Excavated material shall be stored in neat piles and so placed as to cause the least interference with the use of roadways or sidewalks. If so ordered by the Commissioner, such excavated material shall be promptly removed from the site of the work.
A. 
When so directed by the Commissioner, tight sheathing at least two inches in thickness, securely fastened in place with whalers and braces throughout the duration of the work, shall be placed in all trenches; shall be driven to the same depth as the lowest part of the pipe, conduit or structure proposed to be installed; and shall be carried down in such a manner that the bottom of the sheathing shall at no time be more than one foot above the bottom of the excavation.
B. 
Whenever conditions make it necessary, the Commissioner may require that the sheathing be driven ahead of the excavation as the latter proceeds.
C. 
Unless otherwise authorized in writing by the Commissioner, sheathing and shoring shall be left in place with a cutoff line 18 inches below ground surface.
A. 
In rock excavation, drilling and blasting shall be conducted with all possible care. All blasting operations shall be conducted in strict accordance with existing ordinances and regulations relating to rock blasting and the storage and use of explosives.
B. 
Any rock excavation within five feet of water or gas main, pavement or other subsurface pipe, conduit or structure shall be done with very slight charges of explosives and the utmost care shall be used to avoid disturbing or injuring said structure.
C. 
The permittee shall use the utmost caution in properly protecting all surface or subsurface structures from the effects of blasting, and any damage done to such structures shall be promptly repaired by the permittee or by such other parties as the Commissioner may direct, at the said permittee's own expense.
D. 
Sufficient warning shall be given to all persons in the vicinity of the work before blasting. The site of the blast shall be covered with heavy timbers, blasting mats or other devices to prevent damage from flying rock fragments.
E. 
The time of blasting and the manner and size of charges must be satisfactory to the Commissioner. The blasting shall be done only by properly licensed individuals.
F. 
The permittee shall give adequate notice to the City and to the appropriate public-service corporations before proceeding with blasting in the vicinity of water mains, sanitary sewers, storm drains or other drains or other public utility lines.
A. 
No backfilling shall be done by a public-service corporation until the work being done under the permit shall have first been inspected and backfilling authorized by the Commissioner. In the event of failure to comply with this requirement, the Commissioner shall have the right to require that the work be uncovered by the permittee at the latter's expense so that proper inspection may be made.
B. 
The material used to backfill the bottom of the trench up to a level of two feet above the completed pipe or other structure shall be clean earth, sand or rock dust and shall contain no broken rock, stone or frozen earth.
C. 
Above a level two feet higher than the top of the completed pipe or other structures, the material used for backfill shall be approved material containing no frozen earth and not more than 1/3 broken rock, and no stone in place thereof shall exceed 1/2 cubic foot in size.
D. 
The space between the pipe or other structure and the bottom and sides of the trench shall be packed full by hand and thoroughly tamped as fast as placed and up to the level of the top of the pipe or other structure, which shall then be covered by hand to a level at least three feet higher than the top thereof, the backfill material being carefully deposited and tamped in layers not more than six inches thick.
E. 
Tamping shall be done with a light tamper weighing from six to eight pounds and shall be conducted in such a manner as to secure compacted backfill without in any way injuring or disturbing the completed pipe or structure. At least one man shall be provided for tamping for each man engaged in backfilling.
F. 
The use of power equipment or other mechanical means for backfilling will not be allowed except with the prior written authorization of the Commissioner.
G. 
Compacting the backfill by means of flooding or puddling with water will not be allowed except with the prior written authorization of the Commissioner.
Tunneling under pavements or sidewalks is prohibited, but small pipes or conduits having a dimension of six inches or less may be driven beneath pavements or sidewalks, provided that the surface shall not be disturbed or injured and further provided, that:
A. 
The prior written approval of the Commissioner is obtained.
B. 
No excavation in connection therewith shall be closer than one foot to the edge of the sidewalk or 18 inches to the edge of a pavement.
C. 
Such pipes or conduits shall be enclosed in sleeves or larger pipes so that required replacements or repairs may be made in the future without disturbance or injury to the pavement or sidewalk.
D. 
In the event of damage to a pavement, sidewalk or subsurface pipe or structure caused by driving such pipe or conduit, the permittee shall repair and make good the damage at the permittee's own expense.