Waters Protection Ordinance
(WPO)

¹ The per­sons re­spons­ible for stor­age in­stall­a­tions for li­quids that may pol­lute wa­ters that re­quire au­thor­isa­tion must ar­range for an ex­tern­al visu­al in­spec­tion to be con­duc­ted every ten years in or­der to check for de­fects.³⁹

² An in­tern­al visu­al in­spec­tion must be con­duc­ted every ten years for:

a.

stor­age tanks with more than 250 000 l us­able volume that do not have a pro­tect­ive con­struc­tion or a double-walled floor;

b.

single-walled un­der­ground stor­age tanks.

³ The per­sons re­spons­ible must ar­range for the in­spec­tion of the prop­er func­tion­ing of the leak de­tec­tion sys­tem in stor­age in­stall­a­tions for li­quids which may pol­lute wa­ters every two years in the case of double-walled con­tain­ers and pipes and every year in the case of single-walled con­tain­ers and pipes.