Firefighters Manually Draining Fire Hydrant
The firefighters explained that the Chicago Fire Department drains fire hydrants twice a year to prevent freezing in the winter. Apparently, street cleaners and unauthorized users of fire hydrants typically don't properly drain hydrants after using them. As a result, water stands in the feeder pipe to the fire hydrant and can freeze in cold weather, restricting (if not stopping) flow to the hydrant. The firefighters were manually pumping water from the feeder pipe because the water didn't properly drain when they tested it.