Septic tank - concrete ring type

[Bluesofa]

One our bathrooms has a problem with the waste-water going 'down the pan' very slowly.
We had a problem before and had the tank emptied a month ago.
Now it's emptying slowly again.

There's a bit of assumption here:
The house was built 40-odd-years ago and this septic tank is the original one. I'm guessing if it's that old, it's likely to be a concrete ring tank?
I say that because on the ground there's a 1m diameter concrete 'cover' x 10cm deep, with a 3m long inch-and-a-half PVC vent-pipe coming out of the centre.
I've asked, and there were never any drainage pipes to disperse the liquid.
As (again I assume) the liquid drains into the ground at the bottom of the tank? (I don't know how many rings, but have seen that three seems quite common?)
Does the cold weather cause the ground to become hard and absorb the liquid slower?
Or is there a more likely cause?

[Faz]

It's usual to have a septic tank and a drain off tank (concrete rings) for any excess water.
Once the septic tank is full of water, it overflows into the drain off tank a little at a time, giving it time to soak away into the ground.

If you only have the one concrete ring type, there should still be a smaller screw off cover on the concrete top. Unscrew that, or if not, lift the concrete lid off to examine the level of water. You can use a stick to dip in the tank to assess both the depth and level of water.

I take it you don't flush toilet paper down the loo?
The waste pipe from toilet to septic tank should be 4 inch width.

[Faz]

I'm currently renovation the old family village house out in the boonies, and recently installed a septic tank and overflow/soak away tank. The soak away is 3 concrete rings deep. The septic tank is plastic and sealed, with a 4'' plastic connecting pipe.

Another issue, which I've seen Thai builders do in order to cut costs, is to use 90-degree elbows, rather than two 45-degree elbows, or the long sweeping 90-degree elbows that are specifically for toilet wastes.

Over time, a 90-degree elbow (restricts the force of flow)can become blocked with dried faeces and requires rodding to clear the blockage.
 

 

[Bluesofa]

16 minutes ago, Faz said:

It's usual to have a septic tank and a drain off tank (concrete rings) for any excess water.
Once the septic tank is full of water, it overflows into the drain off tank a little at a time, giving it time to soak away into the ground.

If you only have the one concrete ring type, there should still be a smaller screw off cover on the concrete top. Unscrew that, or if not, lift the concrete lid off to examine the level of water. You can use a stick to dip in the tank to assess both the depth and level of water.

I take it you don't flush toilet paper down the loo?
The waste pipe from toilet to septic tank should be 4 inch width.

Yes, I've seen a few drawings of the two tanks system. I don't know if we have that or not.
Ha-ha, there's no screw cover on this particular tank (our others have). It has a 4" hole in the concrete with an old paint tin covering it.

Also trying to put a dipstick in there, while using a torch isn't easy. I suppose ideally a very long dipstick could give me an idea of the total depth too.
Could take a while to find this out, especially as we have nothing to use as a long dipstick in our house.

No toilet paper - never used it for years.
I have to assume it's 4" soil pipe, as it been in for forty years and has worked fine. Also absolutely everything was concreted/built over years ago, so can't see any pipework.
(I've never seen anything smaller than 4" anywhere though)

[Marble-eye]

First IA (immediate action) is a big rubber plunger, always worked for me.

[Faz]

If you can lift the complete concrete lid off, that would be better (watch out for the cockroaches).
Flush the toilet and check the resulting flow into the tank.
If it's slow and takes time, I'd suggest you have a partial blockage.
If the flow rate is fine, then it could be the tank was never properly emptied.

Again, we have 3 tank systems at home and on one occasion, although the waste truck made a lot of noise, there was no suction in the pipe and I had to send them on their way.
Now, I keep a length of plastic pipe handy to dip in to ensure the tanks have been emptied, and a hose pipe handy.

[Faz]

Just now, Marble-eye said:

First IA (immediate action) is a big rubber plunger, always worked for me.

@Bluesofa isn't constipated, though! 

[Bluesofa]

The results of the Belgian jury:
To the top of the liquid: 24 inches.
To the bottom of the tank - unknown, except that it's 45 inches PLUS (ran out of dipstick - what a dipstick I am).

Regarding Marble-eye and the rubber plunger:
Although it seems like a good idea, I'm certain it's s septic tank issue, as last month when the same tank was emptied. the toilet immediately flushed perfectly, so I can't see a pipework obstruction personally, although years ago in the past I was wrong once.

[Faz]

With the lid off, can you see the 4'' pipe?
Water level above or below the pipe?
Did you try to flush, and could you watch the water flow into the tank?

[Bluesofa]

2 minutes ago, Faz said:

With the lid off, can you see the 4'' pipe?
Water level above or below the pipe?
Did you try to flush, and could you watch the water flow into the tank?

 That's beyond me to lift up the 1m concrete lid lid, so I'm afraid I can't answer that one.
Although as I said, it's apparently worked OK for 40 years, I can't imagine it might be less the 4" diameter?
Plus, after the tank was emptied last month, it flushed instantly, after being slow to empty the pan.
Unless there might be another reason for that?

[Faz]

4 minutes ago, Bluesofa said:

Plus, after the tank was emptied last month, it flushed instantly, after being slow to empty the pan.
Unless there might be another reason for that?

It's possible the bottom of the tank has become encrusted with old faeces, preventing the water from draining through into the soil. Lift the lid at one side then roll away, you don't have to physically lift the whole lid.

With that lid off, you can carry out a couple of quick tests to diagnose your issue.
I'm leaning towards a hard crap cake at the bottom of the rings.
Bail out enough water to see the pipe and test the toilet flows OK.
If that's OK, bail out as much as you can, then preferable with a long steel pole, smash the bottom.
If you get 'floaters' the bottom is encrusted.

You get all the best jobs!

[Bluesofa]

2 minutes ago, Faz said:

It's possible the bottom of the tank has become encrusted with old faeces, preventing the water from draining through into the soil. Lift the lid at one side then roll away, you don't have to physically lift the whole lid.

With that lid off, you can carry out a couple of quick tests to diagnose your issue.
I'm leaning towards a hard crap cake at the bottom of the rings.
Bail out enough water to see the pipe and test the toilet flows OK.
If that's OK, bail out as much as you can, then preferable with a long steel pole, smash the bottom.
If you get 'floaters' the bottom is encrusted.

You get all the best jobs!

I get all the shit jobs!
It's gonna take a while, as I've been under the weather for the past few days. Thanks for your 'crap' suggestion - ha ha!
I'll eventually report back.

[Faz]

A clothes peg on the nose for the smell,  and a mask to catch the vomit. 
You've never lived until you've had to clear toilet drainage problems.

[Faz]

If you find yourself knee-deep in shit, the common trend now is to start a "Go Fund Me" page.  

[Rookiescot]

I have one guy I use regularly to empty the sceptic tank but on an occasion about a year ago I had to use another guy.

Within a month the tank was full again. 

It appears the second guy barely removed anything. Just claimed the job was done and took off. I was foolish in that I did not oversee the operation at the time because I was busy with something else.

 

[Rookiescot]

On 1/13/2023 at 3:36 PM, Faz said:

A clothes peg on the nose for the smell,  and a mask to catch the vomit. 
You've never lived until you've had to clear toilet drainage problems.

A facemask with vaporub in it solves all the issues.

Its what the professionals do.

[Faz]

10 minutes ago, Rookiescot said:

A facemask with vaporub in it solves all the issues.

After shave or perfume also serves the same purpose.

[Faz]

22 minutes ago, Rookiescot said:

A facemask with vaporub in it solves all the issues.

You can always improvise as well if you don't have a face mask!

 

 

 

[Rookiescot]

4 minutes ago, Faz said:

You can always improvise as well if you don't have a face mask!

These will all come in handy for when Big H sets another stinker of a quiz. 

[Bluesofa]

The promised update about my septic tank:

In the end, I thought it would be the easiest option first of all to get the tank emptied again, in order to a) check it was empty, and b) see if it got rid of the problem.

Today when the guy came to empty it, my wife wasted no time in explained that it was full after only a month.

This is when it got interesting.
There was I worried about lifting up the 1m diameter concrete tank cover, to lean it against the house wall. No need. The guy just slid the cover open to see inside. Whoa!

The water level was, as I said originally, two feet from the top of the tank. I pointed this out to him. He said that this was a normal level for a single tank, in order for the water to slowly soak into the ground.

Then the revelation!
He asked me to get my wife to flush the toilet. We could see water dribbling out from where the soil pipe should be, obstructed by what I initially thought was a load of 'rubble' in the pipe entrance. The PVC pipe was located about 6" from the top of the tank.
The guy broke the bottom section of the rubble off with a hammer. The water poured out.

You can see the 1" hole he dug out above.
What's missing? The 4" PVC soil pipe.
The guy said the PVC pipe had broken in the ground, so would need replacing.
You can also see above, the circular shape where the pipe should be. Now it's got concrete there instead.
The guy told me it was no good just breaking all the concrete, as he wasn't sure if that was part of the outside of the concrete ring that had dropped. Fair point.

The good news! We know what was causing the problem.

The bad news! The PVC pipe will need replacing. This will involve digging up the concrete between the tank and the bathroom wall - even though it's only about a metre. Then there's having to dig up the bathroom floor to the toilet pan and re-tile it afterwards.
Looks like it's going to cost my wife a few thousand Baht.

 

[Marble-eye]

12 minutes ago, Bluesofa said:

The promised update about my septic tank:

In the end, I thought it would be the easiest option first of all to get the tank emptied again, in order to
a) check it was empty, and b) see if it got rid of the problem.

Today when the guy came to empty it, my wife wasted no time in explained that it was full after only a month.

This is when it got interesting.
There was I worried about lifting up the 1m diameter concrete tank cover, to lean it against the house wall. No need. The guy just slid the cover open to see inside. Whoa!

The water level was, as I said originally, two feet from the top of the tank. I pointed this out to him. He said that this was a normal level for a single tank, in order for the water to slowly soak into the ground.

Then the revelation!
He asked me to get my wife to flush the toilet. We could see water dribbling out from where the soil pipe should be, obstructed by what I initially thought was a load of 'rubble' in the pipe entrance. The PVC pipe was located about 6" from the top of the tank.
The guy broke the bottom section of the rubble off with a hammer. The water poured out.

You can see the 1" hole he dug out above.
What's missing? The 4" PVC soil pipe.
The guy said the PVC pipe had broken in the ground, so would need replacing.
You can also see above, the circular shape where the pipe should be. Now it's got concrete there instead.
The guy told me it was no good just breaking all the concrete, as he wasn't sure if that was part of the outside of the concrete ring that had dropped. Fair point.

The good news! We know what was causing the problem.

The bad news! The PVC pipe will need replacing. This will involve digging up the concrete between the tank and the bathroom wall - even though it's only about a metre. Then there's having to dig up the bathroom floor to the toilet pan and re-tile it afterwards.
Looks like it's going to cost my wife a few thousand Baht.

Sundays Top Tip.  

Include more ruffage in the diet.

[Rookiescot]

10 minutes ago, Bluesofa said:

The promised update about my septic tank:

In the end, I thought it would be the easiest option first of all to get the tank emptied again, in order to a) check it was empty, and b) see if it got rid of the problem.

Today when the guy came to empty it, my wife wasted no time in explained that it was full after only a month.

This is when it got interesting.
There was I worried about lifting up the 1m diameter concrete tank cover, to lean it against the house wall. No need. The guy just slid the cover open to see inside. Whoa!

The water level was, as I said originally, two feet from the top of the tank. I pointed this out to him. He said that this was a normal level for a single tank, in order for the water to slowly soak into the ground.

Then the revelation!
He asked me to get my wife to flush the toilet. We could see water dribbling out from where the soil pipe should be, obstructed by what I initially thought was a load of 'rubble' in the pipe entrance. The PVC pipe was located about 6" from the top of the tank.
The guy broke the bottom section of the rubble off with a hammer. The water poured out.

You can see the 1" hole he dug out above.
What's missing? The 4" PVC soil pipe.
The guy said the PVC pipe had broken in the ground, so would need replacing.
You can also see above, the circular shape where the pipe should be. Now it's got concrete there instead.
The guy told me it was no good just breaking all the concrete, as he wasn't sure if that was part of the outside of the concrete ring that had dropped. Fair point.

The good news! We know what was causing the problem.

The bad news! The PVC pipe will need replacing. This will involve digging up the concrete between the tank and the bathroom wall - even though it's only about a metre. Then there's having to dig up the bathroom floor to the toilet pan and re-tile it afterwards.
Looks like it's going to cost my wife a few thousand Baht.

Hold on.

If I am reading this right the effluent is actually reaching the tank? It was obstructed by part of the inner wall though.

In that case is there any reason to replace the existing pipework? The original PVC pipe may never have extended all the way into the tank. You will be aware of Thai building standards aye?

By the looks of things mate I would suggest the guy who was supposed to empty the tank the last time simply failed to do so.

Give it a period of time to see how things pan out now that the water appears to have an unobstructed inflow and the tank has actually been emptied. 

[Rookiescot]

5 minutes ago, Marble-eye said:

Sundays Top Tip.  

Include more ruffage in the diet.

I have long concluded many of your posts contain large amounts of ruffage 

[Faz]

1 hour ago, Bluesofa said:

The guy broke the bottom section of the rubble off with a hammer. The water poured out.

If that's water pouring out, remind me not to ask for a glass at your house.

[Bluesofa]

12 minutes ago, Rookiescot said:

Hold on.

If I am reading this right the effluent is actually reaching the tank? It was obstructed by part of the inner wall though.

In that case is there any reason to replace the existing pipework? The original PVC pipe may never have extended all the way into the tank. You will be aware of Thai building standards aye?

By the looks of things mate I would suggest the guy who was supposed to empty the tank the last time simply failed to do so.

Give it a period of time to see how things pan out now that the water appears to have an unobstructed inflow and the tank has actually been emptied. 

My father-in-law built the house himself. There is no pipework any more to the tank, he tells me it went right into the tank.
True, we don't how how much of it might be crushed, if we're lucky it may only be the first metre between the tank and the house wall. Hopefully it could be replaced.
Actually looking at it again, it's nearer only half a metre. The location Is not somewhere you can get access to easily.

It was crushed maybe by the concrete on the ground pressing on it for the past 40 years, perhaps by the outer part of the concrete ring that has dropped down. We just don't know.

It doesn't have an unobstructed flow, as I said, there's only a 1" diameter hole there now. When flushing the toilet it allows the water through it fine, but solids will be another (fecal) matter.

I do understand the reluctance of the guy who came today - to empty a tank - get get involved in smashing concrete out of the way. There's a chance it might cause more of the concrete ring to collapse.

The only way to find out is to dig up the concrete outside of the tank, to see what's happened.
It will need part of the concrete ring repairing too.