal household wastewater entering during a temporary interruption.

However, if large volumes of water continue entering while the irrigation or discharge pump is unable to operate, water levels can rise.

Eventually this may trigger a high-water alarm after electricity is restored.

An alarm condition can occur after an extended blackout because water levels within the system may have risen while the pump was without power.

The best protection is therefore not panic, but sensible water conservation.

What Happens When the Power Comes Back On?

Once electricity is restored, the electrical components of the AWTS should normally resume operation.

One of the first things to check is whether the air blower has restarted.

Stand near the system and listen for the normal light humming sound from the blower.

If the system appears not to have restarted, do not open tanks or attempt electrical repairs yourself.

Wastewater systems contain both biological and electrical hazards, and electrical work should only be carried out by an appropriately licensed technician or electrician.

In many cases, the system simply needs time to resume its normal treatment and pumping cycle.

Why Might the Alarm Sound After a Blackout?

An alarm after a power outage does not necessarily mean that the AWTS has failed.

The alarm may activate because the system accumulated more wastewater than usual while the irrigation pump was without power.

AWTS alarm panels can indicate conditions such as:

• high water level

• pump problems

• loss of air

• electrical or control faults

Once power returns, the system may need time to move the accumulated treated wastewater through the irrigation system.

If the warning light or alarm continues after the system has had time to recover, contact Eco Septic or your accredited service technician.

Persistent alarms should not simply be ignored or permanently muted.

The alarm is there to tell you that the system needs attention.

Check the Irrigation Area

After a prolonged blackout, it is also worth inspecting the irrigation or land application area from a safe distance.

Look for:

• unusual pooling of water

• excessively wet ground

• strong wastewater odours

• damaged irrigation lines

• sprinklers that are not operating normally

• water appearing where it normally should not

Avoid direct contact with wastewater or treated effluent.

If you see pooling, wastewater surfacing or strong odours, keep children and pets away from the affected area and contact your service provider.

Should You Turn Your AWTS Off Before a Storm?

No.

Turning the power off to an AWTS as a general precaution is not recommended.

Your wastewater treatment system is designed to operate continuously, and the air blower relies on power to maintain aeration.

The system should normally remain switched on, including when residents are away from the property.

If severe weather causes an electricity outage, then follow the water-conservation steps outlined above.

If you have concerns about electrical safety during a storm, follow advice from your electricity provider, emergency services or a licensed electrician.

What About Generator Power?

Some homeowners in rural areas have backup generators because electricity interruptions may occur during storms, bushfires or network outages.

Whether your AWTS can or should be connected to generator power depends on the system, generator capacity, electrical configuration and manufacturer requirements.

Do not simply run an extension lead to wastewater equipment.

The system includes pumps, alarms and electrical controls located around water, so any backup power arrangement must be safe and compliant.

If reliable backup power is important for your property, speak to a licensed electrician and your wastewater service provider before an outage occurs.

Planning ahead is much safer than trying to improvise during an emergency.

What If the Power Is Off for a Day or More?

A prolonged outage requires greater care.

The longer the irrigation pump and air blower remain without power, the more important it becomes to limit wastewater entering the system.

If the power is expected to remain off for a full day or longer, household water use should be reduced as much as reasonably possible.

That may mean:

• postponing laundry

• taking very short showers

• avoiding baths

• only running the dishwasher when absolutely necessary

• fixing or isolating leaking taps and toilets

• limiting unnecessary flushing

• spreading essential water use throughout the day

For an AWTS, the correct response will depend on the system and how long it has been without power.

Contact your service technician if:

• the outage lasts for an extended period

• the high-water alarm remains active after power returns

• the blower does not restart

• the irrigation system does not operate

• wastewater backs up into the home

• there is unusual pooling around the tank or irrigation area

• strong odours develop

• you suspect electrical or physical damage

What If the Blackout Happens While You Are Away?

An AWTS should normally remain powered even if the house is temporarily vacant.

If a blackout occurs while you are away, the system will generally resume operating when electricity returns.

When you arrive home, check that the system appears to be operating normally and listen for the blower.

If an alarm is active, do not assume it is simply because of the blackout.

Allow the system some time to recover, but if the alarm remains active, follow the troubleshooting instructions for your system or contact your service technician.

This is especially important after long outages or severe storms.

Can Heavy Rain Make a Power Outage Worse?

Yes, in some situations.

Power outages often occur during storms, and heavy rainfall can place additional pressure on an on-site wastewater system.

Saturated soil may reduce the ability of the irrigation or land application area to absorb treated wastewater efficiently.

If the power is also out, the system may be unable to pump treated wastewater at its normal rate.

This combination makes water conservation even more important.

After severe weather, check the area surrounding your wastewater system for signs of flooding, erosion, damage or unusual pooling.

Do not walk through areas where wastewater may be present.

Could a Leaking Toilet Cause Problems During a Blackout?

Absolutely.

A leaking toilet can send a surprisingly large amount of unnecessary water into your wastewater system.

When the AWTS is operating normally, this additional flow can still place unnecessary stress on the system.

During a blackout, the problem becomes more important because the irrigation pump may not be operating.

If you know you have a leaking toilet or tap, isolate it if possible until it can be repaired.

Reducing unnecessary water entering the system is one of the simplest ways to protect an AWTS during a power outage.

Should I Pump the Tank Out After Every Blackout?

No.

A normal short-term power outage does not mean your AWTS automatically needs to be pumped out.

In most cases, once power is restored, the system can return to normal operation.

Pumping should only be considered where there is a genuine system issue or where your service technician recommends it.

If the outage has been unusually long, the system has overflowed, biological treatment has been badly affected or wastewater has backed up, professional assessment may be necessary.

Never arrange unnecessary pump-outs purely because the electricity was off for a few hours.

A Simple AWTS Power-Outage Checklist

If your AWTS loses power, follow these practical steps.

During the blackout

1. Confirm that the property has lost power.

Check whether the outage affects the entire house or whether only the wastewater system appears to have lost electricity.

2. Reduce water use if the outage continues.

Keep showers short and postpone washing machines, dishwashers and other high-water-use activities where possible.

3. Avoid unnecessary water entering drains.

Do not run taps, fill baths or complete multiple loads of washing unless necessary.

4. Do not interfere with electrical equipment.

Never attempt electrical repairs yourself.

5. Keep people and animals away from unusually wet areas.

Treat pooled wastewater or effluent as potentially unsafe.

When power returns

6. Check the air blower.

Listen for the normal operating hum.

7. Allow the system time to recover.

If water levels have increased, the pump may need time to return the system to its normal operating level.

8. Check for alarms.

A temporary alarm may clear as the system catches up.

9. Check the irrigation area.

Look for unusual pooling, odours or obvious problems.

10. Contact your service technician if anything remains abnormal.

A persistent alarm, non-operating blower, wastewater backup or unusual pooling should be investigated.

Regular Servicing Makes a Difference

A properly maintained AWTS is far easier to manage when unexpected events occur.

Routine servicing allows technicians to check key components such as:

• pumps

• blowers

• alarms

• treatment chambers

• control systems

• irrigation equipment

It also means developing problems can often be identified before they turn into emergency failures.

A system with a failing pump, damaged alarm or weak blower is much more likely to experience problems when placed under additional pressure.

Regular servicing also gives homeowners an opportunity to ask questions about how their particular system operates during unusual situations such as blackouts, heavy rain, holidays or increased household occupancy.

Be Prepared Before the Next Outage

Power outages are rarely convenient, but a little preparation can make them much easier to manage.

It is a good idea to know:

• where your AWTS control panel is located

• what the alarm lights mean

• where the irrigation area is positioned

• who services your system

• the service provider’s contact number

• where the electrical isolation point is located

• whether your household has any leaking taps or toilets

If you live in an area where storms or power outages are common, you may also want to discuss backup power options with a licensed electrician.

The important point is that wastewater systems work best when homeowners understand the basics of how they operate.

The Key Message: Reduce Water Use and Let the System Recover

If your Eco Septic AWTS loses power, there is usually no need to panic.

A short outage will generally be manageable, but the system’s electrical equipment cannot operate normally until power is restored.

The most important steps are simple:

reduce household water use during an extended outage, avoid unnecessary high-volume water use, leave the system alone electrically, check that the blower restarts when power returns, allow the system time to recover and contact Eco Septic if an alarm or problem continues.

Most importantly, never ignore an ongoing alarm, wastewater overflow, unusual odour or pooling around the system.

Your AWTS is designed to quietly manage your household wastewater every day. Understanding how it behaves during a power outage means you can protect the system, your property and the people around it when the lights go out.

For advice about your Eco Septic system, servicing or troubleshooting, contact Eco Septic or your authorised Eco Septic service provider.