(a) WORK TO BE DONE. The work to be done consists of furnishing all labor, materials, methods and processes, implements, tools and machinery, except as otherwise specified, which are necessary and required to construct and put in complete order for use in the proposed improvements designated in the Contract, and to leave the grounds in a neat condition. (b) ALTERATION. By mutual consent in writing of the parties signatory to the Contract, alterations or deviation, increases or decreases, additions or omissions, in the plans and specifications, may be made and the same shall in no way affect or make void the Contract. The City reserves the right to increase or decrease the quantity of any item or portion of the work, or to omit portions of the work as may be deemed necessary or expedient by the Engineer. (c) EXTRA WORK. New and unforeseen work will be classed as extra work when such work cannot be covered by any of the various items or combination of items for which there is a bid price. The Contractor shall do no extra work except upon written order from the Engineer. For such extra work the Contractor shall receive payment as previously agreed upon in writing, or he shall be paid on force account. (d) REMOVAL OF OBSTRUCTIONS. The Contractor shall remove and dispose of all structures, debris, or other obstructions of any character of the construction of the street or road, if and as required by the Engineer. The removing and disposing of all obstructions to the prosecution of the Contract, unless otherwise specified, shall be considered as included in the various items of Contract work and no additional compensation will be allowed therefore. (e) ROADWAY FINISHING. Upon completion, and before making application for acceptance of the work, the Contractor shall clean the street or road, borrow pits, and all ground occupied by him in connection with the work; remove all rubbish, excess materials, temporary structures, and equipment; and all parts of the work shall be left in a neat and presentable condition.