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BOC Immingham Dissolved Acetylene Project Environmental Statement: Vol. 2 Main Text
Baseline Conceptual Site Model
Baseline Contamination Sources
7.56 Based on the documentation reviewed, no potentially contaminative historical activities have been
identified on the development site which could have given rise to contaminants in, on or under the
ground at the development site. This is supported by visual evidence from the GI works, which
confirmed that all soils encountered were natural, no made-ground was identified, there were no
visual or olfactory indications of potential contamination and all soil vapour headspace readings
were below instrument detection (i.e. there was no indication of volatile hydrocarbon
contamination in the soil).
7.57 However, the potential for unforeseen contamination to be present in soil and any shallow
groundwater cannot be precluded and absence can only be demonstrated by the site-specific GI
and associated sampling which is currently on-going.
7.58 The existing BOC facility is a potential offsite source for contamination xii as a result of:
� migration of contaminants in windblown, soil-derived dust
� migrating groundwater; and
� migrating vapours ground gas.
Baseline Receptors and Pathways
On and Offsite Human Receptors and Exposure Pathways
7.59 Current potential baseline on site receptors include humans who access the development site,
primarily agricultural workers and public who may walk across the land. Exposure pathways for
current on site human receptors include:
� dermal contact with and ingestion of:
- contaminants in soil and soil-derived dust
- contaminants entrained in surface water run-off from areas where soil (and
contaminants) is exposed at the surface, and
- contaminants in perched water shallow groundwater in natural strata (if pre-construction
excavation takes place below the perched water groundwater table);
� inhalation of contaminants in soil-derived dust from areas where soil (and contaminants) is
exposed at the surface; and
� inhalation of soil and water derived vapours (volatile organic contaminants which volatilise to
the surface) and ground gas.
7.60 Potential current offsite receptors include workers at and visitors to the existing BOC facility to the
north west, agricultural workers on fields to the north east, south east and south west and the
public who may cross these areas (offsite receptors). Exposure pathways for current on site
human receptors include:
xii However, it is noted that this assumes that the existing BOC site is contaminated, that there are areas of exposed contaminated soil,
and that the proposed site is down hydraulic gradient of the existing site.
5100935.404 Environmental Statement August 2011 102