While laying or designing the water distribution system, attempts should be made to keep the
- Asewer lines and waterlines as far away as possibleCorrect
- Bsewer lines above the waterlines
- Csewer lines exactly below the waterlines
- Dsewer lines and waterlines close to each other
Solution
Concept
Separation of water mains and sewers
Step-by-step solution
1. Leakage from sewers can contaminate water mains. 2. So sewers and water lines should be kept as far apart as possible, with the sewer laid below the water line where they must cross.
Explanation
Wide separation reduces the risk of contamination of the drinking water supply from sewage leakage.
Why the other options are wrong
Sewer lines above the waterlines or close to them increase the chance of contamination.
Shortcut
Keep sewers away from water mains.
Common mistake
Thinking that laying lines together saves cost.
Correct answer: A) sewer lines and waterlines as far away as possible