Looks like that time of the year! (to empty septic tank..)

[lostinthelight]

Some reading on septic tanks :
https://www.wte-ltd.co.uk/design.html

 

[Burnerman]

This design is almost exactly the same as my tank - mine has concrete lids, 12" wide by 4'.
My second tank is only half the depth of the first one, and the 'baffles' as they refer to I call dip pipes, made from salt glaze clay. For sure, I haven't seen any of them in builders merchants!
John

 

[conny]

We pay around £115 for up to 1,000 litres up lifted.
Still costs £115 even if they removed only, say 700 litres.
We are in Suffolk so I imagine it's a rough guide to work on.

 

[Brett2021]

I think the image below shows more accurate picture of the system ..

• Also I can confirm round Pipe (2) is inside solid waste chamber but have only liquid, I initially thought that is a separate chamber
• More importantly I was very wrong on the size of chamber, because concrete slab which covers parts other than the metal lid was so thick I thought thats the size of tank.!!
• Now latest size calculations are as below - D/H - 160cm, L-100cm, W - 90 cm (one tank)
• Total Tank capacity is 3000L and filled volume is 2200 L may be now this is inline with my 4 bed house??
• Another revelation is since blue level line in below pic showing current level is nearing inlet flow level (1) I suppose I am very close to what this tank can deal though as per volume calculation I have 800L is still empty. So due to inlet pipe level that empty volume in reality may not be useful..correct..?

 

[lostinthelight]

I think the image below shows more accurate picture of the system ..

• Also I can confirm round Pipe (2) is inside solid waste chamber but have only liquid, I initially thought that is a separate chamber
• More importantly I was very wrong on the size of chamber, because concrete slab which covers parts other than the metal lid was so thick I thought thats the size of tank.!!
• Now latest size calculations are as below - D/H - 160cm, L-100cm, W - 90 cm (one tank)
• Total Tank capacity is 3000L and filled volume is 2200 L may be now this is inline with my 4 bed house??
• Another revelation is since blue level line in below pic showing current level is nearing inlet flow level (1) I suppose I am very close to what this tank can deal though as per volume calculation I have 800L is still empty. So due to inlet pipe level that empty volume in reality may not be useful..correct..?

View attachment 267154 View attachment 267155

Hence my question about just measuring the inspection chamber.
Just because the level is at where you see doesn't mean it's full, the system is meant to work that way.
If your system had an outflow inspection chamber which if not being so old would have had, you would see a constant trickle of liquid flowing.
If you then flushed the toilet that flow increases after a short delay .
With a brick tank , to check its not leaking, note the level before a holiday or weekend away and when you return to see if any difference .
In the absence of any info from pre purchase records you could play safe with a goodly overestimate booking ,then ask the driver what he's pumped for future emptying bookings

 

[Burnerman]

Your drawing of the tank is just what's needed....the blue liquid level line should of course be at the bottom of the outlet.
As the solids etc enter via dip pipe 2, occasionally the solids build up and block the pipe outlet. Pushing some draining rods down the salt glaze at the top of (2) stirs things up a bit and allows more soil in.
Naturally enough, if this does get blocked then things are visible in chamber (1) which should be dry....as should be the outlet, until the loo or whatever is flushed.
I've found with brick tanks when they are emptied, some water often flows back in through unintentional gaps in the brickwork.....this doesn't matter as that's where the soil goes anyway!
The big issue is to stop anything other than liquid from going down the outlet....I have had the outfalls jetted in the past but naturally enough they don't last forever.
I hope you have found this interesting, in a peculiar way
John
PS In France, these things are called 'fosse septiques' - and there is a product called Eparcyl that is tipped in from time to time. There may be something similar available in Blighty.
J.

 

[Brett2021]

(Caution: Please note pics attached may not be suitable to watch while you are around your dining table!)

I got tank cleaned by a local waste collection team. I thought they did a great job until I checked tank again.

Looks like in the process they got pipe (cast iron ?) in the 'water' septic tank chamber dropped to the floor.
Please see the photos...I know its not a DIY work due the dangers involved, but wondering this need to be done?
As If I need to remove that pipe, need to act soon

Secondly waste collected I am told 600 gallons, which is much different from calculations shown in above post which calculated max 200 imperial gallons with 2 chambers together. Now that its empty I could do a better calculation after measuring tank size more accurately.

Third issue is lids are completely rusty, how could I rescue it? Pressure wash & paint?? is there any better option? applying rust removal liquid and paint..?

 

[Brett2021]

may be good to remove rust..

 

[Burnerman]

The cast metal pipe is the 'dip pipe' that I've been referring to. There is one in each chamber.
Basically the soil enters the pipe from the side inlet just below the top....the open top is so you can rod down any blockage that may be there.
I can't see how that pipe has been connected to the piece that remains in the brickwork - I guess that is cast iron also? The size seems to be different too - at least to my eyes.
The tank will work perfectly well without this thing so don't worry - but I would fish it out if you can.
Did the people who did the emptying actually dislodge this thing - or has it been down there for ages? There's a shovel blade lurking in mine!
As for the lids - they sure have seen better days and I'd replace them with galvanised lids and plastic frames - if the sizes are obliging. There's just too much work involved in cleaning them up.
John

 

[freddiemercurystwin]

Your thread needs a health warning, I think I just brought some of my breakfast up.

 

[Brett2021]

Your thread needs a health warning, I think I just brought some of my breakfast up.

I already have this...

(Caution: Please note pics attached may not be suitable to watch while you are you are around your dining table!)

 

[Brett2021]

The cast metal pipe is the 'dip pipe' that I've been referring to. There is one in each chamber.
Basically the soil enters the pipe from the side inlet just below the top....the open top is so you can rod down any blockage that may be there.
I can't see how that pipe has been connected to the piece that remains in the brickwork - I guess that is cast iron also? The size seems to be different too - at least to my eyes.
The tank will work perfectly well without this thing so don't worry - but I would fish it out if you can.
Did the people who did the emptying actually dislodge this thing - or has it been down there for ages? There's a shovel blade lurking in mine!
As for the lids - they sure have seen better days and I'd replace them with galvanised lids and plastic frames - if the sizes are obliging. There's just too much work involved in cleaning them up.
John

Yes its the cast iron pipe in the liquid chamber that connects to outlet from solid chamber. Its dropped from being connected to solid-liquid outlet pipe and left in the bottom of liquid chamber which is empty now. it need to be connected in the same way as image 2 above.

I am not sure if it was left inside the chamber for years or just during emptying that big sucking pipe dislodged it. Most likely its done during sucking process as water was there above the pipe and due care may not been taken while placing heavy sucker inside. Interestingly now same company offered a contact who could help on this , but most likely cost me more than what I spent to empty the tank!

 

[Burnerman]

I can’t work out how that dip pipe was connected to the stub of pipe you can see.....that bit looks suspiciously like salt glaze. Cast iron stuff would have been threaded together, more than likely.
Anyway, the dip pipe helps solids descend to the tank floor rather than allowing ‘floaters’ to head for the outlet so it would still work, there or not.
I have a round rubber disc that fits to my drain rods - it just fits through the top bit of the dip pipe.
John

 

[lostinthelight]

The cast metal pipe is the 'dip pipe' that I've been referring to. There is one in each chamber.
Basically the soil enters the pipe from the side inlet just below the top....the open top is so you can rod down any blockage that may be there.
I can't see how that pipe has been connected to the piece that remains in the brickwork - I guess that is cast iron also? The size seems to be different too - at least to my eyes.
The tank will work perfectly well without this thing so don't worry - but I would fish it out if you can.
Did the people who did the emptying actually dislodge this thing - or has it been down there for ages? There's a shovel blade lurking in mine!
As for the lids - they sure have seen better days and I'd replace them with galvanised lids and plastic frames - if the sizes are obliging. There's just too much work involved in cleaning them up.
John

I would agree that the lids need replacing but the “T” for the dip tube is necessary to get the sewage below the crust which will ultimately form on the surface, without it solids and paper wont get down to where all the action takes place but build up above