Water Distribution Operator Practice Questions - ABC WPI Water Distribution Operator Certification Exam (Grades 1-4) Exam

Flush the main with high-velocity water until the discharge is visually clear, then sample once for coliform Disinfect per AWWA C651 (chlorinate to a minimum 25 mg/L contact concentration), flush to waste, and pass two consecutive negative coliform samples collected 24 hours apart Pressure-test only; disinfection is required only for mains larger than 12 inches Chlorinate the main to 50 mg/L for 1 hour, flush, and take one coliform sample