This contract covers the design, construction, operation and maintenance of devices for treating lead pollution of water from the roof of Notre-Dame Cathedral in Paris

following the fire of April 15, 2019, Notre-Dame Cathedral in Paris lost almost all of its lead frame and roof. The Public Institution in charge of the conservation and restoration of Notre-Dame de Paris Cathedral, project owner of the restoration of the cathedral, proposed the identical restitution of the exterior architecture of the cathedral, based on studies carried out by the chief architects of historical monuments (Acmh), project managers, in compliance with the original materials: oak wood for the frame and lead for the roof. This restoration party received a unanimous favorable opinion from the National Commission for Heritage and Architecture (CNPA) in July 2020.In order to ensure the perfect control of the environmental impact of the presence of lead on the roofs of the cathedral, the restoration work program of the cathedral provides for a complete system of collection of runoff water to ensure that it is fully collected. In parallel, a study was entrusted to the Water, Environment, Urban System Laboratory (Leesu) of the National School of Bridges and Roads, in order to evaluate the characteristics of a treatment device for the water collected, upstream of its discharge into the sewer.The objective of this dialogue is to define and implement said device, namely a system allowing an optimal treatment of runoff water. This system will have to respond to an overall cost approach, resulting from the search for a satisfactory level of treatment while respecting a realistic operation and maintenance plan on the one hand, from a technical and functional point of view as well as from a financial point of view; on the other hand by responding to the various challenges of sustainable development