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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.
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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) Mag nails and PK nails Valve and curb boxes Iron and steel pipes Well casings Manhole & Utility Box Covers Steel drums & tanks Septic tank handles Energized electric cables Marker magnets Unexploded bombs (UXO)
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)
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.
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 • 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 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 heldto 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.
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 Marking Identifiers
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.
