As a condition of any special permit for the placement, construction or modification of a personal wireless service facility, a carrier shall provide a bond, in a form acceptable to the Town, or shall place into escrow a sum of money sufficient to cover the costs of removing the facility from the subject property and, furthermore, said funds shall be held by an independent escrow agent to be appointed by the carrier and the Planning Board. The amount of the surety shall be certified by an engineer, architect or other qualified professional registered to practice in the Commonwealth of Massachusetts. The carrier shall authorize and, as necessary, shall provide the authorization of the owner of the property to allow the Town or the escrow agent to enter upon the subject property to remove the facility when the facility has been abandoned or discontinued.