Consider a polyethylene septic tank

topic posted Wed, March 11, 2009 - 10:33 PM by  Jim
I have recently researched polyethylene septic tanks and suspect they are already in use as buried caches. They are light enough to be transported by pickup and carried or dragged by two people. You could dig a hole by hand in a couple days but I think I would rent a backhoe. They come equipped with manhole covers that could be sealed using toilet ring wax after they are stocked with provisions, plus they are non-metallic so a metal detector cannot be used to find them. These tanks are available for about a dollar per gallon capacity. You can judge for yourself by googling "plastic septic tanks" or follow some of these links to investigate:

Many suppliers also sell underground cistern tanks that might also be used in this fashion, not to mention as rainwater storage tanks for which they are intended. (Don't forget to cache some water!)
posted by:
offline Jim
New Hampshire
  • Unsu...
    I like this idea. But don't septic tanks have leech-line holes in the lower sides?

    This is probably one of those projects you don't want to save a few bucks and get a used one off ebay hahaha
    • Jim
      offline 2
      The polyethylene tanks have port locations ready to be cut but I was pleased to note that the only penetration(s) was/were the manhole(s). Except for some small globular ones these tanks are deeply ribbed so they retain their shape when backfilled. Two people, one inside and one outside, could load a few dozen sealed buckets of storage food into one of these in a half-hour. The manhole rim could be spread thickly with toilet ring wax, a sheet of poly film could be draped over the manhole, and backfilling could commence minutes later. Park a jalopy or a garden shed on top of it and forget about it till well after TSHTF.

      I plan to have smaller caches containing about a month's food supply that I can rely on if the pantry is raided. The main thing is to have most of your food hidden in several locations. Same goes for other survival stuff. The less you appear to have the less you will be targeted.

      Plan to put yourself on restricted calorie intake as soon as TSHTF. It will accomplish at least three things: make your food last longer, keep you healthier, and perhaps most importantly make you look undernourished so others will assume you have little or nothing worth taking. If you have put away clothes, boots, etc. for the depression, wear your ragged or obviously mended and soiled clothing in public so others will size you up as not worth following home. At the same time, be armed so you can defend yourself if needed.

      I decided to obtain a concealed-carry permit from the police department so that, if things got dangerous very suddenly, I could pack heat legally. The downside is that authorities can come directly to my house if there is a sudden gun round-up, knowing that in all likelihood I am a handgun owner. That's OK, I'm prepared to peaceably surrender every gun on the property. After that, I will know the score: time to hit the woods.
  • Unsu...
    I had an aquaintence that bought the biggest one of these tanks (at least I think it was one)he could get his hands on and made it into an underground hidden home. He eventually made it a complex of these tanks Linked to each other with tunnels made with smaller cylinder tanks that required crawling from room to room as it were. It was basically the main biggest tank as living quarters/office and the shortest tunnel distance away secondary storage and others guest bedrooms. It was an interesting place to stay. If you didn't know it was there you'd never find it.
    • holyfscking sh*t, that is awesome.

      how'd he do the heavy digging? did he have to bring in a back-hoe or something?
      • Unsu...
        He owns or did own a construction company, i.e. backhoes, bulldozers etc. I knew him because he could afford to buy all the weapons anyone could want and need someone to teach him how to use them. He walked into a gun range one day watched people shoot, decided I was the best shot he had seen and asked me to teach him. this was many years ago. I got 1000 rounds of Federal 125 grain HP ammo, 250 shotgun rifled slugs, 250 OO buck and permission to deer hunt on his property for 5 years. It was only 5 years because I moved to California.
    • Unsu...
      Curtis, that is a cool Idea. It might be faster for me to install a couple of those big tanks under groung and connect them to me basement instead of adding a concrete bunker to. It could cost a whole lot less as well. Michael
      • Unsu...
        I know a guy in slc who got ahold of one of those chemical tanks and buried it in his yard. But he didn't do it for any 'cache' reasons. Come to think of it, he's had it buried for at least ten years and it's still empty.

        It's completely useless. About a ten foot diameter cylinder, 15 feet tall. Buried vertically. you need a long ladder to get down into it. Once inside, you've got a ten-foot diameter floorspace, with 15 foot high ceiling and smooth walls, all underground. The top is somewhat exposed, so it lets light down into the tank. I guess if you liked kidnapping people, this would be the perfect place to hold them.
    • Jim
      offline 2
      There are a great many creative approaches to creating underground space. I once presented a day-long seminar around Northern California on underground home construction. It was mainly an overview of the amazing variety of materials and techniques that had been used. I don't think polyethylene cisterns and septic tanks were in use at that time.
      • Unsu...
        I studied earth shelers for about a year. Great Idea living under ground but I couldnt sell my wife on an underground house. So I have to rebuild the above ground house AND install a bunker like shelter. Michael
  • Lets ratchet up the interest -

    Has anyone actually gone through the process that can relate their experiences?

    If I was to build up some samples for resale there are a few questions that arise.

    COLOR - I assume black would attract less attention.
    DIRECT BURY - Must be rated to bury without being filled.
    INGRESS:EGRESS - The hole diameter must not be too small.
    FLAT BOTTOM - Ease of walking, cleaning and draining.

    RISERS - Entrance hole must have riser, cap and seal.

    DESIGN - A Tribal design listing features requested would be best.

    AIR - Solar panel hid up tree feeding ventless battery and 1" computer fan will sufice.

    DISCHARGE - A waste discharge pump, check valve and vent.


    LAYOUT - Shelves, layers, sleeping

    MOBILITY - If remote movement is needed a hitch to an ATV with a removeable axle may be needed. Snow coverage may be a usefull exercise for winter camping. A smooth bottom could be easily skided with an ATV
  • Unsu...
    I have concidered this, I have however decided to keep a number of smaller stores in food grade plastic barrels. That way if you lose one store you still have others.
    50 gal (or220 litre) barrels can even be bought on Ebay.
    If you worry about somone using a metal detector that could trace the metalic contents or fittings on the barrel you might think about "salting" the area with any old scrap metal burried a few inches deep, this would make any search more time consuming.
    A large septic tank can make an ideal "hideout" in plain view if you can plug the manhole cover 2-3 feet down and then fill the void with foul water, sh*tty water will put off most searchers!
    Finally, to any of you folks who may have "lost" firearms in an unfortunate boating accident just spare a thought for us poor folks in the UK who have to account for nearly every stupid bullit.

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