Steven Harold Smith, 50, of Aromas shot two fellow employees about 7 a.m. at the Lode Street Wastewater Facility in the Live Oak section of Santa Cruz, according to Sheriff's Sgt. Fred Plageman.
Mike Sotelo, 41, of Santa Cruz died at the scene. He was the supervisor for office administration, Plageman said.
The suspect's wife, Tamara Smith, 45, of Santa Cruz tried to escape in her car, but was shot multiple times, police said. She was hospitalized in grave condition, Plageman said.
Police said co-workers described the shooting as the result of a love triangle, but additional details were unavailable.
Two handguns were recovered at the scene, but Plageman would not comment on who owned them.
Steven Smith went inside the administrative part of the facility and shot Sotelo in his office, Plageman said.
Smith then went outside and shot his wife while she was inside her car. She tried to drive away, but hit a flagpole, a curb and a fence before running into a large eucalyptus tree, Plageman said.
Steven Smith was the pump station maintenance supervisor, and his wife was a maintenance worker. The two were separated and in the process of getting divorced, Plageman said.
More than 30 law enforcement officers searched the scene, but found no additional suspects. Several witnesses also were being interviewed by investigators.
About 40 people work at the facility.