PEPCO Procedure for Working in Close Proximity to Underground Transmission Facilities.pdf

PROCESS AND PROCEDURES FOR WORKING

IN CLOSE PROXIMITY TO PEPCO UNDERGROUND FACILITIES

1. SCOPE

This document provides requirements for the identification and protection of Pepco underground facilities.

2. FACILITY LOCATION

2.1 Planning

Upon request, Pepco will provide Contractor with available information, needed by the Contractor in order to complete their work. All Drawings, specifications and other design related documents (“Design Documents”) provided by Pepco shall be returned to Pepco. Neither Contractor nor any Subcontractor may own or claim a copyright in any of said Design Documents. Unless Pepco provides written permission to the Contractor, neither Contractor nor any Subcontractor shall be permitted to use the Design Documents for any purpose other than completion of the work. Such Design Documents are confidential and may not be copied or reproduced in any manner.

Information provided by Pepco is, in some instances, schematic, and exact locations and arrangements must be worked to fit site conditions.

It shall be the responsibility of the Contractor to make timely requests of Pepco for any information which it requires in the planning and execution of the work. However, each request shall be with sufficient lead time and with adequate specificity to permit appropriate action to be taken by all parties involved. Each request shall be in writing, and shall list the required items of information and the date by which each is desired. If requested by Pepco, Contractor shall furnish promptly any assistance and information that Pepco may need in order to respond to Contractor’s requests. Pepco shall have no responsibility or liability for any delays in providing information.

Pepco shall not be liable for the completeness or accuracy of the information provided to Contractor, whether in character, location, dimension or due to omission.

Contractor shall be responsible for reconciling and resolving all inconsistencies between actual physical conditions and the information provided by Pepco. Obstructions shown on the

STL 085-527 133141 (2/12/2014) TSG

drawings have been obtained from available records. Obstructions must be verified in the field by the Contractor to ensure appropriate final line and grade for trench work.

2.2 “Miss Utility” & “One Call”

Contractor shall notify "Miss Utility" (811) or "One Call" (811) at least forty-eight (48) hours, or such other time required by the jurisdiction within which the Work is being performed, before commencing any excavation in connection with any planned underground work.

All subsequent digging shall be performed in accordance with the applicable Miss Utility / One Call requirements.

2.3 Familiarity with Site Conditions

It is Contractor’s responsibility to investigate each location in and around where any work is to be performed, including both surface and subsurface conditions, and to ensure that it is familiar with and has satisfied itself with respect to

(i) The nature and location of the work

(ii) The location of underground utilities

(iii) All Federal, State, and local laws, ordinances, rules, and regulations that may, in any manner, effect the work (including traffic control and applicable environmental regulations)

(iv) The activities of other contractors that will be working at the project site that may affect the work.

2.4 Test Holes-General

Once Miss Utility / One Call has marked the underground facilities and if the proposed work is three (3) feet or less from this marking, Contractor shall, at its expense, dig a sufficient quantity of test holes to accurately locate underground Pepco facilities which could:

(1) potentially obstruct Contractor’s construction; and/or

(2) need to be properly protected during construction.

These test holes shall be hand dug within compliance of the ‘Miss Utility / One Call’ laws and regulations appropriate to the location of the work. Test holes shall also be completed far enough in advance of construction so that requests to Pepco for necessary changes in line and grade may be reviewed, approved and scheduled by Pepco, without interfering with the progress of the job.

Errors in trench excavation, either line or grade, and manhole locations stemming from insufficient or improper test hole operations shall be Contractor’s responsibility at no cost to Pepco.

2.5 Test Holes-Pipe Type Feeders

Test holes for pipe-type feeders must be performed carefully due to the delicate nature of the steel pipe’s external coating. Test holes for pipe-type feeders must be performed as described in section 2.4 until the layer of thermal sand is reached. Once the thermal sand is reached, the Contractor must vacuum to the steel pipe to ensure that neither forced air nor equipment scratches the exterior coating of the steel pipe. A Pepco construction inspector will need to be on site for the tests holes near pipe-type feeders. Coordination with Pepco personnel will be required to ensure that new thermal sand is delivered to the site to fill the test hole. The removed soil is not acceptable to be used for filling the test hole. Further information can be provided by PHI’s Underground Transmission Engineering group if necessary.

3. NOTIFICATION

The Contractor shall notify Pepco at least 48 hours in advance of any work in the vicinity of any underground electrical facilities.

4. PREVENTION OF DAMAGE

The Contractor shall perform all work in the vicinity of the underground facilities in such manner as to avoid damage to the cables. Any damage resulting from the work of the Contractor will be repaired by Pepco and all costs incurred will be billed to the Contractor.

5. EXCAVATION

5.1 Uncovering

Hand excavation shall be used to locate and uncover the underground facilities. Care shall be taken to ensure that no pipe coatings or concrete encasements area damaged during excavation.

5.2 Support and Protection

All excavations shall be adequately shored or otherwise protected by Contractor to ensure protection of the public, workers, and surface and subsurface structures and utilities encountered in the course of construction. Excavations shall be shored as required by authorities having jurisdiction in the area of construction and/or as required by Pepco. Shoring of Pepco facilities shall be provided as required at no cost to Pepco.

Linear excavations exposing more than five (5) feet of concrete encased ductbank or ten (10) feet of coated steel pipe shall require suitable shoring and lagging to prevent sagging of the unsupported facilities.

In the event the Contractor fails to provide proper support and protection, Pepco may elect to provide such support and protection as may be necessary to ensure the safety of the underground facilities and all costs incurred will be billed to the Contractor.

5.3 Excavation below Underground Facilities

Following Pepco approval of the plans to support and protect the underground facilities, excavation beneath the facilities may proceed with mechanical equipment provided sufficient care is taken to ensure that none of the facilities are damaged. Hand excavation may be required where mechanical means are ineffective or where proper care is not being exercised with the mechanical equipment.

5.4 Interruption in Service

If, during the performance of the Contract, it should become necessary for service to be interrupted to any part of Pepco’s infrastructure, Contractor shall provide a minimum of twenty-four (24) hours advance notice. Such notice shall describe all pertinent particulars of the needed interruption and the maximum duration of the interruption. Pepco will endeavor to facilitate such request. Transmission line outages cannot be granted upon short notice and are often outside of Pepco’s control.

The Contractor will be held responsible for unscheduled interruptions and any damages arising from such interruptions due solely or in part to its negligence.

6. BACKFILLING

6.1 Backfill Below Facilities

Backfill to a depth of six (6) inches below the underground facilities shall be run of bank gravel furnished and placed in accordance with the regulations of the authority having jurisdiction in the area of the construction.

6.2 Inspection

When the run-of-bank gravel has been placed to a level no higher than six (6) inches below the bottom of the underground facility, the shoring and lagging shall be removed. The Contractor shall schedule sufficient time for Pepco to make a thorough visual and/or electrical inspection of the facilities and to make any repairs, if necessary. If the Contractor has surveyors as part of the project, Pepco requests the elevation of the underground facilities.

6.3 Thermal Sand (Pipe-Type Cables only)

Select sand which has the required thermal characteristics and is obtained from a source approved by Pepco shall be placed in six-inch (6”) compacted layers to a depth of twelve-inches (12”) above the top of the steel pipes. Each layer shall extend not less than eight-inches (8”) beyond the sides of the steel pipe. Hand tamping shall be used adjacent to and for the first six-inches (6”) over the pipe after which machine tamping may be used. Care shall be taken to ensure that the select sand is well tamped below the steel pipes and that the pipe coating is not damaged.

6.4 Backfill Above the Select Sand

The remainder of the backfill above the select sand shall be suitable material in accordance with the regulations of the authority having jurisdiction in the area of the construction.

6.5 Marker / Warning Tape

The Contractor shall cooperate in the installation of a plastic marker tape in the backfill over the underground facilities. The marker tape shall be furnished by Pepco and shall be placed on top of the compacted layer of backfill which is six-inches (6”) to twelve-inches (12”) below final grade.