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(a) General - The NIA will established a reference base line, bench marks and principal control points for commencement of the Contract Work. To avoid future conflicts, however, prior to commencement of construction work, a joint survey work by the NIA and Contractor shall be undertaken.

All other surveys and layout of the Works shall be performed by the Contractor, including cross sections where required for the purpose of making progress estimates. The Contractor can use any method for this survey work subject to approval by the Engineer.

From the initial lines and grades established, the Contractor shall furnish and place all additional stakes, templates, and bench marks necessary for marking and maintaining points, lines and elevations for layout of the works. Established survey stakes shall be preserved by the Contractor unless authorized to remove them, and in the case of their destruction or removal by the Contractor's work force, they shall be replaced by the Contractor at his expense. Where construction operations requires removal of the NIA's control points, the Contractor shall refer or replace such marks as directed. The Contractor shall be responsible for the conformance of the finished Works with established lines, grades and elevations.

Field notebooks for recording survey data shall be furnished by the Contractor and all field notes, computations and other records taken by the Contractor for purposes of surveys shall be submitted promptly to the NIA and when required will become the property of the NIA. All data shall be in suitable form to permit checking. During progress of the Contract Work the Survey notes and records shall be kept intact and be available for review by the NIA. The Contractor's method of recording data shall be subject to approval by the Engineer.

(b) Survey Equipment and Personnel -Survey instruments, tools, equipment, supplies and personnel shall be furnished by the Contractor. Instruments shall be accurate and shall be subject to rigid inspection, and any defective instrument as determined by NIA, shall be promptly replaced, repaired or adjusted as directed.

Personnel performing survey work shall be qualified and experienced in the work. All surveys shall be done under the direct supervision of a qualified surveyor who shall be subject for approval by the NIA at all times during continuance of the Contract Work.

The NIA reserves the right to check all survey works at any time; to require correction by the Contractor or any survey inaccuracies in the layout of the work, or in the compilation of field data, at the Contractor's expense.

(c) Accuracy - Accuracy of survey works shall be within the following tolerances:

Points for cross sections shall be located within two centimeters horizontally and vertically.

Levels shall close within one centimeter multiplied by the square root of the length of the circuit in kilometers.

Final grade stakes ( blue tops ) shall set to 0.25 centimeters.

Alignment of tangents and curves shall be within two centimeters.

Points of structures shall be set to the nearest 0.25 centimeter, except where operational function of special features in installation of metal work and equipment requires close fit.

(d) Form Work - When form work has been placed and is ready for concreting, the Contractor shall check the form work for conformance with the drawings and to insure that the forms are sufficiently within the tolerance limits for completed work in accordance with the Technical Specifications.

(e) Quantity Surveys - The Contractor with the presence of NIA representative shall make such surveys as determined necessary by the Engineer to measure or estimate quantities for purposes of progress payments. Likewise, surveys of the completed works will be made by the Contractor with the presence of NIA representative for estimating the final quantities. All such quantity surveys shall be subject for checking and approval. The final quantities for payment will be based on the original cross sections, and the lines shown on the drawings or as prescribed. The Quantities used for monthly progress estimates for partial payments shall be subject to correction in the final quantities.

The Engineer will, when he requires any part or parts of the Works to be measured, give notice to the Contractor's authorized representative who shall forthwith attend in making such measurement and shall furnish all particulars required by the Engineer. Should the Contractor neglect or omit to make such measurement, then the measurement made or approved by NIA shall be taken to be the correct measurement of the Works. For the purpose of measuring such Permanent Works as it is to be measured by records and drawings, the NIA will prepare records and drawings of such Works for every month and the Contractor when called to do so in writing shall within 14 calendar days attend to examine and agree to such records and drawings with the NIA and shall sign the same so agreed and if the Contractor does not so attend to examine and agree to any such records and drawings they shall be taken to be correct. If after examination of such records and drawings the Contractor does not agree to the same or does not sign the same as agreed, the records and drawings shall nevertheless be taken to be correct unless the Contractor shall within 14 calendar days of such examination, lodge with the NIA for decision by the Administrator, a written notice of the aspects in which such records and drawings are claimed by him to be incorrect.

(f) Cost -The Contractor's cost of making the necessary surveys of construction as described above, of laying out the work from established lines and grades, estimated and final quantities, and all works and materials incidental hereto shall be included in the bid prices for the various items in the Bill of Quantities.