A collection of crushed plastic bottles lay in a pile. Each discarded SEI-brand container resembles a 19th century soldier’s canteen. Back then, each canteen held water — a refreshing and prized commodity for any soldier engrossed in grueling combat. At first glance today, each bottle is merely a piece of empty, mangled plastic. In the eyes of Juana Valdes, however, each bottle is an essential component of a work of art.