Occasional Use Sewage Treatment

[RossMcO]

Hoping to have PV, but will need another building for that, as our monopitch roof is north facing.  National Park rules prohibit any new structures without explicit permission.  

 

Consensus of the discussion remains on the aerated system.  

 

Cheers.

[Russell griffiths]

I believe there was some discussion about the bio rock clogging up with gunk, those bags needed changing far more frequently than listed. 
 

what service are you talking about, that’s just a big con, it’s a plastic tank with an air blower in it, lift lid is it bubbling, ok £200 please, just not needed. 

[RossMcO]

@Russell griffiths perhaps, and I applied little critical thinking to the comments from the supplier, but...he wasn't buying or selling, all servicing would be from a third party, so he was a relatively honest broker.  My situation at least initially will be complicated by long absences, and having confidence that I won't arrive to find a non-functioning system has value. 

Also, I suspect he was overestimating the dosing required, as if there might never be any use, rather than occasional longer gaps.  So maybe one cartridge per year, and an inspection/pump out as needed.   Do average users normally have a service contract to cover inspection and any maintenance needed?

 

In general though, I agree with you - I'm starting to get a better appreciation of the complexity, or lack thereof, of the different systems.  Simpler is better, fewer mechanical parts better than more, simple service access better than in tank components, no electricity better than power being needed.   

 

But, beyond all of that, the real life experiences of the community carry most weight, and at least for the active posters on this topic, aerated systems seem to be much preferred.   

 

Ross.

[Russell griffiths]

I have 3 sewage systems I have to look after, two are old septic tanks, the third is the new treatment plant I installed. 
 

they are like chalk n cheese, the treatment plant just sits there bubbling away, I can’t see it needing emptying in the next few years, there is zero sludge in it, it is not in heavy use at the moment as I’m the only one here at the moment. 
 

But as long as it has a power supply there very little to go wrong with it, I’ve had numerous problems with other things on site, but not that. 

[SteamyTea]

Going back to my ignorance of organics, does the amount of water in the tank make a difference?

My thinking is that if it dries out too much, the sludge gets thicker and probably more sticky. Harder to blow bubbles though as well. 

Would some sort of extra water dosing be helpful? Should be easy enough to make.

[RossMcO]

Thanks Russell, that's a very helpful data point.

 

To @SteamyTea's additional fluid question - this also seems rational to me.  Maybe I could have someone go in and flush everything a couple of times once a month or every couple of weeks, or try and rig a system to run water from some source or another periodically.

[JamesP]

I fitted a Vortex treatment plant in 2020. https://www.wte-ltd.co.uk/sewage-treatment-plants/vortex

I was initially a bit sceptical as it seems very basic but in use for 5 years it does the job well.

Have emptied it once and cleaned all the plumbing components with a pressure washer and replaced the air regulator (Free from WTE) as the original was a poor quality component.

Apart from the compressor not much to go wrong.

Requires electricity, about 30W an hour.

[saveasteading]

It has about 2m3 in it, underground so will not dry out significantly in a year.

Close all indoors plugs to keep the u bends wet and avoid smells.

For tiny use, i'd be inclined to install a blower type, and never get round to putting the power in, maybe run a cable in the trench for later. It will work away in its own time. 

[SteamyTea]

46 minutes ago, RossMcO said:

Maybe I could have someone go in and flush everything a couple of times once a month or every couple of weeks, or try and rig a system to run water from some source or another periodically.

We have automatic flushers on the men's urinals at work.

if a bog is left too long, the U-Bend dries out and they start to smell, so may be worth looking to see if there is a ready made solution (pun intended).

[RossMcO]

45 minutes ago, saveasteading said:

It has about 2m3 in it, underground so will not dry out significantly in a year.

Close all indoors plugs to keep the u bends wet and avoid smells.

For tiny use, i'd be inclined to install a blower type, and never get round to putting the power in, maybe run a cable in the trench for later. It will work away in its own time. 

For 'tiny', I'm reading 'low' use.   The challenge is that while there will be empty periods, there will also be periods of potentially full occupancy, so up to 8 adults, plus any weans that emerge in time.  That will drive periods of heavy usage, so we will need to size the system to cope with that while trying to make sure we avoid issues related to low flow periods.  @Russell griffiths's experience seems to be that it isn't such a major issue, and I'll have other things to worry about more. 🙂  

[crooksey]

Ross, just get the Graf and get the dosing system.

 

You can even fit remote monitors to alert you of any failures.

 

I have the 9PE personally and it is a great system. You can even control the discharge time, to suit. It has loads of capacity in there, for instance, I can empty two full baths, shower, washing machine etc and it leaves me loads of capacity. 

 

[saveasteading]

1 hour ago, crooksey said:

It has loads of capacity in there, 

Isn't it always full? Whatever goes in one end, the same comes out of the other?

 

@RossMcO it's right to ask the questions. But stop worrying. Any of the big makes will do the job for a full house. You only have to decide if you risk turning the air pump off when nobody is there. 

I would. Nothing will get worse and no liquid will come out.

The only risk is of the crust hardening a bit....or maybe the pump forgetting how to work  put it on a timer?

Nobody will die and the kit will still work.

 

I've only ever used Marsh products. I'm sure our clients don't look after them and they keep working. The old ones didn't even have air pumps, if I remember correctly.

[dpmiller]

5 hours ago, saveasteading said:

Isn't it always full? Whatever goes in one end, the same comes out of the other?

Kinda.

 

With an SBR (small batch reactor) plant, the unit aerates/settles a number of times, before a longer settle and then a timed pumped outflow. With our Solido, there's about a foot of level difference between the normal pumped/ controlled level and the "safety overflow" level that the liquid ends up at during a pump or power failure

[saveasteading]

1 hour ago, dpmiller said:

With an SBR (small batch reactor) plant

So I'm still learning. How have I not known about these?

Is this batching supposed to be more efficient?

[dpmiller]

Different way of skinning the cat really. There are savings in electricity obviously and ours seems to do well without the various recirculation paths that the likes of the Conder have.  I've yet to see any floating residue on the liquor, it's always a seething mass when aerated and settles quickly to clear water before discharge.

[RossMcO]

@JamesP~Thanks James, Vortex hadn't made my list until you mentioned them. 

For the others, and to keep you all up to date, I'm trying to get in touch with the company that the architect uses for SEPA calculations, so far haven't had a response to email, but will keep on at them.  

 

From their web-site, they seem to be Kingspan reps, so that might go some way to explaining their recommendation.

 

I think all of the systems will do the job, and the majority of the cost is installation (at least in my location and with the quotes I have) so it's not really an economic decision.   I favour the aerator system whether from Graf, Marsh or Vortex might end up being as much to do with local supplier and support as anything else.

[JamesP]

On 05/02/2025 at 15:45, saveasteading said:

The only risk is of the crust hardening a bit....or maybe the pump forgetting how to work  put it on a timer?

Nobody will die and the kit will still work.

Thanks @RossMcO. The above sums it up for me.

 

[Roger440]

4 hours ago, RossMcO said:

@JamesP~Thanks James, Vortex hadn't made my list until you mentioned them. 

For the others, and to keep you all up to date, I'm trying to get in touch with the company that the architect uses for SEPA calculations, so far haven't had a response to email, but will keep on at them.  

 

From their web-site, they seem to be Kingspan reps, so that might go some way to explaining their recommendation.

 

I think all of the systems will do the job, and the majority of the cost is installation (at least in my location and with the quotes I have) so it's not really an economic decision.   I favour the aerator system whether from Graf, Marsh or Vortex might end up being as much to do with local supplier and support as anything else.

 

Ive got (well did have until i moved) a Vortex. I wouldnt get another.

 

But as you asked earlier about maintenance contracts, no i didnt. I looked after it myself. Its not rocket science. Im inclined to agree you are over thinking it. Install, turn on, put the plugs in the sinks and leave.

 

Im not a fan of turning it off. That was when i had issues, with stuff settling, and blocking the sludge return, and on one occasion the bubblers. Easy enough to fix, but its an intervention you dont want or need.

 

Other plants maybe be more forgiving of turning it off.