Damage Prevention Practices
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101 SCOPE: Potholing shall be utilized during construction activities as required herein to prevent excavation damage to existing underground utilities for all open-cut excavations and trenchless installation methods.
102 DESCRIPTION: Potholing is the practice of digging a test hole to expose underground utilities to determine the horizontal and vertical location of the facility.
103 METHODS: The following alternative methods shall be utilized for potholing.
.01 Hand Digging. Hand digging is the method of excavating a pothole by manual means with hand-held, non- mechanical equipment such as a shovel.
.02 Vacuum Excavation. Vacuum excavation shall consist of air or water pressure to break up the soil and a vacuum device to collect the spoil. The Contractor shall determine if air or water vacuum excavation shall be used dependent upon specific site and environmental characteristics. Soil type such as heavy clay may require water vacuum excavation. Air vacuum excavators shall be utilized if mud from water vacuum excavators cannot be disposed of properly. Air vacuum excavators shall be used if damage to utilities, such as cutting through cables, will occur with the use of water vacuum excavators.
- Air: Air vacuum excavators shall utilize a high velocity air stream to penetrate, expand, and break-up the soil. The loosened particles of soil and rock shall be removed from the excavation through the use of a vacuum.
- Water: Water vacuum excavation systems shall excavate the pothole using high-pressure water to reduce and loosen the soil. The wet soil and mud slurry shall be removed to a spoil tank using a vacuum.
104 SIZE OF POTHOLE: Maximum pothole size shall be 12 inches in diameter or 12 inch x 12 inch square.
105 CONSTRUCTION DRAWINGS: Construction drawings indicating the proposed construction and existing utilities shall be present and utilized during potholing activities. The construction drawings shall be compared to locate paint marks to determine if all existing utilities shown on the drawings have been identified in the field. If the drawings and locate paint marks do not match, additional potholing shall be completed to determine accurate locations.
106 MIS-DESIGNATED FACILITY: If locate paint marks have improperly designated the location of a facility, and the facility is exposed during potholing, the facility owner and Kansas One-Call shall be notified. The entity that exposed the facility shall document the horizontal and vertical location of the facility and communicate the information to the facility owner. If a utility cannot be located through potholing used in conjunction with construction drawings and locate marks, the facility owner and Kansas One-Call shall be contacted.
107 CONDITIONS REQUIRING POTHOLING.
.01 Open-Cut Excavations: Potholing shall be completed to expose existing utilities, including mains and service lines, when open cut excavations are within the tolerance zone of the marked utility. The tolerance zone, also known as the “approximate location”, is a strip of land equal to the width of the underground utility plus two feet on each side.
.02 Trenchless Installation Methods:
For trenchless operations with a bore path that parallels a utility (mains and service lines) within 3 feet, potholing shall be completed at the beginning and end of the bore and every 50 feet along the route. For trenchless operations with a bore path that parallels a utility (mains and service lines) within 5 feet, potholing should be required at the beginning and end of the bore and every 200 feet along the route. Potholing shall be completed for all utilities (mains and service lines) crossing the path of trenchless operations.
.03 Congested Utilities: In congested areas having several facilities in close proximity and/or crisscrossing each other, locates have greater potential to be less accurate. Potholing shall be utilized for excavations near congested utility areas.
108 PROTECTION OF EXPOSED FACILITIES: Facilities exposed during potholing shall be protected throughout the project. Utilities that are rendered unsupported due to potholing shall be temporarily supported by shoring or other means. The utility shall be protected from heavy and sharp items falling into the excavation that could damage or cut the facility.
109 BACKFILL AND RESTORATION: Potholes shall be restored within 24 hours after the utility has been located or as otherwise directed by the City of Shawnee. Backfilling and restoration of the pavement shall be in accordance with the City of Shawnee construction standards and specifications.
200 Horizontal Directional Drilling (HDD)
201 SCOPE: This section sets forth safety guidelines and practices for projects utilizing horizontal directional drilling (HDD) techniques in order to protect existing underground utilities and minimize risks to public safety.
202 APPLICABLE STANDARDS: Applicable standards include the Horizontal Directional Drilling Good Practices Guidelines by the HDD Consortium, and the HDD manufacturer’s equipment operation manual.
The HDD Contractor shall become familiar with and follow the safety
guidelines established in the above standards at all times.
203 GENERAL: The HDD Contractor shall implement the following general safety guidelines and practices:
.01 Occupational and Safety Health Act (OSHA): The HDD contractor shall perform all operations in compliance with OSHA guidelines.
.02 Training: The HDD Contractor shall ensure all personnel are properly trained and equipped.
.03 Planned Emergency Response: The HDD Contractor shall prepare an emergency response plan in the event of a utility strike. The plan shall be submitted and on-file with the City of Shawnee prior to the issuance of any permits within the City utilizing HDD techniques.
204 PRE-CONSTRUCTION: Prior to the start of construction, the HDD Contractor shall complete the following:
.01 Work Area Familiarization: The HDD Contractor shall familiarize itself with the work area and the technical requirements of the plans.
.02 Utility Locates. The HDD Contractor shall request utility locates and complete all other utility coordination requirements.
.03 Marking and Staking: The HDD Contractor shall complete
construction marking/staking in the field to establish HDD entry and exit locations and the proposed HDD alignment at 50-foot (max.) intervals.
205 DURING CONSTRUCTION : While the work is being performed, the HDD Contractor shall complete the following:
.01 Calibration and Tracking: The HDD Contractor shall calibrate the
tracking and locating equipment at the beginning of each work day and maintain a calibration log..02 Pressure Potholes: The HDD Contractor shall pothole the alignment of the bore at 50-foot intervals (approximately) to relieve fluid pressure build-up. Pressure potholes shall be no larger than 12 inches in diameter and the depth shall be adequate so that the fluid may be released as it builds pressure.
.03 Monitoring and Recording: The HDD Contractor shall monitor and record alignment and depth readings provided by the tracking system every 25-30 feet for normal conditions, and every 5-10 feet when precise alignment control is necessary.
.04 Maintain Drilling Fluid Circulation: The HDD Contractor shall maintain drilling fluid circulation throughout the HDD process including the initial pilot hole installation, and the reaming and back pull process. The pull back shall not exceed the fluid circulation rate capabilities.
.05 Back-reaming: The HDD contractor shall back-ream as required to accommodate the product size. Compaction reamers are not permissible. The HDD Contractor shall plan the back pulling operations carefully to ensure that all back pulling operations can be completed without stopping and within the permitted work hours.
.06 Clearances. The HDD Contractor shall maintain all required
clearances and offsets from existing utilities..07 Documentation: The HDD Contractor shall at all times and for the entire length of the HDD alignment be able to demonstrate and provide the horizontal and vertical position of the alignment, the fluid volume used, return rates, and pressures.
.08 Inspection: The HDD Contractor shall inspect the work and surrounding area to ensure damage has not occurred to existing utilities due to HDD construction operations.
2O6 CONSTRUCTION RECORDS: The HDD Contractor shall keep detailed and accurate records of all activities associated with the HDD operation.
.01 Data and Logs: The Contractor shall provide data and work logs upon the request of the City of Shawnee while the work is being done at the completion of HDD operation. Data shall include, but not be limited to, tracking and calibration logs, type of tracking equipment used, installation length and depth, steering adjustments, equipment performance parameters, and the names of the HDD operators performing the work.
301 SCOPE. This section sets forth the requirements for the collection and depiction of existing underground utility data on design drawings to be used for construction projects within the right-of-way.
302 DESCRIPTION: During the design phase, the designer shall gather available information on underground utilities in the proposed construction area. The utility information shall be incorporated into scaled topographic base maps of the construction route or area. The consolidated drawings shall be used to determine the final route selection and design.
303 APPLICABLE STANDARD: The design drawings shall incorporate underground utility information based on subsurface utility engineering practices and Standard Guidelines for the Collection and Depiction of Existing Subsurface Utility Data (CI/ASCE 38-02). A copy of CI/ASCE 38-02 is included at the end of this section.
The ASCE standard, based on subsurface utility engineering (SUE), presents a system of classifying the quality of subsurface utility data.
304 COLLECTION OF DATA: Underground utility information shall be collected using the Subsurface Utility Engineering (SUE) process.
.01 Subsurface Utility Engineering (SUE): SUE is an engineering process used to identify and map underground utilities and structures as well as assign a quality level to data. The main components of SUE are:
- Designation: Designation is the use of geophysical investigating methods such as electromagnetic pipe detectors to determine the horizontal position of subsurface utilities.
- Locating: Locating or potholing utilizes non-destructive digging equipment to expose the underground utility at critical points along its path to determine the horizontal and vertical position of the utility.
- Data Management: Data Management is the collection, documentation, reduction, and depiction of information and data in a suitable format.
305 QUALITY LEVELS: A brief description of the four quality levels of SUE data is provided below. Refer to CI/ASCE 38-02 for detailed information on the tasks involved in each quality level.
.01 Quality Level A: Quality Level A provides the highest level of accuracy. Quality Level A involves potholing utilities as well as activities in quality levels B, C, and D. The located utility is surveyed and mapped and the data provides precise plan and profile information.
.02 Quality Level B: Quality Level B involves designating the horizontal position of subsurface utilities through surface detection methods and collecting the information through a survey method. Quality Level B includes Quality Level C and D tasks.
.03 Quality Level C: Quality Level C involves surveying visible subsurface utility structures such as manholes, hand-holes, utility valves and meters, fire hydrants, pedestals and utility markers, and then correlating the information with existing utility records to create composite drawings. Quality Level C includes Quality Level D tasks.
.04 Quality Level D: Quality Level D provides the most basic level of information. Quality Level D involves collecting data from existing utility records. Records may include as-built drawings, distribution and service maps, existing geographic information system databases, and construction plans.
306 DESIGN: Utility data collected during the SUE process shall be combined with the topographic base map to create a composite drawing. The composite drawing shall be used to determine the best design based on avoiding and minimizing conflicts with existing facilities. Proposed facilities shall be routed and designed to maintain 2 feet (min.) horizontal and vertical clearance from all existing utilities, structures, and property lines, unless other standards require stricter minimum clearances.
307 SELECTING THE SUE QUALITY LEVEL: All drawings submitted to the City shall depict existing utilities based on Quality Level D. The City shall reserve the right to request a higher level based on project location and other factors. The utility company may request that the City approve a change in the required SUE quality level.
308 DRAWING REQUIREMENTS: The design drawings shall include existing topographic and utility information and proposed facilities. The drawings shall be drawn to scale, with dimensions indicating the horizontal position of existing and proposed facilities. Distinct line types, symbols, and notes shall be used to indicate different types of facilities, SUE quality levels, and existing and proposed facilities. All proposed construction must be shown in bold face. The drawings shall include a legend and the information described in the following sections.
.01 Identify SUE Quality Level: CI/ASCE 38-02 describes and explains methods of depicting SUE information on the drawings. The basic requisite is to indicate on the drawings the quality level of each set of utility data through various line types or notes. Refer to CI/ASCE 38-02 for additional information.
.02 Identify Information Source: Each set of facility data shall include a note explaining the source of the information in addition to the quality level.
.03 Plans and Profiles: Scaled plan drawings depicting existing and proposed utilities and structures with horizontal positions shall be provided for all projects.
- Plan: The plan view shall have dimensions indicating the clearance between existing and proposed facilities, structures, and property lines. Vertical positions of underground utilities shall be indicated in the same manner. At a minimum, vertical position information shall be included in note format for each existing utility that will be crossed by proposed construction.
- Profile: Profiles are required for all SUE quality level A projects. Profiles shall be depicted in the same horizontal scale as the plan view and shall be aligned directly below the plan view. Profiles shall depict the vertical position of both existing and proposed facilities with dimensions indicating clearances.
401 SCOPE: This section sets forth the requirements for the installation of electromagnetic pipe detection systems in order to detect underground utilities through non-invasive methods.
The requirements set forth in this section apply to all new utility installations in the right-of-way. This section applies to the repair of existing utilities only if the existing facility has an electromagnetic pipe detection system. The repair of a utility that utilizes an electromagnetic detection device shall also include the restoration of the detection device to its original condition.
402 ELECTROMAGNETIC PIPE DETECTION (EPD) SYSTEM: EPD requires a transmitter to directly induce a signal across the utility. The signal is then detected with a receiver. The transmission of the signal requires a conductive element and ,therefore, the utility must be metallic or the utility must be accompanied by a tracer wire.
.01 Direct Signal Method: The direct signal method shall be utilized to transmit the signal from the transmitter to the utility. The direct signal method requires direct connection from the transmitter to the utility or the tracer wire. Access points shall be installed along the utility route for direct connection. The current shall be directly applied and the signal shall be detected and followed with a receiver.
.02 Tracer Wire: Tracer wire shall be installed to enable the detection of plastic pipes, fiber optics, and non-conducting utilities. The tracer wire shall be designed specifically for the purpose of detecting buried utilities. Tracer wire shall 12 AWG (min.) copper wire coated with a 30-mil (min.) polyethylene jacket designed specifically for buried use.
403 INSTALLATION: All new non-metallic utilities shall be installed with tracer wire. Metallic pipes do not require a tracer wire. Metallic pipe systems require access points along the route for direct connection. The tracer wire shall be installed continuously along the new utility route with access points at 300 feet maximum. The tracer wire shall be brought to the ground surface at the access points. Access points may include valve boxes, handholes, manholes, vaults, or other covered access devices. Access point covers shall be clearly marked with the type of facility. Splices in the tracer wire shall be connected by means of a split bolt or compression type connector to ensure continuity. Wire nuts shall not be used. A waterproof or corrosion-proof connector for direct bury applications shall be used. After installation, the tracer wire shall be tested to verify continuity of the tracer wire system and a report indicating continuity shall be submitted to the City of Shawnee as part of the as-built construction records.
.01 Direct Buried Facilities: A tracer wire shall be installed in the trench with all direct buried utilities. The tracer wire shall be placed adjacent to or above, but shall not touch the pipe. The tracer wire shall not be wrapped around the facility. The maximum distance from the utility pipe to the tracer wire shall be 6 inches. Non-metallic spacers shall be installed to keep the tracer wire a set distance from the utility.
.02 Trenchless Facilities: A tracer wire shall be provided with all non-metallic pipe installed by trenchless methods. The tracer wire shall be pre-installed in conduits and innerduct or it shall be blown in after conduit or innerduct installation. In the case where conduit or innerduct is not used, the tracer wire shall be installed at the same time as the pipe as an integral part of the pipe installation.
404 REPAIRS: The effectiveness of the detection system is dependent on an uninterrupted and continuous tracer wire. All tracer wire cuts shall be repaired as they occur, enabling continued integrity and functioning of the tracer wire system.