It is important to understand Septic Tank Systems, only perform well if
operated and maintained in accordance with this guideline and your
Permits to Install and Use.
They DO NOT have an unlimited lifespan.
All septic tank systems have a design
capacity, and design life, due to soil type,
operating conditions and level of misuse.
When septic tanks are misused wastewater
can discharge to ground surface and
impact on you, your neighbours and the
environment.
They can an unacceptable risk to health if
not properly maintained.
WOULD YOU LIKE SOMEBODY ELSES UNTREATED WASTE
WATER ON YOUR PROPERTY?
PLEASE READ THIS MANUAL AND KEEP IN A SAFE PLACE
HANG IT ON THE BACK OF YOUR TOILET DOOR
City of Ballarat
Environmental Health Unit
The Phoenix, 25 Armstrong Street South, Ballarat
PO Box 655, Ballarat Vic 3353
Phone: 5320 5702
Fax: 03 5320 5826
Email: environmentalhealth@ballarat.vic.gov.au
Your Septic System Description
In the box mark direction north, location of house,
street, drive, shedding, septic tank and trenching.
Date installed: .............................................
Phone: .......................................................
Tank capacity: .............................................
Drain dimensions: ........................................
Type: ..........................................................
Why Operate & Maintain Your System ?






Protect the health of your family and friends
It protects the stormwater system
It saves you money in maintenance and
repairs
A failed system reduces property values
It prevents illegal discharges and liability
issues
Wastewater must by law be kept within your
property boundaries
Managing Septic System Performance









NO SYSTEM IS MAINTENANCE FREE!
Septic Tanks operate by biological digestion of organic matter. Minimise the use of
disinfectants and sanitizers.
Inspect your system annually and pump out your tank (3 yearly).
Use water efficiently! Install water saving devices like low flow shower heads, front load
washing machines, dual flush cisterns(6/3L), flow restrictors and rainwater tanks.
Don’t put hazardous chemicals into your septic system.
Plant grasses over your trenches and small shrubs between.
Don’t drive over any part of your septic system. Doing so compacts the soil & damages
tanks/pipes/trenches.
Blocked drains should be cleared with boiling water or drain eel only!
Don’t overload your system.
REMEMBER TO MANAGE YOUR SEPTIC TANK SYSTEM



Reduce water, inspect and pumpout your system regularly.
Fix leaky taps immediately.
Odours or boggy drainfields are signs you have a FAILING system.
Index
OWNERS RESPONSIBILITIES – SEPTIC TANKS ....................................................2
HOW A CONVENTIONAL SEPTIC SYSTEM WORKS .............................................3
HOW A AERATED WASTEWATER TREATMENT SYSTEM WORKS ................5
EFFLUENT TRENCH AREA ..........................................................................................7
LOCAL DESLUDGERS ...................................................................................................8
SCHEDULED MAINTENANCE .....................................................................................8
REDUCE SLUDGE AND SCUM BUILD UP .................................................................9
SHOPPING TIP ...............................................................................................................11
WATER USAGE ..............................................................................................................12
PLANTING AROUND YOUR EFFLUENT DISPOSAL SYSTEM ...........................13
APPENDIX A: 1. DETERMINING SLUDGE & SCUM DEPTH ..............................16
APPENDIX A: 2. TANK DIAGNOSIS ..........................................................................17
OPERATION & MAINTENANCE GUIDELINE ........................................................18
Septic Tank Owners Operation & Maintenance Manual
1
Owners Responsibilities – Septic Tanks
As the owner of a property with a septic tank system, the maintenance of the system is
your responsibility. Council can assist you to understand your system but we can’t control
what you do to it.
WHY MAINTAIN YOUR SYSTEM

It saves you money in maintenance and
repairs

A failed system reduces property values

It prevents illegal discharges and liability
issues

Protects the health of your family and friends

Protects
the
environment
and
prevents
stormwater contamination
Above: A flooded AWTS system in a
backyard like this can effect the health
of the occupants especially children
playing in the yard.
Any septic tank system should be seen for what they are – a sewerage system. However,
unlike a reticulated sewerage system in cities and towns, on-site systems must collect,
treat and safely apply effluent within property boundaries of individual allotments.
Householders should not assume that their system, once installed, will continue to work
effectively without ongoing maintenance and protection against misuse.
The operation and maintenance of an onsite system involves you managing the:

quantity and quality of water going into and out of the septic tank;

desludging of the septic tank every 3 years;

accessibility of the tank and trenches;

protection of tank and trenches from damage; and,

annual inspection of the septic tank system
Septic Tank Owners Operation & Maintenance Manual
2
How a Conventional Septic System Works
Many people who rely on a septic tank system are unaware that it operates by physical
separation and biological digestion of organic matter. Do not overly use disinfectants.
After sewage from your home
flows into the septic tank the
heavy solids settle to the bottom.
Bacterial action helps decompose
these
solids
gases.
into
sludge
and
Materials lighter than
water, such as fats and oils, rise
to the top and form a scum layer.
A
baffle
in
the
septic
tank
prevents it from leaving the tank
and clogging the disposal field.
The sewage then goes out to the
trenches seeping through the soil
and being evaporated or transpired by wind and plants.
Bacterial action needs time to break down sewage. As sludge builds up in your tank and
the scum layer thickens the volume of the tank decreases. Sewage has less time to be
treated
by
settling
out
while
bacterial treatment is less effective
causing solids to be released to the
trenches increasing the risk of the
soil clogging.
Septic Tank Owners Operation & Maintenance Manual
3
After market filters are available to protect your trenches from the
escape of scum and solids. They provide a warning that maintenance is
needed. Contact Council for more information.
Unless removed, the sludge and scum layers will eventually clog either
the septic tanks inlet or outlet pipes, or, the disposal field, and cause
your system to fail.
The level of solids accumulation in the tank cannot be accurately predicted because it
depends on the level of contamination of the sewage from solids and fats or other things.
You can check the sludge depth annually to see if a pumpout
/ desludge is needed.
Remember that you need to be able to access your septic
tank for annual checks and for pumping out / desluging so
building over your septic tank is definitely out of the
question. It can end up quite a costly exercise should this
occur.
If the tank is half full of sludge or if the water leaving
the tank is high in solids, it should be desludged.
Information on determining sludge depth is available
in Appendix A.
Above: Hunting out a
septic tank.
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4
How a Aerated Wastewater Treatment System Works
These systems are often referred to as mechanical treatment plants. They are designed to
treat household sewage to a biological and suspended solid standard.
The Aerated Wastewater Treatment System (AWTS) system consists of a series of
compartments within one or more tanks. The first is a basic septic compartment where
solids settle and anaerobic digestion occurs. In the second, air is pumped through the
effluent to encourage aerobic bacteria to digest the waste. Subsequent compartments
contain filter media that allow clarification whereby slime collects on the media. The
effluent may also be disinfected with chlorine and then pumped to trenches typically subsurface irrigation type trenches. The irrigation area is required to be a permanent
dedicated area within the property.
Mechanical wastewater treatment plants have numerous maintenance issues involving
aerators, pumps and alarms. Aerators should not be wound back to reduce aeration time
Septic Tank Owners Operation & Maintenance Manual
5
or the power turned off. This impacts on the quality of the wastewater produced and can
lead to expensive repairs.
Pumps will periodically require replacement and it is wise to ensure oversized pumps are
installed as they will not need to work as hard. Inline filters should be incorporated and
they too will need to be periodically cleaned. Vacuum breaker valves as well as rotation
and flush valves all help to ensure the wastewater system functions adequately.
These systems must be serviced by a technician. Failure to do so may result in fines under
the Environment Protection Act.
It is critical that these systems are maintained. Contrary to some information provided all
treatment plants must be pumped out/desludged or major damage can be caused.
Before desludging a mechanical treatment plant you should contact the
manufacturer to ensure the correct procedure is followed to avoid any possible
damage to the components of the treatment plant.
Septic Tank Owners Operation & Maintenance Manual
6
Effluent Trench Area
Your effluent trenches usually consist of a series of shallow 400 –
500mm deep trenches ranging from 600 – 1000mm wide. Trenches
are dug perpendicular to the slope of the land so that effluent is
trapped within the trench. Newer trenches
have a concrete box at the beginning of the
trench. The trench has a slotted PVC pipe
that extends for the full length of the trench
and sits within a bed of 20 – 40mm stone.
Irrigation trenches are typically 150 – 200mm square with
perforated polypipe embedded in crushed rock. They are much
narrower and shallower allowing effluent to infiltrate the soil closer
to the surface. More sophisticated irrigation systems are buried
directly into the soil without crushed stone.
The
effluent
is
best
taken
up
by
vegetation so it is important that the
plants and grasses used are regularly
maintained. It is also very important it is
protected against stormwater discharges
and further site development. Stock and
machinery must be KEPT OFF this area.
Whatever
you
do
don’t
treat
your
disposal area like this
REMEMBER, NO SEPTIC SYSTEM IS MAINTENANCE FREE!
Septic Tank Owners Operation & Maintenance Manual
7
Local Desludgers
Ballarat BigVac
5342 7557
Sludgebusters
5333 5121
SepKleen
0437 751 880
Whitford Liquid Waste
5331 1829
Sita Env Solutions
5336 2733
Scheduled Maintenance
Regular maintenance and pumping out every 3 years are good ways to prolong a septic
system’s performance. If you’ve installed an outlet filter these should be regularly removed
and washed clean.
A rule of thumb for having your septic system inspected is once a year. Pick a date you
will remember – your birthday, anniversary, or after the July school holidays when the
weather is hopefully wet and plumbers are quiet.
Don’t wait until your drains don’t work properly.
stinking
mess,
cost,
inconvenience
and
The
disturbance
associated with fixing your failed septic tank system is a
major burden for any household. Environmental Protection
Authority requirements are becoming more stringent.
Failure to obtain permits to repair systems can result in
fines of up to $12,000.
Like changing the oil in your car, regular maintenance is an
‘insurance policy’ against the cost of replacing a neglected
system. Typically a new series of trenches can cost more
than $5000.
Above: A septic requiring
pumping out
Septic Tank Owners Operation & Maintenance Manual
8
Reduce Sludge and Scum Build Up
Minimising the amount of solids entering your septic system will reduce sludge and scum
build-up. This can extend the time between pumpouts and avoid having a failed system.
Do not put fats and oils down the drain. Either let them cool
and solidify so you can scrape them into the bin, or absorb the
oil with paper towel.
Compost kitchen waste if you are able and ensure a garbage
disposal unit is not used for handling vegetable waste. Fruit
and vegetable peelings ground up in a disposal unit tend to
stay in solution/suspension, rather than becoming part of the
sludge or scum layers.
KEEP NON DEGRADABLE & HAZARDOUS MATERIAL OUT!
Whatever you do never flush into a septic tank system materials
that do not break down.
Materials such as coffee grounds,
bones, disposable nappies, sanitary napkins, condoms, paper
towels, paint or cigarette butts, must be avoided. Pharmaceutical
products such as adhesive bandage, wrappers, dental floss, and
packaging materials can quickly accumulate and block up a
system.
Septic Tank Owners Operation & Maintenance Manual
9
THE DEAD POSSUM MYTH
In the old days when a new septic system was started up on
a farm, a dead possum or sheep was said to be thrown in to
the septic tank to kick start the system.
This is a load of rubbish!
In fact the sewage which starts flowing into the tank after connection provides plenty of
nutrients for the bacteria to begin doing their job.
To start up a new or pumped out system, fill the tank with clean water and add a cupful of
lime down the toilet every day for 7 days.
The lime helps prevent odours and increases the pH (alkalinity) to encourage bacterial
growth. Your septic tank system and drainage field area are full of living organisms that
make the system work.
Household
cleaning
chemicals
bacteria within septic tanks.
can
kill
Used in low
concentrations and quantities these may not
unduly affect efficient operation.
However,
users need to be aware that indiscriminate
use of disinfectants and cleaners (particularly
degreasers and bathroom cleaners), strong
acids, medicines, pesticides, oil based paint
or petroleum based paint thinners will substantially affect the biomass in the tank and the
organic digestion process.
Septic Tank Owners Operation & Maintenance Manual
10
The consequence could be the carryover of undigested materials to the effluent field with
trench lines becoming clogged, poisoned and no longer functioning.
Odour may be
experienced shortly after addition of cleaning and household chemicals.
The use of proprietary or chemical additives is not recommended for septic tank systems
(except for lime used as above). They are of no benefit, and can be detrimental to the
system.
There are many septic system additives such as enzymes and cleansers available on the
market. The truth is, these are only suitable for problems which are minor and temporary
(eg. Antibiotics in the system, or occasional water overuse). A well-maintained septic
system which is receiving the correct amount of wastewater should not need these
additives. No amount of additives will help a septic system if it is failing.
Shopping Tip
Changing washing powders can make a difference to the amount of phosphorus entering
the environment from septic systems. Always use the concentrations provided by the
manufacturer and always look for low-phosphorus or phosphorus-free detergents. Look for
NP on the label. The symbol NP is used to identify products which have no added
phosphorus, although levels below 0.5% may be present.
You can help your septic system by using traditional non toxic cleaners, like vinegar and
bicarbonate of soda.
Septic Tank Owners Operation & Maintenance Manual
11
Water Usage
In the average home water consumption is greatest in the laundry and bathroom. You
should install water saving shower heads, bathroom taps and inline water pressure
restrictors. Water efficient washing machines also help to reduce water consumption.
Toilet cisterns are now available with a 6 and 3 litre flush. If you haven’t got one it’s time
to look at changing.
Showers of less than 5 minutes under a low flow shower head is the smart way to go. We
all know how difficult this can be with young adults and especially if you’re used to using
an old water wasting showerhead.
Washing machines can use anything from 40 – 120 litres per wash. Do a wash in the
morning before work and another in the evening after work. Whatever you do make sure
you are washing full loads and avoid doing it all in one day as this will cause overloading of
your tank and trenches.
Baths, and spa baths in particular, also overload your septic system. They also use and
waste a lot of water.
It is important to understand that all fixtures and fittings need maintenance. Always repair
leaks and faults as soon as possible. Not doing so is an unnecessary financial and
environmental burden you don’t need to have.
WATER REBATES MAY BE AVAILABLE
FROM GOVERNMENT AUTHORITIES TO
HELP YOU!
www.ourwater.vic.gov.au
Septic Tank Owners Operation & Maintenance Manual
12
Planting around your effluent Disposal System
The effectiveness of the absorption/evapo-transpiration process is directly proportional to
the amount of effluent that can be taken up by the soil and plants. If the soil and plants
within the drainage area is relatively dry, more effluent will be taken up.
The appropriate use of plants is one way of enhancing this soil evapo/transpiration
process. All plants act as ‘water pumps’. In simple terms soil moisture (water) is taken
up by a plant’s roots, the nutrients in the moisture are extracted by the plant and excess
moisture is transpired or evaporated into the atmosphere through the leaves. When a
plant is growing strongly and there is ample moisture available, many litres of water a
day can pass through the leaves of the plant and into the atmosphere. The greater the
total leaf area of the plants utilising this excess moisture, the more effective they will be
at removing it from the soil.
Those plants that grow naturally in wet boggy conditions will be most suited for this
purpose. Generally plants are more active during spring and summer and hence are
more effective at removing moisture from the soil. Their effectiveness during the colder,
wetter months is often diminished.
Maintain adequate vegetation cover over the drainage/effluent field at all times. Plant
grasses and small shrubs within the field. Care must be taken to ensure plant roots do
not clog the drainage pipes and lines.
The list of plants of the following pages is included as a guide to species that have been
found to grow satisfactorily in excessively moist soils and have the capacity to transpire
moisture from the soil all year. It is by no means, exhaustive.
Septic Tank Owners Operation & Maintenance Manual
13
Shrubs
The following plants are generally satisfactory for planting within 4 metres of a drainage
area.
Acacia verticillata
Prickly Moses
Bursaria spinosa
Sweet Bursaria
Callistemon sieberi
River Bottle Brush
Goodenia ovata
Hop Goodenia
Hymenanthera dentata
Tree Violet
Kunzea ericoides
Buran
Leptospernum Species
Tea Trees
Melaleuca ericifolia
Swamp Paperbark
Ozothamnus ferrugineus
Tree Everlasting
Calllistemon viminalis
Weeping Bottlebrush
Callistemon lilacinus
Lilac Bottlebrush
Eucalyptus preissiana
Bell-Fruit Mallee
Septic Tank Owners Operation & Maintenance Manual
14
Grasses/Sedges (cont).
Juncus holoschoenus
Joint-leaf Rush
Juncus pallidus
Pale Rush
Juncus pauciflorus
Loose-flower Rush
Juncus subsecundus
Finger Rush
Microlaena stipoides
Weeping Grass
Poa ensiformis
Purple-sheath Tussock Grass
Poa labillardieri
Common Tussock Grass
Poa morrisii
Velvet Tussock Grass
Poa tenera
Slender Tussock Grass
Carex appressa
Tall Sedge
Carex breviculmis
Short-stem Sedge
Carex gaudichaudiana
Tufted Sedge
Carex inversa
Common Sedge
Carex tereticaulis
Rush Sedge
Eleocharis acuta
Common Spike Sedge
Eleocharis pusilla
Small Spike Sedge
Elymus scaber
Common Wheatgrass
Festuca arundinacea
Tall Fescue
Lolium perenne
Perennial Ryegrass
Lomandra filiformis
Wattle-mat Lily
Lomandra longifolia
Spiny-headed Mat Lily
Juncus amabilis
Hollow Rush
Groundcovers
Acaena novae-zelandiae
Bidgee Widgee
Dichondra repens
Kidney Weed
Viola hederacea
Ivy leaf Violet
Septic Tank Owners Operation & Maintenance Manual
15
Appendix A: 1. Determining Sludge & Scum Depth





HEALTH WARNING:
Always wear gloves
Don’t smoke and keep naked flames away
Put the cloth strip in a waste bag and burn or
place in the garbage.
Wash down the stick and place in sunlight out
of reach for a few day.
Dispose of the gloves.
Septic Tank Owners Operation & Maintenance Manual
16
Appendix A: 2. Tank Diagnosis
Septic Tank Owners Operation & Maintenance Manual
17
Operation & Maintenance Guideline

CONSERVING WATER WILL INSTANTLY HELP YOUR SYSTEM

Do not construct over or cover any part of the system with concrete, paths,
tennis courts, swimming pools, sheds, stables or any other structure. This
includes protection from vehicular traffic or stock.

Install a water saving fixtures and fittings and immediately repair leaks.

Don’t leave taps running unnecessarily.

Do wash your laundry over several days not all at once .

Restrict the use of chemicals that will kill the bacteria that make the septic work.

Use detergents that are low phosphorus and are low in alkaline salts and chlorine.

Do not flush napkins, nappies or other non degradable material into the system.

Pre clean pots and plates to minimise oil, fat and food scraps entering your septic
system.

A cup of lime down the toilet may cure odours problems.

Inspect the system annually and pump out the tank every three years.

Fill the tank with water after pump out. Do not disinfect tanks.

Do not turn off power supply to mechanical treatment plant other than for
maintenance. Check operation of treatment plants after power failures.

Do not alter any part of your system without Council approval.

Do not flood the disposal area with water.

Your system is showing signs of failing if the area is soggy or water is pooling
over the trench.

Don’t use caustic soda or drain cleaners in a septic tank.

Ensure the right selection and siting of grasses & shrubs near trenches.

PRACTICE WATER CONSERVATION AND SAVE MONEY!
Septic Tank Owners Operation & Maintenance Manual
18
STAPLE A COPY OF THE
CERTIFICATE TO USE YOUR SEPTIC
TANK TO THE BACK PAGE
DON’T FORGET TO LEAVE THIS
BOOK AND THE PERMIT WITH THE
NEW OWNER SHOULD YOU SELL
YOUR PROPERTY
Acknowledgments:
This document was prepared with assistance from;
 USA Environment Protection Authority
 NSW Department of Local Government
 Municipal Association of Victoria
 State Government of Victoria
Septic Tank Owners Operation & Maintenance Manual
19