Remove, by flushing or other means, contaminating materials that may have entered the water line during construction. Where necessary, install temporary flush valves at the end of new lines for flushing and sampling prior to tying into existing system.
(Ordinance 2007-106, App. B, adopted 3/20/07)
A. 
Application Procedure - Apply chlorinating agent by one of the following procedures:
1. 
Tablet Method - Place calcium hypochlorite granules or tablets in the water line at the upstream end of the first section of pipe, at the upstream end of each branch and at 500 foot intervals such that when the pipe is filled with potable water the dose will be a minimum of 25 mg/l for 24 hours. Fill pipe such that water velocity does not exceed one (1) foot per second.
2. 
Continuous Feed Method - Fill line with water, eliminate air pockets and flush water line at a minimum velocity of 2.5 feet per second to remove particulates. Feed chlorine water solution having a free chlorine concentration of 25 mg/l into line until entire line is filled with heavily chlorinated water. Retain chlorinated water in line for 24 hours after which time the free chlorine residual shall not be less than 10 mg/l.
3. 
Slug Method - Place calcium hypochlorite granules in the line during construction, completely fill the line to eliminate all air pockets, flush the line to remove particulates and slowly flow a slug of water dosed with chlorine to a concentration of 100 mg/l through the line such that all parts of the line and appurtenances will be exposed to no less than 50 mg/l of free chlorine for not less than 3 hours.
B. 
Chlorination of Appurtenances - Operate valves and hydrants several times while exposed to the required chlorine concentration to assure disinfection of appurtenances and pipe branches.
C. 
Final Flushing - In order to prevent damage to pipe and linings, flush heavily chlorinated water from system until chlorine measurements show that the concentration in the water leaving the main is no higher than that generally prevailing in the distribution system.
D. 
Bacteriological Test - After final flushing, collect samples and test for presence of coliform organisms. A minimum of one sample shall be collected from each 1,000 feet of water line or at the next available sampling point beyond 1,000 feet as designated by the City of Magnolia, Engineer or the designated representative of the Engineer.
(Ordinance 2007-106, App. B, adopted 3/20/07)
If initial disinfection fails to produce tests showing absence of coliform organisms, the new line may be reflushed and shall be resampled. If check samples also fail to produce acceptable results, the main shall be rechlorinated until satisfactory results are obtained.
(Ordinance 2007-106, App. B, adopted 3/20/07)
Testing for bacteriological quality shall be in accordance with Standard Methods for the Examination of Water and Wastewater. Collection of samples shall conform to the applicable AWWA standard and shall meet with the approval of the DPW or designated representative of the DPW.
(Ordinance 2007-106, App. B, adopted 3/20/07)