Which statement best defines potable water as used in irrigation design standards?

• A. Water free from impurities present in amounts sufficient to cause disease or harmful physiological effects and conforming to the regulations of the public health authority having jurisdiction.
• B. Water that is safe to drink after minor treatment.
• C. Water that comes from any natural source regardless of quality.
• D. Water that has been boiled for at least five minutes.

Answer: (A)

In irrigation design standards, potable water is defined as water that is fit for human consumption and meets the limits set by the public health authority having jurisdiction. This means it must be free from impurities at levels that could cause disease or harmful physiological effects, and it must comply with the specific regulatory requirements for drinking water. The emphasis is on regulatory conformity and health risk thresholds, not merely on whether the water could be made drinkable with minimal treatment. It isn’t simply any natural source regardless of quality, since that could violate safety standards, and it isn’t defined by a treatment step like boiling, which is a disinfection method rather than the definition itself.