Thomco Construction Inc. 6/14/2021

CITY OF EVERETT SPECIAL PROVISIONS I 7-09.3(24) Disinfection of Water Mains I Delete 7-09.3(24), including subsections, and substitute the following: 7-09.3(24) Flushing and Disinfection of Water Mains I (******) Flush, disinfect with a chlorine solution and obtain passing coliform bacteria test reports before placing new water mains or extensions to existing mains in service. Submit I flushing and disinfection procedures in accordance with this section. Provide submittal containing, at a minimum: ❑ location of taps and other appurtenances used for chlorination and flushing purposes, • location of the sample collection taps, • disposal location and treatment procedure for chlorinated water discharged I from the mains, and • procedure for disinfection including application method, point of application, and target concentrations for the contact interval being used. 7-09.3(24)A Flushing I Flush sections of pipe being disinfected to remove solids that may have become lodged in the pipe. Provide a tap sufficient to provide a flush velocity inside the main I of at least 2.5 fps if no hydrant is installed at the end of the main. Flush as long as material or color is visible in the discharge. Flush at a minimum one full pipe volume of water from the section of new main being tested. Guidelines for Required Flow and Openings to Flush Pipelines I (assumes 40 psi residual pressure in water main) Pipe Dia. Flow Required Size of Tap (in) Number of (in.) to Produce 2.5 2 1/z" Hydrant fps (approx) outlets Velocity in Main 1 1 1/2 2 (gpm) (in) (in) (in) 4 100 1 1 6 200 1 1 I 8 400 2 1 1 10 600 3 2 1 12 900 2 2 I 16 1,600 4 2 I I I I I Water Main Replacement"V" Division 7—STORM, SEWER,WATER April, 2021 IIWO No.—UP3730 SP—176 ADDENDUM#1