Septic tank advice please

[Cider]

The Klargester (onion shape) septic tank serving a group of my barn conversions has collapsed.
I think it was due to the builder fitting it poorly as it has leant over at an angle and has discharged solids into the soak away which has now silted up.
I can sort the soak away but need some advice as to what type and size of tank I need to replace the old one.
It serves six houses totalling 26 bedrooms and discharges to a holding tank which is then pumped to the soak away.
The system has worked so no radical redesign needed just specification for new tank please.
I will excavate the original tank which from memory is sitting on a concrete pad and fit the new one so fitting advice appreciated as well.
Power source nearby so could fit an aeration type but would rather keep it simple.
Cheers
Cider

 

[nick...]

They must have made a real cock up if the last tank leant over.ive put dozens in,
In my time.allways sit them on 6/8 inches of lean mix.get the tank upright then fill with water to hold in position then back fill hole with lean mix to about 450/600 mm above centre rib on the tank.if your last tank was ok probably best to replace with the same and will be cheaper than a klargester
Nick...

 

[BAC]

They must have made a real cock up if the last tank leant over.ive put dozens in,
In my time.allways sit them on 6/8 inches of lean mix.get the tank upright then fill with water to hold in position then back fill hole with lean mix to about 450/600 mm above centre rib on the tank.if your last tank was ok probably best to replace with the same and will be cheaper than a klargester
Nick...

Would personally go with kingspan, they supply all our tanks and never heard a bad word about them.

As nick says, 150mm semi dry base, set the tank on the base level, pack semi dry under the base to hold it, use ply board with core holes drilled in the top as a shutter, put backfill behind the shutter and 200mm concrete around the tank then pull boards up using a strap, fill with water at the same level as you are filling with concrete. That's the way we do it, just make sure your hole is safe to work in, what ground are you in??

@Cider

 

[BAC]

Irrigation tank but example

 

[frustratedfarmer]

Just fitted a condor a bit bigger than yours.

Their fitting advice is as above but if low water table use 10mm gravel to hold it in situ and back fill with water at same time. Saves costs of concrete above pad

If high water table, need concrete to help hold it down

 

[Cider]

Thanks for the advice everyone, any suggestions on size or how to calculate?

 

[BAC]

Thanks for the advice everyone, any suggestions on size or how to calculate?

What are you wanting to calculate?? Size of the tank??

 

[tomlad]

Bought my last klargester from chf supplies good to deal with worth a phone call ?

 

[BAC]

I think you need about 10,000 holding capacity working on an average of 3 people in each household

 

[frustratedfarmer]

Thanks for the advice everyone, any suggestions on size or how to calculate?

Just ask the supplier to work it out. It's a half complex calc based on toilets taps bedroom etc

 

[crazy_bull]

I fitted a tricel, treatment plant, so easy and does exactly what it says it will.

C B

 

[Cider]

Ok thanks for the help everyone, looks like I'm gonna settle for a 8000 litre Conder tank.....any comments?
Cheers
Cider

 

[Andrew K]

Mark,

We tend to have our Klargester cleaned out more frequently ,instead of changing to bigger, also would not bother with revolving discs, just go for a bubble up pump to get bacteria working.

 

[frustratedfarmer]

I agree, the rotating motors need more maintance and if you get a long power cut they don't always start back up because the sludge solidifies in the bottom half of the membrane disc throwing of the balance. The BOD on the bubble systems is much better than they were so more suitable to most applications.

I was told to take a bottle and draw 10 lines on it and dip it in to look at the sediment - let it settle and that gives you an idea of when it needs emptying based in what height the coffee goes up the bottle!

 

[Cider]

Thanks everyone.
Andrew K your old Sumo is still going strong, great bit of kit if you miss it I could be encouraged to sell at the right price.........

 

[Knollands]

Try a Graf septic on the septic tank store.co.uk Well give 5% off the price. has a baffle that won't collapse, strong enough to hit and from stock

 

[hutbephotmb24h]

View attachment 312414

View attachment 312418

Irrigation tank but example

Hi @BAC, let me ask you about the material that made the pool of decay that you shared?