02720 Sanitary Sewer Collection System - City of Daly City
02720 Sanitary Sewer Collection System - City of Daly City
02720 Sanitary Sewer Collection System - City of Daly City
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ii. The maximum allowable head <strong>of</strong> water above any portion <strong>of</strong> sewerbeing tested shall be fifteen feet (15'). Where the difference inelevation between successive manholes exceeds fifteen feet (157, a testtee shall be installed between manholes, and testing shall be carried onbetween the tee and the manhole. Test tee shall conform to applicable<strong>City</strong> Standard Drawings.iii. The allowable leakage shall not exceed one-tenth gallon (0.1) perminute per inch diameter per one thousand feet (1,000') <strong>of</strong> main linesewer being tested for a two (2) hour duration test.b. Mandrel Testing <strong>of</strong> PVC <strong>Sewer</strong> Main:i. The contractor shall pull a mandrel through each segment <strong>of</strong> installedPVC sewer main to test the amount <strong>of</strong> deflection incurred duringinstallation. This test shall be done after the pipe trench has beenbackfilled and compacted to the level <strong>of</strong> the pavement subgrade inpaved areas or to the ground surface in unpaved areas. The <strong>City</strong>'sProject Inspector shall observe mandrel testing. The contractor shallgive at least five (5) working days notice to the <strong>City</strong>'s Project Inspectorbefore commencing mandrel testing.. .11. Mandrels shall be full circle, solid or rigid odd numbered (nine legminimum) steel cylinders with pulling rings at each end and approvedby the <strong>City</strong>'s Project Inspector. The circular cross section <strong>of</strong> themandrel shall have a diameter no smaller than ninety (95) percent <strong>of</strong>the average inside diameter <strong>of</strong> the pipeline being tested. The length <strong>of</strong>the mandrel shall be no less than two times the full cross sectiondiameter. A separate pull line shall be attached to each pull ring t<strong>of</strong>acilitate removal <strong>of</strong> the mandrel if an obstruction is encountered.iii.Mandrels shall be pulled through the pipeline by hand without the aid<strong>of</strong> mechanical pulling devices. Any deficiencies found by mandreltesting shall be corrected by the Contractor, at the Contractor'sexpense. Deficiencies shall be repaired by excavating the pipe at leastto the pipe spring line. Pipe bedding and backfill shall be re-compactedafter the repair. Internal rounding or vibration to correct deflectionshall not be permitted. After repair and re-compaction <strong>of</strong> the pipebedding and trench backfill material, the pipe shall be retested usingthe mandrel. Any pipe failing two mandrel tests shall be replaced.Section <strong>02720</strong> - 40
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