(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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Clarified differences in the requirements between new and repaired mains foreword II. This timing is sufficient to allow bacterial regrowth within the line if there was a c651–05 problem and provides more flexibility in the scheduling of various work activities. AWWA standards are intended to represent a consensus of the water supply industry that the product described will provide satisfactory service. Follow all personal protection precautions when working with chlorine solutions.
The existing pipe should be inspected and cleaned with the help of flushing water into the trench, where possible, until the flush water runs visually clear. Yarning or packing material shall consist of molded or tubular rubber rings, rope of treated paper, or other approved materials. Determine additives requirements including applicable standards.
AWWA C Disinfecting Water Mains
If the initial disinfection fails to produce satisfactory bacteriological results, or if other results indicate unacceptable water quality, the main may be reflushed and shall be resampled. The cleaning method used shall not force mud or debris into the interior pipe-joint wwwa and shall be acceptable to the purchaser.
The number of 5-g tablets required for each pipe section shall be 0. This procedure must not be awsa 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. Hagar, Carollo Engineers, Phoenix, Ariz. Aww related to awwa c children s law reform act ontario. It will be necessary to reestablish the temporary connection after completion of the hydrostatic pressure test to flush out the disinfectant water prior to final connection of the new main to the distribution system.
If, in the opinion of the purchaser, the dirt remaining in the pipe will not be removed using the flushing operation, the interior of the pipe shall be cleaned using mechanical means, such as a hydraulically propelled foam pig or other suitable device acceptable to the purchaser in conjunction with the application of a minimum 1 percent free chlorine wwwa solution.
Inspecting materials to be used to ensure their integrity. The free chlorine residual shall be measured in the slug as it moves through the main. In the United States, authority to regulate products for use in, or in contact with, drinking water rests with individual states. If there is any question that damage may be caused by chlorinated-waste discharge to fish life, plant life, physical installations, or other downstream water uses of any typethen an adequate amount of reducing agent should be applied to water being disposed of in order awqa thoroughly neutralize the chlorine residual remaining in the water.
In this situation, activities are well controlled and a aawa shutdown is not needed, thus maintaining positive pressure to the area of shutdown and around the break site at all times. Method of taking samples Sec. Hydrostatic pressure tests should be conducted with potable water. Before approving a main for release, let it sit for a minimum of 16 hr without any water use. Any modification of the provisions, definitions, or terminology in this standard must be provided by the purchaser.
After chlorination and repair, perform scour flushing at 3. Exposure to high levels of chlorine or high pH can cause severe irritation to customers.
AWWA C651-14 Disinfecting Water Mains
A Purchaser Options and Alternatives Nonetheless, the repair work needs to be accomplished using sanitary and safe procedures by well-trained crews with proper supervision and guidance. Water mains taken out of service for inspection, repair, or other activities may or may not require disinfection and sampling, depending on the risk of contamination. This standard was first approved on Sept. After samples have been collected, the gooseneck assembly may be removed and retained for future use and the corporation cock should be capped or taped for future reuse.
After disinfection and final flushing such that typical system chlorine residuals are present, if the system operates with a residual, samples shall be collected as follows: For very-large-diameter pipe where personnel may safely enter the pipein lieu of flushing following disinfection, the interior of the pipe at the repair site may be cleaned by sweeping or high pressure wash using potable water before disinfection.
No bacteriological testing is necessary. This use of the term is discouraged. The publications are referred to within the text by the basic desig If dirt enters the pipe, it shall be removed and the interior pipe surface swabbed with a minimum 1 percent free chlorine disinfecting solution. The stipulations of this standard apply when this document has been referenced and only to the disinfection of water mains. The installation of new mains requires that two sets of samples for coliform analysis are collected at least 16 hr apart, or two sets collected 15 min apart after at least a hr rest period.
Heavy particulates generally contain bacteria and prevent even very high chlorine concentrations from contacting and killing these organisms. The more closely the rate of delivery is correlated to the rate of pipe laying, the lower the risk of contamination. Ionic Bonds Practice worksheet Complete the chart for each element.
Two dropping pipettes that deliver a 1-mL sample in 20 drops. Fill the comparator cell to the mL mark with distilled water. Sealing material or gaskets shall be handled in a manner that avoids contamination.
Thus, users of this standard should consult the appropriate state or local agency having jurisdiction in order to 1.
Use of Annex A procedures may not always be identical, depending on the certifier. ANSI procedures require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of ANSI approval. This hose must be removed during the hydrostatic pressure test.
New water mains shall be disinfected before they are placed in service. No contaminated material or any material capable of supporting growth of microorganisms shall be used for sealing joints.
Figure 1 applies to pipes with diameters 4 in. 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.
The repair site should be cleaned and disinfected by spraying or swabbing with a minimum 1 percent chlorine solution.