Every ATU or septic or wastewater treatment system gradually accumulates sludge and scum. This is because the scum that floats on the surface is mainly oils, grease and fats, and these substances are not readily broken down by the bacteria. Sludge builds up on the bottom as this is foodstuffs and materials that aren’t broken down, as well as a build-up of dead bacteria. Literally millions of bacteria die every day and this accumulates as sludge. Eventually, your system will require a pump out – typically anywhere from two to five years.
Things to Avoid
Don't allow foreign objects, (eg. Nappy liners, disposable nappies, tampons, pads, condoms etc) to enter the system. They do not breakdown and can cause problems.
Avoid pouring large quantities (½ litre or more) of beer, wine, milk or fruit juice or oils into the system. Products that are acidic may affect bacteria production. (Milk, beer and fruit juices, for example, often contain large amounts of sugar which is digested by some bacteria that rob the water of oxygen, and this, in turn, stops the growth and working of those bacteria that rely of oxygen to survive).
Surface cleaners - when using surface cleaners try to wipe excess cleaner with a disposable cloth and discard contents into the bin.
Toilet cleaners - cream cleaner or washing soda (Sodium carbonate).
General cleaners – bicarb soda (Sodium hydrogen carbonate), vinegar (not too much).
Floor cleaners - use hot water and detergent.
Laundry powders and liquids - use suitable products that contain low phosphorus and low salt (used as bulking/fill agents).
Do Not Allow These to Enter Your ATU (not down the drain)
- oil, paint and chemicals
- drain cleaning or clearing products
- methylated spirits, kerosene, acetone or any other solvents
- flea or tick wash
- oven cleaners
- plastics of any type
- disposable nappies, sanitary napkins
Servicing of Wastewater Treatment Plants
Treatment systems can only be serviced by registered authorised wastewater service personnel, and it is an offence for a homeowner to undertake this specialised work themselves.
How You Can Help
- Do not cover tanks and hatches with soil, cement, paving or any material. (Mulch can be placed on the lids of systems that rely on earthworms as part of the treatment process).
- Do not prevent quick and easy access to any inspection openings.
- Do not allow roof or surface water to enter any part of the system.
- Allow free access to your property for the service person. Ensure that the gates are unlocked, your dogs are locked up and your children are supervised.
- Keep plants and grass monitored and maintained on land application areas (irrigation zone/s).