Significant pollutant linkage

The standard of remediation that needs to be achieved on a particular site is therefore whatever degree of risk management would be achieved by the use of the best practicable techniques for remediating each of the significant pollutant linkages on the site. 

This standard can then be used to evaluate any alternative approaches to remediation. These might, for example, be remediation approaches that sought to manage the risks for more than one identified significant pollutant linkage simultaneously. 

Monitoring. As suggested above, the Part IIA enforcement process can require action to be taken to monitor sites after remedial treatment action has been carried out. This obligation covers significant pollutant linkages that have already been identified, and is intended to pick up any changes that may occur in the condition of their component pollutants, pathways or receptors. 

Tests 4, 5 and 6— changes to substances , escaped substances and introduction of pathways or receptors —deal with different types of circumstances where one appropriate person has, in effect, left the site in a safe condition (notwithstanding the fact that he has caused or knowingly permitted a contaminant to be present) only for another person subsequently to change the condition of the land such that there is now a significant pollutant linkage. The tests were included in effect to transfer liability to the person who made the difference. 

In these circumstances, liability under Part IIA passes to the owner or occupier for the time being of the contaminated land in question 33—the current owner or occupier. However, this passage of liability does not take place where the significant pollutant linkage involved has controlled waters as its receptor in a case of that kind, the liability becomes orphan and responsibility for funding remediation passes to the taxpayer. 

Measurement of PICT usually involves carrying out short-term (multispecies) toxicity tests on whole communities from clean and contaminated sites. Pollution tolerance is quantified by reduced sensitivity of the toxicant in these tests. The increased tolerance may result from replacement of sensitive species by less sensitive ones, development of heritable tolerance by one or more species, and/or short-term nonheritable acclimation. A significant increase in community tolerance compared to the baseline tolerance at reference sites suggests that the community has been adversely affected by toxicants. In this way, PICT can establish causal linkages between contaminants and effects in monitoring studies (Blanck 2002). 

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