Finding septic tanks

bczoom · Apr 13, 2005

OK guys. Thanks.

Here's an update followed by some replies to your posts.

Ran down the road and borrowed a metal detector (I traded it to him for some skidsteer work).
I swept between the farthest tank and the house.
With the sensitivity at its highest setting I found some spots that got a hit and marked. The spots are pretty small (about 8" or so) so I don't think it's the pipe between the tanks.
I then turned the sensitivity way down and re-tested. Only 2 got a hit. It works out that they're in a straight line with the exposed tank and almost equal in distance apart (just under 15') but the line is parallel with the back of the house and about 6-8' out.

Do you think this is the top center of the lid or what? I'm thinking of doing the rebar/hammer routine on that spot. Am I close?

( bc, you might try calling your county health office. If septic inspections are required where you live, they may have a sketch on file of where it is. )

44trxfun - Except for renewing my carry permit, I try to stay from the county government. Like Moon noted, it normally gets me into trouble.

( bczoom, When I did mine I took a short piece of re-bar and small sledge and used it as a sonar detector cause when you hit the tank or lid it makes a distinct sound (also stops cold))

Nasty135 - That was going to be my initial plan but also why I noted the surface being packed stone. Wasn't sure if I'd be able to get down to it.

( Probably too late for this solution but in the winter the snow always melts above the septic tank first. Sometimes I get a very precise rectangle outline through the snow.

Right now, it's the area with the greenest grass as the soil is warmer there. )

Rob, I've kind of watched but never noticed any melting in the winter. Nothing different in summer either (grass)

( "There are 3 and I need to find 2 of them "

Why do you think there are 3 of them.. I have seen a separate grease trap before(right next to house).. but 3 tanks in a row.. what would be the purpose.. more capacity? )

Kensfarm - The guy that did the excavating for the house has done some work for me. He remembers putting 3 tanks in but didn't recall exactly where.

( The piping going to your tank should be metal you can use a metal detector to follow the pipe and when it STOPS beeping you should be over the tank )

DaMadman - I thought like Richards that mine was sched 40 as well.

mwechtal · Apr 13, 2005

Our plumbing is PVC, but there are 3 steel loops in the cleanout, and the baffle lids on the septic tank. A metal detector might be able to find them if they aren't too deep. There are special deep detectors made for this kind of work, but a standard "coin" type detector might be able to see down a foot or maybe more. By the way, if you find a steel cable while digging, our septic tank has a cable under it that the installer left there. I'm not sure how much cable will be left in 50 years, but I think the idea was to be able to get it back out of the ground.

Mike

Highbeam · Apr 13, 2005

If it is a concrete tank, there will be steel embedded within the concrete and used for the handles on the lids. A metal detector should pick this rebar up if the tank is shallow.

The tank may be very deep. I have seen them with more than 4 feet of cover. In this case, it will be very difficult.

I work for a city and we have a camera that we use to follow lines and look for clogs. There are cameras available for 4" pipe. Maybe a roto-rooter type plumbing company has one to use. You simply measure how much cord it takes to push the item to the tank and then dig there.

Every septic system I have seen here in the NW uses white PVC pipe. No metal pipe.

MossRoad · Apr 13, 2005

Worse comes to worse, find where the pipe exits your house. Dig down to it and see which way the pipe goes. Then walk out about 8-10 feet and probe straight down with a steel rod. Hopefully the ground will not be too hard. When you what you think is the pipe, mark the spot with a stick. Move out about 8-10 more feet and line up the stick with the first hole and probe again. Mark, repeat, etc... If it isn't too far down when you probe, use a manual post hole digger to make sure you are hitting your pipe and not rocks. I did this the first time I had to locate our pipes. Problem was there was two or three bends in the pipe. With a little probing and only a few test holes, I was able to find everything OK.

HINT: Once you find them, measure to the lid from two corners of your house and write it down so you can triangulate the location next time. /forums/images/graemlins/wink.gif

BRIGUY · Apr 13, 2005

The guy who comes to pump the tank will find it. They use a tool that looks like a straight rod with a bulb shaped point on the end, and a TEE handle on top. He will follow the pipe from the house out to the tank.

When I was having the inspection done before I bought my house. they couldn't find the tank. They were going to flush a transmitter down the toilet and find the tank with a receiver. I found it after 3 days. Half under the pool and half under the pool deck. I disassembled A corner of the deck and dug 3 feet down to the first cover In the winter. What a pain to say the least. The best part is I didn't own the house yet and my attorney (wife's brother) went crazy.

I bought the house and took down the pool and deck.

RobertN · Apr 13, 2005

You posted that you liked to stay away from the County offices. Me too. But...

We went and got the "As Built" plans that have to be filed(at least in California) with the building Dept. This showed the septic tank and the leech field. It was quick and simple. 'Course, it did cost $8 to have them "research" it /forums/images/graemlins/shocked.gif Not too bad though, since they gave us info on the main house and the Granny flat.

bczoom · Apr 14, 2005

The results.

The metal detector did pick up a piece of metal in the tank. There is no visible metal (lifting hooks) in the cleanout lid but there is a metal splash guard where the pipe enters the tank. I believe this is what the metal detector found. The tanks existence was confirmed by driving rebar into the ground. I hand dug a small hole and did find the tank.

Where I got the 2nd hit with the metal detector I did another rebar test. At the right depth, The rebar did stop. Dug a hole. Unfortunately, it was a rock. No tank there.

Spent another hour driving rebar all over the place looking for the 3rd tank. I did finally find the line coming out of the house (with the rebar... glad I didn't puncture) and then did rebar tests from the pipe to the tank I did find. NO 3RD TANK /forums/images/graemlins/mad.gif I was told there was one but I've been mislead. Mrs Zoom did a load of laundry while I was digging and the clean water was a direct dump into the tank that I did find.

Now my arm is tired from pounding rebar all over. Still need to dig a big hole for the tank I did find. No problem, neighbor gets home around 5:00 and I can ask him to dig it out with his backhoe. 6:00... his wife gets home. I inquire as to when he'll get home. Not until 9:00. Dang... I already made arrangements to get it cleaned out today. Did what I could into packed clay with the FEL (no tooth bar) and hand dug the rest. Bummer.

I wrote on the exterior wall with perm. marker where the pipe enters the house. I'll write on the basement wall the exact measurements to get to the cleanout for next time.

Thanks everyone for the posts and help.
Brian

Panache · Apr 14, 2005

What they were calling the third tank could have been the distribution box for the field lines.

MarkLeininger · Apr 14, 2005

Unless you plan to pump it yourself, why do you care where it is? Let the guy who pumps it find it...

MossRoad · Apr 14, 2005

They charge extra to locate it for you around here /forums/images/graemlins/wink.gif They also charge extra to dig it out if it is more than a few inches deep. /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif