Septic tank is actually connected to the mains! How much trouble will I be in not paying for sewerage!

[AgentPidge]

When I bought my house it was advertised as having a septic tank/private sewerage in the garden. The previous owners (an elderly couple) said they'd never had to have it emptied, which seemed a bit odd. When I moved in I took over their water account and only pay for water and not sewerage. (Houses around are all on the mains but mine was built in someone's garden.)
During the buying process there was a (separate) query about right of way over part of the drive. My conveyancer was hopeless and in the end I traced the builder and rang him. During the conversation he said that when they were putting in the septic tank they'd come across the main sewer in the garden and connected it up! So the waste goes into the tank but then the liquid gets siphoned off and treated. I don't know if the previous owners knew about this. Anyway, a couple of years ago there was bubbling in the garden and I got a firm in to pump out the tank (full of baby wipes!). They confirmed that it is connected to the mains. What do I do? If I confess to the water company, how far back will they charge me? If I want to sell, I don't want to have to lie. I don't feel I can aske the water company! TIA

honestly, you need to contact the water company because the situation isn't going to change and the longer you leave it the more you potentially owe. Say you suspect you're connected to the mains but have been told otherwise. I expect they'll send someone out to dye trace to confirm that you are.
The builder is in the wrong here because they shouldn't have connected to the mains without permission from the water co.

You need to contact the water company - you've also known about for the past two years, why didn't you get in touch with them then? I think they can only back bill you for six years. It wouldn't be fair to leave this mess to your purchaser.

Of course it was wrong of the builder - he was laughing when he told me! I'm annoyed they didn't do the right thing (and there are other obvious short-cuts they took inside the house).
I've kept putting off doing anything about it because it's easier to let sleeping dogs lie than to poke a hornets nest (to mix metaphors).
I could get a plumber friend to seal off the tank and bypass it. Then I'd have to contact the water company. Or could get it sealed off and not say anything, but that's just kicking the can down the road, and I want to do the right thing. I'm really not looking forward to contacting them and wish I knew what they'd say.

OK - I know what I'm going to do: contact the water company and say the man who pumped out the tank told me. Which he did. If my conveyancer hadn't been so useless I would never have found out before that.
Thank you for your thoughts .

When did you buy?

They should be able to bill the previous owner for most of it surely?

Also, you were misled by their solicitor.

Cross post, yes you should definitely do that

Yes, and estate agent. I don't want to involve the previous owners as one of them has dementia.

That’s very kind, but you might have to
You shouldn’t be responsible for their debt to the water company

I’d get it sorted that random drain could be connected to anything
it’s probably a rain water one for roads

and if it's surface water then you really shouldn't be discharging wastewater into it!

I hear what you're saying but it's definitely the mains sewer because I found a map online and the mains sewer does go across a corner of my garden, near the tank.

Hmmm, yes, how do you know to trust the builder in what he is saying now? I don't think 'how much will they charge me' is your biggest concern here tbh. Although the illegal connection to the system was not done by you, and presumably your conveyancer bears some responsibility, that is going to be a real issue. What a nightmare, I hope you get it sorted.

Now that you know the truth about the septic tank, you would be best contacting your water company and informing them of this situation.

I am suggesting this, because the issue was not caused by you, you were miss-lead at the the time of purchasing the property so, you should not be liable, It was not your fault.

However, you need to 'cover yourself' by being honest with the water company and declaring what you know, so they do not hold you accountable.

Honesty, no matter what is always best policy.

We sold my mil house a few years ago after she died. She had lived in it for 30+ years from new and never paid sewerage. No idea why as there was no septic tank. We just filled in the paperwork when we sold and left it at that. No one ever came back to us!

I'd be tempted to get a quote for fixing the septic tank, and estimated emptying costs per year to compare to sewerage costs. Prioritise fixing the problem one way or the other first, rather than worrying about whether I owned up to something I didn't previously know about.

If the cost doesn't favour fixing and emptying the tank, then a problem has now occurred with your previously fine septic tank and you are considering connecting it to the mains now rather than rectifying the tank issue.

Is the tank only discharging to the mains when it reaches overflow height? Ours was built in the 1950s and had never been emptied until I arranged it last year, the overflow (mainly when it rained and large amounts of surface water got into it from drains on a concrete yard) had been draining from a pipe into a field ditch scorecards and then, when that was discouraged by the environment agency, through a hole in the side of the brick tank into the soil beyond. The chap from the septic tank emptying company said it was bad practice but very common to knock a hole close to the top in the side or add an overflow pipe to reduce water in septic tanks so only the sludge in the bottom (which doesn't increase quickly as bacteria eat it) needs to be emptied occasionally. There was several tons of sludge in ours but no smell o r issue with the soil beyond (it's away from the house). I wonder if your builder added the,overflow so any excess water would go into the mains and reduce the need to empty it?

I don't think that you were necessarily deliberately misled. The previous owners might have told you and the solicitors what they believed to be the truth. Where I live there are many houses with off mains sewage management and I lived in a rented house in the US that was on a septic tank system. The home owner who had only owned the house for some 5 years didn't even know where the septic tank was! Apparently its not uncommon for old tanks to crack or develop corrosion holes and slowly leak and this keeps the level of the liquid down without needing to have it emptied. Its not right of course, may not even be legal but unless there is a seepage showing up somewhere, no one will know.
OP, its unfortunate for you but I think, as has been said, all you can do is talk to the waterboard and take it from there.

Yes I’d do this. Sounds like you have plausible deniability when you bought it.

Id be intrigued to know what they say! Please report back!

ETA - good luck and I think you’ll feel better once you’ve come clean.

You either want fully connected or keep quiet.

No point in paying for sewage treatment if its only the overflow going into the mains.
And paying to have the septic tank maintained.

You found the sewage drawing, the builder and the planners probably also knew it was there.

There's a reason why your house wasn't fully connected to the mains sewer, possibly because being fully connected involved building a massive MH.

I think I'd ask the water company about being connected to the mains sewage and see what they say.

That's a different thought, thank you. I did wonder why they had gone for a septic tank in the first place when there are houses close by that are on the mains.

What's an MH, please?

That's interesting! Yes, that's how it works, as I understand it, in that it's only the liquid that goes into the mains.

MH manhole

Come clean to the water company but say you only found out when the company came in to pump it. You say you bought it thinking it was a septic tank, hence getting a company in to pump

Sorry Manhole.
Where pipes join is often the place where you'll get blockages.
They get round that by having a manhole which depending on the pipe depth could be 6m deep. And if its a main sewer it could be a really big pipe.

I'd definitely try to figure out why it wasn't connected before you say anything.