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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AWWA C / AWWA C / AWWA C – Disinfection Of Water Package
The reporting and corrective actions of Schedule 16 and the applicable Schedule 17 or 18 of O. Examples of watermain breaks that are typical of Category 1 are included below for illustrative awqa only:.
This section does not require that all of the information be recorded on a single form:. After business hours, the operating authority shall send an e-mail to the wawa address specified by local Ministry office no later than 10 AM the next business day; or in the Special Cases described in sections 3.
This procedure uses a risk management approach to categorize watermain breaks based on the potential for Contamination.
Watermain disinfection procedure
Due to the chlorine demand exerted by the copper, no minimum chlorine concentration is required following the 24 hour contact time, and the effectiveness of the disinfection process shall be demonstrated by the Microbiological sampling referred to in section 1.
Additional steps shall be undertaken as appropriate to remove Contaminants from the aswa, such as:. If planned maintenance, indicate type of planned maintenance e. Corrosion hole leak in a watermain with flow maintained until after an Air gap was created.
If final disinfectant residual is less than 0.
Watermain repairs involving more than 6 metres of replaced pipe are also classified as Category 2. Contamination is typically awea 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.
Spiral watermain break with evident Contamination. Operating Authorities may choose to provide notification to, or seek advice from, the local Medical Officer of Health at any time.
If chlorine disinfection was used, indicate initial concentration, contact time, final concentration and final concentration as percentage of initial concentration. Category 2 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.
Skip to main content. When performing maintenance and repair activities awaa per sections 1. Chlorine Concentrations and Contact Times for New Watermains At cc651 over 10 milligrams per litre, a measurement of total chlorine shall be deemed to be equivalent to a measurement of free chlorine.
The disinfection requirements for new watermains as per Section 1. All samples shall be considered distribution samples, taken and tested in accordance with O. Examples of watermain breaks that are typical of Category 2 are included below for illustrative purposes only:. Flushing shall continue until the disinfectant concentration at the point of Flushing reaches at least 0.
Watermain disinfection procedure |
Flushed water may be discharged from a hydrant, plumbing or Appurtenances. The operating authority shall record the duration of disinfection, as well as the initial dose and remaining residual at the end of aqwa contact time. Where the operating authority opts to undertake Microbiological sampling, samples shall be considered distribution samples within the meaning of O.
The following steps must be performed for all emergency watermain repairs Category 1 and Category 2. The discharged water is deemed to be a Class II spill for the purposes of O. 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.
Appendix B Tools to help determine the category of watermain break – pictures Examples x651 watermain breaks that are typical of Category 1 are included below for illustrative purposes only: The flow shall be directed to ensure that the sample represents water that has passed through the location of the repair.
Appendix D The following flowchart is an example of the typical steps required for Category 2 watermain breaks. After business hours, the operating authority shall contact the Spills Action Centre as soon as reasonably possible.
Examples of watermain breaks that are typical of Category 2 are included below for illustrative purposes only: Appendix C Category 1 flowchart The following flowchart is an example of the typical steps required for Category 1 watermain breaks Note: Notification to the local Ministry office is not required for Category 2 watermain breaks unless: Flushing shall continue until the discharged water is free from discoloration, and secondary disinfection has been restored as per 3.
Appendix E The following flowchart depicts the requirements for special case Contamination sewage or chemical as a result of a watermain break. Longitudinal watermain break with evident Contamination. If Contamination is evident or suspected, the procedures defined under section 3 for Category 2 watermain breaks shall apply.
Upon restoration of secondary disinfection, the system can be returned to normal service, defined as having all valves returned to normal operating position. 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.
If the water level in the excavation rises such 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.