The department responded just before 3 p.m. local time, after the Los Angeles Police Department requested a hazardous materials response. The fire department reported that no patients required evaluation. The department began leaving the scene about 4:38 p.m. local time, according to a statement.
One individual came in contact with the package, but the person had no medical complaints, according to Stewart.
Waters has been a vocal critic of the Trump administration, and she received widespread criticism for comments where she called for the public harassment of Trump administration officials.
In June, the Democratic congresswoman canceled two events after receiving threatening messages and “hostile mail” at her office.
“As the President has continued to lie and falsely claim that I encouraged people to assault his supporters, while also offering a veiled threat that I should ‘be careful,’ even more individuals are leaving (threatening) messages and sending hostile mail to my office,” she said in a June statement.
“There was one very serious death threat made against me on Monday from an individual in Texas which is why my planned speaking engagements in Texas and Alabama were cancelled this weekend,” the statement continued. “This is just one in several very serious threats the United States Capitol Police are investigating in which individuals threatened to shoot, lynch, or cause me serious bodily harm.”
Waters’ representatives in Washington did not immediately respond to a request for comment on the incident.
This story has been updated.
CNN’s Ashley Killough contributed to this report.