AWWA C651 STANDARD PDF
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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If there is evident or suspected chemical Contamination of a watermain, in addition to the procedures in sections 3. Spiral watermain break with evident Contamination.
AWWA C / AWWA C / AWWA C – Disinfection Of Water Package
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. The affected watermain s may not be put back in service before the corrective actions and sampling plan are completed unless a Water Cc651 is declared.
Watermain breaks with no evident or suspected Contamination are classified as Category 1. Operating authorities shall use Certified Operators for functions that must be performed by a Certified Operator. Examples of watermain c561 that are typical of Category 1 are included below for illustrative purposes only:. After business hours, the operating authority shall contact the Spills Action Centre as soon as reasonably possible. The sequence of actions may be varied as appropriate for the specific situation.
The information shall be retained as per the record keeping requirements of Section 27 of O.
Watermain disinfection procedure
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. Longitudinal watermain break with evident Contamination. Flushed water may be discharged from a hydrant, plumbing or Appurtenances.
The disinfection requirements for new watermains as per Section 1. Where there is no discharge point to allow for Flushing, the operating authority shall tap the watermain on the downstream side of the break and discharge from that point.
Refer to Appendices A and B for a flowchart and pictures to better understand the criteria to determine the categories of watermain breaks. 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.
The reporting and corrective actions of Schedule 16 and the applicable Schedule 17 or 18 of O.
The requirements in this section also apply to temporary watermains. For relining of existing watermains, the conditions of section 1. This procedure uses a risk management approach to categorize watermain breaks based on the potential for Contamination. Service pipes of mm diameter and greater shall be considered as watermains for the purposes of this procedure.
The operating authority shall record the duration of disinfection, as well as the initial dose and remaining residual at the end stancard the contact time.
Discharges of flushed water are also regulated under Condition 4. Flushing shall be conducted following repairs by creating a temporary dead end downstream of the break through valve operation, and Flushing through the location of the repair to a discharge point. For new watermains with limited sampling points available, an alternative method of collecting Microbiological samples is called staged sampling.
Watermain disinfection procedure |
The OIC will assess the evidence of Aawwa or potential Contamination of the watermain sttandard and during the repair procedure, and shall classify the break into one of two categories 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.
The flow shall be directed to ensure that the sample represents water stzndard has passed through the location of the repair. When using the slug method of chlorination, with a minimum contact time of 3 hours, the chlorine concentration shall be measured in xtandard slug at the beginning of the disinfection process, as the slug moves through the watermain, and at the point of discharge.
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.
If chlorine disinfection was used, indicate initial concentration, contact time, final concentration and final concentration as percentage of initial concentration. Circumferential watermain break with flow maintained until after an Air gap was created. The following steps must be performed for all emergency watermain repairs Category 1 and Category 2. This procedure also establishes minimum standards for record keeping, and notification to the Ministry and the local Medical Officer of Health.
This section does not require that all of standxrd information be recorded on a single form: This definition does not include recharging the watermain or a requirement to achieve scouring velocity within the watermain.
In addition to the procedures in 3.
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. For all other types of cleaning e. The discharged water is deemed to be a Class II spill for the purposes of O.
Operating authorities may choose to provide notification to, or seek advice from, the local Medical Officer of Health at any time. 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 ztandard cause an adverse effect, as per Condition 10 of Schedule B of the Municipal Drinking Water Licence.
Disinfectant residual on final post repair Flushing. Skip to main content.
Chain of custody Date and time of return to normal service Water Advisory declared: Tags Stnadard and energyDrinking water. The following flowchart depicts the requirements for special case Contamination sewage or chemical as a result of a watermain break.
Examples of watermain breaks that are typical of Category 2 are included below for illustrative purposes only: Staged sampling shall be performed as follows: Notification to the local Ministry office is not required for Category 2 watermain breaks unless:. Excavation dewatering shall be continued for the duration of the repairs tsandard that the Air gap between the location of the break in the watermain and the water in the excavation is maintained.
Notification to the local Ministry office is not required for Category 2 watermain breaks unless: The sampling will typically occur at the point of Flushing, and may take place from sampling ports, hydrants, blow-offs, or premise plumbing. Flushing shall continue until the discharged water is free from discoloration, and secondary disinfection has been restored as per 3.