Why should I delineate?
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 Dig Alert to get the facility owner back
out to re-mark their facilities.
APWA |
Electric |
Gas-Oil-Steam |
Communication and Cable TV |
Water |
Sewer |
Reclaimed Water |
Proposed Excavation |
Suggested Guidelines for Prospective Excavation Site Delineation and Facility Owner Location Markout
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
Single Point Excavations
Delineate the exact area of excavation through
the use of dots or dashes, or a continuous solid line. Limit the
size of each dash to approximately 6" in length and 1"
width with interval spacing not less that approximately 4 feet.
Dots of approximately 1" diameter are typically used to
define arcs or radii and may be placed at closer intervals in
lieu of dashes. Limit width of lines to 1".
Trenching, Boring, or Other Continuous Type Excavations
Mark center line of planned excavation with
6" x 1" arrows (approximately 4' apart) to show
direction of excavation. For boring or continuous operations
where marked paving is not to be removed, mark at critical points
with maximum mark separations of approximately 50'. Mark lateral
excavations with arrows showing excavation direction from center
line with marks at curb or property line if crossed.
Intermittently indicate excavation width on either side of center
line in 3" to 6" high figures. Dots may be used for
curves and closer interval marking.
Guidelines for Facility Owner Location Markout
Marks in the appropriate color should be
approximately twelve (12) to eighteen (18) inches in length,
spaced no more than fifty (50) feet apart. The marks should be
placed over the approximate center of the facility.
As an alternate, or in addition to, marks can be
placed on either side of the facility to define the "Hand
Dig Area". The "Hand Dig Area" is defined as the
width as the width of the facility itself plus the tolerance zone
of twenty-four (24) inches either side of the facility.
An operator designator, such as company initials,
should be placed at the beginning and end of the proposed work
area. Use this instead of a generic designator such as TEL to
avoid confusion between more that one operator of the some type
of facility. Information as to the size and composition of the
facility should be marked at an appropriate frequency, if known.
Examples are: the number of ducts in a multi-duct structure,
diameter of a pipeline, and whether it is steel, plastic, bare
cable, etc. If known, a facility installed in a casing should be
identified as such. Examples are: 6" plastic in 12"
steel = 6PE/12STL, fiber optic in 4" steel = FO/4STL.
Changes in direction and lateral connections should be clearly
indicated at the point where the change in directions or
connection occurs, with an arrow indicating the path of the
facility. A radius should be indicated with marks describing the
arc.
Structures, such as vaults, that are physically
larger than obvious surface indications, should be marked so as
to generally define the parameters of the structure.
Termination points or dead ends should be indicated as such.
If there is "no conflict" and the work
area has been pre-marked, no conflict should be marked along with
company designator within the delineated work area* or the
excavator should be notified verbally, or in writing (e.g. fax).
If the work area is not delineated, the excavator should likewise
be notified verbally or in writing.
* Caution- Allow adequate space for all facility mark-outs. No conflict marking indicates that there are no facilities within the scope of the delineation or within the work area as described on the locate ticket. 
Example of marking with an implied sixty (60)
inch "Hand Dig Area" (12" facility plus 24"
to the right and 24" to the left).
Example of marking with "Hand Dig Area" outlined. 
Common Marking Identifiers |
| E=Electric | G=Gas |
| SD=Storm Drain | S=Sewer |
| SL=Street Lighting | TEL=Telephone |
| TS=Traffic Signal | TV=Television |
| W=Water/Reclaimed Water | USA=Underground Service Alert |
Common abbreviations and descriptions as used in underground construction.
| ABS=Acrylonitrile-butadiene-styrene | P=Plastic(conduit or pipe) |
| ACP=Asbestos cement pipe | PB=Pull box |
| CAP=Corrugated aluminum pipe | PC=Plastic conduit |
| CIP=Cast iron pipe | PE=Polyethylene |
| CMC=Cement mortar coated | PL=Property line |
| CML=Cement mortar lined | PVC=Polyvinyl chloride |
| CSP=Corrugated steel pipe | R=Radius |
| CU=Cooper | RCB=Reinforced concrete box |
| DIP=Ductile iron pipe | RCP=Reinforced concrete pipe |
| DU=Duct | SCCP=Steel cylinder concrete pipe |
| ELC=Electrolier lighting conduit | STL=Steel |
| FC=Fiber conduit | STRUC=Structure |
| GIP=Galvanized iron pipe | T=Transmission facility |
| GSP=Galvanized steel pipe | TR=Transite(asbestos cement pipe) |
| IP=Iron pipe | Trans=Transition |
| MCD=Multiple concrete duct | TSC=Traffic signal conduit |
| MH=Manhole | VCP=Vertrified clay pipe |
| MTD=Multiple tile duct |