Cinderella of remediation and clean-up
Dr Rob Fuller, Laboratory Commercial Manager, at the UK's Southern Water Scientific Services explores the importance of selecting the right kind of samples from contaminated sites in order to achieve accurate analyses.
A remediation programme is only as good as the information available on the
the contaminant present. However many developers and remediation consultants
rely too heavily on scant or inappropriate analytical results to samples taken
in-situ. Here we look at the increasing need for good practice in field sampling
and laboratory analysis.
The development of brownfield (old industrial and/or contaminated) sites, particularly
for housing, is a major issue for developers and contractors in the UK where
the government has clearly stated its intentions for increasing housing stock
and the focus is very much on re-use of existing or derelict sites.
Brownfield development not only satisfies the Government’s aims to increase
housing stock while maintaining greenbelt; it could easily be argued that it
provides a more sustainable approach to building.
Building on contaminated land can however, pose both an operational and financial
risk and, without doubt, accurate sampling and analysis is crucial in managing
and reducing this. It is imperative that consultants and developers know exactly
what they’re dealing with in terms of contamination, in order to implement an
effective and good value clean up programme and to secure regulatory approval.
Unfortunately not all landowners and developers are fully aware of the importance
of accurate and affective sampling and many underestimate the importance of
taking a proper laboratory regime in to the field.
Without the complete knowledge, developers and consultants are in the dark
when it comes to selecting the best remediation programme. An inappropriate
clean up regime, based on a scant analysis of the site, will inevitably mean
higher costs for the developer. One step forward in achieving a quick answer
through cutting corners with sampling, will mean two steps back when the site
fails to comply with regulatory requirements.
A clear indication of the type, volume, distribution and combination of contaminants
on a site is crucial in selecting the most appropriate tools to clean up. Far
from their perception as the ‘bloke with a spade’, contractors, working together
with the analysis laboratory from the first stages of site investigation, hold
the key to the bigger picture – and getting it right first time.
Brownfield development requires a thorough knowledge of the nature and extent
of the contamination present. Each site is unique in terms of its contaminants
so it is important that a sampling regime is implemented, which considers the
following factors: Has the history of the site been fully considered? Is the
sample the correct size and volume? Was it taken from the correct location and
depth? Has the sample been disturbed? How will the state of the sample alter
in transit? How representative is the sample?
Consider a developer who wants to build five new houses on a plot of land previously
used by industry. These homes will need to be connected to the mains water supply.
To rule out the potential for the contamination of drinking water, the developer
must prove to the water supplier that the soil through which the pipes will
run is not contaminated.
Unfortunately, there is currently some uncertainty over exactly what has to
be tested for. Previously the UK’s ICRCL (Interdepartmental Committee for the
Redevelopment of Contaminated Land) guidance spelt out conditions for soil and
groundwater that were acceptable to the regulatory authorities. This still exists
to some extent in the Groundwater Regulations. However, it is no longer an acceptable
path for contaminated soils where ICRCL has been withdrawn.
The regulatory authorities now encourage risk-based assessments, based on the
source- pathway -receptor relationships that characterise the site. If the water
company and the lab communicate from an early stage and set the parameters for
which substances must be identified, it is clear what must be achieved to satisfy
the water company first time round.
The key to keeping one step ahead of the game is to know your site history.
If the site used to home a paint factory, it is likely to be contaminated with
volatile compounds, whereas hydrocarbons are likely to be present if fuel was
used on the site. It’s all about sharing information: From landowner, to developer
to consultant to the labs and back again. A simple note taken at the time of
sample extraction: ‘It smells of diesel’, for example, can give the analysis
lab an idea of substances to test for, which might otherwise only be discovered
at a later stage.
There are various things to consider when selecting an analytical laboratory.
A consultant will look for speed and accuracy of results on which to work out
the risks associated with the site. The developer, on the other hand may be
more concerned with value for money. The cost of analysing a site and developing
a clean up strategy is after all risk money, and payback is only guaranteed
once the site has satisfied the regulatory authorities and planning permission
An holistic approach
To ensure transparency of the management of the clean-up process, I would advise
developer and consultants to work with an accredited lab. An MCERTS (UK Monitoring
Certification Scheme) accredited laboratory will have been certified on its
methodology for the chemical testing of soils. By using an accredited lab, you
can assure the EA of the quality of your analytical results and inspire confidence
in decisions regarding regulatory compliance.
In my role at Southern Water Scientific Services, I am amazed by the number
of enquiries which ask, ‘Is my land contaminated?’ and come armed with no indication
of potential contaminants, and a spade full of earth in a bag. With such a broad
range of potential contaminants, this can make our job very demanding and also
very costly for the developer.
By taking an holistic approach to developing brownfield land and involving
consulting, sampling and analytical parties from the outset, developers can
make an informed decision on the most effective way to minimise their risks,
and get the most out of brownfield land.
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