Correct Answer - Option 1 : Distillation system
Explanation:
Distillation: Distillation, a process involving the conversion of a liquid into a vapor that is subsequently condensed back to liquid form.
Gravity System: Suitable when the source of supply is at sufficient height. Most reliable and economical distribution system. The water head available at the consumer is just the minimum required. The remaining head is consumed in the frictional and other losses.
Pumping system: Treated water is directly pumped into the distribution main without storing. Also called pumping without a storage system. High lifts pumps are required. If the power supply fails, complete stoppage of water supply. This method is not generally used.
Combined gravity and pumping system: Combined gravity and pumping systemMost common system. Treated water is pumped and stored in an elevated distribution reservoir. Then supplies to consumers by the action of gravity. The excess water during low demand periods gets stored in a reservoir and gets supplied during the high demand period. Economical, efficient, and reliable system.