Panama Canal
Colombia, France, and later the United States controlled the territory surrounding the canal during construction. The US continued to control the canal and surrounding Panama Canal Zone until the 1977 Torrijos–Carter Treaties provided for handover to Panama. After a period of joint American–Panamanian control, in 1999, the canal was taken over by the Panamanian government. It is now managed and operated by the government-owned Panama Canal Authority.
Hay–Bunau-Varilla Treaty
The Republic of Panama grants the United States with any lands, buildings, water rights, or other properties necessary for construction or operation and protection of the Canal. This may include any works of sanitation such as the collection and disposition of sewage in said cities of Panama