In addition, my experience/experience shows that membranes that are
commonly available (in this region at least) at relatively low cost have
not been rigorously/independently tested.
Ruth
Ruth Willcox
Environmental Protection Officer (Land Quality)
Plymouth City Council
Public Protection - Floor 6
Civic Centre
City Centre
PLYMOUTH
Devon
PL1 2AA
Tel: 01752 304154
Fax: 01752 226314
Email: [log in to unmask]
-----Original Message-----
From: Contaminated Land Management Discussion List
[mailto:[log in to unmask]] On Behalf Of Chris
Dainton
Sent: Wednesday, August 04, 2010 11:05 AM
To: [log in to unmask]
Subject: Re: Contamination Depth & Indoor Vapour Levels
Hi Steve
Not sure by what you mean by 'very low allowable concentrations', as the
allowable 'CLEA' indoor vapour concentration for speciated TPH fractions
and TEX are actually (what I would consider) quite high ranging from 0.1
to 9.8 mg/m3, although additivity may need to be considered for TPH.
As a guide to put these TPH levels in context, the odour threshold for
diesel is around 0.06 mg/m3. The odour threshold for toluene and
xylenes are around 0.5 and 0.06 mg/m3 respectively.
Naphthalene, benzene & TMBs are much lower at 0.002, 0.003 and 0.002
mg/m3 (though the AQS for benzene of 0.005 mg/m3 might be more
applicable). BaP should be considered non-volatile.
Chlorinated solvents are also low (<0.001 to 0.2 mg/m3).
Some of the membrane producers will now provide an assessment of site
specific suitability of their membranes based on identified contaminant
concentrations.
Chris Dainton
Peak Environmental Solutions
********************************************************************************************************************************************
IMPORTANT: This e-mail (including any attachments to it) is strictly confidential and intended solely for the person or organisation to whom it is addressed. It may contain privileged, confidential or sensitive information. If you are not the intended recipient, you must not copy or distribute it to any other person or take any action in reliance. If you have received it in error, please notify your system manager and the sender as soon as possible and then delete it from your system.
|