There wuz I Digging this 'ole .....

[ToughButterCup]

Right, then, thanks. Obvious case for digging a trial hole today and watching what happens overnight. 

(Yes, I'll cover the hole, and double check nothing is in it tomorrow morning)

[Russell griffiths]

why the trial hole to ascertain what ?

if you should concrete it or not ?

just dig the hole and order the concrete 

not concreting it in will only cause you to worry that you should have. 

£ 300 for concrete is probably the amount you just saved by digging the hole yourself 

why scrimp at a major point. 

I thought you had already been monitoring the water level at a different hole before you started. 

Get it dug lad, get it in, fill with water, order concrete, take pics, have a beer, pat yourself on the back. 

 

[PeterW]

52 minutes ago, recoveringacademic said:

Right, then, thanks. Obvious case for digging a trial hole today and watching what happens overnight. 

(Yes, I'll cover the hole, and double check nothing is in it tomorrow morning)

 

There will be a pair of newts doing synchronized back stroke....

[ToughButterCup]

49 minutes ago, Russell griffiths said:

[...]

£ 300 for concrete is probably the amount you just saved by digging the hole yourself 

[...]

 

I never ever think of that............

49 minutes ago, Russell griffiths said:

[...]

I thought you had already been monitoring the water level at a different hole before you started. 

[...]

 

Our site has a gentle slope: the tank is going in at almost the lowest point on the site - still some 10 meters higher than the discharge point 150 meters away.

 

Right then, off to have a coffee and take some piccies and then get stage 1 done..... just need to check if the digger really will lift the tank. Its not the weight that's the issue: its the vertical reach.

 

[ToughButterCup]

Will the digger lift the tank - weight's not an issue (250Kg) : but in terms of reach? 

 

 

Yo Sushi!

With 300 mm to spare.  I am officially pleased

 

Now to find the end of the pipe which we buried this time last year.... and dig down to it......

[Declan52]

Can you not try it with your small bucket so when you open it out it will give you another 2ft of reach plus shortens the sling lifting it up higher.

[ProDave]

I lifted with the bucket on.

 

 

If you lower it into the hole, and it's not quite deep enough, you don't want to be faffing about putting the bucket back before you can dig further. (even when you have the luxury of a quick hitch)

[Declan52]

With the sling over the bucket and between the teeth to stop the sling sliding off.

 

[ToughButterCup]

And here it is, much deeper than I thought..... about 1500mm down.

 

 

Yes, @Declan52, I'll leave the bucket on tomorrow: the back of the bucket acts as a cam.  Hadn't thought of that.

 

I need to put in a post-treatment inspection chamber, so how much space do I need to allow for that before I start digging the 2100 mm square hole ( 2440 deep) for the tank?  

 

I dimly remember that I need to  embed the chamber in pea gravel.....

 

 

 

 

[Onoff]

@recoveringacademic, so if your soil pipe is at 1500mm is that too low to attach to the unit? Is that the inlet facing out in the picture where you're lifting the tank with the digger?

[ProDave]

This is the sort of sample chamber I used http://www.drainstore.com/premier-tech-aqua-conder-sample-chamber.html

 

I too don't understand your pipe 1500mm down.  The inlet invert on my tank is about 700mm down. If your pipe is really 1500mm down, you are going to have to dig a very much deeper hole, and fit an extension piece to the top of the treatment plant, that is of they make one.

[ToughButterCup]

The pipe in the picture is the post-treatment discharge ' line ' , i.e. the final trickle to the stream some 150 yards away.

To save us going all the way to the discharge point, I'm putting in a manhole so we can sample the treated discharge.  

 

@ProDave

I am trying to work out the exact centre of the hole that I should dig for the treatment unit. To do that, I need to work out where to put the sample chamber. The position of the  post-treatment pipe is a given: about 1500mm down. 

 

So the vertical gap between the tank invert  (700ml -ish) and the post-treatment discharge line needs to be  '' bridged'  with a manhole. 

 

My question is; horizontally, how far away from the treatment unit  do I put the manhole- (sample chamber). I ask because I know there is a rule about putting treatment tanks at least 7 meters away from a dwelling. I don't want to have to nudge the treatment unit any closer to the house than I have to.  

 

 

PS

Just found this schematic diagram. The thing I call a  manhole is referred to as a sample chamber 

Edited August 27, 2018 by recoveringacademic
Added manufacturers link to diagram explaining the layout

[Ed Davies]

For lifting my rafters the digger driver unbolted one of the teeth and put a strop on it then I clipped my rope to that with a carabiner. He could then rotate the bucked up a bit until the rafter was almost against the jib. https://edavies.me.uk/2017/08/7-up/img_0490-medium.jpg

 

 

Edited August 27, 2018 by Ed Davies

[ToughButterCup]

Just now, Ed Davies said:

[...] unbolted one of the teeth and put a strop on it then I clipped my rope to that with a carabiner. [...]

 

There's experience for ya!

[Russell griffiths]

If you want to put your treatment plant at 7m away then do that, the discharge pipe and sampling chamber can be placed on the far side by cutting back the pipe you have already buried 

just cut it back to suit your needs. 

Its the inlet side that is important you get the right height. 

Have you established this bit. 

[ToughButterCup]

Just now, Russell griffiths said:

[...]

Its the inlet side that is important you get the right height. 

Have you established this bit. 

 

Yes.

For an ostensibly intelligent person, I can be remarkably  bloody stupid. 

1 minute ago, Russell griffiths said:

[...]

just cut it back to suit your needs. 

[...]. 

 

Really, seriously bloody thick.

[Jeremy Harris]

Our guys had a special tooth with a bloody great shackle welded to it that they bolted on when needing to lift stuff.  I doubt it had been anywhere near a lifting gear test or certificate, but having the load attachment right out at the end of the bucket did seem to give a give a fair bit more manoeuvrability with the load.

[ToughButterCup]

The clay was dusty: and in today's brisk wind, I almost needed eye protection.

 

 

 

So now....

 

Tomorrow tarting the hole up and popping it in. That should be a laugh.

 

[PeterW]

3 hours ago, recoveringacademic said:

So the vertical gap between the tank invert  (700ml -ish) and the post-treatment discharge line needs to be  '' bridged'  with a manhole. 

 

Is this for discharge water only ..??

 

If so... use a standard 300mm manhole as a discharge and bring the inlet into it on one of the side legs and then outlet down the main channel. Gives you access to put a small sample cup under the edge. And they are a damn sight cheaper than a “proper” one ..!

 

Sample chamber within 900mm of the tank outlet at the same (700mm..??) invert depth then a pair of 45 degree bends to drop you to your already laid pipe. Remember as it’s outflow it doesn’t matter about the gradient. 

[Nickfromwales]

On 24/08/2018 at 17:46, Russell griffiths said:

This also happens with fibre glass swimming pools, never empty one completely. 

You cant say that without then following up with a 'funny story'.  

[Construction Channel]

[...]

a bit late now, but at that kind of depth, she really should have had your harness on attached to your digger, at least when we were digging deep footings thats what we did, its easier to pull someone out than try to dig around them in a hurry........

 

i assume it all went well though? 

[ToughButterCup]

I sent her down for the craik. only there for a few seconds.

[ToughButterCup]

And now I need to fill the damn thing in.

 

 

I can't get a concrete pump close to the tank (unless its a 26 meter machine : £500 + concrete) : nobody round here does a small concrete pump. So it's mix it yer' sel' time.

 

There's 6 inches of water at the bottom of the 'ol, as in this heavily edited image .... Does the water in the bottom of the hole matter? Please tell me I don't have to pump it out.......

 

[ProDave]

It took us a day and a half to concrete ours in. Mixer set up next to "the ole" but still had to barrow it from the mixer to the 'ole and pour.

 

After the first day we had water on the top of the previous days mix and pour, pumped as much as we could off then made the first few barrow loads a bit dry to soak up that puddle.

 

Fill the tank with water as you go, you don't want to over fill it to start with, but keep the water level in it just above the level of the poured concrete.

[Jeremy Harris]

Our guys backfilled around ours with a dry mix, poured down a plastic waste chute fitted in a channel cut into the side of the hole to get it to the bottom.  They kept the tank half full of water suspended from strops on the digger whilst they did this.  The hole was around 1/4 to 1/3rd full of water at the time.  It was a bit like using postcrete, pouring a dry mix into a hole with water in it. 

 

They poured concrete up to around 150mm or so above the triangular anchor lugs that stick out near the bottom of the cone, let the concrete go off a bit, then filled the rest of the hole up with pea shingle, which added to the  ballast holding the tank down as it was resting on the ring of concrete at the bottom.  As soon as the pea shingle was in, they untied the tank from the digger and pumped more water into the tank to hold it down.