Hardly a week goes by without someone bringing us a bottle fo their tank water. “It’s straight out of the sky!” they say. “It has to be good, right?
“Beautiful, pure rainwater: God’s perfect gift of hydration from the heavens, right?”
Sorry folks. No.
And to illustrate this I’ll tell you a quick story. Many years ago I was a pro fisherman, fishing for Snapper nine miles off Cape Byron. It was a grand adventure.. but the price of fish meant we worked very, very hard. Some days we’d come back with fish to the gunnels. Other days we’d be lucky to get enough for dinner. So you can imagine that those good days were economically precious.
Imagine for a minute..
hundreds of beautiful fresh caught fish strewn over the decks of our eighteen footer. They couldn’t be fresher. Imagine now, as we embark on our hour-long journey home… a huge black cloud and torrential rain. God’s heavenly bounty, right? Wrong. In that one hour the ‘pure rainwater’ contaminated our fish to such a degree we had to take them home and bury them.
If you ask an expert like Michael Oelgemoeller, water treatment researcher from James Cook University, he’ll tell you that untreated rainwater is considered not safe for human consumption.
And it gets worse as it is collected on your roof. There are the bacteria that thrive in a water tank, and there are toxic metal traces in roof runoff. Add to that the extreme acidity of the water samples we’ve tested from the newer plastic water tanks: rainwater should be your last choice.
“There is this public view that rainwater is clean and yummy and tasty but it really depends on how you collect it,” said Professor Michael.
Flinders University health researcher Dr. Kirstin Ross recently conducted a review of tank water around Adelaide. She said that although there was no evidence of increased gastrointestinal illness as a result of using rainwater tanks for drinking water, the microbes are present in the water.
.. Which is all very not-nice if you have no alternative, as is the case with so many Country dwellers. Let’s share what we’ve observed over 18 years and what we recommend.
Rainwater’s major ‘baddies’ are microorganisms, including as bacteria that can cause gastrointestinal illnesses, and traces of toxic metals that can come from air pollution or, less commonly, from roofing materials. We had one customer who had his tank water analysed due to the taste. He discovered jet fuel. There are many, many similarly amazing stories.
“When we inspect the rainwater, you do find all sorts of nasties in it,” said Magnus Moglia, a CSIRO researcher who recently completed a study of rainwater tank safety in Melbourne.
The main bacteria that can be found in many rainwater tanks is Escherichia coli (E. coli), which is transmitted via feces. It’s a significant cause of gastrointestinal illness including vomiting and diarrhea. Birds, possums and other animals do poo. You can’t prevent their natural functions even if they are vertically above your roof at the time. In our region, huge colonies of flying foxes pass over homes every night on the way to their feeding grounds. One group can easily exceed five thousand. So the chances of missing your roof are pretty slim. With the feces come to the bacteria, and especially in regions like our where it’s warmer, the bacteria in the feces think they’ve landed in Heaven.
Now.. although all this is true, there’s a surprisingly small number of reported cases of sickness> Most people don’t connect the cause and the effect.
“There’s not much data about people getting sick from drinking rainwater. Most people have a couple of bad days and then they bounce back,” Professor Michael said.
“But we shouldn’t forget that dehydration from diarrhea is the number one killer in the undeveloped world.”
Under lab conditions filtration systems are able to remove E. coli, Dr. Ross said, but filters in homes often became a breeding ground for the bacteria. Sadly, the majority of people buy cheap when they buy water filters, neglecting to bother researching the possibility of bacteria actually finding a new home in the filter.
“Filtering might be enough if they use a well-maintained filter. But the small dataset that we have, seemed to indicate that microbes are getting through as they seem to be growing on the filter itself.”
Dr Ross’s research has examined levels of zinc, lead, chromium, copper, and cadmium in South Australian water tanks.
These findings concurred with similar published studies from around Australia, she said.
Arsenic and nickel have also been found in other Australian studies.
“Filtration will remove some of these metals, but not all – we did a study on the water that we artificially contaminated with bushfire ash, to see what recommendations should be made post-bushfire to landholders, and found that filters were good at removing zinc and copper but not chromium and arsenic,” Dr Ross said.
We have been aware of this for a long time – long before we sat down with our water engineers in California to design the filtration for our own design UltraStream. We’ve incorporated a very special patented media called KDF85, which has the ability to actually electrocute bacteria and neutralise heavy metals.. but at home, we go one step further.
You see, tank water is also high in sediment, and sediment is known in the industry as the ‘filter waster’. It’s like fine mud; not particularly dangerous – but it will fill your filter quickly, meaning new filters far more often. So we use a special prefilter designed specifically to halt sediment, with the ability to be soured with a kitchen scourer hundreds of times before it needs replacement. The sediment-free water, still containing possible toxins, then passes to the highly sophisticated and more expensive Ultrastream for advanced toxin reduction.So filter your water to remove metals, but if your roof has received a lot of ash from nearby fires, it might be worth getting your water tested to make sure poisonous metals aren’t getting through. So you have a low-cost sediment removal and a long life toxin and heavy metals removal system.
The health problems of poorly maintained rainwater tanks don’t begin at the tap.
If mosquitoes can access the water in the tank it can become a breeding ground for the disease-spreading insects, said Dr Moglia, who was part of a research project that inspected 450 tanks across Melbourne.
“We found mosquitoes in quite a few of them. It’s equally as big of a problem in terms of health [as contaminated drinking water],” he said.
To guard your family against mozzies in your tank, cover the inlet with mesh and also ensure the outlet has a mesh cover or sealed pipe.
Check your mesh is in good condition. It takes just days of a gap for a colony of the little blighters to establish. A recent CSIRO study found more than 10 percent of water tanks inspected had a mesh that was in poor enough repair to let pests and vermin into the tank.
I’ve written previously about the danger of the brain-eating amoeba – Naegleria Fowleri
This little critter is found in warm water, but luckily or not, it has to gain entry to the brain via the nose or mouth. The fatal cases reported happened with children playing with hoses for prolonged hot periods.
Ten years ago we had a very bad drought and even homeowners in the city were installing rainwater. Let’s face it, they do allow us to save water if we use them for those functions they are best suited to. Many people still say there’s no point having a rainwater tank if you have town water, but showering, flushing toilets and watering gardens with rainwater all help conserve town water supplies.
And there’s a bigger environmental benefit of more homes having rainwater tanks, especially in urban areas, according to Dr Moglia: reducing runoff into waterways.
“When the rain falls on a city, there’s so much of the surface that’s covered by roofs and concrete — it really changes the flow of the rainwater so you get flooding,” he said.
“It’s bad for humans and property but importantly you get creeks flooding and the environment really doesn’t like it. You get erosion in waterways.
“To protect the urban waterways you need to make sure you capture as much as you can of that rainfall.”
Ian: It’s important to get your ‘water plan’ right. Our team will ask the right questions to configure the best and best value water health systems for your particular location. This, we have found, is not an ‘off the shelf’ approach. There are many factors, including house size, water pressure, local minerals in the water, specific contaminants, size of garden and more.
There are significant savings you’ll make initially and long-term with the correct configuration. That’s why we recommend calling us or going to our web page that helps you get clearer about your discussions – to help yourself and help us help you!