DYI Spetic System

[ColchesterCabin]

I ran across these plans online for a septic system. It looks fairly straight forward but i was curious as to what others may think. Now I know its not a certified system and is not sanctioned by any capacity but I am wondering as to if anyone knows if something like this work work for my cabin. There is 2 adults and 2 children to use the cabin, mainly 2 adults every second weekend for a night perhaps. I am thinking of a seperate system for the grey water from showers and sink perhaps if this won't hold it all..

http://www.wikihow.com/Construct-a-Small-Septic-System

Love to hear everyone's input.

[Rob_O]

There's at least one board member using a similar system on a daily basis

http://countryplans.com/smf/index.php?topic=9259.msg142800#msg142800

[ColchesterCabin]

Thanks Rob! I read his post the trick would be to keep the grey's and blacks seperate if it is going to be everyday use, would you have to for the every second weekend use?

[Rob_O]

Here's info on running a perc test, it's simple enough to do. When you know the perc rate, you can estimate how much water your ground can absorb and size the system accordingly.

How to Run a Percolation Test

[NM_Shooter]

I'd skip the gravel and use the EZ Flow stuff instead, and i'd put cleanouts at the tail end of the thing. 

Keep your gray water separate.  Those 55 gallon drums might handle the black but grey would overload it. 

[ColchesterCabin]

So I have my trench dug primarily because it is behind the cabin and since I had the guy there for the excavation I thought I would have him trench out for the septic. Here is another question:

-  Abviously pending the perk rate, can I run a seperate drain line in the same run(trench) just bypass the tanks (like picture below) or should I run a seperate drain line trench for the grey? The soil is fairly rock and absorbs like a sponge up there, and my trench is about 3.5 ft deep? (picture to follow) Trench is 34 ft long.



I was thinking if I fill with washed stone of which there is a huge abundance of within a short gravel truck haul away covered in landscape fabric, and mounded the top soil back on top at least covering 8 inches of the original soil level.



sorry for the crude mspaint drawing...

[hhbartlett]

Ever consider recycling your grey water for the toilet? Might save on septic needs (and water needs). Just a thought, I've seen it done, not too complicated. As per your above question, that's the setup I used to have in another place - grey water (some of it, anyway) bypassed the tank and went to the leach field.

[ColchesterCabin]

I am going to collect the rain water off the metal roof for toilet use and down the road filter it for washing and showering.

[BADB0Y]

I would not recommend skipping the tanks. Septic works by bacteria breaking down the waste, then the liquid flows out and drains into the ground. If there is nowhere for the bacteria to do its work, you are basically dumping raw sewage into the ground. The drain lines would clog pretty fast.

I've done 2 of that same set up and deer camp and they work good for light usage. I designed a similar set up using the large 274 gallon as the primary tank with a 55 gallon drum for overflow, then out to lateral lines. For my wife and I, and the occasional guest it should suffice.

[Rob_O]

pending the perk rate, can I run a seperate drain line in the same run(trench) just bypass the tanks (like picture below) or should I run a seperate drain line trench for the grey? The soil is fairly rock and absorbs like a sponge up there, and my trench is about 3.5 ft deep? (picture to follow) Trench is 34 ft long.

The drain field still has to absorb the same amount of liquid if there's 2 lines or 3. Skipping the tank on the grey water allows the food/grease/hair/whatever to go directly into the drain line and will eventually clog that line. If you're concerned the waste won't be adequately treated just use more barrels or a bigger tank as BADBOY suggested

How much water do you expect to use on a typical weekend?

[flyingvan]

DO NOT skip the tanks---in fact, ad a grease trap before the tanks, easy to clean out annually.  Just a trash can where fats can gather before the tanks themselves.   For your field use infiltrators instead of clay pipe---superior and cheaper in every way

[Squirl]

I agree with flyingvan.  The tank does very little treatment.  The main purpose is to let the oils rise to the top and the solids that did not break down fall to the bottom and let the liquid sewage be treated by bacteria in the soil.  Don't skip the tank, unless you want early field and pipe failure.

I also noticed you are running your grey water in the same leach line as your black water.  If you are running them in the same line, there is no purpose in separating them.  The soil has to absorb the same amount of water.

[flyingvan]

Your goal though is to maintain a healthy biomat.  What the septic tank does is separate the effluent into floating and sinking material which is then eaten by microbes until it reaches neutral buoyancy, at which point it passes to the next chamber where more bacteria break the effluent down further before it passes to your field.  In your field, a biomat forms (think of it as stinky mud) that absorbs these nutrients and aids the ability of the soil to absorb and transpire water. 
   Your biomat doesn't like gray water.  Put it somewhere else.  There are phosphates and other chemicals specifically designed to kill microbes.  It's a septic tank, not an antiseptic tank.
    Toilet paper is vegetative material easily digested by a septic tank, thanks in part to being submerged in effluent.  If you were to skip the tank that TP will go right to your damp, but not liquid, biomat and choke it.  Think of all the toilet paper you buy but instead of using it you just stuff it in your leach field.
    A few other care and feeding points---every drain should have a screen to keep out hair, onion skins, and other solids.  Your garbage disposal doesn't cut stuff up fine enough.  Never flush antibiotics or any of those 'septic helpers'---they do more harm than good, and all the needed microbes are conveniently supplied by your poo.   When you're leaving for awhile, put a new box of baking soda in the fridge and flush the old one----the microbes love an occasional bump in Ph.  It's like giving them crack.

[ColchesterCabin]

Thanks everyone as your posts have been invaluable in deciding the direction of this system. Morale I think is they grey water from the sink I will put through the tank and the grey from the future shower if it gets that far I'll put in a seperate pit on the opposite end of the cabin as obviously there would be a lot of water in a shower as opposed to a sink full of dishes so not to overflood the system( lets face it that would only be when my wife's out).

I have to say I like this forum a lot and has an extensive amount of resources in one spot.