DIY septic questions?

[nao57]

So I wanted to post a few DIY septic questions here. Many of these were questions that came after watching YOUTUBE videos. It was helpful to see videos and that you can make something cheap for like a place to camp. Or for somewhere extremely rural. But there were differences in how people made them. Some of them were extremely well made.

For the french drain perforated pipe, is there an ideal size for the perforated holes? (And is there more than 1 perforated pipe size used?)

When making the system to accomodate more than 2 people, or if uncertain how many people may visit your site, how do you figure out how many barrels chained together in the system there should be compared to how many people there are? (How many barrels per person?) (Most DIY videos used big barrels or IBC tote cube tanks).

One video quoted 1/2 " drop per foot of pipe length for the length and angle of the pipe going from like an RV or an outside going to the septic tanks. This was the ONLY one I found mention of the an angle or slope calculation going between toilet and tank location... curious if anyone else had thoughts on slope of pipes?

How deep below the surface of the ground does your french drain (perforated pipe drainage) system need to be to have no smell?

A couple videos quoted that if your drainage setup is too close to the surface that animals can get attracted to it and try to get into it, and that so doing could get them sick. This made me wonder if also a certain distance needs to occur between the septic tank and its drainage setup and nearby trees and plants?

If you've got more than a couple people using your system is it better to just build 2 systems, and have 1 for blackwater and the other for normal (non-septic) household graywater with the 2 types of water separated? (I wondered if this idea would reduce stress on the system).

Very much thanks to everyone. Also happy living and homesteading. And may you all be excellent DIYers so we can all live free and have more freedom!

 

[U_Stormcrow]

If you can get pipe, DON'T. Get this instead.

https://www.adspipe.com/water-management-solutions/onsite-leach/arc-chambers

Its used by essentially all modern drain/septic installers because its faster, easier, cheaper, and almost uniformly better then perforated pipe.

2 foot below surface level is optimal - has to do with the availability of oxygen, See here.

For small (personal/small household systems) there is NO reason to build a grey water and a black water. Simply size your system appropriately for both, and count on the grey water to help move black water solids into the tank. Grey water systems are generally made when there is a LARGE grey water source which you want to repurpose for yard maintenance or in particularly dry environements where water is critical. Most household grey water sources are contaminated by an excess of soaps/surfactants (dish water, wash water, shower shampoo soaps, etc) which are ultimately bad for the soil anyways.

Most systems use 2 IBC totes because that's roughly 500 gal between the two tanks. It is suitably sized for two, maybe three people constant use. A typical household tank for a family of four is 1,000 gallons and the baffle often isn't evenly proportioned (down the middle) because much more water is generated than solids, but water rapidly moves to the drain field, solids do not. Better to build bigger than smaller, if you can.

 

[nao57]

If you can get pipe, DON'T. Get this instead.

https://www.adspipe.com/water-management-solutions/onsite-leach/arc-chambers

Its used by essentially all modern drain/septic installers because its faster, easier, cheaper, and almost uniformly better then perforated pipe.

2 foot below surface level is optimal - has to do with the availability of oxygen, See here.

For small (personal/small household systems) there is NO reason to build a grey water and a black water. Simply size your system appropriately for both, and count on the grey water to help move black water solids into the tank. Grey water systems are generally made when there is a LARGE grey water source which you want to repurpose for yard maintenance or in particularly dry environements where water is critical. Most household grey water sources are contaminated by an excess of soaps/surfactants (dish water, wash water, shower shampoo soaps, etc) which are ultimately bad for the soil anyways.

Most systems use 2 IBC totes because that's roughly 500 gal between the two tanks. It is suitably sized for two, maybe three people constant use. A typical household tank for a family of four is 1,000 gallons and the baffle often isn't evenly proportioned (down the middle) because much more water is generated than solids, but water rapidly moves to the drain field, solids do not. Better to build bigger than smaller, if you can.

Thank you very much for the reply!

 

[U_Stormcrow]

FWIW, if using IBCs, I'd do a three tote system (wife and I, occasional visitors, possibility for "surge" use - our property is one of the places the extended family relocates to during severe weather in other parts of the state. I have multiple RV hook ups).

There should be plenty of available drawings, and its sized big enough that it should require only infrequent maintenance. Thankfully, I didn't have to go that route, was able to have a 1,000 gal poly tank delivered and professionally set with leachfield - but I had to do the research because there was good possibility that would not be an option out here.

 

[Egghead_Jr]

Slope has to do with water draining. The minimum is 1/3 inch per foot. This is seen on "flat" roofs. Make no mistake, your septic is fluid. After the settling tank where anarobic bacteria are at work the effluent flows out a baffle into the leach lines. Those leach lines exiting and the line entering the tank system must be sloped.

 

[nao57]

FWIW, if using IBCs, I'd do a three tote system (wife and I, occasional visitors, possibility for "surge" use - our property is one of the places the extended family relocates to during severe weather in other parts of the state. I have multiple RV hook ups).

There should be plenty of available drawings, and its sized big enough that it should require only infrequent maintenance. Thankfully, I didn't have to go that route, was able to have a 1,000 gal poly tank delivered and professionally set with leachfield - but I had to do the research because there was good possibility that would not be an option out here.

How do you safely cover the IBC totes, or barrels with dirt or whatever without it caving them in or damaging them?

 

[U_Stormcrow]

One the top of the tote is usually close to ground level, so it can be accessed to remove solids if required.

Two, most of the better designs I've seen involve placing rebar over the top, then building a concrete cap that extends over the edge to distribute weight and allow it to be walked on. If the tote is full of water when that is done, it won't collapse while the concrete cures - water can't be compressed at the sorts of pressures commonly found in nature - a 4" concrete cap is only about 50 pound per square foot - that's trivial