Production of a deposit is ceased once producing costs more than it yields for a variety of reasons.
In accordance with various regulatory requirements, including the Environment Code and the Mining Code, specialized teams intervene on the site to comply with procedures for permanently closing the site, or Final Work Stoppage (a legal term that includes plugging the well, dismantling all surface installations, and preparing the ground for its return to its initial, usually agricultural, condition).
These works can last from a few months to several years, according to the characteristics specific to each site, and are generally planned and budgeted from the development plan. Once the rehabilitation is completed, the land is returned to its owner.
The 1st phase of work involves the capping of the well.
Before this work, Vermilion proposes to the Prefecture a closure program, which is the subject of a technical review, sometimes requiring certain adaptations, before being validated to be able to launch operations. During and at the end of the capping work, various verifications are carried out, in order to bring all the expected guarantees that the well is perfectly inert.
Once the well is plugged, a DADT (Final Termination of Mining Works) is sent to the Prefecture of the department where the site is located. This file recalls all the information on the site (history, facilities…) and specifies all the measures planned by Vermilion to ensure the rehabilitation (dismantling work…). Beforehand, a complete environmental diagnosis is carried out to assess the state of the environment (soils, surface water, groundwater) and, when necessary, set up remediation work.
After having been informed of this DADT file, the Prefecture (and its DREAL/DRIEE training bodies) validate the work program and issue a Prefectural Authorization Order. Once the work is completed, Vermilion submits to the Prefecture a technical end-of-works memorandum, which provides all the required supporting documents and a letter from the owner attesting that Vermilion has fully complied with its rehabilitation obligations.
Once completed, this end-of-works file enables the Prefecture to issue a Prefectoral Mining Law Order stipulating that Vermilion has fully paid for the remediation of the site. Only then is Vermilion relieved of its responsibility, which is then transferred to the state.
Compliance with mining operators’ commitments to abandon a site is therefore scrutinized with particular attention, since it is the State itself that assumes responsibility for the post-mine.