22 May 2023

How Do I
Disinfect My Water Tank?

Everything you need to know about maintaining a healthy drinking water supply

Blog Water Tanks

Blog Tile May2

So, you're concerned about whether the water from your tank is safe to drink, right? Maybe what's coming out of the tap is discoloured? Perhaps it's cloudy, or smells a bit 'off'. Whatever the case, before you put that glass of water to your lips, it's important to make sure that what you're consuming is safe.

Maintaining clean and safe drinking water is super important for your household. And the good news is that it's not hard to do. As the old cliche goes "prevention is better than cure" and by regularly testing and disinfecting your water, you can effectively eliminate bacteria, viruses and other harmful contaminants that may compromise the quality of your water supply.

Ready to find out more? Let's dive in (to the article, not the tank!)...

How Do I Know if My Water is Bad?

Water contamination isn't always easy to detect, but here are a few tell-tale signs to look for:

  • Unusual Taste
    If the water from your tank tastes funny, don't ignore it: it's important to trust your senses and investigate further if your water tastes unusual.
  • Odour
    Does your water smell foul? If your rainwater has a strong, musty or rotten smell, it's important to look into the cause of this immediately.
  • Discolouration
    If your water has a brown or yellowish tinge, this could suggest the presence of sediment, rust or other contaminants in the water.
  • Sediment or Floating Particles
    Check the clarity of your water by examining it in a clear glass. The presence of suspended particles, sediment or debris obviously points to contamination.
  • Algae or Slime
    Physically check the inner surfaces of your tank for the presence of algae or slime. Algae can discolour the water and contribute to that 'earthy' or 'musty' taste.
  • Sickness
    An increase in water-related illness among household members, e.g. gastrointestinal issues or skin irritations, might suggest that the water in your tank is contaminated.
  • Changes in Plant or Animal Behaviour
    Contaminated rainwater can have negative effects on plants and animals too. Unusual plant growth or signs of sickness among pets or livestock that are consuming the rainwater could indicate contamination.

How Does Rainwater Become Contaminated?

There are several ways that the water inside your tank can become contaminated. And identifying the source of the contamination is important:

Roof Contamination

The primary source of contamination in rainwater tanks is the roof catchment area. Here are some of the things that can affect the quality of the water in your tank:

  • Bird droppings: birds love to perch on the roof and their calling cards contain bacteria and other pathogens
  • Insect infestation: insects such as mosquitoes or flies can contaminate the roof surface with fecal matter or other contaminants
  • Leaf litter and debris: leaves, twigs and other organic matter on the roof can introduce bacteria or other microorganisms into the water

Poorly Maintained Gutters and Downpipes

If your gutters and downpipes are not regularly cleaned and maintained, they can become rusty and/or clogged with debris. The stagnant water which collects in clogged downpipes and gutters provides the perfect environment for the growth of bacteria, algae and other contaminants, which will find their way into your tank at some point.

Animal Access

Are there any openings or gaps in the rainwater tank system where animals such as rodents, possums or insects can gain access to the tank? Their droppings can contaminate the water with harmful bacteria or pathogens. And worst case scenario, an animal can die and fall into the tank, creating big issues!

Cross-Contamination of Water Sources

Cross-contamination can occur if the rainwater system is connected to another water source, such as mains water. Backflow or improper plumbing connections can lead to the mixing of different water sources, potentially introducing contaminants into your rainwater.

How Can I Manage Risks to My Rainwater Supply?

Unfortunately, contamination sometimes happens, but by being proactive and practising good maintenance habits, homeowners can significantly reduce the risk of contamination of their rainwater. Here are some common-sense preventative measures that will go a long way towards maintaining the quality of your drinking water:

  • Keep the roof catchment area clean by regularly removing debris, trimming overhanging branches and preventing access to animals
  • Regularly clean and maintain your gutters, downpipes and inlet strainers to ensure maximum water flow and prevent any buildup of contaminants
  • Install inlet strainers or first-flush diverters to prevent the initial runoff (which may contain the highest concentration of contaminants) from entering your rainwater tank.
  • Conduct regular inspections and cleanings of the rainwater tank to remove sediment, sludge or biofilm.
  • Ensure that your plumbing is correct to prevent any cross-connections between rainwater and any other water sources.

Draining and Cleaning Your Rainwater Tank

If your tank has a buildup of sediment or sludge at the bottom of it, your first job is to drain the tank completely and clean it out.

  1. The process is relatively straightforward:
  2. Disconnect the tank from the water supply
  3. Drain the tank completely, using a hose or pump to remove any water below the level of the tap
  4. Remove any debris, sediment or sludge from the tank
  5. Rinse the tank with clean water to remove any remaining dirt or contaminants
  6. Don't forget to clean your inlet strainers and fittings too

It is important to recognise and take the appropriate steps to minimise the safety risks associated with cleaning out your water tank.

Common dangers include:

  • risk of falls and injuries from slippery surfaces or unstable footing
  • Presence of harmful bacteria, chemicals or other contaminants

What Can I Use To Treat the Water Inside My Tank?

There are a host of different disinfection options for rainwater, and the method you choose will largely depend on the size of the tank and what you are using the water for.

Some of the most common methods of treatment are:

  • Chlorine
    Chlorine is a common choice because it's effective, budget-friendly and easily accessible. Chlorine effectively kills bacteria, viruses and other microorganisms, making it an excellent option for maintaining water quality.

    When using chlorine, it is important to follow the manufacturer's instructions and guidelines for the correct dosage. Regularly monitor the chlorine levels and conduct water testing to ensure the water is safe for consumption.
  • Ultraviolet Disinfection
    Ultraviolet (UV) disinfection is considered an effective method for destroying microorganisms. UV disinfection systems use ultraviolet light to kill or inactivate bacteria, viruses and other pathogens which may be present in the water.

    UV treatment is a chemical-free process that does not introduce any additional substances into the water, making it the preferred choice of homeowners who would rather use a 'green' method of water disinfection.
  • Eco-Friendly Disinfectants
    There are a number of chemical-free disinfectant products such as Puretek TankSafe that are tasteless, odourless and colourless. These products can generally be sourced from your local plumbing or hardware supplier.

    The World Health Organization (WHO) recommends Chlorine Dioxide as the safest disinfectant product for drinking water. Chlorine dioxide leaves no harmful residues or by-products, and it is stable and remains effective over a wide range of pH levels and water temperatures.

    Whatever treatment option you choose, it's important to comply with the manufacturer's instructions regarding dosage and frequency of treatment.

Test Your Water Frequently

Test your tank water frequently. Water testing kits are easy to use and readily available at your local plumbing or hardware supplier or can be purchased online. Home testing provides valuable insights into what's happening inside your tank, including pH levels, bacterial contamination and other potential issues.

If you are using a chemical such as chlorine as a disinfectant, a water testing kit can help you monitor the level of chlorine in the water.

Regular home water testing helps to ensure that your tank water is safe for consumption and if there are any issues arising, you can address them before the situation gets out of hand.

Want to know more about keeping your drinking water safe? The team at Orion Australia is always available for a chat, so phone us on 1800 752 784 or flick us a message here, and one of our water tank specialists will be in touch soon.