Help locating drain field

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DIYDAN8888

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Hi,

I'm planning construction of a detached garage on our property and I'm trying to locate the drain field. I know where the tank is and I believe I accurately found the tank perimeter with a probe. I'm in Madison county Alabama, the house was built in 1984. The health dept. doesn't have a blue print but they told me it is a 1000 gallon system with three 70' lines. I was hoping to find the leach lines by digging for the gravel. I tried digging a couple holes 36" deep where I expected to find it (close to the end of the line where the elevation is lowest).

Does anyone know:

1) Am I wasting my time digging? Go deeper? Is it possible they aren't in a gravel bed? (this soil is easy to dig)

2) Are there tools to rent to find the lines, or or do plumbing companies provide this service? What should I expect to pay?


Thanks,
Dan
 

Twowaxhack

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You’ll need to find the outlet side of the tank and then hopefully the distribution box is within a few feet of the outlet.

The distribution box is where your three lines originate. Depending on the type system you may. be able to have the lines traced with a locator.

It might be easier to determine where the lines are not located rather than where they are located.

It could get expensive, time is money and they might not be successful and charges would still apply for their effort.

Roll Tide
 

Twowaxhack

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Sometimes you can see distinct green rows in the grass that indicate where the field lines are. I suppose that’s a no go with your situation
 

DIYDAN8888

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You’ll need to find the outlet side of the tank and then hopefully the distribution box is within a few feet of the outlet.

The distribution box is where your three lines originate. Depending on the type system you may. be able to have the lines traced with a locator.

It might be easier to determine where the lines are not located rather than where they are located.

It could get expensive, time is money and they might not be successful and charges would still apply for their effort.

Roll Tide
Thanks. I dug about 25" down where I expected the outlet to be. Didn't find the outlet but I think I found a portion of the tank and I was confused because it's an edge and it's not a 90, so the tank may be octagonal? I attached a photo. I'll keep digging for the outlet and Distribution box.
 

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Twowaxhack

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There’s no way anyone online can tell you where your fieldlines are.

You’re showing pics of what most systems are comprised of. This doesn’t give a clue as to where the lines are located. That’s usually found on drawing on the septic plan or at the county septic permit office. You’ve stated they don’t have a record.

Goodluck
 

Twowaxhack

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I will say that the ground where the field line are will be softer than the undisturbed soil. A soil probe may help you find a long narrow soft area, indicating a field line.

They should be no closer than 10’ from your property line

You’ll often find mixed dirt and gravel as well.
 

DIYDAN8888

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I will say that the ground where the field line are will be softer than the undisturbed soil. A soil probe may help you find a long narrow soft area, indicating a field line.

They should be no closer than 10’ from your property line

You’ll often find mixed dirt and gravel as well.
Thank you for the help
 

DIYDAN8888

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I will say that the ground where the field line are will be softer than the undisturbed soil. A soil probe may help you find a long narrow soft area, indicating a field line.

They should be no closer than 10’ from your property line

You’ll often find mixed dirt and gravel as well.
I found gravel around the Tee. Will the gravel in other areas of the drain field be at the same level? So can I expect it to be at the same depth or shallower if the land slopes downhill?

Thanks
 

Twowaxhack

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I found gravel around the Tee. Will the gravel in other areas of the drain field be at the same level? So can I expect it to be at the same depth or shallower if the land slopes downhill?

Thanks
It may drop deeper to contour the land.

Field lines are installed basically level. They can drop elevation then continue level. You don’t want water entering the field to run to the end...... you want it to disperse throughout the entire line, not at the end.
 

Jeff Handy

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Seems like you should have a locating service send a sonde or transmitter down all the leech lines, and run a receiver above ground to locate where they are.
 

DIYDAN8888

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Seems like you should have a locating service send a sonde or transmitter down all the leech lines, and run a receiver above ground to locate where they are.
Thanks Jeff,
That sounds like a good plan. Do you know how much that service typically costs? I’ve called a number of local septic companies for advice and mentioned ground penetrating radar but no one could help, and no one mentioned the transmitter/receiver approach.
I saw a YouTube of a camera inspection of field lines here: Cam inspection, I thought that could be an option but also having trouble finding someone who can do this. Here is a YouTube video I made showing where things are, and all the holes I dug.
Video of property
 

DIYDAN8888

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It may drop deeper to contour the land.

Field lines are installed basically level. They can drop elevation then continue level. You don’t want water entering the field to run to the end...... you want it to disperse throughout the entire line, not at the end.
Thanks for the info. I finally got out my laser level and it looks like the elevation drops 25" going out 48 feet from the Tee into the field (parallel to the outlet pipe). At 35 feet from the Tee, the lines would be 14" deep, and they would be level with the ground at 65 feet out.
 

RS

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My wife could probably find them by dowsing, she could fly her broom down and help you!
 

Twowaxhack

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Field lines can run out any distance and then 90 degree straight down a distance then 90 degree back horizontal and continue out near level.

This contours the slope of the land if need be.

So determining the starting depth doesn’t tell you much if they’ve offset the elevation.
 

DIYDAN8888

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Field lines can run out any distance and then 90 degree straight down a distance then 90 degree back horizontal and continue out near level.

This contours the slope of the land if need be.

So determining the starting depth doesn’t tell you much if they’ve offset the elevation.
Thanks. I would guess that’s what is happening
 
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