Why you should only use a concrete tank to store drinking water
Any water that is stationary will eventually become stagnant and undrinkable. How water is stored and its temperature will determine how long the water stays healthy and drinkable. Spring water is often considered as the best water you can drink. If you store your water in an underground concrete tank you are producing your own spring water.
Why tank water is so acidic Underground concrete tanks normally contain roof-harvested rain water, which is naturally acidic. The acidity of normal rain is attributed mainly to carbon dioxide in the atmosphere which gets absorbed as water condenses from a gas to a liquid and it is these liquid droplets that forms clouds and eventually rain. Even in areas that are minimally affected by human pollution, the pH of rain water can range from 4.5 to 5.0 which is fairly acidic. In built-up areas around cities, above-normal acid rain is generally caused by human pollution and in highly-polluted cities rain water can become as acidic as lemon juice which causes lots of problems for old historic buildings. This acidity forms part of the natural process that allows rain water, with the help of microbes found in the soil, to dissolve minerals from the soil into a colloidal form that now makes the water neutral and full of minerals which can then be taken up by plants. Acidic water is however not choosy and will happily do the same thing in the human body. Resulting in the stealing of alkalizing minerals and therefore a net loss of these vital minerals from the body as the water attempts to achieve a more neutral pH balance. Why is concrete the best material to store water in The very nature of water itself is that it wants to balance out to a neutral pH. and a concrete tank is the only man made storage system that will allow this to happen. To neutralize itself, water will absorb some of the minerals out of the concrete and will generally settle in a slightly alkaline state. An in-ground concrete water tank will keep the water at the temperature that it fell out of the sky at and if you are in an area that gets mostly winter rain, that cold water will remain cold all summer. Even above ground, light cannot penetrate through the concrete walls of a concrete and into the water. All of this become very important, because roof harvested rain water picks up all sorts of dust, bacteria, and bugs and even after being pre-filtered some always gets through. Water that is alkaline, cold and removed from light will not support the growth of any bacteria that makes its way into your tank, thus allowing this water to stay clean and drinkable for years. If you cannot put your tank underground, paint it white; or allow ivy to cover it to keep the sun off it and the water will stay very cold. Yes in time, this leaching of minerals will compromise the integrity of a concrete tank, but a well-made tank is good for a hundred odd years.
If you manufacture, sell or distribute water treatment or distribution products in North America, your products are required to comply with NSF/ANSI 61: Drinking Water System Components – Health Effects by most governmental agencies that regulate drinking water supplies.
The NSF mark, well respected by public health officials and drinking water utilities, is recognized as a symbol of product quality and integrity. Our responsive, personalized service quickly guides your products through the certification process, ensuring that they get to market on time and on budget. We offer product bracketing services wherever possible to help keep costs down, and we provide pricing up front so there are no hidden surprises down the road.
NSF is accredited by the Standards Council of Canada (SCC) and NSF listings satisfy the requirements of the Canadian National Plumbing Code, U.S. Model Codes and the Uniform Plumbing Code (UPC).
U.S. and Canadian Approvals
Drinking water system components that are used in centralized water treatment plants and water distribution systems up through the water meter are typically regulated by state or provincial drinking water agencies.
Forty-eight U.S. states have legislation, regulations or policies requiring drinking water system components to comply with, or be certified to, NSF/ANSI 61.
Eleven Canadian provinces/territories require drinking water system components to comply with the requirements of NSF/ANSI 61.
Get more information and see a comprehensive map of the U.S. states and Canadian provinces/territories that require NSF/ANSI 61.
For additional information on the proper concrete release agent to use for concrete drinking water tanks, read these articles published in Precast Inc. by the Hill and Griffith Company:
"Biodegradability Redefined and Volatile Organic Compounds Update" by Bob Waterloo, Precast Inc., January/February 2010 Download Article »
Biodegradable, NSF Concrete Form Release Agents Offer a Range of Options for Concrete Applications Read More »