Advice please, sewer pipe and veg roots help

[furball]

Hi, i have an ongoing problem and will try to make it as short as possible. Raised bed built over a soakaway.(or well) Soakaway covered by a very large old flagstone. Pipe leading from the soakaway 12" down which leads to a sewer pipe 5ft away and 4ft lower than soakaway pipe. Sewer pipe has been sliced so it is a U shape not a O shape. Is it safe to plant veg in this raised bed or can gases or germs from sewer pipe get to the roots and make it unsafe to eat the veg?
Because of all the rain i can't plant root veg as the bed is getting waterlogged. I wondered about peas or beans. Many thanks in advance.

[bearded bloke]

That is all very confusing,storm water should only be fed into a sewer through a U or P trap so as to prevent foul gases traveling to atmosphere,from your description I would guess that what you have there is an intermediate manhole.
The cut pipe would be access for roding out blockages,has you house been converted from septic tank to mains sewage.
Have you any pictures ?

[furball]

Thankyou for your reply, you are right there is a manhole. The house has never had a septic tank and i am sorry that i can't take pictures as one raised bed is built above the soakaway. I discovered it last summer when building the raised bed and make the mistake of moving the giant flag that covered the soakeaway. I had no idea what was underneath. I had 2 builders look at it and one said it was a soakaway and the other said it was a natural well. The house is 90 years old and the soakaway looks like it was put in when the house was built and not touched since.The sides of the soakaway are old brick and the pipes are clay. I don't think there is a trap to prevent gasses so i think i will play it safe and get rid of the raised beds. Many thanks again for your reply.

[bearded bloke]

I had 2 builders look at it and one said it was a soakaway and the other said it was a natural well.

There is a third possibility of purpose,it could be a collecting tank to drain a high water table

[furball]

Very interesting, never heard of that. I am not sure if its big enough as i forgot to say its only about 12" square. I am going to have to look at it again, hopefully next month. I will take some pictures as i would love to know what it's for. Thankyou

[veggiechicken]

Sounds daft but do you know whether these pipes still carry water/sewage? I have lots of old pipework in the garden but most of it is not in use as new pipes have been installed elsewhere. We had to lift manhole covers and flush the loo or run water from the house and see if anything came along the pipe. Its worth a try before you do anything drastic.

[furball]

I'm sorry to say this is the main sewer pipe from the house. Checked with pink toilet roll and at a time when neighbours were out. Thankyou

[veggiechicken]

Sorry about that Furball. You'll have to ask an expert!

[furball]

Think you are correct that it is a soakaway for high water level. We have heavy clay in our area and after googling it i read that in heavy clay they were built with a run off pipe to streams or sewer whichever was available. Oh well at least i have a summer project now. Thankyou

[Potstubsdustbins]

The gases from that sewer will not harm your veg. After all its only poop 'human poop maybe' but still just poop. Think about how much solid poop a farmer throws onto his fields and your only have a bit of wiffy gas to worry about.

At the time your house was built there was not much consideration given to separating top water from sewage it all went down the same pipe. It was only as the population increased and the sewage works became overloaded that we started to separate the two and conduct top water into local streams and rivers.

One of the main problems we have now is DIYers and some so called plumbers don't know the difference and plumb washing machines etc into top water drains thereby polluting the local water coarses.

colin