Septic System Nightmare

Well, you have come to the right place as much of our conversations have spiraled into the sewer, but that's politics for you.

A few questions.

When did the smell start appearing? Was this after the septic tank repair?

Not knowing the complete layout and history of your house makes it difficult to understand what is actually happening.

Usually, vent pipes are installed for each area of use, such as bathrooms, or other area where volumes of waste water are added to the system.

Venting is an interesting process where the vent stack or pipe that exits the roof creates a low pressure in the drain line to help pull out septic gasses. The vent should be located upstream of the point where the sink or toilet waste water enters the main drain pipe. Your venting system may have been improperly designed and executed.

Sometimes increasing the height and length of the roof vent pipe will fix the problem by lowering the pressure in the drain pipes.

Again, I really don't know if your specific problem is a new problem that suddenly appeared or a chronic issue that you have always had.

If it is a new problem you should first ask, "What's changed?" That may lead you to the root problem.

One thing that may have changed is a clogged vent pipe, If a critter or enough debris have entered the vent pipe it would cause the issue you have. Make sure that pipe is open and clear, even if you smell septic fumes from the vent. The pipe may be restricted enough to render venting inoperative.

Also, septic smells can be generated in other places along the system besides the septic tank. If sewage is pooling in a line somewhere it can generate gas.

Is there a straight section of horizontal pipe in the bath sink before it hits the P-trap?

If so, most likely this straight section has a buildup of soap/shaving-cream scum that is biodegrading, and this is what you are smelling.

Also to prevent a vacuum. Without a roof vent, the flushing of a toilet will suck the water out of the bathroom sink trap. The water in the trap is the only thing between your sink and sewer gases.

save 100 questions.........draw a simple diagram of your system. its hard to believe you only have a sole vent. in your drawing include anything that drains, sinks, toilets, showers, etc.

Your diagram shows an interesting problem we had at a summer cottage. Imagine the outlet pipe gets plugged. you fill a sink with water and pull the plug. The pipes fill with water until it is above the subfloor level, at which point the toilet, shower, (& bathroom sink) all start belching gas, and the lower ones over flowing. Reasonable venting can be defeated with badly plugged pipes.

It may be as simple as a blockage in the existing vent causing gasses to be forced through the water traps at the other points. Try running a hose down from the top of the vent and see if that solves the problem.

Doesn't sound strange to me! We had the same problem when someone flushed a large wad of toilet paper down the toilet. That wad of paper got caught in the roots that were already almost filling the line going from the house to the tank, and completed the clog. Enough water filtered through the roots between flushes to avoid complete back-up.

The problem disappeared after we had the main line rooted.

We had one of our kids "lose" a pair of tweezers down the toilet - they caught sideways at a T under the basement floor. Paper wads and hair packed in behind them. The rooter passed by them - ended up having to smash through the floor (100 year old basement floor was more of a 1" parging) and take it apart - tribulations of a 100 year old money pit.

Before doing anything drastic or expensive, check the top of the stench pipe/vent pipe where it clears the top of the roof, and check that there isn't a bird's nest or even a dead bird plugging it.

Next, invest in a bottle of proprietary drain cleaner (names withheld). This stuff contains caustic soda crystals, so handle using rubber gloves and appropriate eye protection. Cast the granules into the waste outlets where the problem seems to be coming from, and flush some hot water down until the stuff dissolves; there will be a crackling sound and the release of some heat. With a bit of luck, it will break up any accreted solids in the drainage system and everything will be back to normal in a day or two.

If any waste outlet is slow to drain, a common-or-garden plunger is a good investment.

If none of that works, come back to this thread and post the current situation for more advice from forum readers.

<subscribes>

Every time I had this problem it was either a restriction in the waste piping or plugged vent pipe. Both times the problem was vent pipe was in very cold winter and moist fumes were freezing and trapping gases. Boiling kettle of water poured down solved the problem until next time. The other event is was improper slope of main toilet waste pipe causing build up but it also showed as a bad flush. Dropping this pipe 2 inches cured it forever. Take a mirror and reflect the sunlight down the vent pipe it works better than a flashlight for great view, caution if something looks back.

And it is easier to drop the flashlight down the vent then the Sun.

Please check the bathroom piping:

- If you have a floor drain opening in the bathroom, it should be a type with a trap.

- Sometimes, you have a washhand basin that has a drain with a trap, but after the trap, a bypass may have been connected to the floor drain, without a trap.

In conclusion: You have a direct connection to the vent, from the bathroom, without a trap in the line. It is not easy to detect the fault because a lot of plumbers make this mistake. Block the floor drain with a blank cover (available), thus eliminating the floor drain outlet, and try the kitchen flushing process to see if the smell will still be there.

The only thing I can add to the excellent comments here is that if your bed is saturated (about the 25 year mark and I don't think that this is your problem) your first bet is to find the far ends of the runs, and open them to the air. Have your pumper suck them out. Then backfill them back in. Your pumper may pull out a lot of roots and sand. You could do that every second year with no trouble... The new ones want a vent pipe so you can do this without the shoveling! You can usually get another 10 to fifteen years out of your septic bed that way.

When it finally DOES get bio-matted to death, well, you "could" just replace the clogged pipes. That involves trenching, and taking a lot of care. You can do one or two runs at a time, and save your back. Pipes are cheap. Pull one up, lay it back into the bed where it came from. Don't change their slope. But that only works if your pipes are like, totally clogged with roots and sand, and the gravel they are lying on is serviceable. This happens almost all the time. But when the gravel gets bio-matted, well, it will require a significant investment by a trained professional. The church next door dropped 40 grand on a new tank and field. But the new fancy system will now last 40 years (they say) so it balances out.

Now I know this did not aswer your question directly...but others did so. This was just MY experience and how I solved a slow (stopped!) running septic system. Second time, I just dug out a collapsed pipe which dated to the early '40s. Smelly, but simple job, using a shovel.

So I shall just mark it off topic.

joe_r, are u sure that 3" PVC vent is only connected to the main drain pipe?

if so, its a code violation and Uniform Plumbing Code UPC is written as it is to avoid situations like yours.

so....going forward, you can have a plumber bring the house up to code, or......

get a copy of the UPC, maybe from the library, learn where vent pipes should be located, and you can cut the PVC pipes where-ever necessary with a hack saw or even a fine-tooth wood saw, and fix the problem yourself. your lucky your vent pipes are PVC or ABS, it so easy to work with, as compared to black iron.

All excellent comments in here.

It's impossible to determine the exact cause from our location for a number of reasons.

Was the plumbing completed by a plumber, or was it a DIYer project? If it's the latter, then there may lay the crux of the situation because a majority of homeowners haven't a clue about the proper installation of sewage vent pipes.