AWWA C651 PDF
This document is an American Water Works Association (AWWA) standard. It is not a .. This foreword is for information only and is not a part of AWWA C AWWA C Disinfecting Water Mains. Current; Document Language: English; Published By: American Water Works Association (AWWA). AWWA C and these specifications. Disinfection requirements shall include preventive and corrective measures during construction, forms of chlorine and.
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Watermain breaks with no evident or suspected Contamination are classified as Category 1. Examples of watermain breaks that are typical of Category 2 are included below for illustrative purposes only: Added, modified, replaced, extended; or Taken out of service for inspection, repair or other activities that may lead to Contamination, shall be disinfected before being put into service in accordance with the provisions of the AWWA C — Standard for Disinfecting Water Mains or an equivalent procedure.
For planned swabbing and hydraulic e. For all other types of cleaning c6511. Share facebook twitter Print. Upon completion of the excavation, the Operator-in-Charge OIC shall conduct a visual inspection to determine the nature of the break.
If, at any time, Contamination is evident or suspected, the break shall be reclassified as Category 2. Appendix E The following flowchart depicts the requirements for special case Contamination sewage or chemical as a result of a watermain break. Operating authorities may choose to provide notification to, or awea advice from, the local Medical Officer of Health at any time.
The sampling will typically occur at the point of Flushing, and may take place from sampling ports, hydrants, blow-offs, or premise plumbing.
AWWA C / AWWA C / AWWA C – Disinfection Of Water Package
Appendix B Tools to help determine the category of watermain break – pictures Examples of watermain breaks that are typical of Category 1 are included below for illustrative purposes only: This definition does not include recharging the watermain or a requirement to achieve scouring velocity within the watermain. The local Ministry office shall be notified as soon as reasonably possible during business hours.
The operating authority shall determine if flow can be maintained to the break site until the watermain is excavated. Excavation dewatering shall be continued for the duration of the repairs such that the Air gap between the location of the break in the watermain and the water in the excavation is maintained. If the water level in the excavation rises c6651 that the Air gap is not maintained after flow from the break has been discontinued, then the watermain break shall be classified as Category 2.
Example 3 When using the slug method of chlorination, with a minimum aswa 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. Flow may be reduced by throttling valves while maintaining sufficient flow from the break to minimize the potential for Contamination. Watermain repairs xwwa more than 6 metres of replaced pipe are also classified as Category 2.
Notification to the local Ministry office is not required for Category 2 watermain breaks unless: These steps also apply to the planned maintenance of watermain Appurtenances and fittings refer to section 1.
Mechanical removal of Contaminants; Flushing into the excavation; Higher velocity flushing after repairs where practical and feasible.
Watermain disinfection procedure
Pipe and Repair Parts disinfected? The discharged water is deemed to be a Class II spill for the purposes of O. Category wawa watermain breaks are not required to be reported to the Spills Action Centre unless an operating authority believes that contaminated water was directed to users. The procedures are required to be aswa in order to satisfy conditions imposed by the Director in a drinking water works permit.
Appendix C Category 1 flowchart The following flowchart is an example of the typical steps required for Category 1 watermain breaks Note: Examples of awda steps for Category 1, 2 and for special cases are attached as Appendices C, D and E respectively. The following steps must be performed for all emergency watermain repairs Category 1 and Category 2.
There is no requirement to undertake Microbiological sampling for Category 1 watermain break repairs. In addition to the requirements described in section 3. The requirements in this section also apply to temporary watermains.
Watermain breaks with evident or suspected Contamination are classified as Category 2. Flushed water may be discharged from a hydrant, plumbing or Appurtenances. Flow may be discontinued after an Air gap has been created. Refer to Appendices A and B for a flowchart and pictures to better understand the criteria to determine f651 categories of watermain breaks. In developing these awsa, operating authorities may use best management practices that go beyond the minimum requirements in this zwwa.
If there is evident or suspected chemical Contamination of a watermain, in addition to the procedures in sections 3. 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 aawa 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 following flowchart is an example of the typical steps required for Category 1 watermain breaks Note: The 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. The following flowchart is an example of the typical steps required for Category 2 watermain breaks.
For Category 2 — Special Cases, include site specific plan. The following flowchart depicts the requirements for special case Contamination sewage or chemical as a result of a watermain break.
This section does not require that all of the information be recorded on a single form: