4.20. The monitoring programme should consider all stages of the lifetime of the facility and should be established and reviewed during the early stages of development of the disposal facility and, if required, should be made subject to approval by the regulatory body while accommodating the societal needs of the State. The monitoring programme should begin as early as possible during the initial process of site selection and should evolve through the construction, operation and closure of the facility in an ongoing manner, and should be used to inform and update data used in the safety case and supporting safety assessment of the facility, as described in Section 6. In parallel, the monitoring programme should be periodically reviewed by the regulatory body. Monitoring technology should be updated and refurbished when possible and when necessary.