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About Fireplugs

In colonial America, firefighting mostly consisted of bucket brigades. In a bucket brigade, volunteers would form a line and use leather buckets to pass water from rivers or wells to the fire. It was an inefficient process that was soon improved.


By the early 1800s, water was carried underground via wooden mains. While wooden mains did improve response times, they were not as efficient as you might image. During a fire, volunteer firefighters had to dig up the main and chop a hole in it to give their pumpers access to the water. Once the fire was out, the main was repaired and sealed with a fireplug. The location of the fireplug was marked, so they could access it in the event of future fires in the neighborhood.

Today, the term fireplug refers to a cast iron structure above ground that allows firefighters to access the water main quickly, no digging required. Modern fireplugs are connected to an underground water main and have a control valve on top to turn the water on.

Creation of the First Fire Hydrant


Frederick Graff, the chief engineer of Philadelphia Water Works, is credited with inventing the first fire hydrant in 1801. Graff’s hydrant was a short pipe riser with a combination hose, faucet outlet, and a control valve on top. Because of Graff's ingenuity, Philadelphia became the first city in the country to use a fire hydrant system.


In 1890, Carl August Storz patented his quick coupling system in Switzerland. His system used interlocking hooks and flanges and it quickly became the accepted norm.

The Significance of Fire Hydrant Colors

Fireplugs were initially painted red because fire trucks were painted red, and people identified that color with the fire department. Today, many agree that yellow is a more distinctive, highly visible color, especially at night.


The National Fire Protection Association (NFPA) recommends that the bodies of all public fire hydrants be chrome yellow unless another color has been adopted locally. To help firefighters identify sufficient water sources, they recommend that the tops and nozzle caps be color coded to indicate the capacity or rate of water flow.

Fireplug top and nozzle cap color chart:

  • Red: under 500 gallons per minute

  • Orange: 500-999 GPM

  • Green: 1,000-1,499 GPM

  • Blue: 1,500 GPM or more

However, color coding has not been adopted as a federal mandated, and not all communities follow the NFPA's guidelines. In fact, many towns paint over the fireplugs for 'beautification' purposes, but in so doing eliminate crucial information for firefighters.


For example, if a fireplug is painted black, this signifies that it is broken and has been taken offline. A white ring indicates that the fire hydrant needs an upgrade or repair. White hydrants often indicate that they are public system hydrants located on public property (e.g., parkways). Private fire hydrants are often yellow. These, located on private property, are owned and maintained by the property owner. A violet body indicates that the fire hydrant provides non-potable water, such as from a lake or pond.

Fireplug Shapes and Materials


Today there are hundreds of different shapes and sizes of fireplugs. Each municipality typically selects its own fireplug design, which is usually universal throughout the town. If you pay attention, you can tell when you've entered a different town by the style their fireplugs.


Fireplugs are made of cast iron and have bronze fittings. They can weigh between 300 and 600 pounds. On average the cost of a fireplug is around $6,000, which includes material, installation, and fees. Well-maintained hydrants have a lifespan of 50 years. Old fireplugs have a scrap value of about $.03 per pound ($5–$35). There are close to 10 million fireplugs in the United States.

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