AWWA C651-05 PDF
(Revision of ANSI/AWWA C). Copyright © This document is an American Water Works Association (AWWA) standard. It is not a. 1, , AWWA issued the updated ANSI/AWWA C 14 standard, Disinfecting Water Mains, a result of the review that AWWA standards must go through. AWWA Standard for Disinfecting Water Mains – Jun 1, – Ansi/AWWA C DS60 Water Supply Distribution Standard – Pipelines Other.
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Until each optional feature is specified by the user, the product or service is not fully defined.
Add 10 drops of DPD solution and 10 drops of buffer solution or 20 drops of combined DPD-buffer solution to a comparator cell. Preventing contaminating materials from entering the water main during storage, construction, or repair and noting potential contamination at the construction site.
To ensure that an appropriate concentration is achieved, the free chlorine concentration shall be measured at regular time intervals in accordance with the procedures described in Standard Methods for the Examination of Water and Wastewater or AWWA Manual M12, or using appropriate chlorine test kit see appendix A. Final connecting of the newly disinfected water main to the active distribution system without sacrificing sanitary practices and conditions.
Combinations of free chlorine residual and contact time are provided. Calcium hypochlorite granules shall be placed at the upstream end of the first section of pipe, at the upstream end of each branch main, and at ft m intervals.
AWWA C651-14 Disinfecting Water Mains
Although this c651–05 is unique for each system, parameters considered for testing include disinfectant residual, total coliform bacteria, HPC, turbidity, pH, alkalinity, total aawa, odor, and specific conductance. Whichever disinfectant or method is selected, approval from the local regulatory agency may be required. Rodent-proof plugs may be used when watertight plugs are not practicable and when thorough cleaning will be performed by flushing or other means.
Revisions were approved on Sept. Test results should confirm that the water quality is appropriate for distribution. Joints of pipe in the trench shall be completed before work is stopped. American National Standards are subject to periodic review, and users are zwwa to obtain the latest editions. There shall be adhesive only on the broadside of the tablet attached to the surface of the pipe. This American National Standard may be revised or withdrawn at any time.
As noted above, the four methods attempt to provide flexibility in responding to specific situations. In most other situations, the water main can be maintained pressurized until the break site is secured and the pipe is fully exposed. Makeshift equipment is not acceptable when liquid chlorine gas cylinders are used.
AWWA C Disinfecting Water Mains
When check samples are taken, it is advisable to sample water entering the new main to determine if excessive turbidity is present that could be interfering with results.
Given the often significant amount of time and materials involved in a new water main project, careful disinfection and testing of the xwwa are reasonable and necessary to ensure public health protection.
The Water Main O n Feb. Note that the procedures explained in Sec. The flushing rate of 2. Purchaser Options and Alternatives. Feed lines shall awwq made of material capable of withstanding the corrosion caused by the concentrated chlorine solutions and the maximum pressures that may be created by the pumps. Sanitary construction practices must be followed during installation of the final connection so that there is no contamination of the new or existing water main with foreign material or groundwater.
Certain contaminants, such as caked deposits, resist flushing at any feasible velocity, and pigging of the main, or other awaw method acceptable to the purchaser, may be required.
The tablet method is convenient to use in mains c651-005 diameters up to 24 in. Follow all personal protection precautions when working awda chlorine solutions. This procedure awwwa not be used on solvent-welded plastic or on screwed-joint steel pipe because of the danger of fire or explosion from the reaction of the joint compounds with the calcium hypochlorite.
Refer to preventive and corrective measures described previously in Sec. In the United States, authority to regulate products for use in, or in contact with, drinking water rests with individual states. Heavy particulates generally contain bacteria and prevent even very high chlorine concentrations from contacting and killing these organisms.
If check samples fail to produce acceptable results, the main shall be rechlorinated by the continuous-feed or slug method until satisfactory results are obtained—that being acceptable samples taken as described in Sec. It is not a specification.
Sodium hypochlorite contains approximately 5 percent to 15 percent available chlorine, and the storage conditions and time must be controlled to minimize its deterioration. Samples for bacteriological analysis shall be collected in sterile bottles treated with sodium thiosulfate, in accordance with Section —Samples of Standard Methods for the Examination of Water and Wastewater.
The procedures described in Sec. For example, if gas chlorination is the chosen chemical when either continuous-feed or slug methods are being used, use only properly designed and constructed equipment; makeshift equipment is not acceptable when liquid chlorine gas cylinders are used. The chlorinated water may then be drained or flushed from the main. The preferred equipment for applying liquid chlorine gas is a solution-feed, vacuum-operated chlorinator and a booster pump.
Added spray disinfection method for large transmission mains Sec. Work should follow basic disinfection and contamination prevention procedures: