30 The network provider must within 10 days of the date of the receipt inform the landowner whether he/she or the landowner will carry out the works. If the network provider wishes to carry out the works, he/she must do so in accordance with a timetable established by the landowner. If the landowner (or someone employed or contracted by him/her) is to carry out the works, the network provider has the right to supervise these. All alterations carried out by the landowner must as far as possible be to the same standard as the original works and using similar materials. All losses and damages, costs and expenses incurred by the network provider, either in carrying out the alterations or in supervising them, are paid to the network provider by the landowner. In the event that the network provider: 1° does not submit a notice to the landowner stating that he/she wishes to undertake the alterations; 2° does not agree with the landowner on the work timetable; 3° fails to undertake the alterations within the time set out in the timetable; 4° fails to provide the supervision mentioned in paragraph 2 of this Article. The landowner may carry out the alterations him/herself. Notwithstanding the paragraph (4) of this Article, in order to preserve the integrity of the network, alterations must be carried out to the reasonable satisfaction of the network provider. In the event of disputes, the Regulatory Board settles these, when it fails to do so, the case is taken by the court. If the landowner: 1° carries out alterations without having given to the network provider the notice in accordance with this Article and/or; 2° unreasonably fails to carry out any requirements of the telecommunications operator is liable to a fine provided for in Article 69 of this law. CHAPTER XIII. ACCOUTIG STADARDS Article 51 The Regulatory Board has the power, if necessary, to require dominant organizations to implement cost accounting systems which are sufficient to verify that tariffs for telecommunications networks and/or telecommunications services, leased lines, and interconnection of networks are based on the costs of providing these facilities together with a reasonable rate of return as determined by the Regulatory Board.