Final answer:
Non-potable water is approved for irrigation purposes. It is used where water does not need to be of drinking quality, unlike potable water which is safe for drinking and cooking.
Step-by-step explanation:
Non-potable water is water that is not safe to drink because it contains pollutants, chemicals, or microorganisms that could be harmful if ingested. The purpose for which non-potable water is approved from the given options is irrigation. Non-potable water is generally used for activities where water does not need to be of drinking quality, such as washing cars, flushing toilets, cooling water for power plants, concrete mixing, creating artificial lakes, irrigating golf courses and public parks, and hydraulic fracturing. In contrast, potable water is treated and purified to be safe enough for drinking and cooking because it does not contain harmful levels of pollutants or microorganisms.