Cistern help needed

We used a the bottom half of a 1500 gallon septic tank as a cistern. We then built up the sides with hemlock. Our cistern now holds about 2000 gallons. There is an overflow built in to the top of it so any amount over 2000 gallons flows out and down a stream into the horse pasture. We use a shallow well pump to move the water.

 

Be sure and check out the Countryside Archives - this subject has been covered in depth. Yes, you can use a septic tank for water storage but you need to take some steps that the overflow off your roof is pure to begin with. Bird dropping, soil which is on the roof surface and your gutter to your cistern should be flushed off BEFORE going into tank - or there is contamination to deal with.

I know plenty of Hawaiian homesteads use this for their water, with their major rainfall and high costs of building materials. over there. - do a google search on Hawaiian homesteading you are bound to find some information.

One last thing - have you considered having the cistern located at a higher level than your home? Gravity feed would provide the water pressure. How high do you have to go - well, for starters the bottom of the cistern would have to be higher than your highest water fixture outlet. The shower is normally around 48" above finish floor, sinks and lavatories about 36". Toilets and tubs - around 14" or so. You would have to pump the water UP to the cistern for this to work though.

Hope this helped you in some way.

 

Put in a bypass valve - butterfly valve, and a TEE before the water gets to the cistern. Either dump the first 10 min or so of rain away from the cistern, or use a big bucket & lever to move the valve. Bucket (garbage can) fills, the weight pulls the valve shut, cister starts filling. How big a bucket depends on how big your roof is! To prevent overflow, plumb a 4-6" bulkhead about 6" from the top of the tank, run it into plastic drain tile and across the field...

http://www.watertanks.com/category/6/

These will work, I'm go with something in the 2000 gal size (about $1000), and a booster pump ($80) on a 80 gal bladder pressure tank ($299) with fittings ($80). That's for toilet, wash water, clothes, dishwasher, bathing, watering plants.

Potable (drinking water) is on a separate isolated refrigerated pressure tank (20gal), filtered, limestone bed, (taste) to a spout ($30) next to the kitchen sink. Yup, I want COLD, clean drinking water & ice.

I grew up with a 10x10x8' concrete cistern inside the basement, open top - we could see the debris floating... It all settled, the water tasted GREAT, and other than baying at full moons, my wife says I'm perfectly normal. :yeeha: We did have a booster pump and pressure tank. Tractor Store has a nice 12volt (8amp) diaphram pump with built in pressure switch, up to 60psi and 1.8 gal per min full flow (why we're getting a BIG pressure tank)

Most tanks come with a drain on the side, near the bottom. Put your suction pipe 18" from the bottom, open the drain valve for flushing/cleaning. The WIDER the tank, the better the dust & debris will settle out.

We suffer a power outage a month, without fail... generators fail too & cost a fortune to run & fix.

BTW... water weights about 8lbs per gallon... what's gonna hold it up a 2000 gal 16ton tank... is the sun going to preheat your water for you?

Good luck, Merry Christmas, Happy whatever...
Bill

 

Unregistered up above was me. Our cistern is about 7 feet deep and sits underground. We sealed the sides to prevent ground water or run-off during a rain from seeping in. We built a "spring house" over the cistern. The floor is removable so in case of a power failure we can "dip" water out for personal use and to water animals.

 

The responses here have some good information.

Since your ground is flat, and you don't have a well, your roof is the source of water. You might size the cistern and the roof accordingly. For example, if the roof is 1000 sq ft and annual rainfall is 1 foot, you might expect around 6000 gallons annually(after you discard the initial runoff). This could be enough for a frugal family for a year. A 3000 gallon tank might be adequate.

I am planning to build a cistern. A 10 foot diameter cistern, 5 foot tall will hold just under 3000 gallons.

To build this size container using ferrocement I will need about 50 20ft long 1/4" cold roll pencil rod, 1 cubic yard of cement, and 30 sheets of expanded metal. The total cost will be less than $300. The tools needed are a pair of kline pliers, 5 gallon bucket(in which you mix the cement), a sturdy hand drill(to mix the cement), a mixer bit (the best is hand made for about $2), and a hand trowel.

I plan to build it this coming spring. I think it will take one weekend to assemble the armature, and another to parge the cement. If I get a helper, I might be able to finish it in a weekend.

I'll take pictures when as it happens.

 

Works well for washing & such. You run ito real problems using it for drinking/ kitchen. Most likely there are codes preventing it. If not, you end up with expensive filters & such to make it safe. Doesn't mean you can't do it, just check that all out before starting.

Septic tank should work. How much water do you use in a day, and how long between rains? Septic tank isn't that large...

You need to route overflow to somewhere - it is the amount of rain that falls on your roof, so it's not _that_ much rain, but you want it to go away from problem areas, just as you would anyhow from your building. An overflow means you don't have to mess with controlling it, but all the water has to go through your filters (if any) even if it just runs away... Changing the spout manually means you have to be around to monitor how full the tank is & out in the rain to change things.

There are UV filters & sand filters and so on. Better to keep your whole cistern clean & do some filtering first, but means you need to handle large flows of water off the roof - $$$$. Filter from the cistern means a smaller cheaper filter system, but you have a scummy cistern. Probably find a balance.

All this takes electricity.

You could set the cistern on the ground & build a mound around it to protect from frost. Then the water will gravity flow into your building and you can use or pump up a small storage tank for higher levels/ pressure needs. This would actually give you access to grey water at slow-flow/pressure without any electricity if you want to start that way, can add pump & filters later - maybe.

Just random thoughts.

--->Paul

 

My friends and I built our house in southern KY earlier this year. We too have to use rain water for all our water needs. And for a family of 6, we can potentially use a lot of water.

I had initially planned to pour a concrete cistern, and excavated a large hole near our foundation. Due to the cost though, we decided to use the poly tanks from our local tractor supply store. A 1500 gallon tank is around $475, and I installed 4 in series, for a total storage volume of 6000 gallons.

Our house is 1500 square feet, single level, so that gives you an idea how much square footage of roof we have.

There is one gutter downspout in the front, and one in the back. Yas, we do use a mesh product to keep leaves out of thegutters.

At the bottom of each downspout we have a 55 gallon plastic drum which functiions as a roof wash. 2/3 of the way up there is a float valve, which diverts the water into the cistern tanks after collecting the first 30 gallons for disposal. Each drum has a spigot at the bottom to drain the waste water.

In one cistern I have a float valve, connected to an above ground jet pump. This sucks the water out of the cistern as needed, which then runs through a swimming pool sand filter ($200) and finally though a 5 micron whole house filter (Sears product, approx $35)

We reinforced the walls of the tanks, then piled dirt back into the hole around the reinforcement. This entire cistern area is under a deck next to the house, which I can access when needed.

I think the entire setup may have cost $3000 or so, including labor and backhoe work. This summer, during the driest time, our water level never dropped below about 2500 gallons.

Hope this helps!!

--Chris

 

Glad to see your are looking at some property! Hopeit works out for you, and if you need any help, give a shout!

 

i'm planning to use a cistern too, and as it happens just started seriously considering it last nite. i guess buying one of those black plastic tanks that're MADE to hold water would be reasonable, but i always have to try to do things cheaper....

i was thinking of using those heavy grade pond liners. i priced 'em a little bit, and i think it would save some money over buying the tank. plus, it'd be easier to haul in my hyundai. they make a special tape to join seams, but i haven't yet enquired as to how reliable or permanent that'd be.

i thought i'd just dig a really large hole, install the pond liner, then frame a platform to protect it and provide access. then the usual small pump pressure tank etc.

anyone ever worked w/ these types of pond-liners?