Rainwater is a valuable resource and safe to drink as long as proper steps are taken to ensure the different components in your rainwater harvesting system are safe and installed correctly. This includes the materials your tank is made from and how it is plumbed into your house.
Another important component to your water quality is the catchment area that will collect the rainwater.Roof tops are the norm to use as catchment areas – rain falls from the sky, water hits the roof and washes down into gutters that then direct water towards downpipes into your rainwater tank.
To ensure the safety of your catchment area, you need to consider:
- roofing materials – the material of your roof and/or any paints used
- roof contaminants – leaves, debris, animal droppings.
Safe Roofing Materials for Rainwater Harvesting
Drinkable rainwater can be collected from most roof types, including undamaged asbestos, Colorbond®, Zincalume® and galvanized steel.
It is important to find out if the material or the paint used on your roof or in your gutters could contaminate your rainwater. You should avoid roofs with lead flashings, covered with lead-based paints, bitumen and tar or treated timbers. All these elements can contaminate your water supply.
To ensure the best quality in your water, you should clean your roof and discard first few runoffs of rainwater from:
- new concrete tiled or metal roofs
- roofs freshly coated with acrylic paint.
Contaminants in Roof Collected Rainwater
Depending upon your location and area it is sometimes impossible to completely protect your rainwater from all pollutants. The level of contamination generally depends upon the amount of debris collected in your gutters and built up on your roof. Common forms include:
- animal droppings (e.g., from birds, bats, possums, etc.)
- debris containing microorganisms
- aerial chemical spraying
- air pollution from:
- light industries like spray painters, fibreglass fabricators
- heavy industries like chemical plants, quarries and those using kilns
- emissions from vehicles associated with freeways and main rains.
If your roof is overly dirty, or has had contact with aerial chemical spraying, then disconnect your tank from the roof run off and give it a wash. If you choose not to wash, then disconnect your tank, let the next rain be discarded, and then reconnect your tank. This will help to ensure that chemicals do not make it into your tank water.
Proper Roof Maintenance for Clean Rainwater
Steps you can take to reduce contamination include:
- Pruning any tree branches hanging over your roof – this reduces possible contamination from plants and animals who might climb and scamper across your catchment area.
- Avoid collecting rainwater from parts of roofs with chimney pipes from wood burners.
- Ensure overflow or discharge pipes from roof mounted appliances like air conditioners or hot water systems do not run onto your roof.
- Inspect your roof and gutters every 2-3 months and clean as necessary.
When performing maintenance jobs take proper precautions and be safe!
- Do not tackle the job alone.
- Look for any power lines
- Have someone with you to hold your ladder (so it doesn’t fall over if you accidentally kick it or the wind blows), pass equipment and keep general watch.
Need More Information?
For more information you may want to look at these following articles:
- Choosing a Safe Water Tank for Drinkable Rainwater
- Proper Water Tank Maintenance for Drinkable Rainwater
- Plumbing in Your Rainwater Tank for Safe Drinking Water
If you have found this article helpful and are looking for a water tank, talk to our friendly staff today. Our expert team are happy to discuss your needs, please call or email us.