Best Practices 30 Day Review

Proposed Updates and Modifications

Best Practices - 30 Day Review

The wording below has been approved for Committee review by the task team responsible. The proposed wording will be voted on during the next Best Practices Meeting.

TR 2022-06 Proposed Update to 5-8 Positive Response
For Review and Vote at October 19th Meeting
TR 2022-01 Proposed Pothole Definition
For Review and Vote at October 19th Meeting
TR 2022-01 Updates to Practices Referencing Potholing
For Review and Vote at October 19th Meeting
TR 2022-06 Proposed Update to 5-10 Locate Verification
For Review and Vote at October 19th Meeting

TR 2022-01: Pothole Definition


Pothole (a.k.a., test hole)Exposure of a facility by safe excavation practices to ascertain the precise horizontal and vertical position of underground lines or facilities. Accepted safe excavation practices vary by state/local jurisdiction, but the preferred techniques include hand digging with extreme caution and/or vacuum excavation. (See Best Practice 5-32). 

Test Hole:  See definition for Pothole.

TR 2022-01: Practices Referencing Potholing

PROPOSAL 2a – Updates to 5-15

5.15 Facility Avoidance

Practice Statement:

The excavator uses reasonable care such as potholing and other safe excavation practices 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.

Practice Description:

Foremost on any construction project is safety. Excavators using caution around underground facilities significantly contribute to safe excavation of existing facilities.


Existing state laws, including Kansas, Ohio, West Virginia, and others

PROPOSAL 2b – Updates to 5-20

5.20 Excavation within Tolerance Zone

Practice Statement:

When excavation is to take place within the specified tolerance zone, the excavator exercises such reasonable care as may be necessary for the protection of any underground facility in or near the excavation area. Methods to consider, based on certain climate or geographical conditions, include pot holing, hand digging when practical, 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. Hand digging and non-invasive methods are not required for pavement removal.

Practice Description:

Safe, prudent, non-invasive methods that require the excavator to manually determine the actual location of a facility are considered “safe excavation practices” in a majority of state/provincial laws. A majority of states outline safe excavation practices to include hand digging and/or pot holing. Some states specifically allow for the use of power excavating equipment for the removal of pavement. Each state/province must take differing geologic conditions and weather-related factors into consideration when recommending types of excavation within the tolerance zone.


Existing state laws, including Arizona, New Hampshire, Pennsylvania, and others

PROPOSAL 2c – Updates to 2-3

2.3 Identifying Existing Facilities in Planning and Design

Practice Statement:

Designers indicate existing underground facilities on drawings during planning and design.

Practice Description:

During the planning phase of the project, existing facilities are shown on preliminary design plans. The planning documents include possible routes for the project together with known underground facility information. The various facility owners/operators are then given the opportunity to provide appropriate feedback. During the design phase of the project, underground facility information from the planning phase is shown on the plans. If information was gathered from field-located facilities, potholing, underground facility surveys, or subsurface utility engineering, this is noted on the plans. The designer and the contractor both know the quality of the information included on the plans. If an elevation was determined during information gathering, it is shown on the plan. The facilities shown include active, abandoned, out-of-service, and proposed facilities. The design plans include a summary drawing showing the proposed facility route or excavation, including streets and a locally accepted coordinate system. The plans are then distributed to the various facility owners/ operators to provide the opportunity to furnish additional information, clarify information, and identify conflicts.


Providing complete underground facility information and including this information on design drawings reduces hazards, simplifies coordination, and minimizes the cost to produce the final project.

PROPOSAL 2d – Updates to 2-14

2.14 Subsurface Utility Engineering (SUE)

Practice Statement:

When applied properly during the design phase, Subsurface Utility Engineering (SUE) provides significant cost and damage-avoidance benefits and the opportunity to correct inaccuracies in existing facility records.

Practice Description:

In certain cases and environments, it may be difficult or impossible to determine the locations of all utilities and/or impediments with sufficient accuracy to avoid damage or delay during construction. In these cases, SUE is applied during the design phase to locate, identify, and characterize all existing utility infrastructure (and other relevant non-utility features) found within a given project/area. SUE is applied in a structured manner in accordance with practices and quality levels found in ASCE 38-02 “Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data.” The project owner dictates the required quality levels (QL) as well as the amount of effort expended by the SUE provider on each. Although the standard is more detailed and comprehensive, the following is a brief summary of the quality levels defined therein:

  • QL-D involves utility records research and interviews with knowledgeable utility personnel.
  • QL-C involves surface survey and identifying and recording aboveground features of subsurface utilities, such as manholes, valves, and hydrants.
  • QL-B involves application of “surface geophysical methods,” such as EM-based locating instruments, GPR, radar tomography, metal detectors, and optical instruments, to gather and record approximate horizontal (and, in some cases, vertical) positional data.
  • QL-A involves physical exposure via potholing and/or other safe excavation practices that allows the precise horizontal and vertical positional data to be recorded.

SUE results are integrated into the design process, in which design engineers use the information to create construction plans that accommodate existing infrastructure, thereby reducing the overall risk of conflicts and/or damage.1


  • S. Department of Transportation—FHWA (12/1999). Cost Savings on projects Utilizing Subsurface Utility Engineering. Pub. No. FHWA-IF-00-014
  • S. Department of Transportation—FHWA (3/2001). Subsurface Utility Engineering: Enhancing Construction Activities. Pub. No. FHWA-IF-01-011
  • ASCE 38-02 Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data
  • Pennsylvania state law

TR 2021-02: Review of 3-5 Single Toll-free Statewide Telephone Number

3.5:  Adoption of 811 Three-Digit Dialing and Single Toll-Free Telephone Number with Nationwide Access

Practice Statement:

The 811 center adopts 811 three-digit dialing and a single toll-free telephone number with nationwide access.

Practice Description:

811 is used by all excavators within every state in the United States to submit locate requests.  In addition to 811, the center provides a toll-free number that has nationwide access, meaning that a caller can reach the center from anywhere in the country.


  • One Call Systems International Voluntary Recognition Program
  • Existing operating practices from various states’ 811 centers
  • 49 CFR Part 198
  • NTSB Safety Study (NTSB/SS-97/01; PB97-917003)

TR 2022-06: Update to 5-8 Positive Response

5.8 Positive Response

Practice Statement:

The 811 Center notifies the underground facility owner/operator of the proposed excavation area within the time specified.  The underground facility owner/operator notifies the excavator/contractor of the status of the ticket by providing an electronic positive response through the 811 center, if available.

Practice Description:

Once a facility owners/operator marks the location of existing facilities in the proposed excavation area or determines that excavation or demolition is not in conflict with any of its existing underground facilities, it notifies the excavator of the status of the ticket by appropriate response code through the 811 center’s positive response system, usually “marked” or “clear”.  In addition to positive response, additional communication may be made by any reasonable manner including, but not limited to, face-to-face communications, phone, or other electronic means.

The excavator should review positive response from the notified owner/operators on the ticket before beginning excavation.  If an excavator has knowledge of the existence of an underground facility and has received a “no conflict,” a prudent excavator will notify the 811 center that a conflict does indeed exist, and the locator will make marking these facilities a priority before excavation begins.  Better communication between the excavator and the facility owner/operator is required as an area of excavation becomes more crowded with new underground facilities.

“Positive response” means an automated information system that allows excavators, locators, operators, and other interested parties to determine the status of a locate request until excavation or demolition is complete.

This action allows the facility owner/operator to communicate the status of the one-call ticket to the excavator through the 811 center as available.

When the excavator makes the request to the 811 center, the excavator is informed which facility owners/operators will be notified.  The excavator reviews all positive responses and compares these to the list of all owner/operators notified on the ticket prior to beginning excavation.  Upon review, the excavator should notify the 811 center of any discrepancy between the positive responses and the field conditions.


  • Existing state laws, including California, Maryland, Nevada, and others
  • Existing operating procedure for various one call centers (over 40 participating states or 811 centers)

TR 2022-06: Proposed Update to Practice 5-9

5.9 Facility Owner/Operator Failure to Respond

Practice Statement:

If the facility owner/operator fails 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-notifies the 811 center, if required by local law.  The excavator should wait until positive response is received from all remaining utility owner/operators, or may proceed with excavation when the appropriate waiting period as defined by state/provincial law has lapsed, provided the excavator exercises reasonable care in all endeavors.

Practice Description:

The facility owner/operator and the excavator partner together to ensure that facilities are marked in an acceptable time frame to allow for underground facility protection.


  • Existing state laws, including Ohio, Kansas, South Carolina, Michigan, California, Pennsylvania, and others

TR 2022-06: Proposed Modification to Practice 5-10

5.10 Locate Marking Verification

Practice Statement:

Prior to excavation, locators verify that they are at the correct location, verify locate markings have been performed by facility owners/operators who have responded as “marked”, and, to the best of their ability, check for unmarked facilities.

Practice Description:

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

  • Verifies that the dig site matches the 811 request within the lawful dig dates
  • Verifies marks are in agreement with the positive response
  • Verifies all service lines markings are in agreement with the positive response
  • Checks for any visible signs of underground facilities, such as pedestals, risers, meters, and new trench lines
  • Checks for any facilities that are not members of the 811 center and contact someone to get them located.

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


  • Existing practice by excavators, including Pauley Construction, Charge EPC, Inc., and W.F. Wilson & Sons, Inc.
  • CGA Best Practice 4-21