Failed septic tank & soakaway - replacement issues!

[Caroline E]

Hi everyone,

 

I’ve been reading a few threads on here in search of potential solutions and thought it might be wise to post my issue in the hope that someone may have some advice. We moved house about 8 months ago (Angus, Scotland), to a rural barn conversion with a few other properties around. We have a septic tank and foolishly didn’t have a tank inspection before buying. We just checked it was registered with SEPA and that soakaway which is in a neighboring field is in the deeds. Well it turns out the soakaway is ruined - the field’s owners alerted that something didn’t right about a month ago. We had the tank emptied and have a collapsed baffle. At first we thought we were looking at replacing the tank and soakaway which would be bad enough, but it turns out there are further issues. Our deeds only specify the corner of field where our current soakaway is located, and this is far too saturated to reuse (we’ve been advised that even a mound would be likely to fail), and the field’s owners won’t permit us to use another part of the field. Sadly our own garden is too small to fit a soakaway, especially as it is bounded by a road, so taking of the distance it has to be from the house and boundaries leaves about only a meter wide! So we are looking into a couple of options;

1: to upgrade to a sewage treatment plant and drain to a ditch. The catch being the closest ditch is about 150 meters away and would involve pumping up a slight incline. The other is 250 meters, mostly down a slight slope, but there is a rise of trees in the way too. The neighbours who own the soakaway field also own the woods beyond and are happy for us to drain to a ditch there, but we don’t actually know of any (they’re not on google maps). Hopefully over the holidays we can meet with them to see if they know of any, and assess how feasible it is. They have also mentioned the possibility of creating new drainage ditches.

2: there is another neighbour behind us (who we share a driveway with) who owns another couple of fields. We are thinking we could offer to add them to our treatment plant (it would still be the same size) for free if it means placing the soakaway in their field. The soakaway would need to be larger of course, but it beats having having a house with no sewage which is becoming a serious concern!

 

Luckily, there are no issues in the house yet and water is still draining away (I’ve watched it through the inspection hole after a bath!), but we’ve been told it’s only a matter of time until things back up. So I’m after any advice! I was wondering if anyone has experience of draining to a ditch that is a similar distance away and/or maybe needs pumping uphill. Does it work, what we’re the install costs, what are the running costs, what happens if the pump fails? Has anyone gone through the process of getting approval from SEPA to drain to a any hints? Also, does anyone share a treatment plant/nothing I would be aware of? We are also open to any other creative solutions, as ultimately we need to figure something out!

 

Many thanks in advance to anyone who can help:)

[joe90]

I think you will find that treatment plants are all that’s allowed nowadays, we have had several letters reminding us that if we have a septic tank it needs modifying/replacing this year. We installed a Vortex treatment plant and drain to a ditch that is dry a few months a year (via a rumble drain) and that works very well.

[ProDave]

A treatment plant to a stream is by far the best solution if you can find a suitable watercourse. Generally SEPA don't like you discharging to a dry ditch, but at least one person on here has achieved that.  SEPA will start by saying you must discharge to land, and will then ease there position as the options are ruled out. We had to go through that process to get permission to discharge to the burn through our garden.

 

You best bet is put your boots or wellies on and go walking for a suitable stream first. Then you can start negotiating with the owner of the land about access rights.

 

A pumped output system should not be a problem, many treatment plants are available with the pumping gear integral to the treatment plant, and you only need a small diameter pipe, often something like 50mm mdpe for example.  But you will need to check with the manufacturer how far and how high it can pump.

 

Are any of the other houses having issues?  it sounds like the ground used was probably not best suited to a soakaway in the first place.  If so a communal effort may be the best approach.

[Caroline E]

Thanks @joe90, as I understand it treatment plants are only required if draining to water, although we’re happy to upgrade regardless. @ProDave, that’s good to hear. As we have no land of our own and the spot in our deeds in no good, draining to a watercourse/ditch seems the only option. There is a burn but it’s about 300 meters away and down a big ravine. I’m hoping there might be a smaller watercourse or ditch in the woods though. There isn’t really a footpath there and I didn’t want to go wandering around without the owners, but I don’t hear from soon I might just do that!

[ProDave]

Scotland has the right to roam, so just get your boots on and with respect go for a wander and see what you can find.

 

Have you looked on the OS maps? any watercourse of any significance should be shown there.

[Caroline E]

Thanks @ProDave, just checked OS maps and it only has the same watercourses as google. Hopefully one of these will work if no others. How far is too far I wonder?  I’ve attached a screenshot showing our location and the soakaway in red. Looks like it’s time to go for a wander this week:)

[Jeremy Harris]

We have a treatment plant, that drains to a small stream.  Getting consent from the EA to do that here in England was dead easy, but @ProDave had more of a struggle getting consent from SEPA to do the same, although I believe that things may now be easier there than they used to be, especially if there's no other practical solution.

 

Our treatment plant has a pumped outlet - just needs a run of 50mm MDPE pipe out to the stream, ditch or whatever, so not a major engineering job to install.  IIRC our treatment plant, with the pumped outlet option, cost around £2.5k, plus installation.

[ProDave]

I would be aiming for the stream running down the side of the wood, as high up as you can get, somewhere near Nursery house.

 

It looks to be a downhill run. But using a pumped outlet treatment plant should mean you can do that all in 50mm mdpe.

 

 

[Caroline E]

Oh, also wondering what treatment plants people recommend? The company we’re thinking of going with suggested either a Klargester Biotec or condor. Any thoughts? 

[ProDave]

I would recommend one that works with an air blower, and avoid at all cost, those that have moving mechanical parts down in the smelly stuff.

 

I have a Conder, @joe90 is happy with his Vortex, and several have the Biopure.  Graff and a few others also make air blower treatment plants.

 

Check that whichever you choose has an option for pumped outlet built in rather than having to have a separate pumping chamber.

[Caroline E]

2 minutes ago, ProDave said:

I would be aiming for the stream running down the side of the wood, as high up as you can get, somewhere near Nursery house.

 

It looks to be a downhill run. But using a pumped outlet treatment plant should mean you can do that all in 50mm mdpe.

 

 

Thanks @ProDave the only catch with that one is it’s in a gorge about 50ft or more deep. There is a drainage ditch at T junction at the end of the rd that I presume drains to this, so we could aim for that. That’s not too far then in people’s opinion?

[PeterW]

Sorry for the bad drawing but why can’t you go the other way ..?? Could easily get to the other end of the one to the left ..??

 

[Caroline E]

5 minutes ago, PeterW said:

Sorry for the bad drawing but why can’t you go the other way ..?? Could easily get to the other end of the one to the left ..??

 

Hi @PeterW, this was my first thought. The only slight issue is here is that means going up a slight incline, so not sure if this means a bigger pump/high running costs? But is is only about 120 metres away and looks to have a good flow rate. We’re also not sure who owns the verge (it’s a private rd) as apparently it was sold recently but no one knows who too! But if folk here think this isn’t an unreasonable distance and that pumping up a slight hill is feasible that’s great to hear:)

[Jeremy Harris]

Pumping up an incline to a head of 10m or so isn't usually a problem.  The pump on our unit is the lowest rated one they do and will easily pump to 8m head: https://webuildit-ltd.co.uk/product/bio-pure-1-pumped-outlet/

[Ed Davies]

In my limited experience SEPA will want some sort of filter on the output of the treatment plant as a sort of belt-and-braces thing. For me they want a 50m rumbling drain, @ProDave needed a bit less. I'm not sure how that'd work combined with any pumping.

[joe90]

In England we had to have a 10m rumbling drain purely because the ditch dried out in the summer.

[ProDave]

We were just to to discharge to the burn via a "partial soakaway" with no size mentioned.

 

The reality is it passes through a soakaway and anything that makes it to the other end goes to the burn.  In the summer it does indeed attenuate the flow to the burn, but in winter it probably acts as a land drain to limit the local rise of the water table in that area and probably more comes out of the end into the burn than goes in from the treatment plant.

[Stewpot]

5 hours ago, joe90 said:

...we had to have a 10m rumbling drain...

 

What's a rumbling drain?

[Ed Davies]

Bit like a French drain: pipe with perforations surrounded by gravel or whatever to allow mixing and dilution of waste water with surface water and to generally slow the flow down. Allows a certain amount more treatment of the water as a backup to the treatment plant.

[Caroline E]

Quick question, can a treatment plant discharge to an existing land drain? We have an old (clay?) one just opposite running along the side of the road, right outside the house. I know Where it is because it is currently blocked so other neighbours have it exposed for repairs.

[Temp]

7 hours ago, Caroline E said:

Quick question, can a treatment plant discharge to an existing land drain? We have an old (clay?) one just opposite running along the side of the road, right outside the house. I know Where it is because it is currently blocked so other neighbours have it exposed for repairs.

 

That sounds very much like a "piped ditch". Commonly done when rural roads were widened. Where does it run to? 

 

We only had an issue with rainwater and proposed a rainwater recycling tank with overflow into the piped ditch that runs under the edge of the road in front of our house. This was allowed. The rainwater tank is only used for watering the garden and washing the car so its always full. They didn't insist on storm attenuation so the end result is similar to a straight discharge. 

 

If there is space you might consider proposing a treatment plant discharging to small soakaway with overflow to this piped ditch? They might be more willing to accept that than a direct discharge?

 

Edited December 23, 2019 by Temp

[Caroline E]

Thanks @Temp that sounds similar, there is a ditch on the other side further down, so it makes sense there would have been something similar here. It runs towards the burn that I know 3 or 4 new builds already drain into (they are closer). We don’t have space for a proper soakaway but the water would need pumping up a slight incline to the top of our drive (about 20 metres away from where the waste pipe exits the house and the treatment plant will likely go) and then under the road. We could put this under a small patch of ground where we have our chickens and maybe use a rumble drain for 10 metres or so to act as a partial soakaway. It’s good to have some ideas to discuss when we next get someone out in the new year:)

[Caroline E]

Hi again everyone. We have made slight progress over the holidays in that we have found a ditch with reasonable flow starting in the woods just south of the field with our failed soakaway. It is about 80-90 metres away however (on pretty horizontal ground) and we’ve been advised that a pump station would likely be required therefore. I wondered if anyone here (@ProDave)has experience with pump stations? I’m keen to get a rough idea of the running costs involved. Thanks in advance:)

[ProDave]

We have a pump station in our old house.  That is because the soakaway is in the field behind the house and about 3 metres higher.  It was a stand alone pumping station I believe made by Titon, just a holding tank in the ground with a submirsible pump.

 

We did go through a series of pump failures and after the second one I just fitted cheap pumps from screwfix, but last year I investigated further and found a blockage in a pip fitting, it was in fact a non return valve that had failed and blocked.  Since sorting that out it has been working fine.

 

Since you will be changing to a treatment plant, many are available with a pump station built in so that would be a neater solution.

[PeterW]

@Caroline E have you fully ruled out reinstating the existing leach field ..? It may be much quicker and cheaper in the long run and is less complex as you already have easements etc in place. 
 

You say it’s waterlogged but at what level ..? Is this due to groundwater it is it due to a failure in the septic system ..? You could rebuild the existing leach field with a decent granular backfill around the pipework and find It works fine - just go between the current outflow pipes and leave the old ones in situ.