AWWA C Disinfecting Water Mains. Current; Document Language: English; Published By: American Water Works Association (AWWA). This standard presents essential procedures for the disinfection of new and repaired potable water mains. All new water mains shall be disinfected before they. FIELD CHLORINATION. • AWWA/ANSI C – Disinfecting Water Mains. • First standard approved Sept. 30, • Latest revision June 1.
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Pipe and Repair Parts disinfected? For Category 2 — Special Cases, include site specific plan. Stanrard OIC will assess the evidence of Contamination or potential Contamination of the watermain before and during the repair procedure, and shall classify the break into one of two categories as per 3.
This definition does not include recharging the watermain or a requirement to achieve scouring velocity within the watermain. Return to normal service is contingent upon the corrective actions and sampling plan being completed to the satisfaction of the local Ministry office in consultation with local Medical Officer of Health. Category 1 watermain breaks are not defined as an observation of improper disinfection in accordance with Section of Schedule 16 of O.
Flow may be discontinued after an Air gap has been created. Notification to the local Ministry office is not required for Category 2 watermain breaks unless:. This document outlines procedures for disinfecting water mains as part of an addition, modification, replacement, extension, planned maintenance, or emergency repair in a municipal residential drinking water system.
The following flowchart is an example of the typical steps required for Category 1 watermain breaks Note: Examples of watermain breaks that are typical of Category 2 are included below for illustrative purposes only: Skip to main content.
Tags Environment and energyDrinking water. After business hours, the operating authority shall send an e-mail to the e-mail address specified by local Ministry office no later than 10 AM the next business day; or in the Special Cases described in sections 3.
Upon completion of the excavation, the Operator-in-Charge OIC shall conduct a visual inspection to determine the nature of the break.
For new watermains with limited sampling points available, awwaa alternative method of collecting Microbiological samples is called staged sampling. This procedure also establishes minimum standards for record keeping, and notification to the Ministry and the local Medical Officer of Health. Examples of watermain breaks that are typical of Category 2 are included below for illustrative purposes only:. Additional steps shall be undertaken as appropriate to remove Contaminants from the watermain, such as:.
If there is evident or suspected sewage Contamination of a watermain, in addition to the procedures in sections 3. For planned swabbing and hydraulic e. Chain of custody Date and time of return to normal service Water Shandard declared: The operating authority will attempt to maintain flow from the break, where possible, until an Air gap is established.
Watermain breaks with evident or suspected Contamination are classified as Category 2. Watermain breaks with no evident or suspected Contamination are classified as Category 1. If final disinfectant residual is less than 0.
Category 2 watermain breaks are not required to sfandard reported to the Spills Action Centre unless an operating authority believes that contaminated water was directed to users. When performing maintenance and repair activities as per sections 1.
Watermain repairs involving more than 6 metres of replaced pipe are also classified as Category 2. Return to normal service is contingent upon the corrective actions and sampling plan being completed to the satisfaction of the local Ministry office in consultation with the local Medical Officer of Health.
Operating authorities may choose to provide notification to, or seek advice awea, the local Medical Officer of Health at any time. Longitudinal watermain break with evident Contamination. If these disinfectant concentrations cannot be achieved, Flushing shall continue until the disinfectant concentration at the point of Flushing is representative of the system residual in the break area, determined by sampling upstream of the break area and downstream at the Flushing location, or by using documented benchmarks for the area, as long as free chlorine concentrations are at least 0.
The sequence of actions may be varied as appropriate for the specific situation.
Watermain disinfection procedure |
This section does not require that all of the information be recorded on a single form:. Contamination is typically not suspected for circumferential breaks or small leaks where flow is maintained from the break until an Air gap is established and where the Air gap is maintained during the repair procedure.
If the water level in the excavation rises such stnadard the Air gap is not maintained after flow from the break has been discontinued, then the watermain break shall be classified as Category 2. Where copper pipe is used for smaller diameter watermains, Table 1 does not apply.
Notification awa the local Ministry office is not required for Category 2 watermain breaks unless: The operating authority shall implement the plan as prescribed and the watermain cannot be put back in service until the cleaning, disinfection and sampling is completed as per the plan unless a Water Advisory is declared.
Share facebook twitter Print. The requirements in this section also apply to temporary watermains. Where the operating authority opts to standarx Microbiological sampling, samples shall be considered distribution samples within the meaning of O.
With respect to new watermains, relined watermains and temporary watermains, the provisions of this document, including sections 1.
Watermain disinfection procedure
The disinfection requirements for new watermains as per Section 1. In developing these procedures, operating authorities may use best management practices that sttandard beyond the minimum requirements in this document. Example 3 When using the slug method of chlorination, with a minimum contact time of 3 hours, the chlorine concentration shall be measured in the slug at the beginning of the disinfection process, as the slug moves through the watermain, and at the point of discharge.
Flushed water may be discharged from a hydrant, plumbing or Appurtenances.
Corrosion hole leak in a watermain with flow maintained until after an Air gap was created. Upon restoration of secondary disinfection, the system can be returned to normal service, defined as having all valves returned to normal operating position.