Jim,
The black poly tanks ($600 for a 1,550 gallon tank) are better than the clean septic tanks that you mentioned because not only are they buriable, but the black poly is UV-proof and algae will not grow in the black tanks. I use one on top of the ground to supplement the hot water supplied by the water heater. If you can’t bury the tank, then I recommend setting it on the surface and build a protective wall around the tank with native rock and mortar. This will [absorb or] turn away bullets in case your enemies decide to try to deny you water. The wall can also insulate the tank against a fire set by an enemy. You can get these tanks at any feed store, or at a farm and ranch supply store. Regards, L.R. (of SurvivingTheDayAfter@yahoogroups.com)
Jim,
I hate to dispute your advice about using plastic septic tanks for water storage but I think you’re in error here. These plastic tanks are not designed to hold water and many of them have pinhole leaks (that can cause you a world of trouble in the long run). Additionally,if the tanks are buried, you have to remember that they are meant to be kept filled lest they be collapsed by the inward pressure of the surrounding earth (a little known fact is that pumped [empty] septic tanks should never be left empty) and this is particularly true if buried in heavy clay soils or driven over by vehicles. Here in Hawaii we just had a 6.7 magnitude earthquake. Among the hardest hit were those of us who live “off grid” (ironically) as many water tanks collapsed and virtually everybody had problems with damage to piping connections (which are difficult to make earthquake-proof.. Water supply should be one of the most engineered aspect of house construction, and this goes double for survivalists who are counting on independent systems to keep their families alive. The best book, hands down, for calculating what you need is “Water Storage” by Art Ludwig (who, by the way, makes learning ferrocement tank making about as easy as it will ever get.) Your local library likely has a copy, read it and save yourself a ton of money and two tons of frustration caused by an ill-conceived water system! – Hawaii K.
JWR Replies: Thanks for your input. I recommend that any buried poly tank be kept full, regardless of its design or its originally intended use. As for earthquakes, I’ve read that folks in Hawaii mostly had failures of rainwater catchment tanks, both aboveground and underground, and of both concrete and a plastic construction. The only tanks that at seemed to fare better than most were aboveground galvanized steel water tanks. But even for those that kept their integrity, many suffered from cracked water pipes and/or water pipe connections. (So be sure to buy plenty of spare copper or PVC pipe, fittings, purple primer, pipe cement, et cetera.) As for potential pinholes or larger leaks, when you buy any water tank, you should make sure that it is guaranteed against leaks before making the purchase, and definitely do an above-ground water fill test before burying it.