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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Dechlorination of discharged water is required for any water that is directed into surface water or if the discharge into the natural environment causes or is likely to cause an adverse effect, as per Condition 10 of Schedule B of the Municipal Drinking Water Licence.
Circumferential watermain break with flow maintained until after an Air gap was created. Flushing watermain cleaning, the requirements of section 3. Skip to main content. Return to normal service is contingent upon the corrective actions and sampling plan being completed to the satisfaction of the local Ministry office standqrd consultation with the local Medical Officer of Health.
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: The operating authority shall finalize the plan in agreement with the local Ministry office in consultation with the local Medical Officer of Health.
Category 1 watermain breaks are not awws as an observation of improper disinfection in accordance with Section of Schedule 16 of O. The following flowchart is an example of the typical steps required for Category 2 watermain breaks. Flow may be discontinued after an Air gap has been created. For all other c561 of cleaning e. The v651 Ministry office shall be notified as soon as reasonably possible during business hours. Discharges of flushed water are also regulated under Condition 4.
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 sstandard 3.
Watermain breaks with no evident or suspected Contamination are classified as Category 1.
After the completion of Flushing and restoration of secondary disinfection, at least one Microbiological sample shall be collected and submitted as soon as reasonably possible, taking into consideration laboratory working hours and transportation timeframes. This procedure also establishes minimum standards for record keeping, and notification to the Ministry and the local Medical Officer of Aawwa.
The following flowchart is an example of the typical steps required for Category 1 watermain breaks Note: The following flowchart depicts the requirements for special case Contamination sewage or chemical as a result of a watermain break. All samples shall be considered distribution samples, taken and tested in accordance with O. Refer to Appendices A and B for a flowchart and pictures to better understand the criteria to determine the categories of watermain breaks. Standwrd there is evident or suspected chemical Contamination of a watermain, in addition to the procedures in sections 3.
If planned maintenance, indicate type of planned maintenance e.
The requirements in this section also apply to temporary watermains. The sampling will typically occur at the point of Flushing, and may take place from sampling ports, hydrants, blow-offs, or premise plumbing.
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.
This section does not require that all of the information be recorded on a single form:. The operating authority shall record the duration of disinfection, as well as the initial dose and remaining residual at the end of the contact time. If final disinfectant residual is less than 0.
Watermain disinfection procedure |
Notwithstanding the conditions of section 1. Spiral watermain break with evident Contamination. Operating authorities shall develop and document operating procedures for emergency watermain repairs within their systems. If there is c561 or suspected sewage Contamination of a watermain, in addition to the procedures in sections 3.
If Contamination is evident or suspected, the procedures defined under section 3 for Category 2 watermain breaks shall apply. Where the operating authority opts to undertake Microbiological sampling, samples shall be considered distribution samples within the meaning of O. In addition to the procedures in 3.
Watermain disinfection procedure
If the water level in the excavation rises such that the Air gap is not maintained after flow from the break stwndard been discontinued, then the watermain break shall be classified as Category 2.
Appendix D The following flowchart is an example of the typical steps required for Category 2 watermain breaks.
The operating authority will attempt to maintain flow from the break, where possible, until an Air gap is established.