Thanks to SustainaBundy member dwebble, the video interview with Jacques Rohen on water harvesting, storage and conservation has now been transcribed into text. Portions of this interview will form an article on water conservation that will appear in the SustainaBundy guide, but the full transcript will be available here, exclusively for our online readers. dwebble, many thanks for your invaluable help.

Water: harvest it, store it, conserve it!

Andi Hazelwood: Hello, I'm Andi Hazelwood from SustainaBundy, and I'm here with Jacques Rohen. Jacques, thank you very much for joining me.

Jacques Rohen: You're welcome. Thank you for coming.

AH: First of all can you tell us a little bit about your professional background?

JR: Yes, I used to be the past owner of Complas Industries, which is a local Bundaberg based company. We started off making rainwater tanks in 1991 with rotation molding process from polyethylene, same as plastic, and our company was actually the first one on the eastern coast of Australia to make large rainwater tanks from that material, using that process.

So I've had quite a lot of experience, not only making tanks but also researching the use of tanks and the benefits that you can derive from them.

AH: So why don't you tell us some of those benefits? What are good reasons for using rainwater tanks?

JR: Firstly, it enables you to be self sufficient to a certain extent, so you're no longer relying on infrastructure that's provided by councils. And whilst it could be argued that the quality of the water may not always be what it should be, it may not always pass World Health Organisation standards, generally tank water is of reasonably good quality.

Lets face it, in most of the rural areas in Australia, there is no reticulated water and everyone relies on either tank water or on bore water. Most people use their tank water for drinking purposes as well as for cooking and washing and any other household uses without any detrimental effect to their health.

I myself for instance, have lived off tank water for most of my adult life without any detrimental effects to my health. As far as I'm aware, anyway.

AH: And wouldn't you say that also, that if you're using tank water, that chances are you're a bit more conservative in how you use your water?

JR: Certainly, because there will be long prolonged dry periods when the level in your tank drops to somewhere around a thousand gallons or less and, and you tend to sort of anxiously listen to the shower being run by your kids or your wife and knock on the door and say "hey! You know, we're running out of water, cut the shower!" So, yeah of course you become a bit more conscientious about how you use water. You tend to look at how much water washing an automatic dishwasher would use or an automatic washing machine. All those issues become a lot more important to you because you don't just turn on the tap and let it run, knowing that it will keep running for as long as that tap's open.

AH: And what are some of the misconceptions about rainwater tanks?

JR: Oh, mostly the quality of the rainwater, you know, the argument of if you connect the water from your roof you will collect also the bird poop and you will also collect the possum pee and the cat pee and everything else that lands on the roof, including dust and chemical residues from chemical sprays that are applied to crops within the region. And that is true, to a certain extent, and that does happen. And I'm not for a moment saying that tank water is totally free of coli bacteria. For instance you'll always find some minor traces of coli or e-coli bacteria, sometimes in the tank water, but essentially is that going to be detrimental to your health?

That's a question I can't really answer. The only thing that I can say is that, it's never been a problem to me and we've had our tank water analysed at regular intervals and there were always some traces, but, the benefit is that you develop a very good immune system.

Lets face it, if you were to live in India. If you were to move to India right now coming from a country like Australia, then, and you drank the water from the Ganges for instance, you would become terribly ill if not die, yet the locals drink it and don't have any ill effects from it. So, it all depends on conditioning I would imagine.

AH: And also, when you talk about the water that's in rivers and ponds and things that we generally consider to be "clean," that water has to come from somewhere.

JR: Absolutely. A very good point! You know, rain falls on the ground and the water migrates either across the surface or slightly below the surface into a creek, into rivers. Sure, whilst it's doing that, its exposed to the oxygen and the oxygen is certainly one of the greatest mechanisms of killing bacteria. So, that certainly does help. But essentially, that also happens on your roof to a certain extent. So, yeah, there's not a lot of difference between the water that hits the ground, gets collected into a dam .

Essentially you can drink it out of the dam without any further treatment because they allow for instance, recreational vehicles on dams. They allow swimming in dams. And during those recreational activities, quite often you would inadvertently take a mouthful of water.

AH: Tanks are made from poly, steel, concrete, even fibreglass. Are there advantages and disadvantages to the different makes and models?

JR: Yes there are advantages and disadvantages. So the advantages for instance, of polyethylene tanks, is that they're very light, they're robust, they have good impact resistance, so they're easy to roll in place if you can't get the vehicle that delivers the tank to the place where it needs to be positioned, then you can roll it around and relatively easily put it into position between two or three people.

Most polyethylene tanks are made from material that complies with requirements of Australian Standard 4020 which is the standard that applies to material in contact with potable water for drinking, for human consumption. So that's definitely a plus and at least you know that you're not going to get any contamination from the material that the tank is made of.

With concrete that's not quite so easy to determine, because the concrete that the tank is made of would actually have to be tested and those tests take six months and are quite expensive to do, so its not something you can do with every concrete tank. And because every mix of concrete may be slightly different to the previous one, it's difficult to have a compliant issue there.

Most concrete tanks will also leach lime and because lime is a component of cement, over a period of time, so you get a slightly alkaline water rather than neutral water, 'cause rainwater is neutral.

Porosity of the concrete tank over time, because concrete is porous, over time the water will migrate to any metal reinforcements that are in the tank wall and will probably corrode, rust and start to break the concrete apart over time. However that is really dependent on the quality and the process that is used to fabricate the tank.

As far as fibreglass tanks are concerned, again it is dependent on the materials that're used and how well it's processed as to whether you're going to get a good tank or a not so good tank. There are fibreglass materials that also meets requirements of AS 4020, so you can get a potable water approved fibreglass tank. And if a fibreglass tank is well made it's a very good product will give a very long life span. And, it has similar advantages in that its light weight and easy to get into position.

Concrete is probably the worst in that point of view it's a very heavy product, so it needs to be lifted into position with a crane, so you need to get your truck right to it and transporters are relatively expensive.

As far as steel is concerned, again, there are some very good products, aquaplate, very good product. It's a polymer coated steel. Zincalume is a zincalume coated steel. Probably not as good for tank, for rainwater tank purposes as what the aquaplate is. It tends to form little isolated spots of rust. Very small initially, but because the metal is so thin, it very quickly migrates through and then if you have an impact on the tank in the vicinity of that spot, sometimes the rust flakes will break off and you have a minor leak. You fix that, two months later there will be another one. The lifespan of a zincalume tank is between three and seven years. The lifespan of an aquaplate tank is probably in excess of fifteen. Similar with poly - it's in excess of fifteen. However, be a little careful about claims made by some manufacturers about twenty five and thirty year warranties. Be wary of those.

AH: haha, ok. Now with peak oil and climate change and all these environmental issues, some environmentalists have a problem with the idea of poly tanks because of the fact that they're made from petroleum products. How do you respond to that?

JR: Yes, that is an issue, and because its made from petroleum products, it certainly is a finite resource, so the industry itself is looking at that from the point of view of recycling old rainwater tanks made from polyethylene. And possibly even looking at the concept of putting a shorter user life on to a tank when it's sold and then collecting it from the customer after a ten year period. For instance whilst the polymer is still in pretty good shape and can easily be recompounded into as good as new, so that the tank can get recycled time and time again. So that essentially you should never run out of the raw material that we make the product from.

AH: And in that case would you say that the tank is worth it's embodied energy?

JR: I think it is definitely because when you look at the benefit of a tank, how many times does it fill in a year? That's somewhat dependent on the frequency of the rainfall of course, but when you compare that to the current situation, like for instance you may have a centralised storage dam which may cost anywhere from 200 million to a billion dollars, how often does it get filled? How long will it take to actually amortise the cost of that? Taking into consideration all the embodied energies that goes into concrete for instance. It's rather energy intensive, 'cause it goes through a burning process, so it requires a lot of heat. The aggregate and the sand need to be mined, sieved, crushed, recombined, extensive use of water is involved in the manufacture of concrete, so that's another resource you have to calculate into it.

So I think if, if you look at the total lifespan, the total energy input, including construction inputs etc, including treatment inputs as well and the reliability of the dam, right now its proven during these prolonged droughts that dams are not the necessarily the best way of storing water.

Where do we get most of the rainfall? On the coast.

Where are the dams? Away from the coast.

So if you have a rainwater tank and because ninety percent of the population of Australia lives along the sea wall, that's where the rainfall is. So if you have a tank at your house, or several tanks at your house, then you can effectively collect a lot more water off the same surface as what you would in that same surface area in the dam catchment area.

You can be self sufficient totally, with rain water tanks without any great problems and without any huge investments. If you have an average house of say 240 square metres of roof area, and you have an average annual rainfall of 600mm, then you will collect in the vicinity of 310 kL, which is sufficient to last you for a full year. But of course, the amount of storage you need in order to collect that water is dependent on the frequency of the rainfall. If you have regular or light rainfall every week you could sustain with a 2000 gallon tank, probably. But if you get five or six very heavy falls during the year, and long dry periods of three or four months in between, then you're going to need somewhere round the 100 thousand litres of storage to 120 thousand litres of storage.

So, how many tanks do I need? That's a calculation that you can do once you know your average rainfall, the frequency of the rainfall and the intensity of the rainfall and the roof area of the collecting.

AH: Now because of this drought, much of Australia is under water restrictions at this point, but Bundaberg is not. Does that mean we shouldn't worry about conserving water?

JR: I think we definitely should be very concerned about conserving water because Bundaberg is claiming it is not on water restrictions because its got good bores. Ok, the bores are currently good, but we all know that the water in the bore levels is also dropping and it will continue to drop, because there's no replenishment.

So, the resource is finite. And whilst we don't have an emergency situation, or urgent situation to conserve water in Bundaberg, it wouldn't be a bad idea to get used to the idea that we have to actually start looking towards our own water conservation, and become a little bit more water conscious in the way we use it. It's not a God given right to have access to unlimited, clean water. There are very few people in the world, including the western world, that have that privilege. And if you look at such highly developed countries such as Europe, the cost of water is four to five times the cost of what water is here. That's to take clean water into the property. Then you will pay five or six times as much as what you pay here, to get the waste water off your property. So that makes, because it hits your hip nerve, it makes you a lot more water conscious as well. Water tanks are quite popular in Europe. And are becoming more popular.

AH: And I think there's good reason for that.

JR: Absolutely. And Australia being the driest continent on earth, that's inhabited anyway. I think we should be looking at collecting the water when we have it available. Make use of every drop that you get. You get it for free. The water that falls on your property is yours until it leaves your property. You allow it to leave your property, you will pay for it to get it back, and that's essentially what you're doing. The rain falls on your property, you feed it off into the street through your gutters and stormwater pipes, and you take it back through the reticulated water that you pay council for. Doesn't make a lot of common sense does it?

AH: So given these facts, what kind of things can people do to conserve water more carefully?

JR: If they don't want to go to the point of collecting water in tanks for their own use, at least look at how you utilise the water. How long a shower do you take? What sort of dishwasher do you use if you use any? Is it necessary to use a dishwasher? Is it necessary to use an automatic washing machine? And if you do use it, do you make use of it by utilising full loads? Or do you turn it on with two pieces of clothing in there and let it go through its full cycle? Rinsing is another issue. If you don't use quite as much soap powder, you don't have to have as long a rinsing cycle, which conserves water again.

Grey water. Recycle the grey water. There are plenty of systems available now that treat grey water to the point that you can actually use it in the garden, legally. And it definitely makes a big difference to how much water you use because, predominantly, the greatest amount of water that's used, is used outside the home and in the laundry. Let's face it, if you looked at how much water's used for human consumption, you would probably consume no more than 3 to 4 litres per person per day. If you had a similar amount for cooking and making tea and coffee, that's not a lot of water. So the majority of the water goes for washing, washing yourself, washing your clothes, keeping the house clean, washing cars, watering lawns.

Now again, when you think about it, the concept of having a lawn for an energy usage point of view, is extremely energy intensive. We use fertilisers on it to make it grow. Then we use fuels to cut it. We use water to irrigate it, so it grows faster so we can cut it more often so we can use more fuel.

AH: Essentially just so you have something that looks nice out the front.

JR: Right! Maybe we should look at native grasses that don't need cutting and make more use of the native plants more suited to dry land gardens where we don't need to irrigate.

AH: Or growing food.

JR: Or growing food, absolutely. And again, we need to be prudent about what type of, of foods we grow and recycle any food surplus that we have in composting it so that we use it to grow more food in, because that's fertile. It's got a high level of micro-organisms in it and its excellent for the production of vegetables. And, you can grow a lot of vegetables in a very small area.

AH: Any other water saving tips before we close?

JR: Yes, there's some shower head roses that you can get that are very water efficient. There are restriction devices that you can put in taps for garden watering etc. Simply when you turn the shower on for instance, don't turn it on full blast. Turn it on sufficient to get wet and just get a nice water stream, no more.

Quite often you would turn the shower on and go "whoa that's quite harsh on my body!" That's because you have way too much water pressure, in excess of what you actually need. So if you turn your tap so its only twenty five percent on, you'd probably save fifty to seventy percent of the water usage which you would normally use. Turn your tap off when you clean your teeth, don't leave it running.

Toilet flushes; Make sure that you set your half flush to a little bit less than half. Get it down to as little as you possibly can.

Whilst Auckland was experiencing a drought in the mid nineties, they had a saying… "If its yellow, let it mellow. If it's brown, flush it down." Now you don't have to go to that extent of course, but you know, they had to, because they were running out of water. And that was New Zealand, which we normally consider to be a very wet country, and normally is, but even they can go through prolonged dry periods.

So let's never assume we will never have problems with water, because, even in Bundaberg, we will run out of water sooner or later.

AH: And everything is connected.

JR: That's right.

AH: Jacques Rohen thank you very much.

JR: You're very welcome. Thank you for the opportunity.

AH: I'm Andi Hazelwood for SustainaBundy.