Trenching Electrical Conduits

[TheElectrician]

Hey guys,

I am aware of the NEC 300.5 that details the depth of the conduits from the grade level, but is there a code that talks about the distance between electrical conduits and other underground services like gas, sewer, water and septic lines that has to be kept in mind while installing underground electrical conduits? (Something related to New York State will be helpful)

Thanks

 

[hbiss]

Nothing in the NEC. Only concern might be gas lines and that would be determined by the gas utility or supplier. Local jurisdictions may have requirements for water and sewer but I don't know of any. I would think that for lines on private property use your own discretion and consider that what you are next to may require replacement or service some day. You don't want them disturbing your installation.

-Hal

 

[TheElectrician]

Nothing in the NEC. Only concern might be gas lines and that would be determined by the gas utility or supplier. Local jurisdictions may have requirements for water and sewer but I don't know of any.

-Hal

Got it, Thanks. I think I will call the AHJ to get these info then

 

[tom baker]

On Right of Way, there will be requirements, often the water is above the sewer and other side of street. I would suggest adequate separation to allow repair, you don't want them tight. Use a 2 ft bucket and spread lines out.

 

[mlnk]

Utilities have their own rules, On private property I keep water lines 10 ft away from sewer lines, if they have to cross 12" apart. I keep gas lines 12" away from electrical conduits, measured outside to outside of conduits or pipe. I keep parallel communications conduit 6" away from power conduit to avoid electronic noise. Electric conduits can be run close to water pipes but i keep them separate so they are easier to dig up.

 

[kwired]

On Right of Way, there will be requirements, often the water is above the sewer and other side of street. I would suggest adequate separation to allow repair, you don't want them tight. Use a 2 ft bucket and spread lines out.

I think water and sewer generally need a horizontal separation, this to lessen contamination of water supply should they be damaged when excavation is going on.

Sewer needs to go wherever gravity allows, other than at lift stations, it is generally a gravity system. Around here I'm sure you can find sewer lines that are very deep when necessary, but also pretty shallow if needed. Water around here is always ~ 6 feet deep. If not it may be subject to freezing some years.

Was working on a project in a small town a few years ago where POCO hired directional boring contractor to bore across a street. They said they knew they hit something at a point where water line was supposed to be, to make sure things were ok, they broke out a section of concrete and excavated and found the line. Probably only 3 feet below street surface, been there for at least 40 years or better and never had frozen. But at same time the city water tower and a pump house were only a couple hundred feet away and this was like 4 or even 6 inch line - probably always had water moving and because of that never froze.

ETA: they never damaged it, just grazed it when boring past it.

 

[Hv&Lv]

NESC rules have the separations spelled out.

353 and 354 I believe..