View - North East Lincolnshire Council

BOC Immingham Dissolved Acetylene Project Environmental Statement: Vol. 2 Main Text
� low risk: it is possible that harm could arise to a receptor from an identified hazard, but it is
likely at worst, that this harm if realised would normally be mild. It is unlikely that the site
owner or occupier would face substantial liabilities from such a risk. Further investigative
work (which is likely to be limited) to clarify the risk may be required. Any subsequent
remediation works are likely to be relatively limited;
� very low risk: it is a low possibility that harm could arise to a receptor, but it is likely at worst
that this harm (if realised) would normally be mild or minor; and
� no potential risk: there is no potential risk if no PPL has been established.
Land Contamination Impact Assessment and Significance Criteria
7.38 The approach to the impact assessment involves developing a CSM for each phase of the
proposed development and carrying out a land contamination risk assessment for the following:
� baseline condition: development of the baseline CSM based on current use and identification
and risk assessment of baseline PPLs;
� construction phase: development of the construction phase CSM, addressing the potential for
new sources of contamination to be introduced and the change in pathways and receptors,
identification and risk assessment of PPLs; and
� operational phase: development of an operational phase CSM for the developed site,
reflecting final site conditions including the status of contamination sources, changes in the
receptors and pathways, and identification and risk assessment of PPLs.
7.39 Each CSM phase risk assessment is compared with the baseline to identify the potential impact.
This CSM comparison approach allows the changes in land contamination status during the
construction and operational phases of the proposed development to be divided into major,
moderate, minor or negligible impact of adverse, neutral or beneficial effect. The key definitions
are summarised in Table 7.2.
Significance Definition
Major adverse
effect
Moderate adverse
effect
Minor adverse
effect
Table 7.2 Significance Criteria for Land Contamination
Baseline land condition where it is unlikely that PPLs are present and if
so, they are of minor consequence (very low risk), becomes land where
there is a high likelihood that PPLs are present of severe consequence
(very high risk), or a high risk PPL is introduced.
Baseline land condition where it is low likelihood that PPLs are present
and if so, they are of mild consequence (low risk) becomes land where
PPLs are likely and of medium consequence (moderate risk), or a
moderate risk PPL is introduced.
Baseline land condition where it is unlikely low likelihood that PPLs are
present and if so, they are of mild minor consequence (very low low risk)
becomes land where it is likely low likelihood that PPLs are present of
medium mild consequence (moderate low risk), or a very low low risk
PPL is introduced.
Neutral effect No change in contamination risks.
Minor beneficial
effect
Baseline land condition where it is likely low likelihood that PPLs are
present and if so, they are of medium mild consequence (moderate low
risk) becomes land where it is unlikely low likelihood of PPLs of mild
minor consequence (very low low risk), or a very low low risk PPL is
removed.
5100935.404 Environmental Statement August 2011 98