Crews responded to a hazmat situation in Sand City after a foul odor was reported coming from a sewer at Contra Costa St. and Ortiz Street, said the Sand City police department.
According to the police department, whatever was causing the smell was a low grade explosive.
Crews asked people around the sewer line not to flush their toilets so that sanitation workers could find the cause of the problem faster.
The smell was reported just after noon on Tuesday but crews cleared the scene and opened the streets up just before 3 p.m.
According to the fire department, they were unable to find the source of the smell but did say it was coming from the sewer line.