Drainfield depth

[GRWeldon]

Good day y'all. First post.
I have a situation where I need a septic drainfield. The location I have selected will eventually have more fill on top of it after the field lines are installed leaving the leach lines deeper than the generally recommended 36" or less. The selected site is already prepared with sandy fill at least 36" deep on very porous ground. There is never standing water for more than 30min. and this is only after a deluge.

I do not know if there is a specific reason the recommended depth is 36" or less other than cost to dig deeper. Will my proposed plan keep the septic system from working properly?

 

[RS]

Too bad someone more knowledgeable hasn't responded, I 'm no expert, but i have done a couple of drain fields. I would put it in a little shallow and add the fill later. In MN there are lots of regulations, which are good, it doesn't allow someone to sell a substandard property, and reduces pollution. Does your county have and advice on what to do? When I put in my first system 50 years ago I got lots of good advice from our county, with plans how to build a system.

 

[Twowaxhack]

You want a shallow drainfield to facilitate evaporation.

Most of your water evaporates.

 

[Ludington]

You want a shallow drainfield to facilitate evaporation.

Most of your water evaporates.

What about these new systems I've seen where they put this giant half pipe over it, and then bury it. Ive seen that a couple times in my neighborhood. No stone... nothing.. I find it very odd.

 

[Twowaxhack]

What about these new systems I've seen where they put this giant half pipe over it, and then bury it. Ive seen that a couple times in my neighborhood. No stone... nothing.. I find it very odd.

Same is true, shallow as possible for your area. I would assume is deeper up north because the ground freezes.

Down south they’re usually not deep.

 

[Mitchell-DIY-Guy]

What about these new systems I've seen where they put this giant half pipe over it, and then bury it. Ive seen that a couple times in my neighborhood. No stone... nothing.. I find it very odd.

You may be referred to a panel system, such as these: http://www.tjpanel.com

Around here, (Piedmont area of North Carolina ) each county must approve and specify every drainfield system. Since they seem to be increasing the size of the drain fields, as well as requiring a duplicate repair field, and building plots are getting smaller, these panel systems are one tool they use..

And it is completely dependent on the percolation of the soils. My home on the lake in Michigan had maybe two or three 30’ foot runs of drainfield pipe. A similar sized home we wanted to build here required 240 feet of double stack panel… plus that identical sized repair field. The size and location of the drainfield basically limited what we could build and we gave up.

 

[Ludington]

You may be referred to a panel system, such as these: http://www.tjpanel.com

Around here, (Piedmont area of North Carolina ) each county must approve and specify every drainfield system. Since they seem to be increasing the size of the drain fields, as well as requiring a duplicate repair field, and building plots are getting smaller, these panel systems are one tool they use..

And it is completely dependent on the percolation of the soils. My home on the lake in Michigan had maybe two or three 30’ foot runs of drainfield pipe. A similar sized home we wanted to build here required 240 feet of double stack panel… plus that identical sized repair field. The size and location of the drainfield basically limited what we could build and we gave up.

Nope, what I wascreferring to is shown in that picture....
My system has 2 60 foot lengths, buried in gravel 6 feet wide.
My ground didn't perk well. So they doubled the width.
But the neighbor needed his drain field fixed, they dug a trench, .ayed the drainage pipe, covered it with that piece of half pipe and buried it. No gravel. Hopfully I'll never see the failure. I saw the previous fail and it leached into my row of holly bushes and killed 3 of them. Made the soil to wet and killed them.

 

[Mitchell-DIY-Guy]

Nope, what I wascreferring to is shown in that picture....
My system has 2 60 foot lengths, buried in gravel 6 feet wide.
My ground didn't perk well. So they doubled the width.
But the neighbor needed his drain field fixed, they dug a trench, .ayed the drainage pipe, covered it with that piece of half pipe and buried it. No gravel. Hopfully I'll never see the failure. I saw the previous fail and it leached into my row of holly bushes and killed 3 of them. Made the soil to wet and killed them.

OK while there are different versions of this, it is called a "gravel-less system".
https://www.shensoil.com/post/a-word-about-gravelless-drainfield-technology
Gravel is replaced with plastic or something similar...not just a cut half pipe on top of drain pipe. Special pipe used.
The "panel" system is similar in that both allow (when allowed by AHJ) about 25% reduction in drainfield size compared to conventional.
Both work in poorly percolating soils, allowing a smaller drain field compared to conventional.

 

[Ludington]

OK while there are different versions of this, it is called a "gravel-less system".
https://www.shensoil.com/post/a-word-about-gravelless-drainfield-technology
Gravel is replaced with plastic or something similar...not just a cut half pipe on top of drain pipe. Special pipe used.
The "panel" system is similar in that both allow (when allowed by AHJ) about 25% reduction in drainfield size compared to conventional.
Both work in poorly percolating soils, allowing a smaller drain field compared to conventional.

Ok, great... thanks !