Groundwater leaking into soil pipe, possibly

[amfisted]

Admittedly just looking for validation of my own conclusions, but here goes.

Heavy rain this morning which necessitated the bailing out of a garden pond. Whilst doing so it occurred to me that I hadn't checked the drain inspection chamber for a while, so I lifted the massive concrete lid and looked inside. I noticed that there was a minor but constant trickle of water through the underground gully, which I traced to the toilet pipe. The toilet wasn't leaking, or flushing and nothing but the toilet empties into that pipe. My conclusion has to be that there's groundwater leaking into the pipe from above, through a crack or open connector. Its way below ground so would take some effort to dig down to the pipe to effect repairs, but in the meantime I'll try to get photos of the inside of the pipe to assess the situation.

Question: if I find that there's a crack in the pipe and it hasn't partially collapsed, would it be a ridiculous idea to line it with plastic drainage pipe as a temporary measure until I can get round to digging it up? I guess it depends on whether modern plastic pipe will fit inside 1960s stone-glazed drainage. I do have some 80mm downpipe, but I guess that would be too small. Is there any other option that wouldn't involve either excavating the pipe or having it lined by a contractor? Its about 2 metres of underground pipework in total.

TIA

 

[Ivor Windybottom]

It's a fairly normal thing to happen.

Is it doing any harm?

Why are you emptying a pond anyway?

You definitely couldn't somehow thread rigid plastic pipe in, it's just not physically possible.

There is a professional way of doing the same thing, they put a liner down with an inflatable sausage inside it, press the liner against the sides with air pressure then a chemical reaction hardens the liner.

Alernatively, better and probably much cheaper, dig the lot up and start again, it's what I did with all our cracked old clay pipes and it's not actually that difficult.

 

[amfisted]

It's a fairly normal thing to happen.

Is it doing any harm?

Why are you emptying a pond anyway?

You definitely couldn't somehow thread rigid plastic pipe in, it's just not physically possible.

There is a professional way of doing the same thing, they put a liner down with an inflatable sausage inside it, press the liner against the sides with air pressure then a chemical reaction hardens the liner.

Alernatively, better and probably much cheaper, dig the lot up and start again, it's what I did with all our cracked old clay pipes and it's not actually that difficult.

Thanks for the reply. Taking your points in order as above:

Not sure whether its normal because its the first time I've opened the inspection chamber when its raining. On every other occasion I've done so in dry weather and there's been no such flow of water. I've just opened the chamber again about 2 hours after the rain stopped and there's nothing coming out of the toilet pipe at all.

No harm done so far no. But if it was a sign of collapse, I needed to know about it.

I was emptying the pond ( there are no creatures in it yet) because the water contains excessive levels of tannin. No idea why.

No, I'm sure you're right re the plastic pipe. Silly idea.

I'd rather replace the pipe myself than get a contractor in. I know that the procedure for doing so isn't that difficult if you plan it properly, because I've done it before several times and at a similar depth. Problem is that I'm considerably older than when last worked on underground drainage, and my back is a good deal more fragile.

I took some photos with my mobile phone after writing my initial post, and I can't see any signs of collapse. My missus suggested that the water might have been entering the system via the top of the soil stack when the rain was at its heaviest, which probably isn't a really daft suggestion.

 

[Ivor Windybottom]

If the pipes are clay and old then, from what I've seen with our 1950s place, they are much more likely to be cracked than not cracked. In fact it's unlikely they're intact.

Ours were cracked all over the place but nothing had collapsed. But if you have trees or bushes in the vicinity then they may have been ripped apart.

You may be able to get someone to stick a camera down if you need to know.

 

[amfisted]

If the pipes are clay and old then, from what I've seen with our 1950s place, they are much more likely to be cracked than not cracked. In fact it's unlikely they're intact.

Ours were cracked all over the place but nothing had collapsed. But if you have trees or bushes in the vicinity then they may have been ripped apart.

You may be able to get someone to stick a camera down if you need to know.

Thanks again. I took some photos yesterday along with a short video, but it was awkward leaning into the inspection chamber and holding my phone upside down to take pictures whilst trying to protect it from moisture, so I didn't manage to get a clear view of the entire pipe. However, the pictures provided some reassurance and I'll let the matter rest, content to monitor the situation each time I check inside the chamber. Unless the toilet starts backing up, of course.

 

[Hugh Jaleak]

If water is only getting in when it's raining, that suggests to me, there is a rainwater pipe connected to the sewer somewhere, 60's build you may still have a Combined system, where rainwater is directed into the sewer rather than a surface water drain.

I really wouldnt worry about it.

 

[GillObrien]

For the pond, if you leave it long enough and throw in some Denitrol or similar, plus some plants, it will clear after about a month . Then it will go green for a bit and eventually calm down. I assume it is new? In this case it is normal to go through this stage. Every time you add new water it will most likely go through the same cycle.

 

[amfisted]

If water is only getting in when it's raining, that suggests to me, there is a rainwater pipe connected to the sewer somewhere, 60's build you may still have a Combined system, where rainwater is directed into the sewer rather than a surface water drain.

I really wouldnt worry about it.

I considered that possibility because it proved to be the case in our previous, detached bungalow, where one mysterious pipe that emerged into an inspection chambers turned out to be a groundwater drain. However we now live in a semi, and the rainwater disposal system is very simple: straight gutter runs front and back, one downpipe at each end front and back. Originally there was just one downpipe at our neighbour's end but I've installed our own downpipes because our neighbour's gutter was choked with moss from her roof, which resulted in our gutters overflowing. She's since had her roof replaced, so no more moss.

I'm pretty sure there are no other pipes underground, but thanks for the advice anyhow, and I can confirm that I'm no longer worried about it.

 

[amfisted]

For the pond, if you leave it long enough and throw in some Denitrol or similar, plus some plants, it will clear after about a month . Then it will go green for a bit and eventually calm down. I assume it is new? In this case it is normal to go through this stage. Every time you add new water it will most likely go through the same cycle.

Thanks for that. It is a new pond, its been in place about eight weeks and the colour of the water is brown rather than green, so not algae. I've asked the pond goods suppliers for advice and they suggested that I performed a simple test: take a glass or jar of the pond water, and there's no sediment on the bottom after a few hours then the problem is tannin. Which turns out to be the case, and the advice I've been given is to remove and replace small amounts of water until the tannin eventually clears.

 

[GillObrien]

Good luck! Mine was brown for about a month (I did the same test with the jar) and it wasn't sediment or algae, and it did clear eventually. Just in case - be careful adding chlorinated water from the tap. I made this mistake just after it had finally cleared and it killed off all the good bacteria that had built up in the pond and I got loads of nitrates in there and it went green. I had to wait another month for it to clear again! I think this only happens if you add too much at once.

 

[amfisted]

Good luck! Mine was brown for about a month (I did the same test with the jar) and it wasn't sediment or algae, and it did clear eventually. Just in case - be careful adding chlorinated water from the tap. I made this mistake just after it had finally cleared and it killed off all the good bacteria that had built up in the pond and I got loads of nitrates in there and it went green. I had to wait another month for it to clear again! I think this only happens if you add too much at once.

Thanks once more for that great advice. On most occasions I top up the pond from a rainwater butt, though I admit to adding the occasional sneaky bucket from the garden tap. The water does appear to be clearing, albeit very slowly, so I think we’re on the home straight..