Septic tank compliance

dlipner

Hi, sorry if this topic has been covered before, but a quick search didn't quite answer the questions I have.

I am currently in the process of buying a house with a septic tank. From the correspondence received via our solicitor, the septic tank drains into a soakaway.

My understanding is that the law changed for septic tanks discharging into surface water in Jan 2020 and all systems must be compliant with the 2010 building regulations H2.

My question is how do you find out if the system is compliant - does it need inspecting, and if so, who is able to do this.

The seller has (under the instruction of the estate agent) had a CCTV inspection of the septic tank up to the soakaway, but I think this is of no use, in terms of checking the soakaway is compliant?

Thanks for the help

AdrianC

Have a read of this...
https://www.gov.uk/guidance/general-binding-rules-small-sewage-discharge-to-a-surface-water

Is it discharging to surface water? Where's the nearest pond/stream/river to the soakaway field?

Mickey666

OP has already said it drains into a 'soakaway', not into surface water, so this information would be more applicable:
https://www.gov.uk/guidance/general-binding-rules-small-sewage-discharge-to-the-ground 

More info is needed about the "soakaway" because the sort of thing used for surface water drainage is not permitted and the more usual approach if to use a 'drainage field'.  

More info here about drainage field options: https://www.ukdpsolutions.co.uk/guides/off-mains-drainage-regulations

dlipner

Maybe the seller has her terminology mixed up and used soakaway from the inspection report, which reads as follows:

..."Attended site to CCTV cesspit upto soakaway. Everything is flowing fine. No signs of water holding or backing up.

Drain pipes all in good condition all up to standard No problems, Cess pit does need an empty."...

To me a cesspit is something completely different to a septic tank, hence why I'm quite confused!

dlipner

There are no streams or watercourses within 400m

Mickey666

Yes, cesspit and septic tanks are very different beasts though the terms are often used interchangeably so definitely worth checking carefully.
Do you know the approximate age of the installation?
Do you know the tank's location relative to the house downpipes?  This might be a clue as to how likely it is that the tank drains into a surface water soakaway rather than a drainage field.   In my experience, it's more likely that some of the surface water drains empty into the septic tank.  This is not recommended but I believe it's allowed.

dlipner

The house was built in 1994 and the current owner moved in 4 years after this, seeing as she doesn't seem to have any additional paperwork, I assume its the original system.

Ive only been given sketch outlines where the tank is, so I can't comment on the tanks location in relation to the downpipes. Out of interest, how could this give a clue?

ProDave

Simple answer there are no changes needed to a septic tank draining to a soakaway or drainage field.

It was septic tanks that drained into a watercourse that should have now been upgraded to a treatment plant.

greatcrested

A soak-away is typically used for run-off from the roof

A drainage field is typically used for run-off from a septic tank.

However the terms are often mis-used.

You can get both septic tank and soak-away/drainage field inspected, just as you can get the house inspected. You may need to get the septc tank emptied either at your or the seller's expense (by negotiation). eg

https://wes.uk.net/off-mains-drainage-home-buyer-surveys/

(others available!)

Mickey666

dlipner said:

The house was built in 1994 and the current owner moved in 4 years after this, seeing as she doesn't seem to have any additional paperwork, I assume its the original system.

Ive only been given sketch outlines where the tank is, so I can't comment on the tanks location in relation to the downpipes. Out of interest, how could this give a clue?

A fairly modern system then.  Regarding the locations, downpipes usually drain into soakaways reasonably close to the house.  If the septic tank is much further from the house it's less likely to drain in to the surface water soakaway. 

If the seller can't give any information about the system then I'd go with greatcrested's suggestion of having the system properly surveyed - although if it has already been CCTV inspected then it sounds as if that might already have been done?  Did the survey company not offer any advice about whether the system is compliant with the latest rules?

As for emptyin, it would seem reasonable to ask the seller to have it emptied before exchange (vacant possession and all that ) but as a minimum ask them who they use to empty it.  It probably won't be very expensive - our local chap charges about £45 and ours only needs emptying every tow or three years, so no big deal and definitely cheaper than mains sewerage costs.

greatcrested

Re the CCTV, it depends who/why it was done. The firm may be a drain supplier/repairer only and not a septic tank supplier so may be unfamiliar with the rules. Their description of a "cess pit" in combination with a "soak away" makes this quite likely. As you rightly say, a cess pit is very different and any company in the sewage management business would understand that.

But their inspection would at least confirm the condition of the pipework and probably the septic tank.

Are you 100% sure you have a septic tank, not a cess pit?

I missed the build date; if 1994 the tank itself should be fine. Drainage fields can fail over time eg if the septic tank is not emptied sufficiently often (once a year or two?) then solids can end up in the drainage field and/or pipes leading to it can get blocked, or if the drainage field was not big enough, or built in inappropriate soil conditions. But that latter is unlikely in a relatively new system.

Asking the vendor to empty the tank might be appropriate if a) you want the septic tank properly inspected or b) it has not been emptied for more than a year (ask to see a receipt), but emptying them too frequently is actually counter-productive.

Unlike a cess pit which needs frequent emptying so it never overflows, a sepic tank works by bacteria breaking down the solids and allowing liquids to escape to drainage field. Frequently removing all the bacteria means it will not work.......

We (neighbour and I) are currently replacing our septic tank with a Small Sewage Works (apparantly the outflow will be so clean you can [almost...] drink it), but our tank was 100+ years old, leaking, the outflow was partially blocked and we have no idea where it actually goes.......