SUGGESTED
GUIDELINES
FOR
EXCAVATION
SITE
DELINEATION
AND FACILITY
OWNER
LOCATION
MARKOUT
Goals and Objectives
Facility Owners / Utilities will:
• Mark or locate their lines within two working days of
the start of construction.
• Use the APWA Color Code to mark their facilities.
• Be accurate within 24 inches either side of the buried
facility (tolerance zone).
Excavators will:
• Call and give at least two working days notice prior to
excavating.
• Delineate (outline) their job in white paint.
• Hand expose within 24 inches to the point of no
conflict within the tolerance zone.
Locator Qualifications
• Individuals are now to required to be trained and
qualified by their employer to be able to perform the
locating of buried utilities. To obtain this qualification,
the locator must complete a training program in
accordance with the requirements of Section 1509,
Injury and Illness Prevention Program (IIPP), that
meets the minimum training guidelines and practices
of the Common Ground Alliance (CGA) Best
Practices, Version 3.0, March 2006, or the standards
of the National Utility Locating Contractors
Association (NULCA), Standard 101: Professional
Competence Standards for Locating Technicians,
2001, First Edition.
Locator Qualifications
Minimum training guidelines and practices can be found
at:
www.commongroundalliance.com
for the Common Ground Alliance (CGA) Best Practices,
Version 3.0, March 2006;
or
www.nulca.org
for the National Utility Locating Contractors
Association (NULCA), Standard 101: Professional
Competence Standards for Locating Technicians,
2001, First Edition.
DigAlert follows these guidelines
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.
Why should I delineate?
WALNUT CREEK / Blast kills 5, puts 6 in hospital
Gasoline line erupts in flame at EBMUD work site
Delineation and Facility
Owner Location Markout
These guidelines provide 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.
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.
APWA COLOR CODES
RED
Electric power lines, cables, conduit and lighting cables
YELLOW
Gas, oil, steam, petroleum or gaseous materials
ORANGE
Communications, alarm or signal lines, cables or conduit
BLUE
Potable Water
GREEN
Sewers and drain linesWHITE
PINK
Temporary survey markings
PURPLE
Reclaimed water, irrigation and slurry lines
WHITE
Proposed excavation limits or route
LOCATING EQUIPMENT
Best and Most Reliable Method (but often impractical)
Ground-Truthing:
The only way to precisely determine the location and depth of an
underground object is to dig.
Otherwise, you must rely on visual clues, engineering drawings,
locating equipment, experience, knowledge and training. You must
become a “qualified” locator.
LOCATING EQUIPMENT
Magnetic Locators
All magnetic locators operate on the same basic principle; two fluxgate
magnetometer sensors, securely mounted inside a rigid sensor support
tube, measure the local magnetic field. When a metal object is located an
audio signal is given. Some equipment offers features such as a digital
meter that provides for visual signal strength, polarity indication, gain
setting plus battery life display.
Use this equipment to find:
Corner markers (iron or steel)
Valve and curb boxes
Well casings
Steel drums & tanks
Energized electric cables
Unexploded bombs (UXO)
Mag nails and PK nails
Iron and steel pipes
Manhole & Utility Box Covers
Septic tank handles
Marker magnets
LOCATING EQUIPMENT
Pipe and Cable Locator
Designed for the user who needs a simple and easy way to locate;
yet good enough to handle most locates. Especially useful for
contractors who dig in the ground and those that need to mark out
existing utilities
A versatile tool that can be used
to locate the following:
Iron, steel, and copper water lines
Copper tracer wire
Steel cables
Aluminum conduit Metal gas lines
Copper and aluminum electrical wires
Telephone and TV cables
Any continuous metal pipe or line
.
LOCATING EQUIPMENT
Pipe and Cable Locator
. In some situations “blind tracing” must be done. This is where an operator
of the transmitter and an operator of the receiver walk over an area in
anticipation of transmitting onto a utility, and subsequently receiving a
signal from the ground. This search method is advantageous with respect
to locating abandoned or “forgotten” utilities and “surprise” utilities. Once
the pipe is located, often an approximate depth can be obtained. In the
case of a direct pipe contact, a very accurate depth measurement is
obtained. However, in inducing a signal onto the pipe, the signal strength is
somewhat degraded because of the different soil layers, and because the
signal is less focused than when it is directly conducted onto the pipe. As a
result, a depth range can be obtained with a larger margin of error. Locator
should never provide a depth measurement to an excavator.
Safety and Mark Out Equipment
Traffic Vest / Hard Hat
Traffic Control
Marking Paint
Marking Flags
Marking Whiskers
Locating Equipment
Plans and Drawings
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 be 6" in height.
Marking in 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.
• Maximum mark separations along continuous
excavation are not to exceed 50 feet.
• On long locates the facility owner and line size shall
be indicated every 100 feet.
• No matter the spacing, marks should always be
reasonably visible based on the terrain.
Guidelines for Excavation
Delineation
• Excavators are reminded that pre-marking (delineation) of
excavations is a requirement of California Code 4216.
• Delineate the area to be excavated before calling USA.
Delineated areas should be identified in white markings with
the requesters company name or logo within the pre-marked
zones (see examples).
• Failure to pre-mark when practical may jeopardize your permit,
or result in a civil penalty up to $50,000.
• Code 4216.2(f) requires: "If pre-marking is not practical, the
excavator shall contact"...USA..."to advise the operators that
the excavator shall identify the area in another manner
sufficient to enable the operator to determine the exact area of
the excavation to be field marked."
• Code 4216.2(e) states: "delineation must not be misleading,
duplicative or misinterpreted as traffic or pedestrian control.
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” – 2”.
Single Point Excavations
Co. Name or
Logo (6” Letters)
Single Point Excavations
Single Point Excavations
Trenching, Boring, or Other
Continuous Type Excavations
•
Mark center line of planned excavation with 1" x 6”
arrows, every 4 feet, to show direction of excavation.
• For boring or continuous operations where marked
paving is not to be removed, mark at critical points
with mark separations of 4 – 50 apart'.
• 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.
Trenching, Boring, or Other
Continuous Type Excavations
Guidelines for Facility Owner
Location Markout
• Marks in the appropriate color should be
approximately twelve (12) to eighteen (18) inches in
length, spaced four (4) four to fifty (50) feet apart. The
marks should be placed over the approximate center
of the facility.
Guidelines for Facility Owner
Location Markout
•
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.
Guidelines for Facility Owner
Location Markout
•
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.
Guidelines for Facility Owner
Location Markout
Guidelines for Facility Owner
Location Markout
Guidelines for Facility Owner
Location Markout
• 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.
Guidelines for Facility Owner
Location Markout
•
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.
Guidelines for Facility Owner
Location Markout
•
Termination points or dead ends should be
indicated as such.
Guidelines for Facility Owner
Location Markout
•
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.
*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.
Guidelines for Facility Owner
Location Markout
No Conflict Marking
Guidelines for Facility Owner
Location Markout
No Conflict Marking
Guidelines for Facility Owner
Location Markout
Example of marking with an implied sixty (60) inch
"Hand Dig Area" (12" facility plus 24" to the right and
24" to the left).
Guidelines for Facility Owner
Location Markout
Example of marking with "Hand Dig Area" outlined.
Guidelines for Facility Owner
Location Markout
Guidelines for Facility Owner
Location Markout
Guidelines for Facility Owner
Location Markout
Guidelines for Facility Owner
Location Markout
Guidelines for Facility Owner
Location Markout
Guidelines for Facility Owner
Location Markout
Section 1541 amended:
When the excavation is proposed within 10 feet of, or in conflict with, a
high priority subsurface installation, an onsite meeting involving the
excavator and the subsurface installation owner/operator’s
representative shall be held to determine the action or activities
required to verify the location of such installations. High priority
subsurface installations are:
 High pressure natural gas pipelines with normal operating
pressures greater than 415 kPA gauge (60 p.s.i.)
 Petroleum pipelines,
 Pressurized sewage pipelines,
 High voltage electric supply lines, conductors or cables that have a
potential to ground of more than 60,000 volts, or
 Hazardous materials pipelines that are potentially hazardous to
employees, or the public, if damaged.
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(asbestoscement pipe)
IP=Iron pipe
Trans=Transition
MCD=Multiple concrete duct
TSC=Traffic signal conduit
MH=Manhole
VCP=Vertrified clay pipe
MTD=Multiple tile duct
Locator Competencies
Theory of Electromagnetic Locating (Powerpoint)
Use of Equipment (Specific Transmitter / Receiver)
Marking Procedures
Knowledge of Facilities / Plans
Visual Observations Skills
Safe Work Practices, Customer Service and
Regulations
Locate Request Procedure, Documentation and
Mapping
Locator Competencies
Review Job Description and How to “qualify”
Locators
1) Conduct classroom instruction covering the mark out requirements, ticket procedures, colors for utility
mark out, how often to mark utilities, common abbreviations, etc. per the NULCA or CGA guidelines.
DigAlert can be used to assist with this training, but the District or Agency specific requirements
should be included. For reference, the District/Agency should keep a copy of the standard that they
trained to on hand and available.
2) Give a test/quiz to document the level of understanding of locators. This will be kept in a training file.
3) Perform hands-on training using the locating equipment and reviewing the use and care instructions
provided by the manufacturer. This is something that may be supplemented by the manufacturer with
field training or a video. Again, this type of training (date,time,length and by who) will need to be
documented.
4) Evaluate each locator by having them complete a performance based exercise in line locating. This
should include from the time that a request is made, field location, traffic safety, line mark out, and
ticket closeout. Each item should be rated as: Satisfactory, Needs Improvement or N/A. Again, this
evaluation must be kept on file.
This would made a locator "qualified" under the standard. The District/Agency may wish to keep an
updated list (yearly) of "qualified" locators and review if there is a need for any additional training
based new standards or locating equipment.
What Does it Tell Us?
What Does it Tell Us?
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What Does it Tell Us?
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What Does it Tell Us?
What Does it Tell Us?
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What Does it Tell Us?
What Does it Tell Us?
What Does it Tell Us?
What Does it Tell Us?
Do it Right – It is worth the time and maybe
somebody life
Walnut Creek – Where workers did not know
the correct location of a fuel pipeline