Private well specifications

sterling10

Hi,

I am putting in a private well in my new build, through work contacts i might be able to get a better deal on the pump and pressure tanks than the well drillers might offer. The only thing is i cant get a specification off the well drillers when getting quotes for the work.

anyone have any idea what items i require and a specification i should be looking for? i.e pump size, vessel size, etc

shane0007

Pump will depend on the depth of the well. Why can you not get a specification from the well drillers? Surely they must provide an itemised detailed quotation as how do you know what they have quoted for and what is and is not included should they come across variations.

TPM

You wont be able to get details on the well and pump required untill the well is drilled, only then will anyone know the depth of the well, the depth the water was hit at and the amount of water in the well.

Some water diviners claim to know the depth and amount of water before hand!

The well drillers will quote you a price for drilling the well per foot plus a price per foot for steel liners as far as the rock and plastic liners to the bottom. when they are drilling they will hit water (hopefully) they should then de able to test the flow rate and decide if it is sufficient or if they need to find more by drilling further, once they are happy with the volume of water they drill a bit further to provide a "sump" for the pump.
Once finished they can give you the depth of the well, the depth the water was hit at, the volume of water in the well and the distance from the top of the well to the water. and the invoice of course
As you have figured out by now you need to have faith and trust in the well driller so they dont just keep drilling to put the price up.

Once you have the above information plus the height from the top of the well to the highest water point in the house you can size the pump.

The pump should be sized to pump enough water for your needs but not above the flow rate of the well as not to run the well dry. (l/m m3/hr)

The pump head is also required this is not the actual depth of the well but the distance the pump has to lift the water, this the distance from the water level in the well to highest usage point, if the water level is higher than the actual depth the water was hit at when being drilled use the latter for the calculation.

with the required head and flow rate you can then determine the pump size required, just beware that different manufacturers pumps can pump different flow rates at a given head than others (eg. you may need a 3/4hp pump from one manufacturer but only a 1/2hp from another).

If you are getting quotes for pumps/installations make sure they contain
the pump power: Kw hp
Pump manufacturer(not critical but avoid the cheap Chinese ones)
flow rate at given head height
Size of the pipe from the pump to the vessel
Size of the vessel in liters
Size and type of the cable from control box to pump
Type of cable joint in the well
Size and type of rope being used for lowering/raising pump
If well cap is included

Some cheaper installations use cheap pumps and/or undersized pipe/cable which shorten the life of the pump and reduce its performance.

I am sure I am missing something but I will stick up anything I remember, or if you have any questions post them up and I will help where I can.

sterling10

Thanks for that TPM,

I thought that maybe i would have to drill the well and do the pump, vessel etc all in the one go. Didn't realise i could drill the well and do the pump after.

The drilling lads are just giving a price for the kit, with no detail on what this kit is.

I might get the well drilled so to be able to get to the water. I got it divined and have a choice of about 5 different areas, luckily enough the area i'm in, we never have much bother finding water.

TPM

You are welcome

sterling10 wrote: »

I thought that maybe i would have to drill the well and do the pump, vessel etc all in the one go. Didn't realise i could drill the well and do the pump after.

There is no problem with drilling first and fitting the pump after, if it is a fair while later you should run the pump for a while incase the water has gone stagnant in the well.

sterling10 wrote: »

The drilling lads are just giving a price for the kit, with no detail on what this kit is.

They cant really know what they are going to need untill the well is drilled, they can make a good guess at it and could be spot on though. But if they bring the "kit" with them and fit it it could be over sized and more expensive than you need or undersized and struggle shortening its life.

you could find out the depth of wells close by this will give you an idea of the depth and then the cost of the well and the pump.

BTW were you given a price for drilling the complete well or per foot?

sterling10 wrote: »

I might get the well drilled so to be able to get to the water. I got it divined and have a choice of about 5 different areas, luckily enough the area i'm in, we never have much bother finding water.

When picking from the 5 locations you have, keep in mind the distance from the house. Are you going to have a pump house at the top of the well, and the top of the well linet should be high enough to prevent surface water running into it, having it buried in the ground under a manhole cover is not a good idea.

When you know the depth, head, flow rate etc. you can let me know and I will give you an idea of what pump etc you will need.

sterling10

One company that has drilled in the area has given me a price per foot including the steel and PVC lining.
Another has given price per foot drilling, with price of steel per foot and price of PVC per foot.

My intention was to have the garage as the pumping station as my site is rather long and narrow with the septic tank at the back. so the well will be in the front of the house, with a pump and trench back to the garage(which is at the back of the house) and then back into the house again.

Thanks for the advice on the manhole cover, one area discussed was at a lower level with a manhole cover!

sky6

TPM has given you some very sound advice but here is a few other things you might consider.
1. Finding water in Ireland is not a problem, you will find water anywhere in Ireland, so just decide where you want to position the Well and Drill it there. The only difference is maybe a few Feet in Dept between locations.

2. As you have a Septic Tank on site try and keep your Well away from the percolation grid for obvious reasons.
3. If you haven't built you Garage yet then maybe could consider building your Garage so as the Well is in one Corner. That way you can keep everything indoors.
Alternatively you can have the Well Head close to the Garage under a Manhole with the pipes feeding into the Garage Where the Vessel and Electrics are located.
4. Personally I would go for a submersible pump Feeding into a 60 or 80 litre Storage vessel. As this takes up less room in the Garage and the Vessel will prevent the pump from coming on every time someone opens a Tap in the House.

5. Go for a good make of pump like Grundfos and take heed of the points TPM mentioned like Head etc.
6. Decide if you want the Well pump to supply the house or do you intend to use a second pump to pressurize the House.
6. You will also need to decide are you going for a Gravity system in the house or a pressurized system in the House.
Is it a Bungalow or a two Story.?

All the above will influence the type and size of Pump required. Which maybe explains why Well Diggers are not comfortable getting into specifics until they what the requirements of the Customer.
In short do you just want water out of the ground or do you want it into your house.

Decisions decisions decisions.?

Good luck with it.

sterling10

Decisions is right! the problem is making sure you make the right decision though!

I am trying to go as far away from septic tank as possible, hence the distance i will have to travel from well to the garage, but in the long term it will be worth it. Its a bungalow i'm building. i planned to put the electrics, vessels etc in the garage, but the garage will be about 100ft from the well, but dont think that should be a problem.

sky6

I assume what you will be putting in is a Treatment plant as " Septic Tanks " in the old type to the best of my knowledge are not allowed in new builds. Just be careful to do your research as there are some troublesome systems out there.
If you locate the Well 100 ft from the Garage then you will need to take that distance into the pump sizing for the Well. Also you will have the extra Cable which is not that cheap to provide for.
Unless there is some reason you cannot put the well close to the Garage I would just go ahead and bore the well hole about 10 to 20 ft away from the Garage. Make sure the Well borer leaves the liner about 6 inches above the ground to prevent dirt and stuff falling into it. Build a Manhole around it with a cover for access. Remember you might at some time pull the pump up for service or replacement. If you have to take it up you need quite a bit of space to lay it out on the ground depending on the Dept of the Well. ( which is why I personally don't like Wells coming up inside the Garage itself )
Continue the Pipework and Electric Cable through a Duct into the Garage where you can control the Well from.
Make sure to keep all Water pipes below the frost line until they come up in the Garage . That should be it.
Best of luck with it.