Question: waipahu is on what island?
Answer: Waipahu is a former sugarcane plantation town and now census-designated place (CDP) located in the ʻEwa District on the island of Oʻahu in the City & County of Honolulu, Hawaiʻi, United States. As of the 2010 Census, the CDP population was 38,216. The U.S. postal code for Waipahu is 96797.