Drainage Field Location Survey

[saveasteading]

9 minutes ago, flanagaj said:

off mains drainage that has caused the problem. 

Just to be sure. There isn't mains drainage nearby? If there is then you must use it. 

The problem is the vendor having done dodgy work before and hoping to fob it off to an unwary buyer. You're not that person so well done.

 

If you really like the site and there is scope to get your own drainage in, then there might be a right price , accompanied by the agreement that you have no liability for theirs.....wherever it might be.

 

[ProDave]

10 minutes ago, saveasteading said:

Just to be sure. There isn't mains drainage nearby? If there is then you must use it. 

The problem is the vendor having done dodgy work before and hoping to fob it off to an unwary buyer. You're not that person so well done.

 

If you really like the site and there is scope to get your own drainage in, then there might be a right price , accompanied by the agreement that you have no liability for theirs.....wherever it might be.

 

If the vendor carries on like that, they could end up in a tricky position without any functioning drainage if an unsuspecting buyer just buys the plot and digs up their drainage field.  Then the man with the paddock could charge what he likes to give them a drainage solution and make their house habitable again.

 

The logical solution to make this plot viable is design a drainage solution for both houses, possibly shared, and the vendor to install it.  The cost is probably a small fraction of the plot value?

 

Out of interest @flanagaj how would you deal with the drainage if you bought the plot?

[flanagaj]

3 hours ago, ProDave said:

Out of interest @flanagaj how would you deal with the drainage if you bought the plot?

Drainage for the plot we are purchasing is not an issue as it comes with a large garden to the right hand side of the proposed dwelling, and there is no other dwellings that side which will cause us a problem regarding it's position.

 

PS - There is no mains drainage nearby.

[crooksey]

If you are building a new house/property building control will only stipulate that new drainage fields/soakaways meet current regs, they wont/don't know about existing. If you build a new house/extension, building control can not know the location of other properties soakaways/drainage fields. Good landscaping from your new build will mitigate a lot of issues.

 

Why not just propose that as part of the deal the existing vendors upgrade to a package treatment pant as part of their works, so you can know the effluent is well treated.

[flanagaj]

Sorry to keep dragging this topic up, but if you were potentially purchasing a plot that will require a sewage treatment plant and drainage field, how do you go about ensuring that said tank and drainage field can physically be installed so that they meet the current general binding rules.  The rules are very detailed, and it only take a single mistake, and you are then in a whole world of pain.  If I understand things correctly, is it the Architect who submits the proposed location to Building Control to ensure it meets the required rules?

I am just concerned that I have not seen any documentation from the vendors we are buying the land from, regarding whether this has been signed off and is all ok.   British Geological Survey and some trial holes dub on site have shown that it's a chalk bed, but that is only half of the battle.   The environment agency has a whole list of things that need to be met, before you get the green light.

I could be over analysing things, but my sceptical mind starts getting paranoid that we will buy it and then find we cannot build the house.

[ProDave]

38 minutes ago, flanagaj said:

Sorry to keep dragging this topic up, but if you were potentially purchasing a plot that will require a sewage treatment plant and drainage field, how do you go about ensuring that said tank and drainage field can physically be installed so that they meet the current general binding rules.  The rules are very detailed, and it only take a single mistake, and you are then in a whole world of pain.  If I understand things correctly, is it the Architect who submits the proposed location to Building Control to ensure it meets the required rules?

First plot we bought 20 years ago, the vendor had already done percolation tests and deigned a system with a drainage field under the field behind us, and already negotiated a right of servitude with the land owner to allow that.  So that one was low risk.

 

Recent plot, no such pre planning.  We bought the plot because we wanted it, it was 2 doors up the road from our first build, so we already knew the geography.  It was a larger plot, with enough toom for a drainage field on our own land.  BUT it has a seasonal high water table.  We got outline planning on the basis of building a filter mound drainage system in our garden.

 

Come to building regs time, they rejected that, and a second alternative plan.  Squeaky bum time, plot with no building warrant.  It was solved for us  by SEPA allowing a treatment plant discharging to the burn running through our garden.  Up here they only allow discharge to a watercourse if there are no other options.

[crooksey]

On 16/04/2024 at 21:22, flanagaj said:

Sorry to keep dragging this topic up, but if you were potentially purchasing a plot that will require a sewage treatment plant and drainage field, how do you go about ensuring that said tank and drainage field can physically be installed so that they meet the current general binding rules.  The rules are very detailed, and it only take a single mistake, and you are then in a whole world of pain.  If I understand things correctly, is it the Architect who submits the proposed location to Building Control to ensure it meets the required rules?
 

 

If the plot already has planning, you are usually fine, its not as scary as you think.

 

Building control usually happy with any expert on site percolation tests and suitable plants. There are lots of places a plant can go, if the ground is suitable and has passed a percolation test, contact the people who did it and ask if they have any recommendations for drainage filed location etc, or if they can put you in touch with a suitable contractor. 

[flanagaj]

8 hours ago, crooksey said:

 

If the plot already has planning, you are usually fine, its not as scary as you think.

 

Building control usually happy with any expert on site percolation tests and suitable plants. There are lots of places a plant can go, if the ground is suitable and has passed a percolation test, contact the people who did it and ask if they have any recommendations for drainage filed location etc, or if they can put you in touch with a suitable contractor. 

The issue is not with the drainage field of the proposed house, but with that of the neighbours.   The image below shows the current location of their drainage field in relation to the boundary.  The image at the very bottom shows the proposed house and garage.   As you can see, the garage will be literally on top of their drainage field, and the proposed house a little too close for my liking.

 

[Kelvin]

I’ve not caught up with this but it seems to me you need a proper survey completed which should be a condition of the sale. You definitely don’t want to be buying the plot on a wing and a prayer. You’re right to be cautious. 

[flanagaj]

25 minutes ago, Kelvin said:

I’ve not caught up with this but it seems to me you need a proper survey completed which should be a condition of the sale. You definitely don’t want to be buying the plot on a wing and a prayer. You’re right to be cautious. 

 

What's annoying, is that another plot has come to market that ticks the boxes and does not have the associated headache.  Having looked at the scaled drawings, I don't see what options the vendors have for moving their drainage field so that it satisfies the 15 metre away from any dwelling building reg.  They just don't have the space, and I am concerned that as a result it's dead in the water.  I do feel for them, as it appears that nobody involved in their whole planning application process, asked them the question "Just out of curiosity, where is your drainage field located?"
 

[Russell griffiths]

Time to walk away, it looked overpriced to me. 

[Kelvin]

9 hours ago, flanagaj said:

 

What's annoying, is that another plot has come to market that ticks the boxes and does not have the associated headache.  Having looked at the scaled drawings, I don't see what options the vendors have for moving their drainage field so that it satisfies the 15 metre away from any dwelling building reg.  They just don't have the space, and I am concerned that as a result it's dead in the water.  I do feel for them, as it appears that nobody involved in their whole planning application process, asked them the question "Just out of curiosity, where is your drainage field located?"
 

Now that I’ve looked at the block drawings I’d walk away. I wouldn’t want any aspect of my house relying on someone else’s land but nor would I want any aspect of someone else’s house relying on my land. Everything to do with our house is in our land. 

 

It’s easy to get over invested in a plot of land as you can start to see your finished house etc. It’s what I did on a previous plot but my wife hated it. We found a much better plot that very day. My dad used to tell me that if there’s doubt about something then there’s no doubt. So I’m with Russell, walk away. 

[Alan Ambrose]

You could present the sellers with the problem and your view of it and allow them to investigate whether they have any solutions.

[saveasteading]

1. If the vendor doesn't appreciate the issue, then it is polite to advise why you will be ducking out. They may then offer a huge discount.

2. If the vendor knows and is concealing the issue no harm in applying 1.

 

You must not have their drain under your house. And the ground has been messed with

INsist they rebuilddrains on their land. Plus  doundation issues. Your drains. restricted 

£50k discount? Or walk away.

even then you need a derailed solution before committing.

[kandgmitchell]

THought I recognised the shape of the building on that proposed blockplan - so it was a cattery that needs demolishing. There was no answer to the question posed on that thread "where did all the cat shit go"? Just another poo question to consider.

[ProDave]

I would walk away.  There is no way you can build a garage on top of next doors drainage field, even before you think about distances to the house.

 

Unless an off site drainage solution was available for both houses I would say the plot is not viable.  The minimum needed is permission from the land owner to the south for drainage fields for both properties to be installed under that field (assuming it is a field not other houses).

 

If I was the vendor I would be looking for such permission, and then thinking of installing a large TP to serve both houses and the drainage field for it, then sell the plot as a serviced plot.  That is about the only way I think it is viable.

[flanagaj]

They are currently investigating where they can move their septic tank and drainage field to.  Before we even consider moving forward, I would want building control involved, to ensure that the proposed location is acceptable, and it legally agreed that the moving of the field will be done as soon as we have purchased the property.   

 

I agree that installing the drainage field in the paddock behind is a much better option, but they have said that is not viable.

It does also raise the question as to whether the contaminated land near the garden needs to be removed before the garage could be built.

[saveasteading]

1 hour ago, flanagaj said:

whether the contaminated land near the garden needs to

Theoretically it is clean. If it has had any pretreatment and is then distributed over this huge area, the bugs will have cleared it. 

But I fear that most systems are incompetently built and incomplete.

Therefore you should get independent testing,  paid for by the vendor.

Then there are the redundant trenches beneath the building.  They are likely to be unsuitable for building on. You need a strategy for this and some cost set aside.

 

I'd guess that the best solution might be trench footings to beneath the drains, then a suspended beam and block floor.

Slightly more expensive than ground bearing but not too bad.

 

And even allowing  these solutions,  you are at risk and the site is blighted. It should be considerably cheaper than a site without this challenge. 

 

[Alan Ambrose]

In a previous life, we had a PTP plant installed out of the curtilage in a bit of paddock. It wasn't my building project, so I didn't follow the detail -  but this didn't seem to cause the planners / BC any problem. 

[saveasteading]

6 minutes ago, Alan Ambrose said:

didn't seem to cause the planners / BC any problem. 

The planners won't understand it, and it is not their concern who owns the land. BCO would generally agree to it if it has a certificate for their files.

[ProDave]

28 minutes ago, Alan Ambrose said:

In a previous life, we had a PTP plant installed out of the curtilage in a bit of paddock. It wasn't my building project, so I didn't follow the detail -  but this didn't seem to cause the planners / BC any problem. 

Our previous house had the soakaway in the field behind the house, that did not cause any problems.  But I am not sure I would want the actual TP there, what if the field became used for stock?  Would you want cows walking over the top of your TP?

[Alan Ambrose]

I should have said that it was our paddock so there was never going to be cows there. We didn't, but you could always fence it off I guess.