Excavation and trenching - Pennsylvania

Pennsylvania is under federal OSHA jurisdiction which covers most private sector workers within the state. State and local government workers are not covered by federal OSHA.

Underground utilities

Excavators in Pennsylvania must submit a notice to locate to Pennsylvania’s One-Call System prior to excavation, which system notifies operators of underground utilities so that they can locate and mark their utilities to prevent damage, interruption of service, and injury to excavation workers. The notification rules and obligations of excavators, the One-Call System, and operators are found at 73 P.S. §§ 177 through 186.

Subsurface operations on highways by utilities

Drilling, boring, driving or tunneling across an improved area. Drilling, boring, driving or tunneling across improved areas must comply with the following conditions:

• When crossing under an improved area, the opening for a utility facility must be drilled, bored, driven or tunneled to a minimum depth of three feet from the surface to the top of the opening.
  • If the facility or its casing is 30 inches or greater in diameter, the bored cylindrical space surrounding either an uncased facility or a facility casing must be filled with grout, in a manner authorized by the district office.
  • Jet or other nonmechanical boring methods are prohibited. Water may be used under low pressure only to cool the drill bit and to facilitate removal of cuttings from the bore opening, if retrievable liquid is immediately removed from the boring pit.
• No openings for the purpose of placing utility facilities or other structures under the improved area by drilling, boring, driving or tunneling may be made closer than 3 feet to the edge of the shoulder, unless the permit authorizes a lesser clearance.
• A facility or other structure crossing under the improved area may be constructed to assure the safety of the traveling public and to preclude the necessity of entering the improved area to affect future maintenance or replacement.

Trenching across the improved area. Trenching across an improved area may be performed only when specifically authorized by the permit, in accordance with the following:

• The top of every utility facility must be installed at least 3 feet beneath the surface.
• Trenching across the improved area may be authorized by the permit where drilling, boring, driving or tunneling are:
  • Not feasible because:
    • The subsurface is solid rock, as documented with satisfactory evidence such as drill records, or where boring was attempted without success.
    • There are other facilities located longitudinally under the improved area, and their location precludes methods other than trenching, as documented in a detailed plan.
    • Adjacent development in a very congested urban area makes the construction of a tunneling or boring shaft impossible.
  • Not required because of one of the following:
    • The highway is unpaved.
    • The Department’s wearing course is older than 10 years, and the highway average daily traffic—ADT—does not exceed 500.
• When trenching is authorized by the permit, the trenching operation must be performed by one of the following methods:
  • Utility facility placed in one piece across highway.
    • Traffic must be routed over 1/2 of the pavement width.
    • The closed half of the pavement must be opened to the required depth and bridged with steel plates.
    • Traffic must be shifted to the bridged half of the pavement.
    • The remaining half of the pavement must be opened to the required depth.
    • The facility must be placed full width.
    • The open trench must be backfilled and restored to half-width in accordance with this section.
    • Traffic must be shifted to the restored half of the pavement.
    • The bridging must be removed, and the remaining half of the trench must be backfilled and restored in accordance with this section.
  • Utility facility placed in more than one piece across highway.
    • Traffic must be routed over 1/2 of the pavement width.
    • The closed half of the pavement must be opened to the required depth, the facility placed, and the trench backfilled and restored in accordance with this section.
    • Traffic must be shifted to the restored half of the pavement.
    • The remaining half of the pavement must be opened to the required depth, the facility placed, and the trench backfilled and restored.
    • The permittee must protect its openings to provide for the safety of the traveling public, including motorists, bicyclists and pedestrians.
• The permit may authorize the placement at depths less than three feet of traffic signal detectors or other highway facilities which are not capable of operating more than 3 feet below the surface.

Openings parallel to the highway. Requirements for openings parallel to the highway are as follows:

• A utility facility must be placed outside the pavement and shoulder unless there is no feasible space outside the pavement and shoulder for placing the facility, in which case occupancy within the pavement or shoulder may be authorized by the permit.
• The top of a utility facility must be installed at least three feet beneath the surface.
• On an unpaved highway, the near edge of the opening must be at least 12 feet from the general center line of the traveled highway.
• No opening may be made for more than 200 linear feet at one time, unless authorized by the permit.
• The permittee must protect its openings to provide for the safety of the traveling public, including motorists, bicyclists and pedestrians.

Daily stoppage of work requirements. Daily stoppage of work requirements include the following:

• Except for emergency repairs of utility facilities, work within the pavement or shoulder must be stopped prior to peak traffic hours that may exist on a particular highway on a particular day and as specified in the permit.
• At the end of each workday, an opening in the right-of-way must be one of the following:
  • Covered with steel plates or bridging over openings which are less than 6 feet in either length or width. The plates or bridging must be extended a minimum of 18 inches from each edge of the opening and must be secured in a safe manner.
  • Backfilled to the bottom elevation of the pavement or base course, or to the original surface elevation if outside the pavement and shoulder and protected, and an approved traffic control plan until the surface is restored to its former condition.
  • Protected an approved traffic control plan, if the permittee has delivered certificates of insurance.
  • The permittee must protect its openings to provide for the safety of the traveling public, including motorists, bicyclists and pedestrians.

Backfilling. An opening must be backfilled by the permittee in accordance with the following:

• The opening may first be backfilled with fine aggregate material or granular material to protect the facility, placed to a height not to exceed 1 foot over the top of the facility, if the material is compacted in not more than 4-inch loose layers.
• The opening must then be backfilled with select granular material, unless retained suitable material is authorized or other coarse aggregate material is specified in the permit. Select granular material or other aggregate material will be required for use as backfill of openings in pavements, paved shoulders and improved (for example, oil and chip) shoulders as well as unimproved (for example, stabilized or earth surface) shoulders within 3 feet of the edge of pavement. Retained suitable material will normally be authorized for use as backfill of openings outside shoulders and in unimproved shoulders more than 3 feet outside the edge of pavement and up to within 3 feet of the surface.
• Backfill must be compacted as follows:
  • General rule. Backfill material must be placed in loose layers not to exceed eight inches if vibratory compaction equipment is used or as authorized. Each layer must be thoroughly compacted to preclude subsidence.
  • Compaction outside pavement and shoulders. At least 15 days prior to the start of work, the applicant may submit its written compaction plan to the district office requesting backfill in an opening outside the pavement and shoulder to be placed in layers thicker than 8 inches prior to compaction. The compaction plan must include full details on equipment, materials and work methods as well as the permittee’s acknowledgment of its obligation and commitment to regularly monitor the restored surface until 2 years after the acknowledged completion of the permitted work and to promptly correct failure or subsidence of the highway.
  • Existing pavement elevation. Compaction must be completed to the bottom elevation of the existing pavement.
• The Department may require the permittee to have material proposed for use as backfill and compacted material tested, at the expense of the permittee, for conformance to the applicable gradation and compaction requirements.
• Openings made in the pavement or shoulder under §459.6 (relating to emergency work) may be immediately backfilled with excavated material that is treated with a recognized chemical soil stabilizer at a minimum rate of 100 pounds stabilizer per cubic yard of backfill, if the stabilized backfill is compacted.
• Test holes must be backfilled, as soon as safely possible, with existing type material or other material authorized by the Department and sealed. The district office may authorize test holes in the pavement or shoulder to be restored without a 1-foot cutback of the surrounding surface.