G. Galvanic Anodes - Colorado · PDF file G. Galvanic Anodes Anodes shall be high potential...

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Transcript of G. Galvanic Anodes - Colorado · PDF file G. Galvanic Anodes Anodes shall be high potential...

  • Colorado Springs Utilities Water Line Extension & Service Standards – 2014 5-33

    G. Galvanic Anodes Anodes shall be high potential magnesium and shall be supplied and installed by the Contractor in conformance with Detail Drawing A8-2.

    Anodes shall be inspected to ensure that bentonite material surrounds the anode. The cloth containing the anode and bentonite mixture shall be intact, and any torn anode bags shall be rejected. Anodes are to be kept dry until installed. The lead wire must be securely connected to the anode and should be inspected to ensure that it is not damaged. The anode should be placed as far from the pipe and other anodes as possible. Anodes should be backfilled with compacted native soil, not sand, pea gravel, or flow fill. Care should be exercised so that lead wires and connections are not damaged during backfill operations. Lead wires shall have sufficient slack to avoid strain. Wires shall be connected via a thermite weld per the manufacturer’s recommendations. Copper sleeves shall be used for #10 AWG and smaller wires. Any exposed metal shall be coated or wrapped with corrosion tape.

    H. Impressed Current Systems Impressed current systems shall be installed in conformance with these Water LESS. Anodes shall be inspected for conformance to Specifications including anode material and size, length of lead wire, and end cap. Care should be exercised to avoid cracking or damaging anodes during installation and handling. Lead wire shall be carefully inspected to detect defects in insulation. Care should be taken to avoid damaging the insulation on the wire. Defects in insulation must be repaired or the anode rejected. Rectifiers shall be tested after installation for proper lead wire connection and function prior to the Inspector’s final approval.

    I. Test Stations Electrolysis test stations shall be installed per Section 2.6I.7, and Detail Drawings A8-4 through A8-8. Colorado Springs Utilities shall provide the test stations, and the Contractor shall install the test stations. Test stations shall be tested prior to final acceptance to ensure proper functioning. Lead wires shall be labeled to identify where they are connected.

    5.18 Backfill and Compaction The trench shall be backfilled to finished grade as shown on the Approved Construction Plans. No section of Water Main, Water Main appurtenance or Water Main Structure shall be backfilled until the Inspector has examined and approved that section of the installation.

    Wet, soft or frozen material, asphalt and concrete chunks, cinders, ashes, refuse, plant or organic material, boulders, rocks or other deleterious substances shall not be used for backfill. If the excavated material is not suitable for backfill, as determined by the Inspector, suitable material shall be hauled in and utilized, and the rejected material hauled away and disposed.

    No backfilling will be allowed in freezing weather except by permission of the Inspector. No additional backfill will be allowed over any frozen material already in the trench.

    Water required for backfill and compaction operations may be furnished from a designated fire hydrant subject to permitting and installation requirements described in Section 5.7.

  • Backfill shall be consolidated and/or compacted by vibrating, tamping or a combination thereof, to the satisfaction of the appropriate controlling authority. The fill shall be placed in maximum 8 inch horizontal layers of un-compacted thickness and shall be compacted per the following criteria:

    • For Cohesive Soils, a minimum compaction requirement of 95 percent of maximum Standard Proctor dry density (ASTM D698) at ± 2 percent of optimum moisture content.

    • For Cohesionless Soils, a minimum compaction requirement of 95 percent of maximum Modified Proctor dry density (ASTM D1557) at ± 2 percent of optimum moisture content and 100 percent of maximum Standard Proctor dry density (ASTM D698) at ± 2 percent of optimum moisture content.

    • For highly expansive soils (swell potential >2.00 percent under 200psf surcharge pressure), paving will not be permitted without a subgrade treatment approved by the controlling authority.

    Compaction tests should be taken at a minimum of every 250 feet for utility mains in 2 foot vertical increments. One compaction test shall be conducted for every service line trench at alternating depths. The Inspector or the Governing Agency has the discretion to require additional compaction tests. (Reference City of Colorado Springs, City Engineering Standard Specification, Section 200 – Street Section).

    Satisfactory compaction reports shall be submitted to the Inspector and the Authority Having Jurisdiction prior to the completion of the Project. The Authority Having Jurisdiction shall specify the exact number and locations of tests required. Railroad, airport and other private or special situations will require investigation and research to determine specific requirements.

    Flow-fill will be required as utility trench backfill for all trenches less than 1 foot in width. This requirement applies to all pavement and gravel locations. For trench excavations greater than 1 foot in width, the slurry concrete cap in newly overlaid or newly constructed streets will be required in accordance with City of Colorado Springs Standards or as directed by the Controlling Authority. Compaction and testing of utility trench backfill will not be required if material meeting the flow-fill Specification in Section 4.4S is used.

    The methods of compaction shall be sufficient to attain the required density in accordance with these Water LESS. Performance of the compacted trench shall be the responsibility of the Contractor and any failure, as defined by the Authority Having Jurisdiction, which occurs within 2 years following the completion of Construction shall be corrected at the expense of the Contractor.

    The method of testing the compacted material shall be the responsibility of the Professional Engineer certifying the results. The Professional Engineer shall be responsible for the validity of all test results.

    Colorado Springs Utilities Water Line Extension & Service Standards – 2014 5-34

  • Colorado Springs Utilities Water Line Extension & Service Standards – 2014 5-35

    Fly ash or “Flashfill” materials used in public ROWs or in off-site applications i.e. under Structures must be in accordance with Section 4.4S.

    5.19 Hydrostatic Testing Disinfection Procedures Hydrostatic testing shall be completed as directed by the CSFD and may be required on a case by case basis at the discretion of Colorado Springs Utilities. All hydrostatic testing on newly installed or repaired Potable Water pipeline and associated appurtenances shall be performed prior to disinfection activities unless otherwise arranged with onsite Colorado Springs Utilities personnel. Disinfection may be performed concurrently or prior to hydrostatic testing at the discretion of Colorado Springs Utilities.

    Hydrostatic testing shall be performed by an independent Contractor who is responsible for providing any pumps, temporary piping, Backflow devices and associated appurtenances needed to carry Potable Water to the section of pipeline being pressure tested, disinfected and flushed. The water source, pumps, piping and all equipment used for the purpose of hydrostatic testing shall be cleaned and disinfected using the swab method as defined in Section 5.20 before any connections are made to the Potable Water System.

    5.20 Disinfection All Water Main Extensions and Private Water Main Extensions shall be chlorinated in accordance with AWWA C651. The chlorination method used for main disinfection shall be approved by Colorado Springs Utilities as outlined in this section.

    It shall be the Inspector’s responsibility to notify Colorado Springs Utilities, Laboratory Services Section 2 working days in advance of the disinfection date. The Inspector, Contractor, and Lab Services shall be present during all disinfection and Flushing activities.

    An acceptable bacteriological sample result shall be verified prior to the line extension being placed in service or the installation of any service taps. The disinfection procedure may need to be repeated at the expense of the Contractor if the following disinfection criteria are not met:

    A. Water Mains 12 inch or Smaller The Contractor shall provide High Test Hypochlorite (HTH) granules to be used for disinfection of Water Mains of 12 inch in diameter or less. A minimum of 2 oz HTH granules shall be used per 20 ft section of pipe installed to achieve a chlorine concentration acceptable to Colorado Springs Utilities. Tablets shall not be used for disinfection. The granules shall be placed inside each joint of pipe as the pipe is installed in the trench. Once the chlorine is placed in the pipe, the Contractor shall provide labor, material and an acceptable plan to transmit and contain water discharged during Flushing.

    The main shall be filled with water at a rate to ensure that the water within the main will create a chlorine solution throughout the length of the pipe. The fill rate shall not exceed 1 foot/second. Precautions shall be taken to ensure that air pockets are eliminated.

  • Colorado Springs Utilities Water Line Extension & Service Standards – 2014 5-36

    Chlorinated water shall remain in the pipe for a minimum of 24 hrs to ensure adequate contact time and shall have a minimum concentration of 50 mg/L at the end of a 24 hour period.

    B. Water Mains Larger