“…In instances of a risk of water pollution, there are a number of measures which if necessary can also be officially imposed; further, there are specific approval obligations for installations which are potentially dangerous ( § 31a and § 31c) as well as approvals concerning impact ( § 32). 27 The different precautionary elements of the Water Act aim at preventing water pollution, especially by acts which, when normally conducted, would not lead to any impairments, but in the case of incidents pose a special danger to water. Installations which store and transport water hazardous substances according to § 31a are to be constructed and operated in a manner that water pollution or any other impairment is not to be expected.…”