If you need to disinfect a newly installed potable water line, what is a common and approved method?

Question: If you need to disinfect a newly installed potable water line, what is a common and approved method?

Answer options:

• Flush the line with hot water at 80°C for 30 minutes.
• Introduce a steam flow at 15 psi for one hour. ✅ Fill the line with a solution of 50 mg/L chlorine and let it stand for 24 hours.
• Scour the line with a mixture of sand and water.

Correct answer: Fill the line with a solution of 50 mg/L chlorine and let it stand for 24 hours.

Explanation: A standard method for disinfecting potable water lines, per AWWA standards and referenced by code, is to introduce a chlorine solution (typically 50 mg/L or ppm) and allow a contact time of 24 hours to kill any bacteria.