Res10 14996 - Laserfiche WebLink

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EXHIBIT B (continued) II. REDWOOD CITY SEWER PROTECTION AND REPLACEMENT REQUIREMENTS 1. Before and after Project construction, the Contractor shall conduct closed circuit television (CCTV) of the existing sanitary sewer mains at each location, where the proposed pipeline will cross such sewer mains, from the closest upstream manhole to the closest downstream manhole. Contractor shall submit the videos and inspection reports to Redwood City for review. Any defects found in the post inspection videos shall be repaired at the Contractor's expense. 2. Contractor shall protect and support all existing sanitary sewer pipelines at each location where they are crossed by the proposed pipeline. If any deflection or damage to the sewer pipeline is detected, Contractor shall immediately implement the bypass pumping plan and repair the defect. 3. When working underneath City's sewer pipelines, Contractor shall have three (3) stand -by portable pumps and (300' - 400') long flexible hoses in different sizes (2" to 4" in diameter). This emergency pumping system should be capable of relieving large build -ups of sewage in sewer mains. 4. CCTV monitoring shall occur during low flow periods, 9:OOAM to 12:OOPM and 3:OOPM to 5:OOPM. 5. The Contractor shall not stop or impede the sewer main flows under any circumstances. In case of a pipe break, the sewage flows shall be conveyed safely around the work area in a manner that will not cause surcharging of sewers, damage to sewers, and that will protect public and private property from damage and flooding, including the routing of sewage overflow in the event of failure of any bypass system. 6. The Contractor shall protect water resources, wetlands, and other natural resources from sewer overflows. 7. The Contractor shall replace the existing sanitary sewer pipeline damaged during the construction with the same size Polyvinyl Chloride (PVC) pipe. Mission bell or approved couplings shall be used to connect the existing and new PVC pipeline. III. REDWOOD CITY WATER MAINS PROTECTION AND REPLACEMENT REQUIREMENTS 1. SFPUC Contractor shall protect Redwood City's water mains at each location where they are crossed by the proposed pipeline. Should any portion of the existing water main be damaged by activities related to the construction of the BDPL #5, the section of pipe shall be replaced immediately. Old cast iron pipes (CIP) are the most vulnerable and represent a risk of breakage during construction, resulting in disruption of service and more costly replacement. Therefore, these mains require to be secured by replacing a length of pipe to extend at least to the first joint passing the trench edges of the new pipe; or further, if needed. See table below for detail. 2. The cast iron water mains that require field evaluations and replacements as described herein are listed by station and street name. All other mains, not listed in table below or found in the field, including PVC and other materials, shall be braced and secured during construction. 3. Replacement of these sections of CIP water mains shall be performed using C -900 Class 200 PVC pipe in conformance with Redwood City Engineering Standards — Section 02660 — "Water Systems" and the City Standard Details. The pipe couplings used to connect the new pipe section to the existing main shall comply with these specifications. The coupling sleeves shall be at least twelve (12) inch long. Pipe trench shall be backfilled per Standard Detail UT -1 or using CDF to meet compaction requirement, as applicable. 4. The Contractor shall coordinate with Redwood City's Inspector, and Public Works Services Department to schedule water shut down; allowing plenty of time for notification and planning. 5. The Contractor shall conduct the following chlorination procedure to disinfect the new pipe and fittings used to replace any portion of Redwood City water mains. This procedure shall be conducted the same day as the pipe and fittings are to be installed. 6. Prior to installation and connection to the existing water system, a chlorine solution of 200 -mg /L available chlorine shall be applied directly to the inside of pipes and inside and outer surfaces of fittings. The chlorine solution shall be applied with suitable brushes or spray equipment and thoroughly coat all surfaces to be treated. 7. The disinfected surfaces shall remain in contact with the chlorine solution for at least 30 minutes and be covered and protected all around using clean polyethylene bags. Following this procedure, and subject to satisfactory inspection by the City Inspector, the pipe and fittings can be installed to the existing distribution system using gloves and proper handling to prevent dirt or contaminants from contacting the inner surfaces through the installation process. 8. The area of existing pipeline which the new stretch of pipe is to be connected shall be swabbed with chlorine solution mentioned above. 9. After the pipe and fittings are installed, the Contractor shall safely flush the water system using the nearest available downstream hydrant until the chlorine measurements show that the concentration in the water leaving the main is no higher than it is in the distribution system or acceptable for domestic use. A minimum flushing time of 15 minutes shall be provided 10. A neutralizing dechlorination chemical shall be applied to the water to be wasted to thoroughly neutralize the residual chlorine. The product used for this purpose shall be Bio- Neutralizer, with 35% concentration Sodium Sulfite dechlorination tablets as produced by NORWECO, or approved equal. 11. The Contractor shall protect storm drains, water streams, wetlands, and other natural resources from chlorinated water. IV. PROTECTION AND REPLACEMENT OF EXISTING CAST IRON WATERMAINS AT PROPOSED BDPL #5 CROSSINGS With respect to the existing cast -iron water mains owned by Redwood City located within the CCSF right -of -way and at the street - crossing locations listed below, Contractor shall: • In coordination with City Engineer, expose pipes within CCSF right -of -way sufficiently to allow pipe condition to be assessed in place before 60" -pipe trench excavation. City shall make a good faith effort to provide its representative to :: City of Redwood City MOA ver 030910