500 / 648
CDOIF
Chemical and Downstream Oil
Industries Forum
CDOIF is a collaborative venture formed to agree strategic areas for
joint industry / trade union / regulator action aimed at delivering
health, safety and environmental improvements with cross-sector
benefits.
4.
For the purpose of application of this guidance, CDOIF has developed 3
categories of groundwater (as described below). Consequence thresholds have
been assigned based on the relative value of these 3 categories (note the third
category of groundwater, “Other groundwater outside of groundwater bodies” is of
least value and impact here would be sub-MATTE with this category of
groundwater being a potential pathway only.)
5.
For screening purposes, Groundwater bodies can be identified by reference to
aquifer maps (see Appendix 3). In accordance with Seveso reporting thresholds,
the area threshold strictly relates to the aquifer (rock type) and not the area of
groundwater within it. In England and Wales, all Principle and Secondary
aquifers (coloured areas on mapping) are groundwater bodies, whilst
unproductive strata (un-coloured areas) are not groundwater bodies. Scotland
also has an equivalent aquifer map.
6.
The resolution of mapping is such that at specific locations, the groundwater in an
aquifer that is depicted on the map at that location might not actually meet the
formal definitions for groundwater body, i.e. detailed assessment of local
groundwater might show the groundwater is not a groundwater body and thus not
a receptor for the purposes of MATTEs. This circumstance is expected to be
exceptional and the level of demonstration would be resource intensive and
beyond the level of work envisaged for screening.
This guidance sets out a MATTE definition, based on different areas/values dependent
on the type of groundwater.
Groundwater body – Source of Public or Private Drinking Water
The level of harm that would constitute a MATTE is defined as follows:
a) For England and Wales only, 1 ha or more of an SPZ where public
drinking water standards are breached; or,
b) Interruption of public or private drinking water supplied from a ground or
surface water source, where: (persons affected x duration in hours {at
least two hours}) > 1,000
Groundwater body – non Drinking Water Source
The level of harm that would constitute a MATTE is defined as follows:
a) 1 ha or more of a groundwater body where the Water Framework
Directive (WFD) status has been lowered
Other Groundwater (outside of groundwater bodies)
Not applicable. Where the groundwater does not meet the definition of a groundwater
body it is considered as a
pathway
to another receptor, and assessment should be
against the criteria defined for that receptor (for example marine, fresh or estuarine water
habitats)
Guideline – Environmental Risk Tolerability for COMAH Establishments v1.0
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