1. Distillation is one method of obtaining pure water, but this method is not currently used anywhere in the United States for municipal drinking water supplies. Which of the following statements best helps explain why distillation is not used for municipal water purification?
Answer: D
Distillation requires large amounts of energy and is expensive to perform on a large scale.
Distillation is not utilized for municipal drinking water supplies primarily because it requires significant energy and is costly when implemented on a large scale.
A) The purified water would become contaminated between the purification plant and the tap at home.
While contamination can occur during water transportation, this does not specifically address the fundamental limitations of distillation itself. The primary issue with distillation is not about contamination after purification but rather the feasibility of the distillation process for large populations.
B) Water that has been distilled is not safe for human consumption.
This statement is incorrect. Distilled water is safe for human consumption; the process effectively removes impurities. The challenge with distillation lies not in safety but in the practicality of applying the method on a municipal scale.
C) The technology involved in distillation is too complex for individual municipalities to perform.
This option misrepresents the nature of distillation technology. While it can be technical, it is not inherently too complex for municipalities to implement. The real barrier is the operational costs and energy demands associated with large-scale distillation.
D) Distillation requires large amounts of energy and is expensive to perform on a large scale.
This statement accurately reflects the main reasons why distillation is not favored for municipal water purification. The process is energy-intensive and incurs high operational costs, making it impractical for widespread use in municipal systems.
Conclusion
The correct answer, D, highlights the significant energy and cost implications of distillation, which are the primary reasons for its absence in municipal water purification practices. Other options fail to address the core issues of practicality and economic feasibility that determine the choice of water purification methods in the U.S.