Septic Tank Lid Issue

[fjd]

Hello All,

I have been lurking here for a couple years or so.  I have learned tons and tons from everyone here and I thank you for that.  I have not built my own home yet but I am having an issue with my current home.  I figured this was the place to get some good answers so thanks in advance!

Although I don't think the type of system matters for my question I wanted to give a little background info:  I live in Florida and have a raised mound septic system, it uses an in ground lift station which I am all too familiar with (pump issues) and then a main tank with leach field.  The main tank has lost some grout/concrete/whatever between the top lid and the tank.  I don't mean the access lids, I mean the WHOLE top which covers the WHOLE tank and was originally set there with some heavy equipment.  I know it has lost some grout because I heard air leaking and dirt has been blown back from the area of the leak, and of course there is a certain odor associated with the above process.

This is the kind of issue one has when one has an above ground tank and the "dirt" of your state is actually called sand everywhere else in the world.  Anyway, previously when accessing the lift station tank interior, I replaced the lid and then sprinkled actual grout around the lid for sealing purposes.  This is what the guy who installed the whole system instructed me to do.  But the large tank has a bigger gap and now we are talking about a horizontal area which needs to be filled with something to stop the leak of air, etc.  Please give me some ideas of what to use and how you would go about it.  By the way I think the grout edge cracked off when a large animal may have accidentally gotten into the leach field area as they sometimes do.

thanks in advance for all your help, sincerely,

francis joshua

[fjd]

Hello again,

duhh, I think I meant now I am dealing with a vertical surface,

thanks again!

francis joshua

[ScottA]

They make a product called non-shrink grout. You can mix some up fairly thick and use it to fill the gap. Wet the concrete a little to help it stick better. Another thing you could try is plastic roofing cement in a caulking tube. Neither of these methods would be as good as removing the lid and regrouting it in place. Why is the tank under pressure? It should be vented.

[glenn kangiser]

Some fiberglass drywall joint tape -- the open weave kind could help hold things together.  Hydraulic cement could work if wet or leaking.

[fjd]

Hello again,

thanks scotta and glenn for the ideas, caulk or hydraulic cement both sound great.  the tank is not leaking except for air during lift station pumping.

scott, in my understanding of septic systems yes it should be vented which is through the house vent system if i understand correctly.  so my guess and i do mean guess, as an amateur jack of all master of none is that when the lift station is pumping upwards to the tank there is a time when the pressure in the tank would forcefully vent back but due to the grout issue it just goes out into the environment.  although i am also guessing there is a backflow preventer valve of some type to keep the sewage from going backwards downhill into the lift station tank and this may prevent air from going backwards during pumping, not sure about other times.  these are the joys of not having a simple humanure setup!!  or just plain old gravity, ah florida!

i will try these remedies and maybe have the system pumped out and then i can pick the brain of the original installer if i can track him down.

again thanks so much,

francis joshua

[glenn kangiser]

Seems Scott is right about the vent.  If all comes from the lift station to the tank, then it is pressurized to that point and should be vented after that point or you would be pressurizing your tank and drain field which could force solids through the system and blow the grout or seal out of the seams.

[ScottA]

Usualy when a lift station is used it discharges into a larger gravity drain pipe which is open to the atmosphere at some point. Sounds like your pump discharge is piped directly to the septic tank. This is a bad setup. You need to find some way to vent that tank if possible.