Washout hydrants are likely to be small, covered chambers on the footpath which connect to the mains water supply. Under the cover, the hydrant connection is usually fitted with a blue security cap.
Fire hydrants are commonly accompanied by a yellow ‘H’ sign. They should only be used by the fire service and not for water extraction. Under the cover, the hydrant connection is usually fitted with a red security cap which should only be removed by the fire service.