Investigators determined that an employee’s unintentional mistake accidentally over-chlorinated a Pacific Marine Mammal Center pool in April that injured 17 sea lions and have dropped their criminal investigation, police said Thursday.
Police initially suspected someone with knowledge of the center’s filtration system intentionally harmed the animals and questioned former employees. The inquiry changed course once investigators analyzed the center’s water system and found a spike in chlorine levels on April 27, said Sgt. Tim Kleiser, the day before sea lions were discovered with ulcerated eyes due to chlorine poisoning. They have all since recovered.
Police now believe that a center worker, who had drained the pool in question for cleaning, mistakenly left open a valve involved with monitoring chlorination levels. “The pump is reading that there is no chlorine,” Kleiser said, and continued to add the chemical, used in low concentrations to kill bacteria.
