Table 1.

Statutory Guidance on use of Guideline Values (after DETR 2000).

B.47To simplify such an assessment of risks, the local authority may use authoritative and scientifically based guideline values for concentrations of the potential pollutants in, on or under the land in pollutant linkages of the type concerned. If it does so, the local authority should be satisfied that:
(a)an adequate scientific and technical assessment of the information on the potential pollutant, using the appropriate, authoritative and scientifically based guideline values, shows that there is a significant possibility of significant harm; and
(b)there are no suitable and sufficient risk management arrangements in place to prevent such harm.
B.48In using any guideline values, the local authority should be satisfied that:
(a)the guideline values are relevant to the judgement of whether the effects of the pollutant linkage in question constitute a significant possibility of significant harm;
(b)the assumptions underlying the derivation of any numerical values in the guideline values (for example, assumptions regarding soil conditions, the behaviour of potential pollutants, the existence of pathways, the land-use patterns, and the availability of receptors) are relevant to the circumstances of the pollutant linkage in question;
(c)any other conditions relevant to the use of the guideline values have been observed (for example, the number of samples taken or the methods of preparation and analysis of those samples); and
(d)appropriate adjustments have been made to allow for the differences between the circumstances of the land in question and any assumptions or other factors relating to the guideline values.
B.49The local authority should be prepared to reconsider any determination based on such use of guideline values if it is demonstrated to the authority's satisfaction that under some other more appropriate method of assessing the risks the local authority would not have determined that the land appeared to be contaminated land.