Septic System Issues

[vogt_51]

Hello all.

I have been having a nightmare getting started with my build as I can't get approved for a building permit until I have been approved for a septic permit.  I was originally told after my soil test that the limiting layer was only 23 inches down so I would not be able to reach the 2ft separation possible between leach field and limiting layer to have a traditional septic system.

I was initially approved for a buried sand filter until the EPA put a kabosh on that.  The local health department suggested I install a perimeter drain to lower the seasonal high water table of 13 inches and then install an aeration system.  This would lower the required separation of leach field and limiting layer to 12 inches and is doable.  Fine and dandy, right?

Wrong.

This is going to be an off-grid house as I was quoted nearly 100K just to bring the power lines in.  Septic aerators must run 24/7 and range from 100 watts to as high as 400 watts I have found.  Thats between 2500 and 10000 watt/hours per day.  Not worth it in my opinion. 

Here is what I am considering.  I have a decent amount of acreage and access to tons of black dirt and am willing to haul some in.  Would it be possible to raise the proposed area of the leach field with black dirt about 2 feet?  Compact.  Have soil retested.  Viola!  That would lower seasonal water table down to about 3 feet, lower limiting layer to 4 feet.  Does this sound possible?  Is it overly crazy?

[Patrick]

Sounds like your talking about a mound system they are common in Wisconsin, I think that is who came up with them U of W. they are done with sands tons of sand sometimes as big as a small hill . But stil think they use electricity to pump the effluent into the mound on a cycle. I hear they can cost over 20k to install 2 tanks,pumps alarms .

[vogt_51]

I have read about the mound systems, but that is not really what I am thinking about.

Since a house hasn't been constructed I believe I can make sure the septic tank and plumbing outlets are level with the leach field even after raising the surrounding ground level 2 feet with dirt.  I could aim for about a 2000 square foot area surrounding the rear half of the hole that has been dug for the house.  I was planning that when the house was finished I would need about 4 feet of backfill on that side so it shouldn't be too high.

I would just essentially be mounding the entire backyard of the property.  As the leach field essentially uses dirt as the filter to clean the effluent I would think placing an additional 1 foot of good soil(1 foot on top) under the leech field would be suffice?

[Bob S.]

Vogt;  Years ago my in-laws had a acreage that had clay soil and would not pass a perk test. They solved the problem by digging a pit and filling it with soil that would pass the perk-test. I do not know if you can still do any thing like this today. But it did not require a pump when it was finished.

Bob

[ajohnson]

Where are you located? In Georgia we also have the 2 foot separation requirement.  With your limiting factor of 23 inches you would be required to install a mound system or an alternative sytem that will clean up the waste water to where you would be allowed a 1 foot separation.  The are  alternatives to an aerobic system in Georgia, but not sure about where you live.  One is called the Eljen sand filter system: http://www.eljen.com. Cleans waste water to a class 1 effluent, which allows a one foot separation to a restrictive layer or water table.  I work with the health department and have saw many Eljen systems as well as mounds installed. Cost wise at least here, you are looking at 10-12k for either.  I always try to steer people to Eljen if gravity flow is possible.  The Eljin product cost more, but uses less certified fill.  With a mound you will have to have more certified fill, pump, alarms, and its above ground.  There are other systems, such as peat,etc. but may or may not be approved in your state.  Let me know if you have any questions and i'll try and help you.

One problem with soil replacement as suggested is you create a bath tub underground.  If you have a clay that will not perc and you dig it out and replace the area wiith better soil, effluent will perc through the better soil and sit on top of the restrictive layer.  I have seen where this has failed on several engineer designed systems.  We have water tables issues and once you dig out your trenches and replace with better soil, your groundwater, which is under pressure, will flow to the least resistance and fill up your trenches.

Ansley

[Dave Sparks]

Are you on a hill or in the flats?