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LOOSE ROCK EXCAVATION shall include all stratified rock, sandstone, cemented gravel, shale and boulders not otherwise defined as solid rock, regardless of how removed. BLASTING for excavation will not proceed until the CONTRACTOR has notified the ENGINEER of the necessity to do so. This notification shall in no matter relieve the CONTRACTOR of the hazards and liability contingent on blasting operations. The hours of blasting will be fixed by the ENGINEER Any damage caused by blasting shall be repair~ by the CONTRACTOR at his expense. The CONTRACTOR's method of procedure relative to blasting shall confonn to local and State laws and municinal ordinances. When excavation is encountered that is unsuitable for backfill, it shall be removed as directed by the ENGINEER. 603.200 PREPARATION OF SOIL DURING PIPE LAYING At the time of pipe placement, the bedding conditions shall be such as to provide unifonn and continuous support for the pipe between bell holes. Bell holes shall be excavated as necessary to make the joint connections, but they shall be no larger than . would be adequate. No pipe material shall be laid in water nor when the trench or bedding conditions are otherwise unsuitable or improper. If trench bottom conditions are encountered which appear to require stabilization, the ENGINEER shall be infonned. The trench conditions shall be examined by the ENGINEER to determine the nature of such instability, employing the services of a testing laboratory if necessary. If it is determined that the trench bottom cannot support the pipe, a further depth and/or width shall be excavated and refilled to the pipe foundation grade with granular foundation material and thoroughly compacted. If the examination by the ENGINEER reveals that the aforedescribed conditions are caused by the CONTRACTOR's manipulation of the soils in the presence of excessive moisture or lack of proper dewatering, the CONTRACTOR shall take such steps as are necessary to stabilize the trench bottom including the use of pipe support material and improved dewatering methods. In such case, the cost of measure necessary shall be borne by the CONTRACTOR When the bottom of the trench consists of a material suitable to properly support the pipe the following methods of bedding shall apply: (1) Granular bedding material will be placed below the midpoint of the pipe, prior to pipe installation, to facilitate proper shaping and achieve unifonn pipe support, using hand compaction methods. (2) Granular backfill ;material at pipe zone shall be free from rock, boulders or other unsuitable substances and shall be deposited into the trench simultaneously on both sides of pipe for the full width of the trench in six-inch lifts thoroughly compacted to a minimum elevation of one foot above the top of the pipe. Compaction shall be accomplished by mechanical tamping. 600-4