Paragraph 1 RadonI1

must ensure that a representative survey is carried out in accordance with sub-paragraph (2) to determine the likelihood of a private water supply failing to comply with the relevant parametric concentration or value specified in the radioactive substances parameters table; and

must carry out monitoring where there is reason to believe, on the basis of the results of the representative surveys or other reliable information, including any risk assessment carried out in accordance with regulation 6, that the parametric value for the radon parameter laid down in the radioactive substances parameters table might be exceeded.

as to be capable of determining the scale and nature of likely exposure to radon in water intended for human consumption originating from different types of groundwater sources and wells in different geological areas; and

that underlying parameters, especially the geology and hydrology of the area, radioactivity of rock or soil, and well type, can be identified and used to direct further action to areas of likely high exposure to radon.