CGA (Common Ground Alliance) Best Practices

In this module, we shall explain the highlights of CGA best practices.

The actual document is also highlighted for potential exam questions and brought in module 16.

Note: The actual document is also highlighted for potential exam questions and brought in module 16.

1. Introduction

Pipeline and Hazardous Materials Safety Administration (PHMSA) invited 1,700 individuals, organizations and sponsors in every facet of the underground utility industry to prepare the best practices in the pipeline construction using the consensus process (approved by all 9 groups before implementing).

CGA is a member-driven association of 1,700 individuals, organizations and sponsors in every facet of the underground utility industry.

CGA has nine study teams:

1. Planning and Design,
2. One Call Centers,
3. Locating and Marking,
4. Excavation,
5. Mapping,
6. Compliance,
7. Public Awareness and Education,
8. Reporting Evaluation, and
9. Emerging Technologies.

One of the most controversial elements of the process for determining a “best practice” was the use of the consensus process.

For a practice to become a “best practice,” all stakeholder groups must agree that they could live with the practice; if one group disagreed, the practice would not become a “best practice.”

This single element of the process is what arguably gives the CGA its integrity and ensures that all elements of an issue are vetted comprehensively.

Major lesson learned during the CGS were that communication is the key to ensuring safety and protecting vital facilities.

The CGA uses icons to assist readers in identifying the groups:

Best Practices Process

How is the Best Practice (BP) Developed or Revised?

Once a proposal received, it goes to BP committee who review and either approves or dismisses it.

If approved in principle, it goes to specialist committee who review and return it to BP committee who shall then finalize and present it to board of directors who in turn may approve it straight away or return it with comment in which case the previous cycles is repeated once again.

Editorial subgroup has the duty to edit it grammatically and ensure using an standard format without making substantive changes.

2. Planning and Design

Plat or a plot of land should show any existing buried facilities and rights of way.

During the planning phase of the project, all available information is gathered from facility owners/operators.

This includes:

maps of existing, abandoned, and out-of-service facilities;

cathodic protection and grounding systems;

as-builts of facilities in the area if the maps are not current;

proposed project designs; and schedules of other work in the area.

Information gathered, also may include a review of the site for aboveground indications of underground facilities (for example, permanent signs or markers, manhole covers, vent pipes, pad-mounted devices, riser poles, power and communication pedestals, and valve covers).

The one call center provides a listing of operators directly to the designer.

Benefits:

- Gathering underground facility information and including this information in the planning phase minimizes the hazards, cost, and work to produce the final project.

- Safety is enhanced.

- Unexpected conflicts with facilities are eliminated.

- Facility relocations are minimized.

2.3 Identifying Existing Facilities in Planning and Design

During the planning phase of the project, existing facilities are shown on preliminary design plans.

The facilities shown include active, abandoned, out-of-service, and proposed facilities.

2.5 Markers for Underground Facilities

The presence and type of underground facilities are indicated by permanent aboveground and below ground markers and material.

A combination of aboveground and below ground markers is used to identify and locate underground facilities.

The purpose of aboveground markers is to identify underground facilities, not to locate for excavation or circumvent the one call process.

Aboveground markers are developed during the design process and include the company name, type of facility, emergency contact, and the one call number.

Road decals, stencils, tracer tapes, electronic markers, or other appropriate systems may mark areas where traditional markers are considered impractical.

References: 49 CFR Parts 192 and 195

2.6 Follow All Applicable Codes, Statutes, and Facility Owner/Operator Standards

When planning and designing the installation of a new facility or replacement of existing underground facilities, the designer follows all federal, state/provincial, and local guidelines, codes, statutes, and other facility owner/operator standards.

Regulations, codes, standards, and other design documents generally specify depth of cover and horizontal and vertical clearances between adjacent facilities.

The designer must also consider the protection and temporary support of adjacent facilities and any interference to existing cathodic protection and grounding systems.

2.7 Use of Qualified Contractors

Qualified contractors are used to excavate on and near underground facilities.

Contractors that excavate on and near underground facilities possess the qualifications necessary to conduct such activities in a manner that is skillful, safe, and reliable.

Benefits:

- Enhances safety

- Increases the quality of work

- Reduces damage to facilities

2.8 Mandatory Pre-bid Conferences

Pre-bid conferences provide a forum for the contractor, owner, and other interested parties:

to discuss a project and record the binding changes or clarifications to the scope of the project;

to review contract documents, regulatory requirements, schedules, and submittal formats.

2.11 As-built Drawings

As-built drawings are prepared and the information is recorded to aid future excavations and locates.

Installation is made in accordance with the approved construction plans. Any deviation to the plans is documented and such changes are indicated on the as-built drawings.

As-built information is recorded, retained, and made available for subsequent excavation.

2.12 Supply-line Separation

When installing new direct-buried supply facilities in a common trench, a minimum of 12" radial separation is maintained between supply facilities, such as steam lines, plastic gas lines, other fuel lines, and direct-buried electrical supply lines.

If 12" of separation cannot be feasibly attained at the time of installation, then, mitigating measures such as insulators, casing, shields, or spacers are used to protect lines against possible damage that might result from proximity to other structures.

If there is a conflict among any of the applicable regulations or standards regarding minimum separation, the most stringent are applied.

3. One Call Center

3.1 Proactive Public Awareness, Education, and Damage Prevention Activities

The one call center has a documented and proactive public awareness, education, and damage prevention program. Reference 49 CFR Part 192

3.2 Specifically Defined Geopolitical Service Area with No Overlap

The one call centers serving a specifically defined geopolitical area are structured so that an excavator need only make one call, and a facility owner/operator need only belong to a single one call center.

There are three requirements that a one call program must meet to be considered as having implemented this best practice:

- The program permits an excavator to use a single point of contact to submit and follow up on a notice of intent to excavate and to notify affected facility owners/operators.
- The program permits a facility owner/operator to join a single one call center and receive all appropriate notices.
- The program is designed so that all pertinent information is shared among one call centers in the event more than one exists.

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3.5 Single Toll-free State-wide Telephone Number with Nationwide Access

All one call centers have a single toll-free state-wide telephone number with nationwide access.

3.14 Meeting between the Excavator and Facility Operator(s) Initiated by One Call Notification

The one call center requires that the excavator provide sufficient information to fully identify the boundaries of the proposed work site.

3.16 Locate Request

The one call center captures the following information, as a minimum, on a locate request:

- Caller’s name and phone number
- Excavator’s/company’s name, address, and phone numbers
- Specific location of the excavation
- Start date and time of the excavation
- Description of the excavation activity

In addition to the minimum required information identified in the preceding paragraph, the locate request includes any available information that will help establish the specific location of the excavation site. For example:

- X/Y coordinates - a means of defining horizontal position - the dig site can be a point, an area or box, or a polygon. For a spatial rectangle (maximum/minimum latitude/longitude), the dig site must be wholly within the included area.

- Latitude/longitude coordinates (s) or specific address of the dig site. These may be done automatically by GIS subsystem (A data input subsystem allows the user to capture, collect, and transform spatial data into digital form), or determined by a computer-assisted customer service representative.

- GPS Coordinates. When the excavator provides GPS coordinates to the One Call center and when the call center has the technical capabilities to capture this information, the GPS format is also specified (decimal degrees; degrees/decimal minutes; or degrees/minutes/seconds) and included on the ticket.

- Map grids

- Distance to nearest cross street

- The intended start date and time of the excavation

- Type of excavation activity (e.g., boring, blasting, trenching, trenchless, etc.)

- For whom the excavation work is being done

- The purpose of the work (i.e., what will be installed or built)

3.25 Identification of Unknown Lines

The one call center has a defined and documented policy for handling calls from excavators regarding the discovery of an unidentified line.

To facilitate damage prevention, one call centers have an established procedure that is implemented when an excavator calls and reports an unidentified facility.

4. Locating and Marking

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4.1 Available Records

Facility locators use available records at all times. Facility records indicate approximate location, number of facilities, and access points for buried facilities within a requested area.

4.3 Color Code

A uniform color code and set of marking symbols is adopted nationwide.

A national standard is adopted defining color specifications relevant to facility type and marking symbols for identifying facilities. (See Appendix B, “Uniform Color Code and Marking Guidelines.” See below the color codes. Remember these colors; for example, you may be asked what the color code is for Gas/oil (yellow) or electrical lines (red) or potable water (blue) or sewers (green):

4.4 Single Locator

A single locator is used for multiple facilities.

Note: This best practice does not suggest that all facilities be located by a single locator, but rather that conditions exist in which locating multiple facilities with a single locator will reduce the likelihood of errors and resulting damage (e.g., multiple facilities with the same owner or multiple facilities that are marked with the same or similar color codes).

4.7 Visual Inspection

A visual inspection is completed during the facility locating process.

This inspection includes the following:

- All facilities within a facility owner/operator’s service area (to evaluate the scope of the locate request)

- Identification of access points

- Identification of potential hazards

- Assurance that plant facilities shown on records match those of the site

A visual inspection helps determine if there are facilities placed that are not on the record.

Evidence of a facility not on record includes, but is not limited to, poles, dips, enclosures, pedestals (including new cables found within the pedestals), valves, meters, risers, and manholes.

4.8 Facility Marking

Facilities are adequately marked for conditions.

Facility locators match markings to the existing and expected surface conditions.

Markings may include one or any combination of the following: paint, chalk, flags, stakes, brushes, or offsets. All marks should have a reasonable distance from the boundary of the requested area. Conditions that may affect markings are rain, snow, vegetation, high traffic, construction, etc.

4.9 Positive Response to Locate Request

All facility locate requests should result in a positive response from the facility owner / operator to the excavator.

A positive response may include one or more of the following: markings or documentation left at the job site, call-back, fax, or automated response system.

A positive response allows the excavator to know whether all facility owners/operators have marked the requested area prior to the beginning of the excavation.

4.10 Marking Multiple Facilities in the Same Trench

Multiple facilities in the same trench; are marked individually and with corridor markers.

In circumstances where the total number of lines buried in the same trench by a single facility owner/operator may not be readily known, a corridor marker is used.

The corridor marker indicates the width of the facility.

4.11 Abandoned Facilities

When located or exposed, all abandoned facilities are treated as live facilities. (Note: Because we don’t know if there is hazardous liquid or gas in it or not; until examined and pronounced safe).

Abandonment of an existing facility, damage to an abandoned facility, limited or non-existing access points may render an abandoned line non-locatable.

4.12 Locating Electromagnetically

The preferred method of actively applying a signal onto a facility; is to use direct connection. Direct connection is the process of connecting a direct lead from the transmitter to the target facility and connecting a ground lead from the transmitter to a ground point to complete a circuit.

4.16 Damage Investigation

A damaged facility is investigated as soon as possible after occurrence of damage.

Anytime a damage occurs, proper investigation is performed not only to determine the responsible party but also the root cause of the damage.

The information gathered from damage investigations is essential in preventing future damages.

4.19 Trenchless Excavation

Locate the trenchless excavation path in the area of the entrance pit and the exit pit when trenchless excavation is being used.

4.20 Locating and Marking in Navigable Waterways

Permanent markers are placed as close as practical at the entrance and exit points of facilities located underneath bodies of water (river, stream, lake) where facilities are at risk of being damaged.

Facility type, name, and contact number of the facility operator are included on markers for all facility types.

5. Excavation

5.1 One Call Facility Locate Request

The excavator requests the location of underground facilities at each site by notifying the facility owner/operator through the one call center.

Unless otherwise specified in state/provincial law, the excavator calls the one call center at least two working days and no more than ten working days prior to beginning excavation.

Currently 50 states and 5 Canadian provinces have one call legislation and/or established one call centers; recognizing that excavation performed without prior notification poses a risk to public safety, excavators, and the environment, and can disrupt vital services provided by facility operators.

5.2 White Lining

When the excavation site cannot be clearly and adequately identified on the locate ticket, the excavator designates the route and/or area to be excavated, using white pre-marking.

The route of the excavation is marked with white paint, flags, stakes, lines, polygons, or a combination of these to outline the dig site prior to or during notification to the one call center and before the locator arrives on the job.

5.3 Locate Reference Number

The excavator receives and maintains a reference number from the one call center that verifies that the locate was requested.

All calls from excavators processed by the one call center receive a unique message reference number, which is contained on all locate request messages.

5.6 Separate Locate Requests

Every excavator on the job has a separate one call reference number before excavating.

There are often several excavators on a job site performing work.

The construction schedule may dictate different types of work requiring excavation from different specialty contractors simultaneously.

In these situations, it is imperative for each excavator to obtain a one call reference number before excavation to ensure that the specific areas have been appropriately marked by any affected underground facility owner/operator.

5.7 One Call Access (24/7)

The excavator has access to a one call center 24 hours per day, 7 days a week.

5.9 Facility Owner/Operator Failure to Respond

If the facility owner/operator fail to respond to the excavator’s timely request for a locate (e.g., within the time specified by state/provincial requirements) or if the facility owner/operator notifies the excavator that the underground facility cannot be marked within the time frame and a mutually agreeable date for marking cannot be arrived at, then the excavator re-calls the one call center.

However, this does not preclude the excavator from continuing work on the project.

The excavator may proceed with excavation at the end of two working days even if the facility owner fails to respond, unless otherwise specified in state/provincial law, provided the excavator exercises due care in all endeavors.

5.10 Locate Verification

Prior to excavation, excavators verify that they are at the correct location, verify locate markings and, to the best of their ability, check for unmarked facilities.

Upon arrival at the excavation site and prior to beginning the excavation, an excavator does the following:

- Verifies that the dig site matches the one call request and is the latest revision.

- Verifies that all facilities have been marked and reviews color codes, if in doubt.

- Verify all service feeds from buildings and homes.

- Check for any visible signs of underground facilities, such as pedestals, risers, meters, and new trench lines.

- Check for any facilities that are not members of the one call center and contact someone to get them located.

Use of a pre-excavation checklist is recommended by insurers and practiced by responsible excavating contractors.

5.11 Documentation of Marks

An excavator uses dated pictures, videos, or sketches with distance from markings to fixed objects recorded, to document the actual placement of markings.

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5.12 Work Site Review with Company Personnel

Prior to starting work, the excavator reviews the location of underground facilities with site personnel.

5.13 One Call Reference at Site

Except in case of an emergency, the excavator at each job site has a complete description of the dig site, a list of the facility owner members impacted at that dig site as identified by the one call center, and the one call center ticket number.

5.14 Contact Names and Numbers

The excavator’s designated competent person at each job site has access to the names and phone numbers of all facility owner/operator contacts and the one call center.

5.15 Facility Avoidance

The excavator uses reasonable care to avoid damaging underground facilities.

The excavator plans the excavation so as to avoid damage or to minimize interference with the underground facilities in or near the work area.

Foremost on any construction project is safety.

5.16 Federal and State Regulations

The excavator complies with all applicable federal and state/provincial safety regulations, and, when required, provides training as it relates to the protection of underground facilities.

5.17 Marking Preservation

The excavator protects and preserves the staking, marking, or other designation of underground facilities until no longer required for proper and safe excavation.

The excavator stops excavating and notifies the one call center for re-marks if any facility mark is removed or is no longer visible.

During long, complex projects, the marks for underground facilities may need to be in place far longer than the locating method is durable.

Painting, staking, and other marking techniques last only as long as the weather and other variables allow.

When a mark is no longer visible, but work continues around the facility, the excavator requests a re-mark to ensure the protection of the facility.

5.18 Excavation Observer

The excavator has an observer to assist the equipment operator when operating excavation equipment around known underground facilities.

The excavator designates a worker (an observer) who watches the excavation activity and warns the equipment operator while excavating around a utility to prevent damaging the buried facility.

5.19 Excavation Tolerance Zone

The excavator observes a tolerance zone that is comprised of the width of the facility plus 18" on either side of the outside edge of the underground facility on a horizontal plane.

This practice is not intended to pre-empt any existing state/provincial requirements that currently specify a tolerance zone of more than 18”.

5.20 Excavation within Tolerance Zone

Methods to consider, based on certain climate or geographical conditions, include hand digging when practical (pot holing), soft digging, vacuum excavation methods, pneumatic hand tools, other mechanical methods with the approval of the facility owner/operator, or other technical methods that may be developed.

5.22 Exposed Facility Protection

Excavators support and protect exposed underground facilities from damage.

Protecting exposed underground facilities helps ensure that the utility is not damaged and, at the same time, protects employees working in the vicinity of the exposed facility.

Exposed facilities can shift, separate, or be damaged when they are no longer supported or protected by the soil around them.

The Occupational Safety and Health Administration (OSHA) also has addressed this issue in Subpart P—Excavation Standard 29 CFR 1926.651(b)(4), which states “While the excavation is open, underground installations shall be protected, supported, or removed as necessary to safeguard employees.

For example, an unsupported sewer main could shift, causing the pipe joints to separate, which could result in flooding the trench where employees are working, endangering the safety of employees.

5.24 Facility Damage Notification

An excavator discovering or causing damage to underground facilities notifies the facility owner/operator and the one call center.

All breaks, leaks, nicks, dents, gouges, grooves, or other damages to facility lines, conduits, coatings, or cathodic protection are reported.

5.27 Backfilling

Trash, debris, coiled wire, or other material that could damage existing facilities or interfere with the accuracy of future locates are not buried in the excavation.

Extra caution must be taken to remove large rocks, sharp objects, and large chunks of hard-packed clay or dirt.

No trash or pieces of abandoned lines are backfilled into the trench.

5.28 As-built Documentation

Contractors installing underground facilities notify the facility owner/operator if the actual placement is different from expected placement.

For example, it is common for the contractor to make adjustments in the location of the new facility when rocks or other underground obstructions are encountered or when the location of the new facility conflicts with another existing underground facility.

5.29 Trenchless Excavation

The excavator requests the location of underground facilities at the entrance pit, trenchless excavation path, and the exit pit by notifying the facility owner/operator through the one call center.

The trenchless excavation operator confirms and maintains the path and the minimum clearances established by the project owner and design engineer by tracking and recording the path of the trenchless excavation until complete.

Means of tracking trenchless excavations include electronic locating/guidance devices, pipe lasers, water levels, visual inspection.

When existing facilities are known to be present but cannot be potholed as a result of local conditions, the facility owner and the excavator meet to discuss how to safely proceed with the excavation.

6. Mapping

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6.2 Latitude/Longitude

The land base and database use latitude/longitude (Lat/Long) coordinates.

Appendix B; Uniform Color Code and Marking Guide

As-built Drawing: A detailed depiction of facilities as installed in the field.

Cathodic Protection: The process of arresting corrosion on a buried or submerged structure by electrically reversing the natural chemical reaction. This includes, but is not limited to, installation of a sacrificial anode bed, use of a rectifier-based system (impressed current), or any combination of these or other similar systems.

Wiring is installed between the buried or submerged structure and all anodes and rectifiers.

Wiring is also installed to test stations that are used to measure the effectiveness of the cathodic protection system.

Longitude (Long): Distance measured east or west from a reference meridian (Greenwich).

Near Miss: An event where damage did not occur, but a clear potential for damage was identified.

Plat: Plot of land; a map or representation on paper of a piece of land subdivided into lots, with streets, alleys, etc., usually drawn to a scale.

Positive Response: Communication with the excavator prior to excavation

Root Cause: The primary reason as why an event occurred.

Subsurface Utility Engineering (SUE): An engineering process for accurately identifying the quality of underground utility information that is needed for excavation plans

Test Hole: Exposure of a facility by safe excavation practices used to ascertain the precise horizontal and vertical position of underground lines or facilities.

Ticket Number: A unique identification number assigned by the one call center to each locate request.

Tolerance Zone: The space in which a line or facility is located and in which special care is to be taken.

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CGA Common Ground Alliance Best Practices - YouTube

Tolerance Zone

The following examples are of tolerance zones for a 1" & 12" line:

Trans Adriatic Pipeline Construction Phases

Right of Way Construction; ROW

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