Delineation Guide

Why should I delineate?

(reprinted from the "Delineation Guidelines" pamphlet which is available from our Advertising Items page)

Marking of underground facilities and proposed excavations is the key to damage prevention in the field. With both parties, the excavator and the locator, marking in harmony will make life simpler for both parties. For example: If an excavator does not properly delineate his dig location the locator may not mark the entire area or he may waste his time marking too much area. Or if the locator does not properly mark his facilities the excavator may waste his time calling DigAlert to get the facility owner back out to re-mark their facilities.


General Guidelines

This guide provides for temporary uniform surface markings of both planned excavations and of substructures in potential conflict of planned excavations. White markings are used for excavation delineation. Substructure markings are of a specific color. Appropriate color and common abbreviations are listed herein. Full facility operator and excavator responsibilities are detailed in Section 1. Chapter 3.1 "Protection of Underground Infrastructure", Article 2, of California Code 4216 through 4216.9.

Note: Temporary markings should be clearly seen, functional, and considerate to surface aesthetics and the local community. Also, check to see if any local ordinances apply.


Marking in Paved Areas

Avoid excessive or oversized marking, especially if marking outside the excavation area. Conditions permitting, use spray chalk paints, water based paints or equivalent less permanent type marking. Limit length, height, and interval of marks to those recommended. Letters and numbers should not exceed 3" to 6" in height.


Marking in Non-Paved Areas

When paint is not used, use appropriately colored stakes, lath, pennants or chalk lines. Select marker types that are most compatible to the purpose and marking surface. Adhere to paved area marking suggestions to the extent practical.


Guidelines for Excavation Delineation

The following marking illustrations are examples of how excavators may choose to mark their area of proposed excavation. The use of white marking products (e.g. paint, flags, stakes, whiskers or a combination of these) may be used to identify the excavation site.


Single Point Excavation Markings

Delineate in white products the proposed area of excavation through the use of a continuous line, dots marking the radii or arcs, dashes marking the four corners of the project or dashes outlining the excavation project. Limit the size of each dash to approximately 6" to 12" in length and 1" in width with interval spacing approximately 4' to 50' apart. The maximum separation of excavation marks is to be reduced to a length that can be reasonably seen by the operator’s locators when the terrain at an excavation site warrants. Dots of approximately 1” are typically used to define arcs or radii and may be placed at closer intervals in lieu of dashes.

Single Point Excavation Markings; underground wire locator; orange county utility locating


Single Stake Marking Center Point of Excavation Site

When an excavation site is contained within a 50' maximum radius, or less, it can be delineated with a single stake that is positioned at the proposed center of the excavation. If the excavator chooses this type of delineation they must convey that they have delineated the excavation site with a single stake at the center of the excavation and include the radius of the site on their DigAlert. This single stake is to be white in color with the following information: excavator's company identifier (name, abbreviations, or initials) and the radius of the excavation site in black letters on the stake or with a notice attached to the stake.

Single Stake Marking Center Point of Excavation Site; underground wire locator; utility locating los angeles


Trenching, Boring, or Other Continuous Type Excavations

Mark in white paint the proposed centerline of planned excavation 6" to 12" x 1" arrows, approximately 4' to 50' apart to show direction of excavation. The maximum separation of excavation marks is to be reduced to a length that can be reasonably seen by the operator's locators when the terrain at an excavation site warrants it. Mark lateral excavations with occasional arrows showing excavation direction from centerline with marks at curb or property line if crossed. Dots may be used for curves and closer interval marking.

Trenching, Boring, or Other Continuous Type Excavations; utility locator


Stakes, Flags or Whiskers Excavation Markers

Delineate the proposed area of excavation through the use of: stakes, flags or whiskers to mark radius or arcs, the four corners of the project or outlining the excavation project instead of using spray paint. Limit the interval spacing to approximately 4' to 50'. The maximum separation of excavation marks is to be reduced to a length that can be reasonably seen by the operator's locators when the terrain at an excavation site warrants it. Stakes, flags or whiskers provided to illustrate arcs or radii may be placed at closer intervals in order to define the arc or radius. Stakes, flags or whiskers are white in color with the excavator's company identifier (name, abbreviations, or initials) provided on the stake, flag or whisker.

Stakes, Flags or Whiskers Excavation Markers; san diego utility locating


Guidelines For Operator’s Facility Field Delineation

Operator markings of facilities include; the appropriate color for their facility type; their company identifier (name, initials, or abbreviation) when other companies are using the same color, the number and width of their facilities and a description of the facility (HP, FO, STL etc). Use paint, flags, stakes, whiskers or a combination to identify the operator's facility(s) at or near an excavation site.

1) Marks in the appropriate color are to be approximately 12" to 18" in length and 1" inch in width and separated by approximately 4' to 50' in distance as an example. When marking facilities the operator is to consider the type of facility being located, the terrain of the land, the type of excavation being done and the method to adequately mark its facilities for the excavator.

Guidelines For Evacation Delineation; utility locating services

2) The following marking illustrations are examples of how an operator may choose to mark their subsurface installations.

a. Single Facility Marking: Used to mark a single facility, marks are placed over the approximate center of the facility (Figure 1) or over the approximate outside edges with a line connecting the two horizontal lines (in the form of an H) (Figure 2). These examples indicate an operator’s 12” facility. When a facility can be located or toned separately from other facilities of the same type it is marked as a single facility.

Single Facility Marking; utility locating services

Single Facility Marking; utility locating services

b. Multiple Facility Marking: Used to mark multiple facilities of the same type (e.g. electric), where the separation does not allow for a separate tone for each facility but the number and width of the facilities is known. Marks are placed over the approximate center of the facilities and indicate the number and width of the facilities. This example indicates 4 plastic facilities that are 4" in diameter (4/4" PLA).

Multiple Facility Marking; utility locating services

c. Conduit Marking: Used for any locatable facility being carried inside conduits or ducts. The marks indicating the outer extremities denote the actual located edges of the facilities being represented. An example would be 4 plastic conduits that are 4" in diameter (4/4" PLA), and the marks are 16" apart indicating the actual left and right edges of the facilities.

Conduit Marking; utility locating services

d. Corridor Marking: Used to mark multiple facilities of the same type (e.g. electric), in the same trench where the total number of facilities is not readily known (operator has no record on file for the number facilities) and that are bundled or intertwined. Marks are placed over the approximate center of the facilities and indicate the width of the corridor. The width of the corridor is the distance between the actual located outside edges of the combined facilities. This example indicates a 12" corridor (12" CDR).

Corridor Marking

3) Changes in direction and lateral connections are to be clearly indicated at the point where the change in direction or connection occurs with an arrow indicating the path of the facility. A radius is indicated with marks describing the arc. When providing offset markings, (paint or stakes), show the direction of the facility and distance to the facility from the markings.

Radius Example

Lateral Connection Example

Painted Offset (off) Example

Staked Offset (off) Example

4) An operator's identifier (name, abbreviation or initials) is to be placed at the beginning and at the end of the proposed work. In addition to the previous, subsequent operators using the same color will mark their company identifier at all points where their facility crosses another operator's facility using the same color. The maximum separation of identifiers is to be reduced to a length that can be reasonably seen by the excavator when the terrain at the excavation site warrants it.

GOTHAM ELECO TELECO

5) Information as to the size and composition of the facility is to be marked at an appropriate frequency. Examples are: the number of ducts in a multi-duct structure, width of a pipeline, and whether it is steel,

GASCO TELECO WATERCO
4" PLA 9" PLA 12" STL

6) Facilities installed in a casing should be identified as such. Two examples are: 6" plastic in 12" steel = 6"PLA/12"STL and fiber optic in 4" steel = FO(4"STL).

GASCO TELECO
6"PLA/12"STL FO(4"STL)

7) Structures, such as vaults, inlets, lift stations that are physically larger than obvious surface indications, are to be marked so as to define the parameters of the structure.

ELECO Vault

8) Termination points or dead ends are to be indicated as such.

Termination Points

9) When there is "No Conflict" with the excavation complete one or more of the following:

  • Operators of a single type of facility (e.g. TELECO) would mark the area "NO" followed by the appropriate company identifier in the matching APWA color code for that facility (e.g. "NO TELECO")
  • Operators of multiple facilities would mark the area "NO" followed by the appropriate company identifier in the matching APWA color code for that facility with a slash and the abbreviation for the type of facility that there is "No Conflict" (e.g. "NO GASCO/G/D"). The example illustrates that GASCO has no gas distribution facilities at this excavation site. The abbreviation for gas transmission facilities is "/G/T", electric distribution is "/E/D" and electric transmission is "/E/T" these should be used when appropriate.
  • Place a clear plastic (translucent) flag that states "No Conflict" in lettering matching the APWA color code of the facility that is not in conflict. Include on the flag the operator's identifier, phone number, a place to write the locate ticket number and date. Operators of multiple facilities would indicate on the flag, which facilities were in "No Conflict" with the excavation as in the previous example.
  • If it can be determined through maps or records that the proposed excavation is obviously not in conflict with their facility (s) the locator or operator of the facility may notify the excavator of "No Conflict" by phone, fax, or email, or through the One Call Center, where electronic positive response is used. Operators of multiple facilities would indicate a "No Conflict" for each facility as in the previous examples.
  • Place "No Conflict" markings or flags in a location that can be observed by the excavator and/or advise the excavator by phone, fax, or email that there is "No Conflict" with your facilities. When the excavation is delineated by the use of white markings, place "No Conflict" markings or flags in or as near as practicable to the delineated area.

"No Conflict" indicates; that the operator providing the "No Conflict" has no facilities within the scope of the delineation, or when there is no delineation, there are no facilities within the work area as described on the DigAlert.

No Conflict; utility locating services

Caution: Allow adequate space for all facility mark-outs.

 

APWA Color Codes

Proposed Excavation
(white)
Temporary Survey Markings
(pink)
Electric Power Lines
(red)
Gas, Oil & Steam
(yellow)
Communications (Telephone & Cable TV)
(orange)
Water
(blue)
Reclaimed Water
(purple)
Sewer and Storm Drains
(green)

 

Common Abbreviations:


Facility Identifier
CH = Chemical SS = Storm Sewer
E = Electric SL = Street Lighting
FO = Fiber Optic STM = Steam
G = Gas SP = Slurry System
LPG = Liquefied Petroleum Gas TEL = Telephone
PP = Petroleum Products TS = Traffic Signal
RR = Railroad Signal TV = Television
S = Sewer W = Water
SD = Storm Drain W = Reclaimed Water "Purple"

 

Underground Construction Descriptions
C = Conduit HH = Hand Hole
CDR = Corridor MH = Man Hole
D = Distribution Facility PB = Pull Box
DB = Direct Buried R = Radius
DE = Dead End STR = Structure*
JT = Joint Trench T = Transmission Facility
HP = High Pressure  
*Vaults, junction boxes, inlets, lift stations.

 

Infrastructure Material
ABS = Acrylonitrile - Butadiene - Styrene ACP = Asbestos Cement Pipe
CI = Cast Iron CMC = Cement Mortar Coated
CML = Cement Mortar Lined CPP = Corrugated Plastic Pipe
CMP = Corrugated Metal Pipe CU = Copper
CWD = Creosote Wood Duct HDPE = High Density Polyethylene
MTD = Multiple Tile Duct PLA = Plastic (conduit or pipe)
RCB = Reinforced Concrete Box RCP = Reinforced Concrete Pipe
RF = Reinforced Fiberglass SCCP = Steel Cylinder Concrete Pipe
STL = Steel VCP = Vitrified Clay Pipe

 

Guide for Abbreviation Use

(This is a guide for placing the above abbreviations in the field.)
The Company Identifier is to be placed at the top or at the left of the abbreviations. Place the abbreviations in the following order, Company Identifier / Facility Identifier / Underground Construction Descriptions /Infrastructure Material (e.g. TELECO/TEL/FO/PLA). This example indicates that the telephone company has a Telecommunication Fiber Optic line in a single plastic conduit. The use of the abbreviation /TEL is not necessary, because the orange marking would indicate that the facility was a communication line, but its use is optional. To leave out one or more of the abbreviation types you would continue to follow the order of the abbreviations above leaving out the slash and abbreviation that does not apply (e.g. /TEL), the result would be the following (e.g. TELECO/FO/PLA).