length of septic tank soakaway

[dtl]

Hi,

I am in the process of buying a small cottage in Rural Scotland.

Drainage from the house is to an old brick septic tank which is within the garden.
The cottage was built in 1850, at a guess the septic tank and associated system is at least 70 years old.

The title deeds describe a servitude right to maintain the tail pipe from the septic tank.
However, this tail pipe is not shown of the title plot plan drawing.

I asked the Vendors to show the approximate location of the tail pipe/soakaway on a drawing.
They have produced a sketch which shows the tailpipe being only 2m long and just terminating at the garden fence, which separates the garden from the adjacent farmer’s field.

My question is; I thought soakaways were generally quite a lot longer than 2m.
Is it possible that the soakaway is only 2m long and it would adequately function at this length, I.E in the olden days maybe soakaways were built this short?
Or is this unlikely?

Thanks

 

[Flyfisher]

I'm no expert on the construction of septic tanks so my comments are based only on our house having two, both of which are functioning and neither have caused any problems apart from a couple of occasions when I left them for too long before having them emptied (normally every two years).

I've also wondered about the outflow arrangements and have no real idea what they are for our tanks, except to note that in very hot dry summers when the grass has turned brown the area close to and around the septic tank remains quite lush, presumably from the tank outflow, suggesting that any pipes forming a 'drain field' must be fairly short (or perhaps leaking close to the tank! ).

I suspect much depends on the nature of the soil. Ours is very sandy and free-draining. We can have a torrential downpour all day and the ground will be fairly dry the following day. If the soil was heavy clay and poorly drained then I suspect we'd have problems, but presumably such things were well understood when the tanks were built and the drainage field would have been designed and built accordingly.

One thing to check is whether surface water drainage (ie downpipes and patios etc) drain into the septic tank or other soakaways. Ideally they should not drain into the septic tank, though we have a small section of roof that does but we seem to get away with it.

If the septic tank has functioned perfectly well for around 70 years and remains structurally sound then I wouldn't worry too much about it. I know that's easy to say because I had similar concerns with ours at first, but nearly 20 years on with no problems I've long forgotten about them. In fact the only 'worry' I have now is remembering to have them emptied every couple of years.

 

[a twig]

Depends on the construction of the soakaway - drainage “fields” only became a requirement in the last couple of years, before that a soakaway was allowed - basically a big hole full of gravel and rubble) and 2m away isn’t unusual.

Solicitors often recommend a drain survey of such systems before buying, but there is also an argument for “let sleeping dragons lie” here.

In one friend’s case a perfectly functional but old system was declared non-compliant with current legislation and they ended up having restrictions placed on them to remove the old pit and install a new sewage treatment system within 6 months of completion. They had to hurriedly find an extra £20k to get the work done.

Obviously an extreme example but depending on your financial situation and how much you want the house there can be an argument for not investigating too thoroughly too early and then keeping your head down and addressing any issues once you are settled in and can do so under your own budget and timescales.

Alternatively if finances are tight and you aren’t dead set on this house being “the one” then get the survey done and adjust your offer appropriately according to the outcome of the survey

 

[dtl]

Thanks for the responses.

I like the idea of a drainage survey, I'm wondering how a drain survey is performed, is this done with a CCTV camera?

With regards to potentially discovering a non compliant system if we pursue this too deeply;
I'm a bit confused by this as the septic tank is registered and the certificate mentions that drainage should be via a soakaway.

I cant see that the council can enforce that a historical soakaway should be to current standards, as this would mean 1000's of homes would have non compliant septic tank drainage.

What am I missing?

Thanks

 

[a twig]

Requirement to bring system up to modern standards kicks in when the property is sold

 

[a twig]

So you can happily live with a system that was compliant when it was installed for as long as you like.

When the property is sold though it needs to be brought up to standard:

Good overview here although I obviously don’t recommend selling your house to bettermove…

Selling a House with a Septic Tank: 2025 Guide

Selling a house with a septic tank is not impossible but it can be made harder if it doesn’t comply with the 2020 laws. Find out how to get compliant.

www.bettermove.co.uk

And then there is loads of lovely detail if you search on “General Binding Rules” for septic tanks on gov.uk

 

[a twig]

I would say that the article is a little light on detail and a bit alarmist as I’ve never known any domestic septic tank owner get fined as the EA generally realise that fining the wotsits out of someone means they won’t be able to afford the necessary remediation

 

[dtl]

Thanks for your response.

The general binding rules apparently don't apply in Scotland

 

[a twig]

Good to know! I’d assumed the EA and SEPA would be aligned, shows the danger of assumptions and all that.

A quick Google seems to give the impression that SEPA are a lot more relaxed and it looks like in Scotland as long as it’s registered with SEPA and has a certificate than you’re fine?

 

[dtl]

Yes I believe so, as long as the discharge meets what is stated on the SEPA certificate.

The only place I can see it going wrong is if the discharge from the septic tank was discharged direct into a ditch or watercourse, because the certificate specifies the use of a soakaway.

Having said that I'm not 100% on the above.

 

[a twig]

As it’s more of a paperwork issue then I’d be inclined to take the opinion of your solicitor on this.

I suspect he or she will recommend a drain survey to ensure that the system matches the paperwork and is all in good condition then you’re good to go.

 

[a twig]

And to return to your original question, if it’s a soakaway type then 2m isn’t unusual, if it’s a drainage field that goes into the adjacent agricultural land then it’ll just be a matter of confirming the access is in place for any future maintenance required, which it sounds like it already is from that servitude right.

 

[dtl]

It has been suggested that in the 2m situation that it might just be a 2m long pipe which then dumps to a rubble filled pit.
Although the certificate from SEPA is conditional on the use of a soakaway, do you know if a rubble filled pit counts as a soakaway?

For sure I am going to encourage the vendor to perform some kind of survey, I'm thinking a CCTV survey could fail due to the age of the system/roots/rocks/blockages etc.

I don't suppose you know if ground penetrating radar is ever used?

Failing the above I guess it will have to be hand dug at spots to trace its path.

 

[a twig]

Pretty sure a rubble filled pit does count as a soakaway - the plastic crates that people use nowadays are a relatively recent thing, they were all rubble and gravel filled before they came along.

There are all sorts of techniques used for a drain survey, flushable sensors, CCTV, sonar systems etc, the surveyors will use different techniques to map the system out and then assess its condition

 

[a twig]

I wouldn’t worry about what ifs in terms of blockages etc until the survey is done.

If there are blockages, roots etc then finding out about them now is exactly what the survey is for so you can make a plan to resolve and negotiate with the vendor as required

 

[dtl]

Twig and Flyfisher, Thanks for all the input on this thread.

I'm working on getting the vendors to perform a drain survey.

However, to plan ahead a bit.

We know the tank is an old brick tank.

The current set up is fully licensed by SEPA.

After the survey if we find out the soakaway is only 2m long, then I'm pretty confident that the system cant be upgraded if constrained within the garden, because a 2m soakaway is not going meet the requirements.

The property will be an unlet 3 bed holiday cottage probably only occupied for 8 days a month.

The septic system has probably been there for at least 70 years and has probably been working fine.

If it was to have problems in the future will it be possible to maintain my way out of any problems, ie repair the brick tank?

And, if a 2m soakaway stops working can I not dig out all the muck and replace it with fresh stone?

Thanks

 

[montyjohn]

Requirement to bring system up to modern standards kicks in when the property is sold

This isn't true. Get's repeated often, but all wrong.

It needs to follow 2020 binding rules (England). not sure about Scotland.
This is not the same as needing to meet current regulations.

For systems installed before 2015 the binding (England) rules state that it must be original (not recently modified), not moved and no increase in volume, no more than 2000l per day and it must not be causing pollution. That's it.

So if it doesn't smell, not ponding anywhere and you've not been told by the EA to sort it, then you're fine to sell with no changes.

Word of warning, any improvements to the system and you need to meet current regulations.

Leave it well alone.

 

[a twig]

Splitting hairs a bit here - in England if you are selling a property then it must comply with the binding rules and it’s the responsibility of the vendor to make sure it does.

Most folk who should have upgraded their systems in the 1 year period since the 2020 changes around water courses etc will not have received a visit from the Environment Agency to check that their systems were upgraded so the reality is they end up having to upgrade their system at the point of sale as that’s when it comes under legal scrutiny.

But OP is from Scotland so none of this applies.

Generally agree with the thrust of your post though as per my original response - as far as septic systems go in England, as far as possible let sleeping dragons lie

 

[a twig]

France is a whole different kettle of fish and the responsibility is on the vendor to resolve within a set period (usually 6 months). It’s a fair bet that whenever you see a cheap Chateau in France it needs a new roof (often €100k) and has a non-compliant septic system (often €40k)