The contractor shall excavate all rock encountered in the trenches and areas occupied by structures as directed by the Engineer and dispose of all such rock in accordance with the requirements under Article IV, Excavation and Backfill.
A. 
In removing rock, special care shall be taken to excavate it as closely as possible to the required shape and with no projection into the neat outside line of such trenches. The surfaces of all rock foundations shall be sufficiently rough to bond well with masonry. Before any masonry is built on or against a rock surface, the latter shall be scrupulously free from all dirt, gravel, boulders, ice, snow or other objectionable substances, including loose fragments of rock. The space between the springing line of the pipe and the surface of the rock shall be filled with crushed stone or gravel.
B. 
Unless otherwise directed by the Engineer, rock shall be fully taken out at least 25 feet in advance of pipe laying and to a point six inches below the invert of the pipe and to a width sufficient to enable good working room for the size of the pipe to be laid therein. Rock shall also be excavated so as to provide a minimum clearance of six inches from the outside face of all pipes and structures.
(Reserved)