Maintaining Your Rainwater Tank for Potable Water

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Maintaining Your Rainwater Tank for Potable Water

Harvesting rainwater into a water storage tank can provide you a valuable source of water to be used throughout your home or property. Provided your rainwater tank has been correctly installed and is safe to use for storing drinking water (AS/NZS 4020), you will need to ensure that your tank in properly maintained.

Maintaining your rainwater tank isn’t difficult and involves inspecting:

  1. your roof catchment area, gutter and tank every 6 months or less
  2. inside your tank every 2-3 of years and cleaning out any tank “sludge” (sediment that manages to accumulate at the bottom).

If you have a poly water tank, then we would highly recommend installing the TankVac self-cleaning system. This will ensure no sludge builds up in your tank and that your rainwater remains fresh.

If you have not setup an automated tank cleaning device such as a TankVac, then you could hire a professional Water Tank Cleaning company for the task. This is preferable to risking rupturing an inner poly lining (if you have a steel water tank), or possibly becoming frustrated and damaging your tank in some other way.

What to Inspect (6 Monthly Inspections)

Here is a list of areas that you should inspect in a regular 6 monthly periods:

  • Rainwater tank – this obviously goes without saying. Check the structural integrity of your tank, clear leaves and debris off the roof and access cover. Holes or gaps should be repaired.
  • Roof and gutter catchment areas – clean any accumulated debris and leaves, insects and the like from roof and gutters. If spray cleaning your roof, ensure that your water tank is disconnected from the water flow so you do not contaminate your water.
  • Leaf strainers and first flush devices – empty strainers and remove leaves and debris from pipes in your rainwater diverter as necessary.
  • Inflow and overflow screens – ensure screens around your tank and on any accessories are clean, secured and not broken to keep mosquitoes and pests out of your tank.
  • Internal inspection – inspect inside your tank with a torch. Check for evidence animals, mosquitoes, insects or algae. If present, you will need to rectify and fix any sunlight entry and properly seal all access points.
  • Tank fittings, pump, mains switch and pipes – should all be inspected to ensure they are in full working order.

Preventative Maintenance Tips

While a routine 6 monthly inspection will help to ensure your rainwater remains of a high quality, some preventative actions can also be taken. For example:

  • cutting back nearby trees or branches that overhang your house will stop leaf accumulation and reduce any animal droppings and insects on your roof
  • animal droppings are a major hindrance to maintaining high quality water, especially if there are lots of birds or bats in your area. If this is the case, then routinely cleaning your roof is recommended, but may only do so much (please ensure you detach the pipe to your tank before any roof cleaning!)
  • having your tank in an area that is clear of plants and bushes and sheltered from sunlight can reduce risk of algae building up in your water, or microorganisms breeding (since bacteria and the like often thrive in warm water).

It is also highly recommended that you install filtration at your taps where it will provide water for drinking or cooking, and to safely chlorinate the water in your actual rainwater tank to kill of any microorganisms at your water source.