Coincidently, I spoke today with a representative from the Ohio Utility Protection Service (OUPS). One interesting factoid was that during the busy digging season, they handle 4000 locating calls a day!

Here is a link to the excavator manual for the Ohio Utility Protection Service, the "one call" organization in Ohio. The last page has the current color scheme used in Ohio.
http://www.oups.org/docs/Excavator%20Manual.pdf

Although by Ohio law, technically not all of the colors in the above manual are required (go figure). [Linked Image]
The required colors are:
Red... Electric
Orange... Communications
Blue..... Water
Green.... Sewer
Yellow.... Gas/Oil
White.... Proposed Excavation

Here is a link to the Ohio law on identifying underground utilities: http://www.oups.org/thelaw.asp

There is also another interesting site on this subject that is a nationwide effort in the US to standardize all underground utility work. The organization promoting this is called the Common Ground Alliance. Here is a link to their website: http://www.commongroundalliance.com/

[This message has been edited by safetygem (edited 03-04-2005).]