Domestic Service Water (DS)

Question 1

What is the purpose of DS?

Answer 1

Supply potable water to:

• People
• Eye Wash Stations
• Evaporative Coolers
• Service Connections

Question 2

What systems does DS support?

Answer 2

• Essential SP makeup
• FP tank makeup
• Evaporative cooling for HVAC systems
• Blowdown stack quench water for ED
• Backup cooling water for Air
  Compressors

Question 3

How is DS supplied to the units?

Answer 3

Supplied through two PCVs (500/502)

Control building supply has a back flow preventer in the basement

Question 4

What is the purpose of the backflow preventer assembly and what does it consist of?

Answer 4

Designed to prevent any backflow per the Uniform Plumbing Code

Each BPA contains two spring-closed check valves, with a third spring-loaded check valve, which opens to the atmosphere upon a loss of line pressure

Any backflow is vented to atmosphere

Question 5

Where are the pressure control valves and BPAs located?

Answer 5

North side of 74’ Control Building