Septic Tank Repair

[rodney_morgan]

HI all,

When I last had my tank pumped 2 years ago a small hole was discovered half way up the side. It is\\was the size of a roll of pennies. Having waited two years to get it fixed I finally started digging out the tank at the approximate location of the hole. I got down about two feet when my hole started to get waterlogged. I was able to dig a trench almost the entire side of the tank about 3 feet down before it got to messy with all the waste water. I still dont have an exact location of the leak but should not have a hard time locating it tomorrow. I have a septic company scheduled to empty my tank tomorrow morning so I will be able to make the repair. Having talked to a friend who was employed in the septic/excavation field for many years he advised me to fill the hole with hydraulic cement and then put an asphalt shingle on both sides with roofing tar or some other sealant. Does this sound like the proper approach? Will I be able to get roofing tar to stick on the wet cement. How would a professional perform this repair? The reason I waited so long to perform the repair was based on an estimate of about $1000 to get it professionally fixed. If I am able to do it myself it will only cost me the price of the cement and a $200 pumping fee. From what I read it sounds like I have a mid seam tank (1000 gal.) (25 years old) and these leaks at the seam are a notorious problem for this style. I was also told by a different source that their were holes used to lift the tank in place which are then plugged. The reason I say this is that the hole appeared too perfect to be caused by natural wear on the tank. Any advice would be GREATLY appreciated.

Rod M.

[brent]

why fix it? there's no problem unless you dig it up is there?

[JC]

That's a fairly common method. But most country folks around here just dig down to the hole, drive a piece of coroplast or other plastic sheeting down far enough to hide the hole, backfill it and leave it. It would probably never cause you an ounce of trouble. If you want to go to the trouble, just get you some chicken wire, ball some up and cram it in the hold, then cut a sheet big enough to cover the hole, hold it over the hole and plaster it with some ready mix concrete. Just make sure the area around the hole is damp, preferably wet, when you put the concrete on it. Let it sit for a day and then backfill with dirt and forget about it.

[rodney_morgan]

Thanks Brent and JC. I really wouldnt have much of a problem with the hole except every 3 years the township requires that my tank be inspected. When it failed 2 years ago I got a notice to get it repaired. Luckily my township is fairly lax with these type of problems as we are mostly rural where I live, that is one of the reasons it took so long to get to. Anyhow, more bad news, I just got done digging the rest of the hole and it seems now there are more then one leak. And that is just the side that I have exposed. JC, I think I am going to use your idea with the chicken wire which should give the plug extra strength, unfortunately it is looking like I might just end up replacing the tank. This is extra sad because just the other day I was staking out the corners of my future garage which will now be put on hold for another couple years. Anyone have any real world experience with the costs of replacing a tank? I was always told around 4-5 thousand.

Thanks Rod M.

[JC]

It depends upon your "township", whether or not they will allow you to do it yourself. If they will, it should cost the price of the replacement and the rental on a backhoe, if you can use it. I'd say under a grand total. But, it would be so much cheaper to just dig out all around it and patch whatever needs patching. It's a lot of work, but just look at it as good exercise. And then you can try to find a place to put the new boat or whatever you spend that 4-5 thousand on.

[DerbyDad03]

Don't have a cost but I did see on TOH where they used a tank which Rich said was manufactured via a "monolithic pour" - i.e a solid piece of concrete with no seams to ever leak.

[rodney_morgan]

Honestly I was just thinking that. Probably 2-3 days of work and showering down the road at my parents. I am just worried with the pressure from the tank pushing outwards any patching I do will eventually come loose. As far as replacing the tank myself I would still need a crane to lower the new tank in place and jackhammer out the old one as well as doing all the plumbing fittings which I have no experience with. Not to mention I am not well informed with the codes regarding the new tank installation. What if I were to trench out around the tanks seam tamp down all loose dirt and then pour a 6" thick "footer of sorts" around the tank seam??

Rod M.

[Oren]

It will leak, imo.

Can you abandon the old tank, collapse it and fill with soil - then install new tank adjacent the old?

[JC]

Just patch it. The backfilled dirt will hold it.

[David L. Martel]

Rodney,

The approach you propose sounds reasonable. There are roofing cements that are used on wet roofs and they should stick to the tank once you hose the sides clean. I'm a little uncomfortable about you getting inside the tank without a respirator. At least have a helper outside the tank keep an eye on you..

Dave M.

[franz frippl]

In some states the DNR has a program to help septic owners with repairs. You might wish to contact the DNR and see what help is available.

[Kathy]

Fix it. If you replace the tank you may have to bring the whole system up to code which is a lot stricter now than it was 25 or 30 years ago.

[rodney_morgan]

So here is the update... The pump truck came at 10 AM and did a thorough job of cleaning and rinsing out the tank for me. They were annoyed by the fact that the little leak I pointed out to them warranted me to shell out money to repair it. They said if it was ever up to them they would have never reported it. Therefore I have a new company that will pump my tank out for now on! After the pumping was complete I went to the store and bought a 10# bucket of hydraulic cement. Climbed down in the hole, which was not as disgusting as I imagined. I scrubbed the seams first with a wire brush which seemed to tear away at the concrete too much. Then I switched to a stiff bristled brush designed for pots and pans. Once the cement appeared fairly clean I smeared the cement on with my hands and then pressed it in with a putty knife. Instead of doing just the problem area I decided to use all the cement and got 3 out of 4 sides sealed up. I also did the outside seam where the leaks were coming out which I already had excavated. I really hope this fix lasts at the very least for one more year when I have to get it inspected. The cement was easy to work with at first but if you messed with it too long while it was on the walls of the tank it would start to get soupy. Also after studying the leak some more it was not the size of a penny but rather a slit the size of 2-3 pennies on their side. My only concern now is that the seam I scrubbed with the wire brush may have created more potential leaks in the future. I doubt it but I tend to worry too much when it comes to $. If there is any advice I can offer to others is that you purchase a top seam septic tank and not have to worry about this sort of problem. So now I am going to prohibit water usage in the house until at the very earliest late tonight so the cement has time to cure. Even so it will take a couple days for the tank to fill up to the seam. I just dont want water splashing the sides when it hits the floor of the tank. That is about it...now I am off to my parents to take a shower.

Thanks all, Rod m.

[franz frippl]

It would seem that climbing into a septic holding tank is not all so wise due to lingering methane gas. Good way to make it one's final DIY project.

[Chris Lewis]

According to franz frippl :

True. Every so often you hear of one or more people getting killed after climbing into a holding tank or enclosed manure pit.

However, he did say:

Once you've pumped out a septic tank, and did a thorough clean and rinse, there's not going to be a lot of methane gas left, nor much (if any) being produced.

Especially if the tank lid was the size of the full tank (rather than just a small hatch) - methane rises.

[rodney_morgan]

True, I was advised by many people to be careful about the fumes and definately to have someone watch over me while I was inside. Though when the truck pumps out the liquids they are replaced with clean air sucked down through the hatch. Just to be safe I opened the other (outflow) hatch and ran a fan for 15 minutes down the main hatch. The girl was entertained and digusted at the same time watching me climb down in. She took several pictures of me wearing fishing waders, poncho and rubber gloves which will soon be developed. I do recall though a few stories involving farmers dying while working with sanitary systems usually animal wastes. I had an incident where my old boss asked me to stain the wood paneling in his racing trailer not telling me that a few hours before he had someone else hanging up the panels with chemical adhesives. When I stepped in the trailer to begin work after sitting in the summer sun all day I was immediately overwhelmed by fumes and lost my vision and most of my motor functions. Luckily I stumbled back outside (not sure how) and recomposed myself. Ever since then I am very alert to any dangers posed by harmful gases.

Rod M.

[JC]

How about this one? When I was in the Air Force back in the 1960s, stationed at Altus AFB, I was put on a detail to paint the concrete floor of an Atlas F missle site. So here I go down into the bottom of what seemed like a mile deep hole in the ground, with my little bucket of Air Force gray paint and a roller. After I had poured a little paint out and was rolling it out, a full blown one star general came walking down the gangplank type stairs and screamed at me "what the hell are you doing?" I told him and he wanted to know just who in the $^&*^%(&(^% told me to do that. I was instructed to follow him to the 2nd Louie that gave me the order. Come to find out, you can make bubbles with a paint roller and if I had made one big enough, stepped on it, I could have blown up the whole damn base. So, always get a second opinion before you take on a task you know nothing about.

Glad you got your problem solved.

[Oren]

I did my own second opinion on an Army 2nd LT. Smart left hand salute, real snappy. He saluted with left and walked a sort distance, before running back to straighten me out :-)))

[Chris Lewis]

According to :

Glad you were aware of the hazard. Some people aren't.

Doing a google search for "manure pit asphyxiation" yields altogether too many examples.

We had one near here a few years back like the one described here:

[5 deaths]

While this is a lot less likely with a residential septic tank, it still needs to be treated with considerable respect.

Methane is the most obvious hazard, but you need a fair amount of it to displace enough air to asphyxiate or become explosive.

H2S (hydrogen sulfide) is a different beastie. It's very toxic even at quite low concentrations. While the rotten egg smell is an obvious indicator of its presence, a little known fact is that concentrations of H2S high enough to kill you have paralyzed your sense of smell. So if you smell rotten eggs getting stronger, and then the smell abruptly fades away, _don't_ assume that the H2S is gone - drop everything and run!

[In other words, as long as you can smell it, you're probably okay.]

Then of course there's CO2 and Ammonia potentially present...