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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Operating Authorities may choose to provide notification to, or seek advice from, the local Medical Officer of Health at any time. In addition to the requirements described in section 3. Chain of custody Date and time of return to normal service Water Advisory declared: 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.
The operating authority shall determine if flow can be maintained to the break site until the watermain is excavated.
AWWA C / AWWA C / AWWA C – Disinfection Of Water Package
Watermain repairs involving more c6651 6 metres of replaced pipe are also classified as Category 2. Operating authorities shall use Certified Operators for functions standarf must be performed by a Certified Operator.
The following flowchart is an example of the typical steps required for Category 2 watermain breaks. 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.
Spiral watermain break with evident Contamination. 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. Examples of typical steps for Category 1, 2 and for special cases are attached as Appendices C, D and E respectively.
This procedure also establishes minimum standards for record keeping, and notification to the Ministry and the local Medical Officer of Health.
This definition does not include recharging the watermain or a requirement to achieve scouring velocity within the watermain. In developing these procedures, operating authorities may use best management practices that go beyond the minimum requirements in this document.
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. Operating authorities shall develop and document operating procedures for emergency watermain repairs within their systems.
Notification to the local Ministry office is not required for Category 2 watermain breaks unless:.
Follow the steps described in section 3. Notwithstanding the conditions of section 1. Mechanical removal of Contaminants; Flushing into the excavation; Higher velocity flushing after repairs where practical and feasible. Watermain breaks with no evident stndard suspected Contamination are classified as Category 1. For Category 2 — Special Cases, include site specific plan. Tags Environment and energyDrinking water.
Watermain disinfection procedure |
Flow may be discontinued after an Air gap has been created. For planned swabbing and hydraulic e. Examples of watermain breaks that are typical of Category 2 are included below for illustrative purposes 6c51.
If there is evident or suspected sewage Contamination of a watermain, in addition to the procedures in sections 3.
The sequence of actions may be varied as appropriate for the specific situation. Drinking water system operating authorities shall ensure that emergency repairs to watermains and Appurtenances are undertaken in accordance with this procedure by any person authorized to perform the repairs. Return to normal service is contingent upon the corrective actions and sampling plan being completed to the satisfaction of standardd local Ministry office in consultation with local Medical Officer of Health.
Staged sampling shall be x651 as follows:. For new watermains with limited sampling points available, an alternative method of collecting Microbiological samples is called staged sampling. Flushed water may be discharged from a hydrant, plumbing or Appurtenances.
Examples of watermain breaks that are typical of Category 2 are included below for illustrative purposes awda 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.