Trenching for Utilities...

ultrarunner · Jan 20, 2016

I'm in the county in Washington State.

As some here know I have been unsuccessful in getting Comcast to run 500' from the pole to the rent home I have...

Also, the direct bury electric cable installed by the utility has been repaired twice at no charge by the utility and I have been told it is at the end of its useful life and they no longer direct bury and require the owner to provide conduit.

Third... I've been thinking it might be nice to have a camera/intercom and a hose bib at the start of the driveway.

Comcast is supposed to be sending the requirements and a sketch... from what I can tell they really only care that I install 2" conduit.

Thinking about doing my own trenching and would like to kill all birds with one trench/excavation...

The previous owner told me they had trouble with a trench that went straight to the house channeling water and suggested I not go down the driveway and instead go down the property line and make a 90 sweep to the house with a concrete vault because water doesn't flow uphill...

I realize utilities often don't play nice when it comes to sharing... on the other hand adding a couple of empty conduits seems like a win/win for me even.

Qapla · Jan 20, 2016

What is it you want Comcast to run ... just cable TV or Internet?

If it is Internet and/or On Demand TV they are probably needing a "Hard Line" to go that far (unless they run fiber all the way to your house) - a Hard Line is a much larger cable (insert more expensive) and does not always insure working Internet so they shy away from those long runs.

If all the Utilities are asking for Conduit, you should be able to dig one ditch, run all the conduits with some space between them, fill the trench back in and then call them.

amaxwell · Jan 20, 2016

I can see them not playing nice if THEY were doing the trench, but if it is YOUR trench and if you are providing them what they require as far as conduit ,it should not be up to them what else you put in there ,unless codes prevent it.

MossRoad · Jan 20, 2016

2" conduit for Comcast? Yikes!

ultrarunner · Jan 20, 2016

Moss...

Just had a big install of Comcast here for the Hospital... had to bore under the State Highway etc... they use 1.5" orange corrugated flex pipe in California

In WA it has to be 2" rigid conduit... with at least one concrete vault midway...

My thought is if I do it myself... I will add extra conduit runs for future... might even run PEX through one for a hose bib out by the gate.

Never taken on a trench project this big alone...

Maybe GRStheGreat will see this thread and add to it?

My house panel is 400 amp with a small pedestal transformer out in the yard... don't know for sure what the feed voltage is... heard 600v but don't know.

MossRoad · Jan 20, 2016

Aren't there some code about water lines, communications lines and electric lines in same trenches, distances apart, etc...? Are you going to have to dig multiple trenches? Are you going to use a trencher or a backhoe? How deep do you have to go? Are you allowed to dig your own? Man, I'm a pest. :laughing: I ask because I went through similar questions back around 1989 with our rural property. We never did it due to cost. Now, I wish I would have done it back then due to the price increases in everything today. Close to 5X as much now.

ultrarunner · Jan 21, 2016

Comcast started this and other than the 2" conduit requirement it seems on end user private property to cover it.

The closed circuit TV, PEX well water hose bib and intercom I would think I'm pretty much on my own.

Comcast even said if a suitable conduit just happened to be there we would be good to go.

No idea on electricity other than the conduit is suppose to be on me...

The last thing I would want is a trench running down my drive... I have many places with drainage tile and and geo fabric... digging that all up I would imagine would cause problems.

Tractor Seabee · Jan 21, 2016

Ultra, if you have a transformer feeding your 400A house panel at that location, who owns the transformer? Normally the utility owns up to the secondary side of the transformer. Seems they would not want to have you run the conduit if it is their side of the system. Normally only industrial customers own or install any of the primary side as they are metered on the primary feeders.

Idea, why not get the Power Co and Com Cast together and develop an grade plan. Power may let you dig the ditch and lay pipe for ComCast and they lay there pipe in foryou to cover; or some variation. Primary power work is expensive that is why hook up fees are so high. At least talk to their install engineers for guidance. As far as I can remember the governing codes there is no separation required between conduits of the two systems other than common sense.

When I was a facility/utility planner for the Navy we never installed less than 2" for UG comm and 4" for primary power and secondary feeders. Those long pulls are murder and some times impossible in smaller pipe and/or the stretch limit is exceeded. The vault requirement is a code thing, Power Company will do the same and the vaults have to be separate.

Ron

grsthegreat · Jan 21, 2016

I havnt done much work in wash state for many years, but the utility company has always been responsible for all work between transformer and their meter. Customer is responsible for enverything after the meter. That being said, the utilities sometimes do require the homeowner or contractor to provide a trench. Ive run into this a few times in the past.

As far as utilities laying in common trench, we do that all the time. here in Idaho, we dig a 24" wide trench 4-5' deep and put water at bottom of that, then cover with 1-2' of fill. Then we place all other utilities except for electric on one side and place electrical on other side and cover trench. This leaves 18"+ separation between all utilities. We place water so deep due to our frost zone issues here. Wash will be different. Ive also seen people trench 3' wide common trench with water on one side, power on other and all other utilities in middle. NEC does not have any rules governing this, it will be a city/state issue.

dstig1 · Jan 21, 2016

Power is generally required to be buried deeper and with more separation from other stuff. Gas may be the other stickler, if you have that. Low voltage stuff, nobody seems to care about much from a code standpoint. And to echo Seabee, the transformer should be the utility's, and not yours, but after the transformer is yours. I would expect thousands of volts to that transformer, not 600V. I think my current one is 4800V or 9600V I forget, and our old house was 19.2kV

A mid sized backhoe can dig the needed trench to the depths required for multiple feeds much more easily than other methods. Easier to work in an open trench than to pull individual feeds a billion times. Dig to the bottom, put the lowest stuff in, backfill a bit and level it out some, then put then next layer in, etc...