New Septic System Troubles

[aczlan]

So is the bottom of the trench clay? Seems that there isn't enough percolation under the new layer of gravel/rock and its just ponding.

Aaron Z

 

[RNeumann]

Here are some very basic design guidelines. The chart is based on 2' wide trenches with standard (rock and pipe- sounds like what you have) design. The number of feet decreases a bit with 3' wide trenches.
Septic DrainField Size Determination Methods: how big should the drainfield be &map what leachfield or absorption bed capacity is needed?

 

[CADplans]

New York state is not far from Pennsylvania,,
maybe a similar septic system is needed?

I hear a LOT about the mounds used in PA,,, that might be the needed answer?

Elevated Sand Mounds for On-lot Wastewater Treatment — Water Quality — Penn State Extension

Also, you can Google search "Pennsylvania leach mound" and get lots of info.

 

[jrdepew]

Two things stand out. 1) my original comment above about getting below the clay. I'll follow up and say a perk test would be valuable at this point. 2) my spider senses were way up when I read 30' of leach line. That seems way to short. A typical 3/2 house with typical soil needs 150'-200' of leach line. You are way under 100'. Adding between the two existing lines doesn't add much. Their is a space requirement between lines- both for evaporation and leaching.

I looked at the as-built again. Here is a snippet:



According to this, we had 4x 30' drain lines originally. These were placed in 10' wide rock beds. So that would be about 120'

The area between the two rock beds is what was dug up, and an additional 30' added, with a significantly thicker layer of rock than the existing 10' beds had. This was done to get through the organics layer. Although, because the trench filled with water so fast, who knows if they fully got through the organics layer.

We are in a very low spot in the country, and the soil here is typically sandy/loamy, with some clay mixed in. Even the drainage ditches will hold water for a couple days after a storm. But our house has the advantage of being built up on 2-3' of heavy sand fill. We have neighbors on either side that are not built up, older homes, and their septic system is working fine. I do not know how much drain line they have overall.

Thanks for all the posts and information!!

-Joe

 

[jrdepew]

New York state is not far from Pennsylvania,,
maybe a similar septic system is needed?

I hear a LOT about the mounds used in PA,,, that might be the needed answer?

Elevated Sand Mounds for On-lot Wastewater Treatment — Water Quality — Penn State Extension

Also, you can Google search "Pennsylvania leach mound" and get lots of info.

I should have updated my profile...I have moved to Johns Island, South Carolina.

I am familiar with the sand mounds, because I have been in PA very often. They also used them on the island I live on now. The issue is that sand mounds were only available on double lots (about .8 acre in this case). My house is on a single lot (0.4 acre). Unfortunately, I left a lot of land behind when I moved from NY to SC, but I just couldn't afford a large plot of land in the area I wanted to live down here.

Thanks,
Joe

 

[RNeumann]

I looked at the as-built again. Here is a snippet:

View attachment 508097

According to this, we had 4x 30' drain lines originally. These were placed in 10' wide rock beds. So that would be about 120'

The area between the two rock beds is what was dug up, and an additional 30' added, with a significantly thicker layer of rock than the existing 10' beds had. This was done to get through the organics layer. Although, because the trench filled with water so fast, who knows if they fully got through the organics layer.

We are in a very low spot in the country, and the soil here is typically sandy/loamy, with some clay mixed in. Even the drainage ditches will hold water for a couple days after a storm. But our house has the advantage of being built up on 2-3' of heavy sand fill. We have neighbors on either side that are not built up, older homes, and their septic system is working fine. I do not know how much drain line they have overall.

Thanks for all the posts and information!!

-Joe

Ok that makes more sense. An "as built" is a drawing of something that is existing. I'm guessing that drawing is the drawing of the repair?
Leach fields are required to have 100% replacement areas. That may end up in that area. If the soil layering is consistent with the neighbors and you brought in 2-3' of nice sand I'm guessing the leach lines will need to be about 6' deep. A test pit can be dug to verify the soil layering. A perk test down at the leach line depth would help too. If it was perked the test was done on that top layer which isn't your reality.

 

[jrdepew]

Ok that makes more sense. An "as built" is a drawing of something that is existing. I'm guessing that drawing is the drawing of the repair?
Leach fields are required to have 100% replacement areas. That may end up in that area. If the soil layering is consistent with the neighbors and you brought in 2-3' of nice sand I'm guessing the leach lines will need to be about 6' deep. A test pit can be dug to verify the soil layering. A perk test down at the leach line depth would help too. If it was perked the test was done on that top layer which isn't your reality.

That drawing is what was done when the system was originally designed. It does not include the new "repair" line, which is located between the two rock beds shown in that drawing. I asked for a new as-built and asked if it was submitted to the county. The engineer said that they don't generate an as-built for repairs and there is no need to submit anything. Is that normal?

The septic installer just showed up and took pictures. They suggested the same thing to me that they originally did, months ago!! "Bring a couple loads of dirt in to cover the low spots and get some grass growing...hopefully that will tighten everything up and it will work fine". This to me, seems like total crap. There is 12" of soil over the rock at the area of the current blow-out, bringing that up to 15-16" is just going to ensure that the next time the system blows out, it will be in a different area (the new low point in the system, wherever that may be).

The installer also said that they have this same issue at another site, where the original land clearer left the organics layer intact, and the fill sand was brought in on top of it. They ended up having to install a system with a pump on that site :thumbdown:

My other worry is now going to my foundation....if the layer of organics was not cleared, and the sand that my pad is poured on was brought in...how long until the decay of that organics layer results in foundation issues? Maybe I shouldn't be worried, but not knowing is a scary thing.

Thanks,
Joe

 

[RNeumann]

If the house hasn't moved I'd stop with that worry! .

I don't know if they needed to pull a new permit to do repair work. That depends on LJHA. My guts says yes though. They don't need a pump system if it perks at a reasonable depth. If the neighbors have no issues I'd dig a pit and check the soil layering. I'm guessing you will want to be down about 6'- this is based on the imported material and the neighbors not having issues.
The mound idea the installer suggested may work but may not. Without some type of testing he/you are shot gunning this. If it doesn't work you have a literal sh** show on your hands with tons of extra material onsite. Maybe not an issue on a large site. But with 4/10 acre you don't have a lot of space to lose the material.

 

[jrdepew]

If the house hasn't moved I'd stop with that worry! .

I don't know if they needed to pull a new permit to do repair work. That depends on LJHA. My guts says yes though. They don't need a pump system if it perks at a reasonable depth. If the neighbors have no issues I'd dig a pit and check the soil layering. I'm guessing you will want to be down about 6'- this is based on the imported material and the neighbors not having issues.
The mound idea the installer suggested may work but may not. Without some type of testing he/you are shot gunning this. If it doesn't work you have a literal sh** show on your hands with tons of extra material onsite. Maybe not an issue on a large site. But with 4/10 acre you don't have a lot of space to lose the material.

House has only been standing for a year...hopefully it doesn't do any moving on me!

Thanks for the input! It has been and is continuing to be valuable. I think you are right...

If the soil test shows that we need to dig down 6'...wouldn't they have to tear the whole system out and replace it?

Thanks,
Joe

 

[RNeumann]

The existing is doing a little.......not a lot. I'd be inclined to add a line or 2 at a depth below the clay before a complete R&R. I'm surprised they didn't get into the good soil when they added before. Seeing the photo of the water gushing out of the existing fields shows it isn't leaching into the ground. They should have dug down till all the effluent leached into the ground- this would indicate a good perk number (minutes to the inch).