Answering Your Questions about Your Inherited Septic Tank System

Posted on: 3 June 2016

If you've just bought a house with a septic tank, and you've never had one before, you may have a lot of questions. This guide should help you to understand how domestic treatment plants work and what you need to do.

What Is a Septic Tank and How Does It Work?

A septic system is an independent wastewater treatment system located underground somewhere on your property. The waste from your property goes into the tank via an inlet pipe. Here, the solid waste settles at the bottom of the tank and is broken down by bacteria. Scum rises to the top of the tank creating a scum blanket. The scum blanket forms a hard crust that acts as a seal keeping air away from the sewage. This lack of air helps bacteria to break down the solid waste. Excess liquid (effluent) in your tank drains out via the outlet pipe to a disposal system such as a lagoon. This effluent still contains germs and parasites that are then killed off by natural soil processes. Over time, the effluent is taken up by nearby plants or leaches into a groundwater zone.

What Should You Be Doing to Ensure Your Septic Treatment System's Working Well?

Your septic tank can only hold so much water. Use water wisely in your home to ensure that you do not create too much waste. Keeping sludge buildup to a minimum is also important. You can do this by placing food scraps and other waste in the trash instead of allowing them to end up in your septic tank. Do not flush sanitary products and minimise the use of toilet tissue. You should also limit the chemicals going into your septic tank. You can check whether it's possible to divert wastewater from your washing machine into a grey water capture system to reduce the need for frequent pump outs.

How Often Will You Need to Get Your Septic Tank Emptied?

Eventually, the sludge that gathers at the bottom of your septic tank will need to be removed. You should be able to find a septic tank service that will do this for you. How often this needs to happen will depend on the capacity of your tank and how much waste you generate. As a guide, it's usually necessary to pump out sludge every 3 - 5 years. Ask your pumping person to measure the thickness of your scum and sludge layer as this will help you gauge how regularly you should have your tank pumped out in the future.

If you want, you can do yearly checks of the sludge yourself. You do this by digging up the lid and using a long stick to see how deep the sludge is. It's essential not to allow the sludge to get deep enough to reach the outlet hose.

How Will You Know If Your System Is Working Properly?

You need to keep a check on your septic tank so that you notice problems as they arise. The following are indicators that something is amiss:

  • Being able to smell the septic tank

  • Waste from toilets and sinks that drains away slowly

  • Liquid overflowing from the disconnector tap

  • Visual wet areas at the top of the septic tank

  • Fast growing grass around the tank

Speak to your Environmental Health Department if you notice any of the above.


Composting for the environment

Starting a worm farm compost pile has been a really good move for us. It saves us a lot of space in the rubbish bin and it also helps make our garden much more efficient. Since we started using the compost our garden uses much less water and we are getting great yields from the veggie patch. The kids love seeing the worms wriggling around and eating all of the food and they are learning a lot about the natural environment in the process. This blog is all about the environmental benefits of composting at home and doing other things to improve the environment.