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1 <br /> CITY OF EVERETT SPECIAL PROVISIONS <br /> • location of taps and other appurtenances used for chlorination and flushing <br /> purposes, <br /> • location of the sample collection taps, <br /> • disposal location and treatment procedure for chlorinated water discharged <br /> from the mains, and <br /> • procedure for disinfection including application method, point of application, <br /> and target concentrations for the contact interval being used. <br /> 7-09.3(24)A Flushing <br /> Flush sections of pipe being disinfected to remove solids that may have become <br /> lodged in the pipe. Provide a tap sufficient to provide a flush velocity inside the <br /> main of at least 2.5 fps if no hydrant is installed at the end of the main. Flush as <br /> long as material or color is visible in the discharge. Flush at a minimum one full <br /> pipe volume of water from the section of new main being tested. <br /> Guidelines for Required Flow and Openings to Flush Pipelines <br /> (assumes 40 psi residual pressure in water main) <br /> Pipe Dia. Flow Required Size of Tap (in) Number of <br /> (in.) to Produce 2.5 2 1/2" Hydrant <br /> fps (approx) outlets <br /> Velocity in Main 1 1 1/2 2 <br /> (gpm) (in) (in) (in) <br /> 4 100 1 1 <br /> 6 200 1 1 <br /> 8 400 2 1 1 <br /> 10 600 3 2 1 <br /> I <br /> 12 900 2 2 <br /> 16 1,600 4 2 <br /> Guidelines for Water Main Volume <br /> Inside Dia. Volume per 100 LF <br /> (in) (gal) <br /> 4 65 I <br /> 6 147 <br /> 8 261 <br /> 10 408111 <br /> 12 587 <br /> 20 1,632 <br /> Provide taps and other appurtenances required for temporary release of air, <br /> I <br /> chlorination, or flushing purposes as a part of the Work. <br /> To protect aquatic life in receiving waters, neutralize the chlorine contained in the <br /> discharge water before disposing into a natural drainage channel or feature <br /> draining to a natural channel. Dispose of disinfecting solutions to the satisfaction <br /> of the City of Everett and the Washington Department of Ecology. Discharge water <br /> disposal may be directed to an available sanitary sewer, if approved by the <br /> I <br /> Engineer and provided the rate of disposal will not overload the sewer. <br /> 7-09.3(24)B Disinfectant Concentration and Retention Period (Contact <br /> Interval) I Provide disinfection concentration necessary to obtain a free chlorine residual of <br /> not less than 10 mg/1 remaining in the disinfectant solution after a 24 hour contact <br /> time. Provide the initial free chlorine residual concentration of disinfectant solution <br /> Water Main Replacement"Q" Division 7—STORM, SEWER,WATER February 9, 2018 <br /> -Evergreen Way Rebid <br /> WO No.—UP3612 SP—154 <br />