How to create a septic drain field in clay? 3

[CmpMan]

I have a parcel of land 70 x 240 ft.

I need to install a drain field for a septic system that would allow approx. 360 gal of water to dissipate and keep effluent from pooling on surface.

A septic system would aerate the waste before draining.

The site has clay that is at least 10.5 ft deep(below water table) in some areas and has failed a perc test.

Is this idea possible? Excavate an area (like a small rectangular swimming pool) that would be limited to 7 feet deep(water table restriction). Then fill with a three foot layer of "good" soil. Then allow a three foot layer of concrete sand with a distribution system of pipes. Then cover the remaining foot with top soil?

What would the demensions of the pit need to be? Would the layer of sand and soil be different?

An alternative idea: Have a couple smaller pits "daisy-chained" together along the drainage line.

Is this a realistic solution?

TIA,
CmpMan

 

[cvg]

http://www.webdesignpros.net/consult/septic/evaporation.htm

An Evapotranspiration System might be possible. I have seen this done in areas with bedrock outcrops where there was zero percolation. However, this was an area in the desert with a very high rate of evaporation. Don't know if it will work or be permitted in your area.

 

[CmpMan]

Thank you for your response. We are on the east coast and while it is hot we do not have dry air, but humidity.

I learned recently that a large developement several miles from my location has installed a large pond and have received permission to spray water into the air.

I need to check into this as a possible solution. I suppose you have some holding tank or a pond? My lots are small but if I could add another lot I might have a little room to do this? What do you think?

 

[cvg]

I would discuss with your local DEQ and maybe they can also provide some ideas

 

[CmpMan]

What is DEQ?

 

[cvg]

department of environmental quality - probably some other name in your neck of the woods. they would normally issue the permit for your sewer system.

 

[CmpMan]

Ah, I have spoken to them and they are at the end of their rope, so to speak. We had five inches of rain two weeks ago and now existing septic installs are having problems. This area has always had deep clay 7 to 10 feet and a low water table, 7 feet.

They are requiring two lots to build so the drain field would be large enough (one lot) to accomdate just a two bedroom house or 240 gals per day. I checked out your link about a green house and have contacted them via email. Evaporation might be the way.

Thanks for your input.

 

[cvg]

note that the installation I was involved with didn't use the greenhouse, just the beds. very similar to your original idea. Planting grass or other plants will also provide transpiration.

you might also look into a wisconsin mound system. see the link

http://www.cet.nau.edu/Projects/WDP/resources/treatmentsyst/Mound.htm

 

[CmpMan]

How costly was the installation? How many years has it been in operation?

>> C The bed must be sectionalized with a series of valves that control effluent flow to each section proportional to the evapotranspiration potential of the season.

Did you install these valves?

The mound system is intriguing and I need to study that for some ideas. This has been very helpful information.

 

[cvg]

I'm sorry, but I don't have details or cost of the installation, as that was done by others. But as far as I know, valves were not used.

 

[CmpMan]

How many years has been in use?

 

[cvg]

I believe the project was built in about 1996 or 1997

http://www.wisc.edu/sswmp/SSWMP_15.24.pdf

 

[CmpMan]

I see what about the bed project?

(The link is very helpful too, need to study with a cup of java)

 

[oldestguy]

CmpMan:

Hello and hope you resolve the way to go.

In our area (Wisconsin) the state has allowed the mound system where the natural soil won't take the infiltration.

As a last resort, they then OK holding tanks. You hire a pumping guy to take it away to a city WWTP. However, then folks sometimes cheat and run a pipe out to the roadside ditch and get away with it until caught, OUCH.

Have you tried other forums here, such as those frequented by sanitary engineers? (Waste Disposal & Treatment). Those folks work with this subject every day.

 

[CmpMan]

The mound system was suggested by the previous post also. In fact the soil engineer thought this would be a viable alternative.

Thanks for your advice. I have not tried other forums.
Can you recommend one?

Hadn't thought about having it pumped elsewhere, sounds expensive though but it is a solution if soemone will do it.

Pumping into a roadside ditch is NOT a good solution,
unbelievable what some people will do.

Thanks again ...

 

[oldestguy]

Hi CmpMan:

In our area the pumping guys charge about $75 to pump a septic tank, requiring a lot of time fooling with earth cover on tank lids, etc. So where it is easily reached, cost may be less.

They are in the yellow pages and competitive.

You realize these disposal fields are not permanent solutions and require periodic fixing or changing, so add up the cost of frequent holding tank pumping against those costs to see where you will stand.

Down the road the State agencies may come along and require a community sewage system, even in the country. In this area they did that with each house having a pump-grinder into a force main (1-1/4" dia. imagine). They don't take kindly to diapers, etc.

 

[CmpMan]

Hi Oldestguy,

Thanks for the info. I'll check into this for sure.

CmpMan

 

[proletariat]

Sand mound systems are widely used in pennsylvania. You can hunt around on the PA DEP website for more info. Basically, they take the effluent from the house by gravity to a septic tank. Then the "treated" sewage runs by gravity to a dosing tank. A dosing pump timed at regular intervals pumps from the dosing tank into an above-grade sand mount to disperse the treated effluent. If your daily flow is about 400 gallons, the pump may be timed to pump 17 gallons every hour into the mound over the 24 hour day. This smooths out the peaks in usage and tries not to overwhelm the mound's "capacity".

There are also "peat" systems in wide use in coastal North Carolina. I don't know much about those, except they are used to place a huge house on a tiny lot in beach-sandy soil.

 

[CmpMan]

Thanks for the info.