Certain areas around the Notre-Dame in Paris have been closed off to allow for deep cleaning efforts to decontaminate the ground for the safety of workers.
The Paris Police has already set up barriers marking out an area around Notre-Dame where ultra-pressure cleaning will begin on Tuesday to decontaminate the ground of the lead that has entered it after the fire, according to the Ministry of Culture.
The operation will start on rue de la Cité, which will therefore be closed to passers-by and car traffic.
The method used, ultra-high pressure, is made more effective by the addition of a chemical agent that increases the spreading and wetting capabilities of a liquid. This surfactant should be aspirated and recovered.
The ultra-high pressure solution, which will cover the main surfaces, should be faster than the gel solution which takes at least five days.
At the end of the work, the effectiveness will be checked. The work – which will happen in several phases – will last until 23 August.
The fire that partially destroyed the cathedral both melted and released the hundreds of tonnes of lead contained in the spire structure and roof in the form of particles.
The reconstruction of Notre-Dame, which was suspended at the end of July, should gradually resume on August 19 after the implementation of new drastic protection measures targeting worker safety.