The remains of a woman found at two sewage treatment plants 30 miles apart in California were identified as Erin Lynn Cruz, police said. Los Angeles County Sheriff's Department spokeswoman Nicole Nishida said the cause of the East San Gabriel Valley woman's death has not been determined. Cruz was last seen Oct. 23 in the La Puente area, sheriff's homicide detectives said. Parts of her body, including her pelvis and legs, were discovered Oct. 26 at the at the Joint Water Pollution Control Plant in Carson, Calif. Her upper torso was discovered at the San Jose Creek Water Reclamation Plant near Wittier, Calif., the Los Angeles Times reported Tuesday. "Anything that comes into the Los Angeles water plant must move through a 17-inch line before going through a central pump, Rosson said. "So you imagine what kind of damage to a person's body would [cause]." Detectives are treating the woman's death as a homicide, sheriff's Lt. Mike Rosson said. Authorities said they believe the body entered the sanitation system somewhere in the San Gabriel Valley. A spokesman for the Sanitation Districts of Los Angeles County said the two plants are interconnected.