Minium vertical distances between water, storm, sanitary

[civilbjp]

I need some help with utility design. I am a designer in Wisconsin and below are the guidelines I follow, but they are simply what I have been taught. I have not been able to find a definitive code that defines these distances. My local code only lists minimum horizontal distances. I

Water over sanitary = 6" between invert and crown
Water under sanitary = 18"
Water over/under storm = 6"
Sanitary over/under storm = 6"
Minium 6" cover over water

Any help would be appreciated.

 

[civilbjp]

By the way, I meant to put 6' of cover over water, not 6"

 

[cr1973]

Check the Standard State Specs

 

[Maury]

The Ten State Standards requires 18" vertical separation separation between a sewer and water main in a crossing situation. Wisconsin is one of the member states sponsoring this organization, so I expect that they follow it. Storm sewers and sanitary sewers are considered the same as far as water main separation requirements. I don't know of any minimum separation requirements for storm and sanitary sewers.

Get a copy of Wisconsin's Standard Specifications for Water and Sewer Main Construction. How have you been getting permits without knowing these requirements?

 

[dicksewerrat]

The separation has to be large enough to work on either or both pipes. Should always make the separation as much as practical both directions. I've had to repair sanitary sewers that had 5 feet of horizontal clearance with a 'parallel'storm drain.. Not a problem, until the storm drain edge was 6 inches into the edge of the sanitary line. It was hard to dig down 15 feet with that at the 10 ft. mark.