Building your own cesspit in Thailand

[Marmite the Dog]

I do hope you guys are just joshing!

[Thetyim]

My understanding of it is that these sulphates are heavier than water and so will always collect at the lowest point.
Any one know if this is true ?

[man with no head]

Last year near where I live 2 lower floor apartment blocks became uninhabitable due to sulfates collecting in the pipes due to settling (the upstairs ones were OK).. our water source is near Mt. Hood which is a volcano, after all....

[Skeets]

This is a shity topic, but it has caught my attention. The question I have is it important to glue or cement each ring together to prevent ground water from seaping into the cesspit? I would think so, but haven't seen it mentioned. Also, it was mentioned that stones should be added around the rings, is that really necessary?

[dirtydog]

The cement ring type cess pit is for use as a soakaway, ie you want the water table to be lower than the cess pit, the reason we put stones between the rings was so we could concrete over the whole thing and build a garden on top of it.

[Dougal]

DD I suspect that Skeets needs a bit more info.

i.e. there are two types of hole for getting waste from your house. One for bath, shower and sink stuff (grey water) and a different design for shit (black water).

The type that consists of a stack of concrete rings with a surround of stones should only be used for grey water.

If you are considering doing this at your house Skeets, then look some of the more exhaustive information on the internet first.

[DrAndy]

I think we have mentioned this before somewhere

There are some terminology problems, as well. A cesspit is a big tank that gets filled with shit and associated water. When full, you have to have it pumped out. When I lived in Nigeria, we had one outside our office and they actually drained it manually with buckets. One guy even got into it near the end and passed up the buckets....it stank in the office, never mind outside.

A septic tank is what we are talking about here, I think. This is a tank, as pictured by DD, which has concentric rings inside, through which the shit gradually passes, being broken down as it does.

The concentric rings just make the journey as long as possible, giving the bacteria lots of time to work properly. The concentric ring design therefore lets you have a septic tank in a small a hole as possible.

When the shit eventually reaches the outlet, it should have been broken down to just a liquid. The bacteria should have eaten all the solids and a lot of the nutrients in the water. This liquid should be relatively smell free, and fairly safe hygenically.

This liquid should then go to a soakaway, along with the other household water (like shower and kitchen water), and slowly soak into the ground.

The septic tank should never need opening or draining out if the bacteria are working well. They are usually happy as long as you dont use strong chemicals to clean the toilet.

The soakaway does not depend on bacterial action, so you can use bleach etc to clean the kitchen sink.

[corvettelover]

when you have your tank pumped out or install a new one fill with water and through in a handfull of lime this will make a healthy enviroment for the bacteria to live in. We also use to use absorbition trenches the liquid outlet goes into a trench with plastic pipe with holes drilled into it the bottom of the trench is filled with gravel (blue metal) and covered with same and then topped up with soil.
Then plant some nice water loving trees or shrubs around pit.
Ensure you mesh the outlet pipe to stop the solids getting out otherwise your absorbition pipe will become blocked and your septic tank will over flow.
When installing tank think about putting a plastic tube down the full length and inserting a copper rod inside it and mark a level on it that is below the top of the tank,then put a screw cap on top of pipe so you can dip test the level of your tank without having to pull the inspection cover off. dont stink as much.

[Dougal]

If you buy a plastic tank it will be constructed with a couple of chambers, and some bits of plastic designed to break up the solids as they flow in. The tank should always be full of liquid as it is only the overflow which has been broken down by the bacteria in the tank which is supposed to flow away to the leach field.

A systen that is working effectively should only need emptying when the broken down solids reach such a level in the tank to inhibit correct operation.

[blackgang]

Dougal said it, and they do make and sell a septic tank made in black plastic that has two chambers and they sell bacteria culture to use in the thing, and you do run leach lines from it into a drain field as Corvette said, works well especially if above the high water mark during monsoon so it doesn't flood.
They sell them at HOME MART here in Phetchabun. or you can get plans off the net under septic tanks and build one out of concrete, it will be a 2 cell tank..

[farmerfloyd]

I have a 1000 gallon tank with a divider inside to keep solids apart and then it runs into leach field to 4 or 5 lines 60 feet long with gravel on top with angels hair on top of gravel that lets more water to evaporate then stays in pipe to soak in ground, it is 13 years old, pumped once this year, was like perfect, did not need pumping, bugs working overtime,But no soap from washer goes into septic tank, seperate. in Florida with high water table but sand so settles fast. NO smell, just 2 adults no diapers. ha farmerfloyd

[robd]

ok then, i am just about to start building in middle of nowwhere so need a cesspit/soak away, i want to use grey water for plants/trees etc but land is sloped down t oa natural water course which i dont want t opollute.
Have enough land but need t oknow size etc of cesspit, any ideas for family of 4? how many rings high,how many in line and what diam etc and then does grey water need a tank as well?? how big an area do you need for soak away? any help will be great cheers rob

[dirtydog]

I think you need to work out how much water you will be using perday, ie baths jacuzzis or showers etc, and also soil density and water table height.

[tsicar]

i did my own cesspit when i built my house, roughly to the spec. that dd has given. worked well for around two years, then.......
the night i was due to leave for bankok to collect my daughter at the airport (her first visit to thailand), disaster struck! shit smell and upon investigating, found the bloody thing had decided to back up and overflow. no chance to get it sucked out in time, so spent a few hours digging a 3 cubic metre hole and diverting the toilet pipe to it. due to leave in three hours, no time to concrete or close it up properly, so i covered it up with a couple sheets of that asbestos fibreboard and shovelled some soil around the edges. well, my daughter's visit went well, and so did the new cesspit, and since it was working, and in an area nobody ever ventured into, it kind of got forgotten about, and the boards got covered with a layer of dried bamboo leaves.
a few months later, i had to leave thailand because of the visa rule change, house boarded up , and not a thought about the cesspit.
i have a friend in the village (he posts on this forum), checking the place over from time to time, and a while ago he reported discovering a man-sized hole in the fibreboard where somebody had fallen in! he sed he did not bother to investigate further, since he was afraid of what he would find! shit surprise for some thai snooping on my property. if he is still in there, at least i will not have to source a dead animal to get the bacteria going!

[robd]

ok dd so how does one go about working this out without getting to technical,surely lots of you have done this sort of thing already so just an idea would be great!

and how big do you think i should go for for the black water cesspit??

thanks rob

[DrAndy]

as a rule of thumb, it would be good enough for 4/5 people to use three of those concrete 1 metre rings for the tanks in the ground, stacked on top of each other and stuck in a hole like this




you would make on septic tank (not cesspit) for the shit, and another one for the grey water. The shit water would overflow into the second grey water tank after processing. You may then have a third tank for it to overflow into and from this, percolate into the surrounding earth. It should not pollute anything by then as the bacteria would have cleaned it up.

If you wanted to use the water for your plants, then the third tank could be made waterproof and you could pump it out rather than letting it filter out

[robd]

ok all so septic tank, they can be done using same concrete rings??? or am i looking at buying1 of teh plastic ones? thanks
rob

[blackgang]

Buy one of the 2 chamber plastic septic tanks, that way there is a digesting chamber, and a runoff chamber and have them put in a leach field with a couple of leach lines with 4" perf pipe set in gravel and then covered over, they should be as long as you have room to make them.

[DrAndy]

yes you can use the all-in-one plastic tanks, but it works out more expensive. neater though

[sunderlandstephen]

Did you consider wrapping pond liner around rings before concreting