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 2021-01 Proposed White Lining Definition
For Review and Vote at July 27th Meeting
TR 2022-01 Proposed Pothole Definition
For Review and Vote at July 27th Meeting
TR 2022-01 Updates to Practices Referencing Potholing
For Review and Vote at July 27th Meeting
TR 2021-02 Proposed Update to 3-5 - Single Toll-free Number
For Review and Vote at July 27th Meeting
TR 2022-04 Proposed Update to 4-4 - Single Locator
For Review and Vote at July 27th Meeting
TR 2021-02 Proposed Update to 3-6 - Hours of Operation
For Review and Vote at July 27th Meeting
TR 2022-05 Proposed Update to 4-17 - Forecasting Workload
For Review and Vote at April 5th 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 to the depth of the proposed 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 provides precise horizontal and vertical positional data.

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 2021-01 - Proposed White Lining Definition

Electronic White Lining (EWL): The process in which an excavator identifies where proposed excavation will occur by drawing a polygon shape on a GIS map; that shape is delivered electronically by the one-call center to its member facility operators.

TR 2021-02 Proposed Update to 3-4

3.4:  811 Center Governance

Practice Statement:

The 811 center is governed by a board of directors representing the diverse makeup of stakeholders with a process in place for recruiting, onboarding, training, and retaining board members. Board members have appropriate industry qualifications and experience, along with policy and financial authority within their own company to best benefit the 811 center and its constituents.

Practice Description:

To ensure that an 811 center functions to the best benefit of the entire community, it is governed by a board of directors made up of a diverse representation of stakeholders such as facility owners/ operators, contractors, designers, project owners, and government representatives. Each board member has an appropriate executive level of authority within their own company/agency, is knowledgeable in their own industry as well as how it interacts with the 811 center and all of the other represented stakeholders.  The 811 center has a process in place for recruiting, onboarding, training, and retaining board members with appropriate qualifications.

TR 2021-02 Proposed Update to 3-5

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.

The excavator is responsible to ensure they are contacting the appropriate 811 center for the state in which they are performing their work.

TR 2021-02 Proposed Update to 3-6

3.6:  Hours of Operation

Practice Statement:

The 811 center can process locate requests 24 hours per day, 7 days per week.


Practice Description:

The 811 center has a process in place where an excavator who has a locate request can, at any time of the day or night, every day of the year, contact the 811 center and have that request processed.

TR 2022-04 Update 4-4 Single Locator


Review Committee Summary & Recommendation

The Review Committee determined 4 business model types exist in the Damage Prevention Industry to provide efficient, safe, accurate and timely locates:

  1. Operators who choose to locate utilities “In House” whereas the Operator utilizes company employees to locate facilities.
  2. Operators who choose to outsource locating to 3rd party utility locating firms who locate multiple utilities – “Single Locator” as referenced in Best Practice 4.4.
  3. Operators who choose to outsource locating to 3rd party utility locating firms who locate only for their company; often referred to as “Dedicated Locating Service.”
  4. Operators who choose a hybrid solution of “In House”, “Single Locator” and “Dedicated Locating Services.”

The Committee acknowledges there are benefits to each of the aforementioned business practices, however, no known data nor case studies exist to claim “Single Locator” as the “Best Practice” for the entire industry. Therefore, the Review Committee recommends removing Best Practice 4.4 Single Locator in its’ entirety.


Best Practice 4.4 Single Locator Review Committee


4.4 Single Locator

Practice Statement:

A single locator is used for multiple facilities.

Practice Description:

This practice is employed when determined to be advantageous by the facility owner/operator.  The use of a single locator to mark multiple facilities may provide several advantages to both the facility and the excavating communities.  These advantages can include the following:

  • More responsive service to the excavation community
  • Better communication with the excavating community (fewer points of contact)
  • Improved safety as a result of less traffic on the road
  • Improved worker safety
  • Reduced environmental impact
  • Maps of 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).  This practice has been employed by a facility owner in Michigan to enhance safety.  The use of a single locator to locate multiple facilities is analogous to the use of a one call center to handle locate requests from excavators.  The use of a one call center allows locate requests for multiple facilities at an excavation site to be issued through a single point of contact, simplifying communications.  The use of a single locator to carry out locate requests for multiple facilities further simplifies communications, with fewer links needed between excavator and locator.

TR 2022-05 Modification Practice 4-17


4.17 Forecasting/Planning for Workload Fluctuations

Practice Statement:

A plan including an annual forecast, quarterly review, weekly/monthly engagement, or another agreed-upon frequency is developed to manage ticket volume and locate workload fluctuations.

Practice Description:

Facility owners/operators or their representatives develop methods to sufficiently forecast and plan for future workloads so that ticket requests may be completed on time.  This best practice ensures that adequate personnel and equipment are available to complete all locate requests.