Environmental Engineering Reference
In-Depth Information
project; site characterisation that is driven by compliance with particular sets of pre-
scribed criteria will be less effective, and so more expensive, than one based on
effective Risk Management decision making. Technical innovation may also reduce
costs, in particular iterative approaches to site characterisation that allow “real-time”
decision making, such as the US EPA Triad approach (
www.triadcentral.org
).
It must be noted that no single solution can provide the optimum management
approach for all contaminated sites. The approaches to investigation typically evolve
alongside the refinement of the respective site conceptual model, which serves as
the ultimate basis for the subsequent Risk Assessment and remediation strategy. It
is important to ensure that such a site conceptual model does indeed represent all of
the relevant source-pathway-receptor linkages.
24.5 Remediation of Contaminated Sites and Waste
Management
The definition of waste hinges on the term “discard” and “intent to discard”,
although “discard” itself is not defined in the original 1975 Waste Framework
Directive. Over the last 25 years a large body of case law has arisen to help to better
define waste. Whilst soils and other materials from Brownfield reclamation and con-
taminated land management have long been considered waste when sent to landfill,
it has only been in about the last 10-15 years that these materials are sometimes
considered waste when managed and reused on site. A consensus has emerged that
significantly contaminated soils normally become waste at the point of excavation,
but there has been much confusion and variability in waste regulation practice over
other materials such as marginally contaminated soils, made ground, natural ground
and other materials.
Whilst being waste may simply appear to be a label, it in fact carries significant
legal responsibilities. Materials with the waste label, even though they may be safe
and suitable for use, may be subject to stigma and cause blight at the site where they
are reused. Once such materials have been classified as waste there is also much
inconsistency over the point at which they cease to be waste. This variably may be
at different points in the value chain either on site, off site (at soil treatment centres),
at receiving sites, or when the material reaches its final resting place in the ground.
Some countries have attempted to dually regulate soil as waste (where definitions
are hazard based) alongside risk-based soil management processes. This typically
leads to complexity and contradiction and to non-optimal resource management. In
some cases this has led Member States to put in complex arrangements in order to
reconcile waste law with planning law and national law in relation to contaminated
land. Others have simply declared soil as a resource and never treat soil as waste
except where it is clearly discarded to landfill. In between these extremes there is a
whole spectrum of approaches.
Overall the complexities and variability around soil as waste can have signifi-
cant impacts on contaminated land and Brownfield project management, costs and
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