Galvanised Water Tanks

Addressing a few things in relation to tanks, I want to cover as much as I can in this. I am calling it an opinion piece, but I have been making galvanized tanks now for over 30 years (in fact I started my apprenticeship on 8th May 1989, so as I write this, I am approaching 35 years).

Firstly, I want to point out a quick reasoning for this:
We are having an issue with the supply of material. We have prided ourselves over the years on using local products where possible. We buy rivets from a local supplier, the sealant same, the components come from S.A. and the iron from ™Bluescope (through suppliers).
Now ™Bluescope don’t want to make the Z600 .6 galvanised coil we use, instead offering only Z450 coating. They are trying to push us into making ™Aquaplate tanks, or tanks with liners/bladders.
This is not what we do.

To fully understand this and the implications it is incumbent on me to explain in more detail about these coatings.
Z600 is a thicker coating used for manufacturing water tanks, it is as close as possible to the traditional material used. For years this method of storing water has allowed pioneers and country people to exist and before reticulated water supply, townsfolk too.

Z450 Is a lighter galvanised coating. The base material is the same (either .55 or .6 which is 24# in the old money) known as BMT (base material thickness) but the galvanising is lighter and so hasn’t got the heavier anti-corrosion barrier the Z600 has. It can still be used to make tanks and is, but the lifespan is diminished.

This has put us in an awkward position and with an unfavorable choice. Either we use the Z450 or we use imported Z600 from Korea!
This means we can no longer claim to be 100% Australian made from 100% Australian product, or we use slightly inferior product.
This makes me angry!

So now to another part of this:
Water quality.
How good is the water you drink?
Well, that depends on who you ask as to what sort of an answer you get. Reticulated water is treated with chemicals – chlorine, fluoride, hydrochloric acid……. The list goes on.
Is that really good for you? According to Australian Standards it is.
Australian standards don’t consider the tanks we make as “potable water storage” – instead they come under a classification of “Stock & Domestic” water storage.
Is the water contaminated? Obviously, it can be. Many things can contribute to this. Animal and bird excrement, hail has a spec of dust in it, summer storms are often full of dust and there is an element of that build up on your roof. Saps, leaves and the like can enter your tank as can ash after a fire. Some things can be toxic, others benign, but there are always going to be things that can enter the water. Helicobacter can be an issue in tank water.

For mine, I have been so many times out to replace old tanks, seen the disgraceful remnants of an old tank that people have been drinking from, but then when I see the old couple who live there, often in their eighties and even nineties, still running their farm I come to the conclusion that it hasn’t done them any harm! Contrast that as I drive back into town and see a fella in his 60’s on a scooter or a walking stick ……. You can see where I am going there.
Now they talk of “good gut health” and “good bacteria” “pro biotics” and the like, is there a chance that those exist in the tank water?
As an opinion, I say the evidence I have seen certainly suggests so.

™Aquaplate (a ™Bluescope product) has got a food grade rating. It has the tick to be considered a potable water storage vessel.
The polymer film is a 200µm thick polymer film which does not contain BPA (Bisphenol A), DEHP (Diethylhexyl phthalate), calcium stabilisers or zinc stabilisers.  AQUAPLATE® steel meets AS/NZS 4020:2018 - Testing of products for use in contact with drinking water. (This doesn’t say what it does contain though).
These tanks HAVE to be sealed with a sealant, they CAN NOT be soldered. All sounds good, but the same contaminants exist and can taint the water supply in an ™Aquaplate tank just as in a galvanized tank. Does the ™Aqauplate leech? Good question, according to ™Bluescope – no.
Does galvanised iron leech? If it does, it has been doing so for as long as there have been people drinking tank water – see opinion above.

This can lead to as many arguments as people want to have – and we haven’t touched on solder yet. We used to solder all our tanks until 2 years ago. We now seal them with a product called T-Rex. We still offer soldered tanks to those who prefer that.
So, lets visit this now.
Solder is made out of a blend of tin and lead – we use 50/50. I have faced the barrage of questions over the years always fearful of some “expert” wanting to challenge me on my knowledge, understanding and experience. I have consistently tried to address any questions as best as I can given my education level and my experience. For those who wish to know, I left school in 1989 at the start of Yr. 10 – so Yr. 9 is my highest school level. I finished my trade as a sheet metal worker, so I have that qualification.
In trade school we were told lead can affect your virility – I have a 25-year-old son, a 13-year-old son, an 11-year-old daughter, a 6 (he’ll be 7 in a month) year old son and a 6-year-old Granddaughter. I have been soldering tanks since I was 15 years old, I’m 51 now (although I have barely soldered for the last 2 years) so I’ll leave you to decide if it affected me or not in this way.
Realistically speaking as the water in the tank has bare minimal contact with the solder and given the capacity it holds, when it comes to toxicity, my opinion tends to be that you would be more likely to get heavy metal poisoning from all the sinkers and pellets (remember, duck shooting was a prolific sport for a long time and at this point in time is still legal) that exist in dams, reservoirs and rivers than from a soldered tank. But that is just my humble opinion!
As the water in a tank is not heated, I would be doubtful if much if any leeching occurs, I’ve certainly in my years doing this never had to confront anyone claiming to have been poisoned from a tank by the solder.
Just for a bit of fun and relevant understanding, I have been running/owned Rural Tanks since 2002, prior to that when I was working/contracting for the previous owner (my old boss’ son) we sat and worked out that in the time since Rural Tanks was first registered in 1982 until then (about 1998) we had soldered the equivalent distance of Melbourne to Brisbane & back. That’s a lot of soldered tanks out there (some of which are still in place and functioning to this day).
People did fall ill though in days gone by, lead paint on roofs flaked and went into the water. People ingested this and became ill. I also know of one occasion whereby a woman fell ill due to rat poison, the rats ate Ratsak, went for water and died in the tank. Either of those scenarios though it would be irrelevant to what sort of tank the water was held in; the outcome would be the same.

Does plastic or ™Aquaplate taste?
Honestly, depends on who you ask! Some swear it does taste, others say not. Personally, I don’t find it does on any occasions I have drank the water from either of those type of tanks.
Do I drink tank water?
Yes – and no. Out at the factory we do (we have town water, but we all choose to fill our water bottles from the tank here). At home we are in town and the small tank we have is for the kids play water. We could if we bothered, but usually either drink from a purification dispenser or have boiled then cooled town water in the fridge.