installing sewage treatment plant with discharge to stream

[Tom]

So, we're going to be installing our sewage treatment plant soon as we'll need it to connect to the caravan when we move to the site and start the build. Had all the percolation tests etc, FD1 done etc etc Think we're going to go for the Conder (toss up with the Bio Pure, Conder won in the end as it just looks a bit more substantial tbh), and it will need to discharge down a run of buried pipe down a slope to a stream about 80m away. I've been trying to find info on how exactly this should be done: depth of trench, depth of pea shingle, inspection chambers, rodding points etc, but not getting very far. It's essentially a straight run down a field (that's ours). Can I ask for some pointers?

Thanks all

[ProDave]

Treat the outflow like any other drain run, provision for rodding at intervals inspection chambers etc and at any change of direction.

 

I have the conder if you need any specific questions.

[joe90]

Is the stream wet/running 365 days a year? If not you need to use a rumble drain.

[Tom]

Thanks Dave. Is there a maximum gradient? As an estimate the field is about a 1/10 I reckon.

[Tom]

Yep, runs 365 Joe.

[Tom]

Just found a PDF version of Part H building regs for foul drainage (for future reference: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/442889/BR_PDF_AD_H_2015.pdf), says manholes need to be 45m apart on a run (I think), so looks like I would potentially only need one in the middle of the run of approx 80m. No mention of max gradient though - any ideas?

[ProDave]

It should only be liquid exiting so there is not the usual concern of "solids separating" on a normal drain run.

 

What I found was building control had absolutely no interest in checking the outflow pipework. but probably wise to run the design past them.

 

I would want rodding access less than 45 metres or you will want a lot of rods if you ever do get a blockage.

[Temp]

+1 Otherwise I think they recommend aiming for 1 in 60 with 1 in 40 max and 1 in 80 minimum.

 

[PeterW]

If it’s only outflow from the system then gradient is irrelevant - follow the level of the ground and just put 10mm pea gravel all round it.  If it does run all year round, you may want to run the last few metres in clay (UPVC is not UV stable) and also put one of these in the run just before you convert to clay. Make it accessible in a simple concrete chamber. 

 

https://www.plastics-express.co.uk/underground-drainage/Underground-Drainage-110mm/110mm-non-return-valve-28single-flap29-p-pte348

 

 

 

[Tom]

Grand, thanks all.

[juncopartner]

On 13/11/2020 at 18:44, Tom said:

says manholes need to be 45m apart on a run (I think)

Its 90m, no part of the drain should be 45m from a chamber.

[Tom]

Hmm, so on a run of 90m - treatment plant at one end, stream at the other - I wouldn't have to have an inspection chamber somewhere?

[joe90]

As said above, no solids, only fluid so can’t see why it would need rodding.

[PeterW]

Not required. It’s a run from a plant with no solids. You ideally need a sample chamber and then a chamber at the far end before the stream to put a back flow valve in (more to stop animals etc) and you’re fine as you are. In the event this got blocked it would be due to root infiltration or collapse so tbh you would be digging it out anyway to repair. 

[Bart1664]

On 13/11/2020 at 18:09, ProDave said:

Treat the outflow like any other drain run, provision for rodding at intervals inspection chambers etc and at any change of direction.

 

I have the conder if you need any specific questions.

Hi ProDave

Which model Condor do you have please?

Pro's and con's?

Thanks

[Bart1664]

On 13/11/2020 at 18:04, Tom said:

So, we're going to be installing our sewage treatment plant soon as we'll need it to connect to the caravan when we move to the site and start the build. Had all the percolation tests etc, FD1 done etc etc Think we're going to go for the Conder (toss up with the Bio Pure, Conder won in the end as it just looks a bit more substantial tbh), and it will need to discharge down a run of buried pipe down a slope to a stream about 80m away. I've been trying to find info on how exactly this should be done: depth of trench, depth of pea shingle, inspection chambers, rodding points etc, but not getting very far. It's essentially a straight run down a field (that's ours). Can I ask for some pointers?

Thanks all

Hi Tom

I'm just looking at options for replacing my septic tank (domestic property. 3 bed. Discharge to stream) I like the BIOROCK but doesn't seem like many people have chosen it so a bit wary but do like the fact that it's non electric and zero noise from any pump or blower.  Can I ask if there were any other reasons you went for Condor brand other than build? 

[Tom]

Hi Bart

The biorock sounds good on paper, but I'm not sure it has stood up to scrutiny, and I've certainly read some bad reports. The other two realistic options are a mechanical type like the biodisc - which has too many moving parts- or one relying on an air blower, which seems far more simple and efficient in my opinion. I liked the idea of a diamond shape as it just seems to make more sense - more efficient recirculation of water and suspended solids compared to a drum shape like the Vortex which I'm guessing must allow crud to collect in the corners. As for the choice of which diamond shaped one, there's probably no more than a fag paper between them tbh.

[SuperJohnG]

I've been looking at this recently too. Hadn't quite finished my assessment and I'll go.back to it soon enough,  but the WPL diamond is very similar to the condor. 

 

Condor seemed good value and helpful woth some feedback from @ProDave it worked well. The only downside for me on that was the vent sticks out the ground whichnis a pain if its located ina viewable area im your garden and mine will be right out my back door. Other than that it's a good selection. 

[ProDave]

13 hours ago, Bart1664 said:

Hi ProDave

Which model Condor do you have please?

Pro's and con's?

Thanks

ASP6

 

Here it is going into the ground

 

One thing I liked compared to some others is the legs for it to stand on when you lower it in the hole,. and that "ring" around the base, you concrete in to above that level to anchor it into the ground.

 

And this is what it looks like all finished.

 

 

The big green lid with the vent is the housing for the blower pump.  the small screw on green lid at the right is where you insert the hose to pump it out.

[SuperJohnG]

@ProDave ehat did you backfill with above the concrete? It sayd self compacting like pea gravel. But pea gravel is more than  double the cost of concrete so it doesn't really make sense to do that. 

[ProDave]

Just soil,. all the rubbish stony subsoil mostly.

[Carrerahill]

On 13/11/2020 at 18:50, ProDave said:

It should only be liquid exiting so there is not the usual concern of "solids separating" on a normal drain run.

 

What I found was building control had absolutely no interest in checking the outflow pipework. but probably wise to run the design past them.

 

I would want rodding access less than 45 metres or you will want a lot of rods if you ever do get a blockage.

He suggests the pipe run is 80m long and the field is 1 in 10 - so 8m height difference from plant to stream - I don't think a NRV is needed and would probably cause more issues, I'd just make sure the pipe is exiting into the stream in such a way that a high stream level would not potentially block up the outfall with debris, a simple grate would probably be best. 

[joe90]

1 minute ago, Carrerahill said:

a simple grate would probably be best. 

+1 ?

[PeterW]

1 hour ago, Carrerahill said:

I don't think a NRV is needed and would probably cause more issues, I'd just make sure the pipe is exiting into the stream in such a way that a high stream level would not potentially block up the outfall with debris, a simple grate would probably be best. 

It’s more for animal / rat protection. They can easily get through a grate which is better handled with a 45 bend in the clay to direct the outflow down the course of the stream. 

[Bart1664]

@ProDave

How much noise does the blower vent thing make? acceptable/barely notice it unless you stand next to it?