The American Public Utilities Association (AWPA) has established a uniform color code standard for marking underground utilities. It is used for the tiny flags you see along the side of the road to mark location of utilities below, along with the spray paint markings on the ground where future work is planned. Red indicates electrical, orange is telecommunications, yellow means natural gas, green denotes sewer lines, and so forth.

     It is also used for meter boxes. Purple means reclaimed water and the tops of boxes for recycled water are often painted purple to distinguish them from the meters for drinking water. Blue is the color used for drinking water, and you may also see meter boxes painted blue. But, in our area, usually only the reclaimed water boxes are painted to differentiate them. By the time you see one, the color will likely have faded in the sun to something more like lavender.

    The in-ground boxes for sprinkler system solenoid controls may also be purple if they are using reclaimed water.  Some boxes will even have an embossed marking like the one shown below. 

To understand the standards for reclaimed water, see our blog post What is the difference between regular tap water and recycled/reclaimed water for landscape irrigation?

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Here’s links to a collection of our other blog posts about PLUMBING PIPES:

• How can I protect my pipes to keep them from bursting during a hard winter freeze in North Florida?

• Can galvanized steel pipe still be used for new water lines in a house? 

• How can I tell if I have cast iron pipes in my house? 

• Why can't a sanitary tee be used for a horizontal-to-horizontal drain pipe connection? 

• What causes a gurgling sound when a bathtub or sink drains? 

• What is a "combination waste and vent" in a plumbing system? 

• What is a building trap?  

• What is a galvanized nipple?

• What are the pipes sticking out near my water valves?

• How do you accurately find a broken water pipe leak under the floor slab?

• What is the difference between water pipe and sewage (waste) pipe? 

• Are plastic pipes (PVC, CPVC, and PEX) safe for drinking water? 

• Is a hot water faucet handle required to be on the left? 

• What is a dielectric union? 

• What's that powdery crust on the pipe connections at the water heater? 

• If all the plumbing drains have water in them and you can still smell sewer gas, what's causing the problem?  

• How can I tell what type of plumbing pipe I have?

• Why is there a flexible accordion pipe under the sink? 

• What is the difference between PVC and ABS plumbing pipe?

• What is the difference between water service pipe and water supply pipe? 

• What are the pipes on my roof? 

• How can I find out what type of water pipe runs underground from the water meter to the house (service pipe)?

• What is a P-trap?

• Why is old galvanized steel water pipe a problem for homebuyers?

• What does polybutylene pipe look like? Why is it a problem? 

• Which water pipes are an insurance problem and possibly uninsurable?

• Can you connect CPVC pipe directly to a gas water heater?  

     Visit our PLUMBING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.