Hi Chris,
Hope you are well
Off list response as I sit on the expert panel.
You pretty much summed it up - decisions have to be in context and pragmatic when considering you could be digging up peoples gardens and any 1970/80s housing will likely have many ACM's within the soil matrix.
Far too much SI as well...most of the garden I think ended up in the lab anyway which is an interesting concept ..remediation by sampling..
As to the C4SL...thats for a better person than me...
Kind regards
Dave
David Jackson
Land Quality Officer
Wakefield Council
Regeneration & Economic Growth | Environmental Health
Wakefield One | P.O Box 700 | Burton Street | Wakefield | WF1 2EB
t 0345 8506506 [Contact Centre]
m 07810152565
e [log in to unmask]
w www.wakefield.gov.uk/landquality
-----Original Message-----
From: Contaminated Land Management Discussion List [mailto:[log in to unmask]] On Behalf Of Chris Dainton
Sent: 08 December 2017 11:37 AM
To: [log in to unmask]
Subject: Re: Contaminated Land Expert Panel Case Study 2 published
These are general Friday musings, please take this into account.
Into the bear pit again.
What the panel may be implying is that if you have identified non-friable intact cement bonded ACM fragments in shallow soils in residential lawned and plant borders (not an uncommon occurrence on urban land), that a few incidents (detection in 13% of samples analysed (~1 in 8) in this case study), of measurable levels % w/w (max ~0.5% w/w in this case study) in a data set is likely to mean the site is within Cat 4.
To me, on a precautionary basis, the study site could be a candidate for the dodge-the-issue fence-sitting Part 2A Category 3 (Human Health) wrt to asbestos: i.e. not quite sure was the risk level is, but definitely not Cat 2.
As it's Friday, anyone care to take a stab at an implied C4SL %w/w for intact cement bonded ACM fragments ..... (the straight average w/w across the 15 samples analysed from the case study is 0.036% w/w).
Interestingly, if I use the JWIG Work Categories DST and this average %w/w (which is a 'Low Quantity' in the DST) and apply to a soil sampling investigation at a site with similar conditions, then it would be probable NLW. The need for RPE/dust-suppression/hygiene during the soil sampling works revolves around the DST Stage 2 Choices, including anticipated airborne fibre concentration, host matrix and respirable fibre index.
Chris Dainton
________________________________
The WMDC Disclaimer can be found at:
http://www.wakefield.gov.uk/site/terms-and-conditions
|