[Pil-pc-oceania] - Water tank options

[Laurence Gaffney]

Jedd

My preference is for concrete tanks for large storages of drinking water.
Have used plastic and steel in smaller capacity drinking and non drinking applications. 

Some points:-
1.    Sceptical of food grade quality standards on plastic for drinking water storage.
(A cheaper grade of plastic tanks now available which does not meet food grade standards)
2.    Believe that concrete life will be longer. (Plastic life not yet really known so this may prove to be wrong).  I assume a plastic liner could be used in the concrete tank at some point to increase life further.
3.    Concrete obviously better able to withstand fire though have been told not absolutely immune if the fire is hot enough. 
4.    A reliable consistent quality of concrete tank build more likely from reputable supplier of smaller truck delivered tanks. The sizes you mention are clearly "poured on site" tanks which introduces additional variables which can affect build quality such as weather, ready mix travelling distance, vibrating, curing  etc.  There is an Australian Standard covering Concrete Tanks which is worth a look at for any one considering a "poured on site" Tank though not specifically for domestic water storage. This will be news to even some of the contractors which should indicate something about such. Getting a contractor who really knows what he is doing is the big problem with poured on site Concrete Tanks. 
5.    Concrete tanks able to be buried if better suited to your design.
6.    Do not forget that the surface area on the top of these larger tanks is not insignificant when it comes to capturing rainfall. If thought about sooner rather than later such rainfall can be easily harvested. 

Laurence Gaffney     


Date: Fri, 23 Nov 2007 18:47:52 +1100
From: jedd <jedd at progsoc.org>
Subject: [Pil-pc-oceania] Water tank options
To: "'permacultue discussion list'"
<pil-pc-oceania at lists.permacultureinternational.org>
Message-ID: <200711231847.52367.jedd at progsoc.org>
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 How do we feel about concrete water tanks?

 I was kind of against them, but was assured they had a similar
 cost-per-litre thing going on when compared to plastic, etc, and
 what you lost in portability you gained in fire-proofness.

 I have a couple of 27k plastic tanks that were, a few years ago,
 around $A2,500.  A friend had a 120k concrete put in about 5
 years ago, and that was around $A8-9k, so I was assuming that
 a 120k concrete now would be around about twelve grand.

 I've been quoted night on $A18k .. which is worrying as it's way
 more than the same cost (using plastic) of several smaller tanks.

 Thoughts from people who've been down this path?

 Jedd.
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