The goal is to rent a ditchwitch to trench a waterline below the frost line (2ft here) to a series of frost-free hydrants/spigots both at the barn and adjacent paddocks.
The house and well are located together and are about 200 ft from the barn & paddocks.

Should waterline originate from the house or the well?

In either case, I really want to have a main shutoff in the event that any of the hydrants has a failure, and I'm not sure how that would be possible if the line originates from the well.
Also, how do I get pressure if the line generates from the well? (Well has submersible pump, 1/2 HP I believe? and house has an oversized Well-Xtrol pressure tank.)

If the waterline originates from the house, the trench would have to navigate past (under? over?) the buried electrical from the street to the house. No way around it!

What's the best piping? I like the idea of ease of installation using a flexible line of some sort (since 200 ft is pretty far), but also need something the groundhogs/gophers can't chew through, so plastic/PVC conduit of some sort?

Another concern about ensuring enough water pressure: does terrain matter? The barn is downhill from the house, but there's a valley between. So from the house, the trench would go downhill then back uphill to get to the barn.

You can call your local code enforcement office or any local contractor that does any excavation work, I.E. excavaton contractor, gas company, water company, plumber or electrician, and they will gladly give you the local phone number.

They will be able to mark the location of any buried public utility lines which are on your property such as your electric line, gas lines, municipal water, sewer or steam lines, cable tv lines or commercial gas or oil pipe lines. Generally the public lines are only in the easements adjacent to the roadway but such is not always the case. By example, my sister has a 60 acre farm and there is a 16" diameter commercial fuel pipeline running across her property from end to end.

Once again, this is a free service but if you fail to do it and you happen to damage one of those lines you can and will be held both civilly and criminally responsible for any damage that results from damaging one of those lines so I caution you to take this step very serious.

The line to the barn must originate on the discharge side of the pressure tank which if I understand your description correctly is in the house.

You should install a full bore type valve (ball valve or gate valve) where the line ties into the pressure tank or at any convenient point inside the house before the line goes through your footer wall.

The line must be buried a minimum of 6" below the frost line. Your frost depth is 24" so your minimum line depth is 30".

The line must pass through your footer wall and into the structure at the required depth and you must sleeve the pipe where it passes through the wall. To make a sleeve you first install a short length of pipe at least two nominal pipe sizes larger than the desired pipe through the wall and extending out 2" to 4" on either side. The sleeve is then sealed to the masonary wall by any convient means, mortar, tar pitch, expansion foam etc. After the desired pipe is passed through the sleeve the space between the OD of the desired pipe and the ID of the sleeve pipe is then filled with expansion foam.

Operating a ditch witch is fairly easy but they tend to jump around a lot and even an experienced operator will refrain from operating within 3 or 4 feet of the foundation wall or within 5'either side of any buried utility line. For safety these areas should be carefully hand dug.

Whether you go over or under the electrical line would be dependant upon the depth of the electrical line in reference to the required depth of the water line. This would be a judgement call once you have hand dug that area and located the electrical line or confirmed that it is below the depth you need. Also, in some jurisdictions buried electrical lines are encased in concrete. When encasing an electrial line in concrete they add a red dye to the concrete so if you happen upon any red concrete try to avoid disturbing it.

You could install a Curb box type main shutoff valve at the barn end of your line in the same manner as a residential water service curb side shutoff but these valves are rather expensive and if you have the main shutoff at the house you really won't need it.

Check the installation specs on your hydrants carefully. The actual valve of a hydrant is below grade at the bottom of the valve and when you turn the water off any standing water in the riser then backflows and discharges below grade. Genearlly they require a pea gravel bed at the base of the valve to absorb the water in the same fashion as a french drain.

Typcially we use roll polyethelene pipe for this type of run.

At the pressures permitted on residential water service a 3/4" roll poly line has a friction head loss of one foot of vertical static head per 100 linear feet. (-.434psi per 100ft). Your run is 200' so the friction loss would be approximately 1psi (not enough to be a problem).

The change in pressure from elevation is determined by the total difference in vertical elevation from the source at the house to the demand at the barn. The change is .434psi for every foot elevation change. In this case the barn is lower than the house so the pressure at the barn end is actaully higher than the pressure at the house.

When the line goes down then back up the pressure loss to the rise is offset by the pressure gain on the fall so that portion is self cancelling and the overall pressure remains the same at the load end.

Of course I agree with you 100% about calling the utilities to come mark their lines & will do that.
We had the lines marked a year ago when we first bought the property, as we were installing some board fencing. I took a ton of photos of all line markings as future reference, too. Will call again before we begin the project just to get a refresher.

I think we *may* be able to avoid crossing paths with the electric lines altogether if we run the waterline out the rear of the house, now that I think of it. duh.

Would it be possible to encase the polyethelene pipe in some sort of protective conduit as an extra measure of caution?

thanks again!

You could run the poly or a PEX line through a PVC pipe but for reasons known only to rodents, rabbits, mice, rats, and oppossums all seem to have a propensity to chew on plastic pipe so they would most likely chew through a PVC conduit pipe as well.

The options at this point then become:

1.Galvanized iron pipe. Expected service life about 60 to 75yrs but it requires the trenching to be very straight, it is very expensive and would be very labor intensive to lay it over your terrain conditions.

2. Run copper pipe which would not require a conduit. Estimated service life would be about 40-50 years or more. Fairly expensive but when you consider the cost of both a pipe and a conduit it may prove cost effective. For maximum serice life all underground joints should be wrought copper fittings and brazed joints.

3. Having spent the greater portion of my life on or around the farm in my experience most ground burrowing animals do not dig there dens in a high traffic area. I would assume this line is running basically straight from the house to the barn and you have horses so there should be enough foot traffic in the area of your pipe to dissuade them from burrowing in that area. Considering that your burial is only 30" and roll poly pipe is very easy to repair unless you are totally infested with the rodents I would simply lay the pipe and worry about the rodents later.

The advantage of PEX over polyethylene roll is that it can withstand freeze/thaw, correct? (I mean it shouldn't freeze, don't want it to freeze, but insurance is nice)

Is PEX tubing more $$ and harder to install/connect?

Sorry, I should have clarified: I wonder if PEX is cheaper than Polyethylene?

That's a valid point about the PEX tools, as I don't have any!