New well. Is this enough water?

[Rman]

Hello I’ve had to have a new well drilled at my house but because the lot is small and no access to the back yard it was drilled in the front yard 10 feet from the septic. The DEP and town required a min of 140 feet of 6 inch casing and 10 inch casing to bedrock which was 80 feet. The well was drilled to 325 feet. At 275 it started to produce water at 4 gpm. At 325 it’s 4 gpm. The static level is 5 feet from grade. I’m on a mountain can’t explain why. But is my column of 320 feet in the 6 inch hole enough for a single family home 2 adults ?? If I draw 10 gpm and the well produces 4 gpm will I run out of water and how soon ? No yard irrigation just Home water stufff. Concern is when there is a house full of people on special occasions. There is a small 10 gal pressure tank on a cpv valve system. Should the pump be sized at 5 gpm or will the 10 gpm pump set at 300 feet be ok. Oh all the fixtures are low flow type. Thanks

 

[LLigetfa]

4 GPM is 5760 gallons per day. I like to round off numbers on what the casing holds to 1 gallon per foot, so around 320 gallons which is more than an average household might use. I would use a 10 GPM pump since the casing has such a large reserve. I would put a cycle sensor on the pump for run-dry protection.

 

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[ThirdGenPump]

Running it at 10gpm you'd run out of water in about 75 minutes. The well has an effective reserve of about 450 gallons.

I'd set a 3/4hp 7gpm pump at 300ft. If it is left running and pulls down to that depth it can't run dry if there is even the slightest amount of friction resistance.
A 1hp 10gpm would function similarly but it's performance curve has a steeper drop that starts earlier. I prefer the performance of a lower gpm that remains consistent down to a greater depth.
A 5gpm pump rarely meets peoples expectations these days, run multiple things at the same time and you'll notice a pressure decrease as it can't make volume. A 5gpm 1/2hp would work in that well but the price is too high to have a dissatisfied multi-person household. Living alone it'd be fine.

For regular household usage the well won't be an issue. Even with a bunch of guests it's refilling that reserve of 450gallons at 4gpm. You'd need multiple people showering at the same time for multiple hours to exhaust it. If you try to irrigate off it though you'll blow through that reserve in short order.

 

[LLigetfa]

@ThirdGenPump what do you think about possible upthrust with the water being just 5 feet from the top? I think it can be a challenge to find a pump that can both tolerate the upthrust and perform all the way down to 300 feet. I'd be tempted to raise the pressure in the house to add to the total head.

 

[Rman]

4 GPM is 5760 gallons per day. I like to round off numbers on what the casing holds to 1 gallon per foot, so around 320 gallons which is more than an average household might use. I would use a 10 GPM pump since the casing has such a large reserve. I would put a cycle sensor on the pump for run-dry protection.

Thanks for your quick response that I didn’t spend $17k and would run out of water. Do you think the 10 gpm pump would build up enough pressure to continue use of my CPV valve system set to 55-70 psi and if doesn’t should I lower the pressure to say 50-65 psi
Thanks
Btw do you think $17k is a fair number for northern New Jersey. That’s just the drilling pipe electrical and pump extra.

 

[LLigetfa]

Also, @rman mentioned a cpv valve system. I presume it to be a CycleStopValve and from what I read, it too has some challenges WRT holdback pressure when paired with a pump working a wide range from 5 to 300 feet. ISTR @valveman spec a similar setup with two CSVs in tandem.

 

[LLigetfa]

Btw do you think $17k is a fair number for northern New Jersey.

Prices vary so much by region so you'd have to ask someone in your area. In these parts the going rate is between $40 and $50 per foot. Mind you, the Canadian dollar is not worth as much as USD. See my other post about CSV and maybe @valveman would be better the expert to advise you.

 

[Reach4]

think it can be a challenge to find a pump that can both tolerate the upthrust and perform all the way down to 300 feet.

How about a 7 GPM pump with an 8 GPM Dole valve.

 

[ThirdGenPump]

@ThirdGenPump what do you think about possible upthrust with the water being just 5 feet from the top? I think it can be a challenge to find a pump that can both tolerate the upthrust and perform all the way down to 300 feet. I'd be tempted to raise the pressure in the house to add to the total head.

In my area high static levels are the norm. On the smaller pumps upthrust is of little concern. On larger pumps we take more precaution.

The pumps I mentioned don't produce enough pressure to blow out piping when they are throttled. They cap out at about 160psi.

 

[Reach4]

Hello I’ve had to have a new well drilled at my house but because the lot is small and no access to the back yard it was drilled in the front yard 10 feet from the septic. The DEP and town required a min of 140 feet of 6 inch casing and 10 inch casing to bedrock which was 80 feet. The well was drilled to 325 feet. At 275 it started to produce water at 4 gpm. At 325 it’s 4 gpm.

You need a flow inducer on your pump. I think most people with a 4 inch pump in a 6 inch casing should have a flow inducer, but you probably have a top-filling pump. So you really should have the flow inducer. And if you were to restrict the flow somehow such as having the water draw down so you only get 4 gpm of flow, you would really really need a flow inducer.

 

[GTOwagon]

Have you considered putting some water tanks in your basement for storage/chlorine contact? If you added about six hundred gallons to go with your fancy constant pressure system, I can't see how you could run out even if you had a house full of guests, give the volume in the casing pointed out above. Irrigating your yard is a foolish thing in the northeastern if you ask me. Get drought resistant plants, use mulch etc. your lawn can get brown for a few weeks and it will be fine. If you water your flowers by hand you not use much water either.

Folks, Correct me if I am wrong:

Also I know nothing about the quality of your water but I am going to assume you may have sulphuric, iron or turbid water and possibly need chlorine or H2O2 for oxidation in addition to the more pressing concern that it sits next to the septic system which makes me nervous and I would preemptively wish to chlorinate for bacteria. But I am not an expert so take what I say with a grain of salt unless some of these more experienced folks can Second what I am pointing to.

Cheers.

 

[Rman]

Have you considered putting some water tanks in your basement for storage/chlorine contact? If you added about six hundred gallons to go with your fancy constant pressure system, I can't see how you could run out even if you had a house full of guests, give the volume in the casing pointed out above. Irrigating your yard is a foolish thing in the northeastern if you ask me. Get drought resistant plants, use mulch etc. your lawn can get brown for a few weeks and it will be fine. If you water your flowers by hand you not use much water either.

Folks, Correct me if I am wrong:

Also I know nothing about the quality of your water but I am going to assume you may have sulphuric, iron or turbid water and possibly need chlorine or H2O2 for oxidation in addition to the more pressing concern that it sits next to the septic system which makes me nervous and I would preemptively wish to chlorinate for bacteria. But I am not an expert so take what I say with a grain of salt unless some of these more experienced folks can Second what I am pointing to.

Cheers.

I will run the system and see if we are satisfied with the water quantity
My concern is also enough pressure for the second floor shower. Wife needs her good shower. Old well was only 75 feet and produced 20 gpm but was contaminated with high very high sodium level that ate up my tankless water heater in 3 Years and many pex elbows are dripping. I would consider a holding tank maybe 300 gal needs to fit thru the house 36 inch door to basement. But then another pump set up maintenance etc. I’ll see how that goes. Thanks for all your help. Retired and trying not to go too much broke on this water situation. Need to get to our golden years

 

[Reach4]

Have you considered putting some water tanks in your basement for storage/chlorine contact? If you added about six hundred gallons to go with your fancy constant pressure system, I can't see how you could run out even if you had a house full of guests, give the volume in the casing pointed out above. Irrigating your yard is a foolish thing in the northeastern if you ask me. Get drought resistant plants, use mulch etc. your lawn can get brown for a few weeks and it will be fine. If you water your flowers by hand you not use much water either.

Folks, Correct me if I am wrong:

I agree about the irrigation. I don't agree with the tanks in the basement, unless there is something not disclosed above. I don't agree with the chlorine unless there is something else going on.

will run the system and see if we are satisfied with the water quantity
My concern is also enough pressure for the second floor shower. Wife needs her good shower.

You want a water test anyway. You can have your pressure switch set to 40/60 or 45/65 or even higher. A regular shower head is 2.5 gallons. There is enough water to run a sprinkler in the yard too.

 

[Valveman]

Like Thirdgen says with that much standing water in the well it is effectively acting like a 450 gallon storage tank than gets refilled at 4 GPM. So I don't think you need to store anymore water. But I would use a 1HP, 10 GPM pump to be able to utilize water if the well pulls down to 300'.

CPV or Constant Pressure Valve is the generic term for a Cycle Stop Valve. Usually means it is a copy of, but not an actual CSV. Since I have been doing this for 25 years and my patent only protected me for 20 years, these copies are now pretty close to a real CSV. However, just like in this case, the people that sell them just make copies and don't really know how they work. When they have a question the homeowner or installer is usually told to contact me, and just not mention that it is not an actual Cycle Stop Valve. LOL

 

[Rman]

Like Thirdgen says with that much standing water in the well it is effectively acting like a 450 gallon storage tank than gets refilled at 4 GPM. So I don't think you need to store anymore water. But I would use a 1HP, 10 GPM pump to be able to utilize water if the well pulls down to 300'.

CPV or Constant Pressure Valve is the generic term for a Cycle Stop Valve. Usually means it is a copy of, but not an actual CSV. Since I have been doing this for 25 years and my patent only protected me for 20 years, these copies are now pretty close to a real CSV. However, just like in this case, the people that sell them just make copies and don't really know how they work. When they have a question the homeowner or installer is usually told to contact me, and just not mention that it is not an actual Cycle Stop Valve. LOL

I have a real cycle stop valve ( not cpv my error)
Stainless steel about 3yrs d works great with old well
Will see if pressure switch needs adjustments after new well is hooked up