Under the provisions of article R. 1322-14, the Prefect may require the operator, on a proposal from the Director General of the Regional Health Agency, to carry out analyses in addition to those defined in article R. 1322-41 in the following cases:
1° The water does not comply with the quality criteria set by the order mentioned in article R. 1322-3;
2° The water shows signs of instability or deterioration;
3° Certain people present disorders or symptoms of an illness related to the use of the water supplied;
4° Evidence has shown that a substance, a figurative element or a micro-organism for which no quality criteria have been set may be present in quantity or number constituting a potential danger to human health;
5° Work or improvements being carried out on the installations are likely to be harmful to human health.