Trench or mole for waterline

I have been told conflicting stories by a couple of different plumbers who have given estimates. So I would appreciate some independent expert help.

I need to replace my waterline from the meter. I am told I need a 1 inch meter and a 2 inch waterline since I have quite a few fixtures and need a sprinkler system. My house is about 300 feet from the meter and the hose drops about 30 feet in elevation from the meter. The line needs to travel down the driveway which is about 250 feet long.

One said I should trench down the side of the driveway since I need to run a poly line since he couldn't run copper in 2" size. And since it is poly I should trench down the side of the driveway so it can be bedded in sand to protect it. He said he couldn't mole because he couldn't bed the pipe in sand and that he would only use copper if he had to mole under a driveway.

Another said I could mole down the middle of the driveway and that I didn't need to bed the poly pipe in sand since they were digging 3 feet below the driveway and going down the middle of the driveway.

Do I need to bed a poly line in sand?
Is poly the only cost effective choice for 2"?

I would really like this line to last since it is going to be pretty costly to put in.


Thanks for any comments/recommendations!

https://terrylove.com/forums/index....ice-sewer-line-repair-outdoor-plumbing.73835/

pipe

I am confused by your term "mole". Normally that means drilling a hole and pulling the pipe through it. Obviously that could not be done for a 300' line. If the ground is rocky so that the pipe could be damaged, you would want it protected from contact with sharp surfaces. And if the line should develop a leak, I doubt that you would want to start digging up the driveway to find and fix it. My preference based on your description would be to install it next to the driveway.

The plan was to mole every 50 feet or so they would have to dig up a 3 foot square of asphalt every 50 feet for the mole.

One piece I also forgot to mention was that there are other utilities like gas and electrical which also run down the side of the driveway where they would have to trench. This is where the current waterline also existed. Possibly that also a problem with trying to put the new waterline there?

If they do mole should it be copper instead of poly because they can't backfill with sand? (I don't know how rocky it is 2-3 feet underground) Or because it is a 2" line it can't be copper so it needs to be trenched?

thx!

Clayton

From the information you have posted I would trench the line in down the side of the driveway. There should be a noticable price difference in the job between using the poly or the copper. I would prefer to use Polyethylene pipe and make sure it is rated to at least 200 PSI. Install a #12 insullated wire with the pipe for future line locating. If you bed the water line in sand would be determined by if you have rock or debris in your excavated soil.

Have all those utilities, cable, phone, gas, water, electric service lines located before any digging is done. Don't forget to locate underground electric to out buildings or yard lights if you have them.

dvkjy said:

The plan was to mole every 50 feet or so they would have to dig up a 3 foot square of asphalt every 50 feet for the mole.

One piece I also forgot to mention was that there are other utilities like gas and electrical which also run down the side of the driveway where they would have to trench. This is where the current waterline also existed. Possibly that also a problem with trying to put the new waterline there?

If they do mole should it be copper instead of poly because they can't backfill with sand? (I don't know how rocky it is 2-3 feet underground) Or because it is a 2" line it can't be copper so it needs to be trenched?

thx!

Click to expand...

The "mole" must be pneumatic because any mechanical drill would need more than a 3' square opening. And you would not likely to be able to pull 2" copper through an opening 3' down that was only 3' across, without severely distorting it. I would also not be enthused about having joints every 50' under a blacktop driveway.

I had a new PVC waterline run last summer. 1 1/4" line from the well about 175 ft. down a hill, under my garage, etc. Had a directional boring company run the line. Used a "mole" with a RF head on the end so it could be "steered" depth and right/left. They hit a 18" x 18" hole coming up into the basement floor - FIRST SHOT. Even the guys were shocked.

They said their equipment can go 1,000' feet max. Depending on soil condtions, they can make pretty severe angles too.

I was amazed. Only evidence was where the head entered the ground - and where the access to the well was excavated to connect the new line.

Then you didn't have PVC which requires a joint at least every 20', right? IMO the only material you could have is rolled PE tubing and it is the best choice.

As to the OP's middle of the driveway plan with the line being 3' deep. Not a good plan with any material due to vehicles using the driveway which will increase the load on the tubing and yes, even if they stay on/in the lines/tracks. But I don't think they would with a paved driveway; unless it is only paved in the middle. I know you want to run it down the driveway but it's really a bad idea if you want long term service free opeation from the line. It only takes the right situation of a vehilce and soil conditions and the line gets squished.

I suggest 200 psi rated rolled PE tubing in one piece; we have it here in rolls from 100-500' for well installations. It's very tough stuff and you don't need sand underbed; just no sharp edges or stones, and that's in the backfill also.

Gary
Quality Water Associates

Sorry, right... not PVC - rolled water line.

That would be rolled PE; polyethylene tubing.

Gary
Quality Water Associates