Soil investigation

[Declan52]

If it's just too see if there is any mines why are they do environmental testing plus soil strength tests??

40m with a rotary rig would take 2 days easy enough. If it's using a shell and auger rig it will take longer. It's doing the tests that will slow it down. 

[Triassic]

28 minutes ago, Tyke2 said:

I have to undertake a borehole 40m depth to determine if there are shallow mine workings, plus install water sampling and gas monitoring points. SPT and percolationtest. Contamination sampling.

First quote - £14,000 yes fourteen thousand plus vat.

A bit too silly.

 

Wow what you building a multi storey block of flats. Go for a Hilliard Tanner low ground bearing pressure insulated foundation and fit a radon gas membrane, job done!

[Gone West]

53 minutes ago, Tyke2 said:

I have to undertake a borehole 40m depth to determine if there are shallow mine workings, plus install water sampling and gas monitoring points. SPT and percolationtest. Contamination sampling.

First quote - £14,000 yes fourteen thousand plus vat.

A bit too silly.

 

I don't know what all the others bits would cost but I had a 47m deep borehole drilled through clay in 2010 and it cost £3000 all in.

[Tyke2]

23 minutes ago, Triassic said:

Wow what you building a multi storey block of flats. Go for a Hilliard Tanner low ground bearing pressure insulated foundation and fit a radon gas membrane, job done!

The foundation solution is not a problem, its convincing the planners that  I don't need to do the survey if I do such a solution to mitigate any possible ground gas from possible shallow mine workings at 40 m that are highlighted by the coal searches.

I would still need to do the contam testing though to discount any residual contamination from the old gasworks that was in the next field 100 years ago.

[Tyke2]

Just now, PeterStarck said:

I don't know what all the others bits would cost but I had a 47m deep borehole drilled through clay in 2010 and it cost £3000 all in.

I do have a separate quote from a "friend" a drilling rig for a day is £1000, which can do up to six boreholes in the day. So all in I would think £3000 ish with the contam testing lab tests which are £140 each.

[Tyke2]

53 minutes ago, Declan52 said:

If it's just too see if there is any mines why are they do environmental testing plus soil strength tests??

40m with a rotary rig would take 2 days easy enough. If it's using a shell and auger rig it will take longer. It's doing the tests that will slow it down. 

Sorry missed this. I think it will be quite easy drilling so hopefully be a lot quicker.

[Gone West]

1 minute ago, Tyke2 said:

I do have a separate quote from a "friend" a drilling rig for a day is £1000, which can do up to six boreholes in the day. So all in I would think £3000 ish with the contam testing lab tests which are £140 each.

It took three or four days to do our borehole.

[Triassic]

6 minutes ago, Tyke2 said:

its convincing the planners that  I don't need to do the survey if I do such a solution to mitigate any possible ground gas

A radon barrier is a government mandated solution To a radioactive gas, it is more than acceptable for coal gas.

Edited September 12, 2018 by Triassic

[Triassic]

@Tyke2  Right, I’ve had a thought! I have a feeling your plannng guy is ticking boxes here and your expectated to pay!

 

Let’s break this down, he has concerns about mine subsidence, mine gas (methane!?) and contamination from next door (old coal gas plant). These three things need to be dealt with seperatly. 

 

Dealng with the mines, have you done a historical review of mine workings in n the area, do you have a mines department for the area (where are you?). If there is no history of mines, it’s  job done, write a short report saying so.

 

Mine gas, this is a safety issue. If there are mines in the area then you need to do in-situ absorption tube testing with a shallow bore hole ( shalllow is just below the foundation level) again once you have results you can then design a mitigation method. Mine preferred method would be the radon barrier approach, coupled with radon sumps under the property and high level passive vents.

 

The contamination next door, start by carrying out a historical review, where was the plant in relation to you proposed home, were there any tar pits on site, where were the raw materials stored. What is the source- pathway - receptor - linkage. What remediation was carried out by the previous and current landowner.

 

Starting by drilling a deep borehole will be a waste of money as it won’t necessarily answer your questions, in fact it could open up a can of worms ( search DNAP chasing).

 

 

Edited September 12, 2018 by Triassic

[Tyke2]

Just now, Triassic said:

Right, I’ve had a thought! I have a feeling your plannng guy is ticking boxes here and your expectated to pay!

 

Let’s break this down, he has concerns about mine subsidence, mine gas (methane!?) and contamination from next door (old coal gas plant). These three things need to be dealt with seperatly. 

 

Dealng with the mines, have you done a historical review of mine workings in n the area, do you have a mines department for the area (where are you?). If there is no history of mines, is job done, write a short report saying so.

 

Mine gas, this is a safety issue. If there are mines in the area then you need to do in-situ absorption tube testing with a shallow bore hole ( shalllow is just below the fo7ndation level) again once you have results you can then design a mitigation method. Mine preferred method would be the radon barrier approach, coupled with radon sumps under the property and high level passive vents.

 

The contamination next door, start by carrying out a historical review, where was the plant n relation to you proposed home, were there any tar pits on site, where were the raw materials stored. What is the source- pathway - receptor - linkage. What remediation was carried out by the previous and current landowner.

 

Starting by drilling a deep borehole will be a waste of money as it won’t necessarily answer your questions, in fact itbcoulf open up a can of worms ( search DNAP chasing).

Hi

 

Im afraid you are correct. The site took 11 years to get planning as it is in the grounds of a stately home and in a conservation area.

There has been an extensive desk top study, which does include all the historic maps , hence the gas works,

There has been a mining report provided by the coal authority which highlights the possibility of mine workings. At a different local manor house locally the coal authority sunk shafts as close as 10m to the front of the building so it is possible.

I'm not inexperienced at such matters, so my first approach is to get my engineer to revisit the desk study to do a risk assessment and provide evidence that using a suitable gas barrier would be a more sensible solution. However the contamination testing is a necessity as Im sure there could be elevated hyrocarbons that I will need to sort, and at present I can negotiate this off of the land price.

 

[Triassic]

14 minutes ago, Tyke2 said:

However the contamination testing is a necessity as Im sure there could be elevated hyrocarbons that I will need to sort, and at present I can negotiate this off of the land price.

I’d suggest you keep this as simple as possible, you need to look at near surface contamination.