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Soil survey findings implications


Incipiens Mox

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I recently received the results back of a soil survey which I commisioned as a stipulation of planning acceptance.

 

The survey repoort comes to >170 pages and I asked the surveyor to summarise whether there were any issues found. He said that there were no showstooppers, but that within the made ground there was asbestos detected in one sample and lead in another. 

 

Since this is a brownfield site and the plan is to demolish the house and build a basement as part of the new structure, I'm wondering what the implications of this are. Does anyone have experiience of problems like this? I'm wondering what cost / delay  I may have to factor in. 

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WHat are his recommendations?

 

Imo you need him to say clearly that remedial ground works are unnecessary, or similar words, or how they can be made unnecessary which proposals you then incorporate in your plans, otherwise you could land a very expensive Plannign Condition from an overcautious LPA, added for mainly better-do-it-anyway reasons.

 

Edited by Ferdinand
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Most brownfield land has small quantities of contaminants.  You may need to commission further WAC testing to see how the material should be classified for waste disposal (inert, hazardous etc.) as this will influence the muckaway cost.

 

You may need to replace the soil in any soft landscaped areas with new and have it re-tested and a verification / remediation report.

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Echoes of our soil survey. And I must admit to panicking a bit about the cost implications.

 

Until I realised the significance of  our site being on a gentle slope. That meant we would be bringing 400 tonnes of MoT1 in (and take no soil out) to level the site.  So any contaminant (in our case lead , Pb) would be even more hidden than it is now. 

 

We have built on 'Made Ground' - spoil from an old clay quarry.

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5 hours ago, Mr Punter said:

Most brownfield land has small quantities of contaminants.  You may need to commission further WAC testing to see how the material should be classified for waste disposal (inert, hazardous etc.) as this will influence the muckaway cost.

 

You may need to replace the soil in any soft landscaped areas with new and have it re-tested and a verification / remediation report.

 

if you're digging a basement then this is an important consideration (it was for us). From where did they detect the contaminants? How much made ground do you have under your feet?

 

Worst case you may need to dispose of the made ground and the as yet undisturbed ground separately which will add to your costs but some further clarity on the scope of the contamination will help quantify this (and minimise cost).

 

 

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I used to do site investigations. 

How many areas where contaminated??? 

How much of the lead/ asbestos was found???

Are they looking a gas monitoring standpipe put in to see if any other nasty things have leeched into the water table??

Are you are to find out what the site was used for in the past, was it a factory, garage repair place, shops etc??

What depth of  made ground is there on the site and did they probe any where to see what the water table is??

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6 hours ago, Declan52 said:

I used to do site investigations. 

How many areas where contaminated??? 

How much of the lead/ asbestos was found???

Are they looking a gas monitoring standpipe put in to see if any other nasty things have leeched into the water table??

Are you are to find out what the site was used for in the past, was it a factory, garage repair place, shops etc??

What depth of  made ground is there on the site and did they probe any where to see what the water table is??

2

 

The report goes into a large amount of detail (> 177 pages) hey found two areas with contamination:

o Asbestos was detected within a sample from [area on the driveway]; and
o An elevated lead concentration was detected within a sample from [area on the back lawn].
Three of the near-surface soil samples were analysed for asbestos. Amosite was detected within one sample,
[area on the driveway], J1, taken at a depth of 0.15-0.65m.

 

The lead I'm not so concerned about since it's on an are that won't be disturbed, but the asbestos will definitely need addressing as it's right on the footprint of the house/basement.

 

They have put in a gas monitoring standpipe but have detected no significant issues with gases or issues with the water table. As regards the lead and asbestos (only found in two of the samples that they took) they have stated:

 

it is recommended that additional shallow sampling of the made ground is undertaken to allow
for a better assessment of the extent of the lead / Asbestos which should include quantification of the
Asbestos to allow for a better assessment of the risk posed by the presence.
Alternatively, if the Made Ground is to be removed as part of the construction works, this can be disposed
to a licensed waste
centre (with appropriate waste acceptance testing) then hazard is removed.
Consideration may be given to leaving areas with elevated Lead and presence of Asbestos in situ if these are
to be left under permanent hardstanding such as permanent concrete driveways to the front of the property

 

I'm not aware of any previous industrial use and am assuming that this most probably came from a previous asbestos walled garage (it's right next to the existing brick garage) though I've no evidence that one existed. The current building has stood there since 1930's

 

Made Ground is from 0.01 – 0.20mbgl to 0.40 – 0.70mbgl

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It's good news that there is nothing in the water table. As made ground is quite shallow you will be excavating the majority of this out to put in the founds of the house including the basement, roads in and everything else that needs done. When this is all being dug out depending on how much more asbestos you find will determine how you dispose of the spoil. Check with who ever done your report if this is suitable for them. If you find anything you can bag a few samples up and if you come across something major then you will get them out again.

As you say its probably just from the old garage wall. 

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  • 2 months later...

 

So I had a bit of a follow up to my original post. After the survey was done, I duly reported the findings to the local planning office who didn't respond and have yet to do so. Since, by this stage, we were in the process of applying for building control (BC) approval, the condition became a stipulation of BC approval. As I'd received nothing from the planning department, I contacted the BC officer, who turned out to be a very nice chap and suggested that I contact the local authority environmental health (EH) department to ask them to confirm whether drawing up a method statement on the basis of the report findings would be acceptable.


After badgering EH for about two weeks I'm still no closer to getting a call from an officer to discuss this. However, in the meantime, I asked the original survey company if they could quote me for drawing up a method statement. I was surprised when they came back with the following:

 

Project Management (Production of RAMS) £45.00

Site visit to attempt to zone areas of lead and asbestos, installation of 1 shallow monitoring well to rear of property £400.00

Monitoring of Wells for Ground Gas and Groundwater (5 No. Visit(s)) £1,350.00

Environmental Laboratory Testing Suites £300.00

Remediation Method Statement £950.00

Total excluding VAT £3,045.00


It's another £3,500 (I've already paid them over £2,500 for the original survey and this doesn't include the actual soil removal) and many of the tasks seen irrelevant since we plan to remove a substantial amount of the soil anyway as we are building a basement. I was going to just put the survey companies suggestion forward to the EH officer, but now I'm tempted to hold off and argue the toss with them.


Could anyone with some experience comment on whether this quote seems reasonable and what you'd do in these circumstances?

 

Edited by Incipiens Mox
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On ‎1‎/‎4‎/‎2018 at 01:27, Incipiens Mox said:

it is recommended that additional shallow sampling of the made ground is undertaken to allow
for a better assessment of the extent of the lead / Asbestos which should include quantification of the
Asbestos to allow for a better assessment of the risk posed by the presence.
Alternatively, if the Made Ground is to be removed as part of the construction works, this can be disposed
to a licensed waste
centre (with appropriate waste acceptance testing) then hazard is removed.
Consideration may be given to leaving areas with elevated Lead and presence of Asbestos in situ if these are
to be left under permanent hardstanding such as permanent concrete driveways to the front of the property

 

I think the key word here might be "Alternatively". As I read it they are recommending further sampling or "Alternatively" send all the spoil to a licensed waste centre.

 

That would probably be expensive so ideally you want to do what Declan proposed which is to dig some out, sample it and if no asbestos found send that lot for regular disposal. The question is can you write your own method statement that documents the process or will the BCO insist you get an expert to write it. I think it will need to include things like warnings to site workers for example.

 

 

 

 

 

 

 

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Don't see the point in putting another standpipe in for ground water testing of the previous one found nothing. I am not sure they understood what exactly you where looking for with regards a mission statement. 

Get in contact with them again and ask if during the excavation of the basement you come across something that you think is contaminated will they test it and how much will it cost and from these findings you can dispose of it either way. Run this by EH guy and see if this scenario suits him. 

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49 minutes ago, Declan52 said:

 

Don't see the point in putting another standpipe in for ground water testing of the previous one found nothing. I am not sure they understood what exactly you where looking for with regards a mission statement. 

Get in contact with them again and ask if during the excavation of the basement you come across something that you think is contaminated will they test it and how much will it cost and from these findings you can dispose of it either way. Run this by EH guy and see if this scenario suits him. 

2

 

I was surprised that they came back with so much work. My initial thought was to simply get the top 600mm removed by a specialist given that (a) a lot would have to come out anyway as the basement was dug, (b) that spoil which comes out outside of the footprint of the basement could be back-filled using the spoil from the basement dig, saving me the expense of getting (at least some of) it removed and (c) it would save the cost of further samples.

I'm new to this (of course) but I see no point in constantly taking samples (especially as you point out when most previous ones found nothing) I'll push to speak to the EH officer in the hope that pragmatism prevails. Thanks.

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2 hours ago, Temp said:

I think the key word here might be "Alternatively". As I read it they are recommending further sampling or "Alternatively" send all the spoil to a licensed waste centre.

 

That would probably be expensive so ideally you want to do what Declan proposed which is to dig some out, sample it and if no asbestos found send that lot for regular disposal. The question is can you write your own method statement that documents the process or will the BCO insist you get an expert to write it. I think it will need to include things like warnings to site workers for example.

2

 

To be honest, it never even occurred to me that I could write my own method statement. Certainly something I'll look into. Thanks.

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3 hours ago, Temp said:

BCO insist you get an expert to write

Do BCO have any say in muck away, that is your responsibility, I would perhaps have thought that all you have to do is prove to the carrier, of the muck away, what they are conveying.

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14 hours ago, Incipiens Mox said:

To be honest, it never even occurred to me that I could write my own method statement.

 

I wrote my own "Tree Protection Method Statement" but that was rather easier.

 

Google can find templates for asbestos removal method statements but I've no idea if they are any more than section headings or have far too much content...

 

https://www.haspod.com/documents/method-statements/asbestos-removal-template?gclid=CjwKCAjwhcjVBRBHEiwAoDe5x3fRgKgIoXVFKWV2_BgHu84hFZ2j9vaizwIjACKZStGPYZ1uM9MLoBoCjnQQAvD_BwE

 

https://www.hsdirect.co.uk/product-information/method-statements/asbestos-removal-method-statement.html

 

You can also find examples that other people have written for specific projects.

 

This might be useful ... DIY Asbestos sample and test kit for £37..

https://asbestossamplesdirect.com/

 

 

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14 hours ago, MikeSharp01 said:

Do BCO have any say in muck away, that is your responsibility, I would perhaps have thought that all you have to do is prove to the carrier, of the muck away, what they are conveying.

 

Not normally but I see Incipiens Mox said..

 

On ‎3‎/‎20‎/‎2018 at 00:57, Incipiens Mox said:

Since, by this stage, we were in the process of applying for building control (BC) approval, the condition became a stipulation of BC approval.

 

 

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