Rainwater Filtration Article

What is truly in rainwater?

Raindrops fall to earth when water droplets build up and saturate a cloud. On the way down, the water picks up C02 which is naturally present in the atmosphere, which dissolves into the water to form carbonic acid. It is the hydrogen ions present in the carbonic acid that makes water acidic and lowers the pH².It’s important to note that this is not ‘acid rain’ nor is it necessarily harmful to health - it’s a natural phenomenon.

In reality, many rainwater collection tanks are being used without proper filtration and pH correction. When this rainwater with low pH reaches your plumbing system, it can cause corrosion to any metals in your home that it comes in contact with. Metals such as brass, zinc and copper are especially susceptible to corrosion. This can cause build up and damage to your plumbing system. A common symptom is blue/green staining around taps, shower heads, in toilet bowls and basins. This indicates copper from pipework and fittings is leaching into the water.

According to NSW Health, it is important that rainwater tanks and associated plumbing, together with appropriate water treatment and disinfection systems are correctly selected, installed and regularly maintained in order to protect drinking water quality³.

Puretec’s NTS pHNeutralising Treatment Systemscorrect the pH of this acidic water. These systems utilise a natural calcium carbonate media to slowly dissolve into the water, lift the pH, and protect the plumbing system from corrosion. They require no power, no backwashing and only take the pH to ‘neutral’ meaning the system doesn’t over-correct.

How does rainwater become contaminated?

A wide range of local factors can contribute to the impurity of rainwater, such as how often and how long each rainfall is, and the methods used to collect, treat, and store the water. The list of potential rainwater contaminants can include anything that may land on your roof, including leaves, pollen, pesticide sprays, fertilisers, debris, birds, small animals, animal waste, and insects⁴.

Air pollution from any nearby industrial emissions or heavy road traffic can also affect the safety of the rainwater stored in the tank⁵.Gutters and piping may also introduce harmful substances such as asbestos, lead, and copper, depending on their condition and the materials they are constructed from. All these elements from the roof and air can flow through the roof gutters, into your rainwater storage tank, and contaminate your water.

A CSIRO researcher recently conducted a study of rainwater tank safety in Melbourne and she shared, "When we inspect the rainwater, you do find all sorts of nasties in it, waste from possums and birds and snakes sometimes’’. She continued to say ‘’It's not so strange because your roof is your catchment and you'll find creatures like that on there"⁶.

When we think about the purity of our drinking water, we assume it’s safe to assess just by visually looking at it. Whether the water is cloudy, discoloured, or even if it is perfectly clear! However, not all nasties can be seen, and you might be surprised by what you find.

Puretec has launched a brand new innovative Water Analysis Test Kit to easily understand what contaminants are in your water. The convenient test kit includes everything you’ll need to effortlessly collect your sample and send to us at Puretec. Rather than a list of numbers, you will receive an easy to understand digital report for the 14 most common contaminants (metals and minerals) and our recommended solutions approximately 5 days after we receive your sample. The analysis kit is a simple way to get a clear, independent picture of your water, for your peace of mind and to help ensure that you’re treating what actually matters.

How does bacteria in my rainwater affect my health?

If harmful bacteria such as E.coli is present at a low level, there may be no ill-effects, however, given the right conditions, most bacteria have the ability to rapidly reproduce, which is when significant health risks can arise. In summer when water levels may be lower and temperatures may be higher - these are the perfect conditions for many bacteria to flourish.

Now if you have been using rainwater without filtration you may be thinking to yourself - “But ‘Ive been drinking rainwater for many years, and I'm fine? I’ve survived!’ How good is your health really? You may think you are fine…so far! However, those stomach aches you get every so often? This could be a reaction to your water. We know as humans we can build up a tolerance to most things we ingest, even if they aren’t healthy for us. However, we also know the prolonged effects of ingesting unhealthy elements can come to a tipping point. What are the long term effects of fueling your body with water that can have potential bacteria and nasties from an unfiltered rainwater tank?

Stuart Khan, who is a professor in the school of civil and environmental engineering at the University of NSW, shared with The Guardian that ‘’people should not assume all rainwater is safe to drink, if you’ve got bat or bird waste on your roof … then there is a real risk of bacterial contamination’’. Khan also shared ‘’Particularly where you have trees that overhang a rooftop where the water is captured and you might have birds or bats that are populating those trees, you can end up with things like salmonella”⁷.

Another question to ask yourself is - do you have family come and visit from the city who live on mains water supply with chlorine or filtration systems installed? The important note here is, you may have built up a tolerance for rainwater so far, but they certainly haven’t. Your family could quickly fall ill from your unfiltered rainwater supply.

How does sediment in rainwater affect my health and home?

Firstly, what is sediment? Sediment can consist of dirt, sand and dust, as well as the remains of plants and animals and accumulate at the bottom of the rainwater tank. Turning into sludge that can harbour microorganisms capable of producing unpleasant odours and affecting the taste of the water⁸,which in turn negatively affects our desire to drink and keep hydrated each day.

Sediment can cause damage to home plumbing and appliances, as over time the particles can build up in pipework eventually causing blockages, and shortening the lifespan of appliances, and other fixtures. Additionally, Tannins, which is a byproduct of the fermentation process from decaying leaves and vegetation found in roof gutters, can also cause the water to have a faint yellow to tea-like colour and can result in staining on fabrics, fixtures, china, and laundry.

How can a Puretec Rainwater Filtration System help you?

The first step in getting great tasting, safe water from your water tank is to keep gutters clear, reducing the contaminants that the water comes in contact with. The second step is a multistage filter system with separate cartridges to filter out sediment, chemicals, colour & odour and then an ultraviolet system to kill bacteria.

The ultimate solution is thePuretec Hybrid Plusseries, which combines a three stage filter system with UV all packaged in an aluminium weatherproof cover to protect it from the elements. But the key is that the Hybrid Plus also includes a pump, or provision to install your existing pump, ensuring that you get the water pressure you need. The Hybrid Plus does come with a higher price tag, but will generally be a cheaper solution to buying a filtration system, pump, pump housing or shed, and having them all plumbed in separately. Not to mention the space saving and improved aesthetics that come with the Hybrid P.

Alternatively theHybrid-G13is a triple filtration system with UV that can attach to your wall. The G13 reduces sediment, chemicals, bad taste, odour and bacteria. The G13 is ideal for situations where you have mains to rain switch over, where you have your tank topped up with town water or if you live in an area where your rain water regularly picks up chemicals off your roof. For other rainwater applications where chemicals are less of an issue, you can consider theHybrid G7, a 2 stage filter system with UV.

For drinking filtered rainwater only, the undersinkHybrid M12 stage filtration system can be connected easily to any existing mixer tap. The system uses Radfire ultraviolet technology to kill 99.9% of bacteria, turning your rainwater into pure, safe, healthy drinking water.

For a manual, low cost, and non-toxic alternative to disinfecting your rainwater tank,Puretec’s Tanksafeis a tasteless, odourless and chlorine free formula to pour into your tank to keep it protected from bacteria and pathogens for up to 2 months. This is a great alternative to not saturate your water with chlorine as other brands may suggest. Tanksafe is recommended to use after fresh or major rainfall as new particles flow into the tank.

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