This article describes the minimum acceptable well yield or water flow rate for a well to be functional. Next we describe how to increase the yield or flow rate of a water well using several approaches, and we define hydro-fracturing for well stimulation.
Green links show where you are. © Copyright 2017 InspectApedia.com, All Rights Reserved.
Some wells can produce a flow rate of 20 gallons per minute (gpm) or more. But for a single family home, 5 gpm is good, and 3 gpm is livable. In some communities the health department or building department will require at least 3 gpm (or more) to approve a new well for new construction.
These are general flow rates, but a more accurate answer to the required well yield flow rate for a specific property depends on the anticipated water quantity need for a given home, number of occupants, types of water usage, and thus the anticipated daily water usage, factored against the well yield (and possibly well recovery rate).
A risk with a well that already has a low yield is that the yield is at risk of dropping still further seasonally or permanently (common), or possibly failing entirely (less common). Therefore in buying such a property it would be prudent to presume that you will face additional costs to provide more or better water quantity. You might want to consult with local well drillers to get an idea about their experience in success in drilling wells in your immediate neighborhood as well as the typical well depth, yield, and cost. See WATER USAGE TABLE for a table that will help calculate the water flow rate or daily water usage for a property.
In the worst case with a slow or low yield well people install additional water storage/holding tanks to collect water at the low rate available from a well and provide water and then deliver it at the needed rate.
If a well yield is too low, in addition to reducing unnecessary water usage (conservation), increasing the onsite storage quantity (holding tanks), making sure equipment is working properly (no leaks), and the option of drilling a new well and hoping for a better yield, there are various methods to increase well yield.
Just below we explain How to Improve Well Yield or Improve the Quantity of Water Available. Other Related articles:
WELL YIELD IMPROVEMENT - increasing well yield.
How to diagnose loss of water pressure or flow from a well (or municipal supply)
The sketch at page top, courtesy of Carson Dunlop, outlines what happens during a well drawdown or well flow test procedure. At WATER PRESSURE LOSS DIAGNOSIS & REPAIR we outline the first steps to take if you have lost all water pressure. We discuss well flow rate and methods for testing the well yield in detail at WELL FLOW RATE
Readers should also see Water Tank Types and before assuming that a water problem is due to the well itself, see WATER PUMP REPAIR GUIDE an specific case which offers an example of diagnosis of loss of water pressure, loss of water, and analyzes the actual repair cost.
Before drilling a new well to get more water, some plumbers or well installers will try these things:
Continue reading at WELL FLOW TEST for WATER QUANTITY or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES. or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.
Or see WELL FLOW RATE
Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia
Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
If a well has not been used for 6 years it was a good well then we hooked up to it again and you can run water about 40 minutes then it quits. With the well setting for that long will this hurt the well, Will it not be as strong as before? - Diana 5/25/12
Diana your question seems to have two parts that I can't quite relate.
Running or not running water won't damage the well itself, though a well in use often finds over years that its yield or recovery rate may decline as minerals and crud clog the rock fissures through which water enters the well. Less use, slower clogging.
Running out of water after 40 minutes?? That is a bit unclear - 40 minutes at 1 gallon per minute, or 40 gallons, is an inadequate well. 40 minutes at 10 gpm is 400 gallons and is a lot of water.
We have a well that is about 100' - water starts about 20' below the well cap. We are forever running "dry" after running the water for about 20 minutes. e.g. I fill my kids kiddie pool with about 40 gallons of water (takes 15 minutes or so) and then run the dishwasher we will run out of water and draw nothing but air in the lines. We have to turn the pump off (it will keep running) then I turn it back on 30 minutes later and it will build pressure again. We have a deep well jet pump 1/2hp. Would increasing the hp of the pump to 3/4 allow us to draw more water? or do we just have a crappy well? All of our neighbours have lots and lots of water. - Ella 6/11/12
RE: will putting a more powerful pump on our well system improve how much water we get?
Ella, from your description your well has a static head of 80 feet. Figuring that the pump is perhaps 5 ft. from the bottom, you have a column of 75 feet of water in the well when it's at rest and fully recovered - that's about 112 gallons of water. If you draw water out of the well at 5 gallons a minute you have about 20 minutes of water on hand in the static head.
If you are running out of water quickly that means that your well has a slow recovery rate - you are taking water out of the well faster than it recovers so you just get the static head and then run out of water.
Putting on a more powerful (higher hp) well pump will NOT improve matters, it will make them worse. You will draw the water out of the well faster than ever - running out sooner, probably wasting water by running faster than need be.
Your options to get more water are to add local storage tanks or to try to increase the yield of the well (the article found above).
I have heard from some of the old timers that putting crawdads in your well will help to open up the clogging where the water comes in. They should not get sucked up the foot valve and I don't think they would produce enough bodily waste to contaminate the water but I would have the water tested to be safe. If you know any thing about crawdads they like to dig and just a few of them can dig many holes and they are content to stay under water. - Mike 7/2/2012
RE: Should we put crawdads or other animal a drilled well?
Mike I'm doubtful there being any benefit whatsoever from putting crawdads into a drilled water well - we used to find them in our springhouse but not at the bottom of a drilled well - I don't recommend it - they won't like it down there. I doubt that crawdad fecal waste would be an issue - there's nothing for them to eat in a drilled well, they will die, and body parts might even clog the foot valve or intake on a submersible pump.
Water enters most drilled wells through rock fissures - not something a crawdad can excavate. If your well has lost yield, hydrofracking (discussed in the article above) using one of several methods can help improve the well recovery or flow rate, and unlike the crawdads, it has a track record of success. (And costs more too).
I have a a well with 5 " casing that is 45 ft deep. The submersible pump is at 40 ft and water will fill the casing up to about 30 ft. After pumping it starts to pump air. Will jetting the well help to clear out sand and increase water flow or do I need to deepen the well. How does one go about jetting a well or how does one deepen the well. My neighbor's well is 60 ft and he has plenty of water. - Lee 7/24/12
Your well has only a ten foot static head - about 15 gallons - or nothing. So it is almost entirely dependent on the inflow rate to the well to provide a functional water supply. The fact that your system is pumping air sure sounds as if the well is getting ahead of the water flow rate into the well.
You should talk to your local well drillers about steps to increase yield; some procedures guarantee the result; if that doesn't work, it's new well or deeper well time. A makeshift interim measure is to install a cascade of above ground water tanks that are filled slowly, at the flow rate of the well.
Is there any way to help a well that is located in a basement. My well is 82 years old and is giving me issues. It will run dry (suck mud) after only 50-60 gallons. It will take about 1/2 hour to recover to a point where the jet pump can re-prime and come up to pressure. The well is presumed to be pretty shallow (40-60ft) but needs to be measured. I have spoken to others in the neighborhood... My neighbor 4 doors down has a 13ft deep well that he has never been able to run dry. He fills his pool! Could the poor recovery be clogging? could this frac packing help? can that be done in a well located in a basement? - Aaron 9/23/12
Aaron, a shallow well like your neighbor's 13-foot deep one can be hard to keep sanitary - but that's a different issue from running out of water.
It's not a surprise that well flow rate would decline in an 82 year old well - mineral deposits or silt tend to clog up rock fissures through which water flows to the well.
There are two approaches: this is a drilled well, right? If so you can hire a company to try hydro-fracking to increase well yield;
THe second and in your case not so great approach, is to add water storage tanks.
have a low yield well 2 gallons 15 min put 2500 gallon holding tank drilled 200 foot well no water can not find someone to go into 6in casing in old well to clean or hydro frack western pa help - Anonymous 10/3/12
My wife and I are considering moving to a property, but only recently found out that it has a water flow problem where the flow is approximately 1/2 gal per min. We are considering a water storage tank as the property has a large basement big enough to house a high volume tank. We are concerned however about how much electricity is used by the pump when the tank is filling. Can you give me some idea about that extra cost? - Matt 10/5/12
Matt, adding a large water storage tank can help live with a marginal well, though the remaining life of the well may also be in question.
Take a look at WELL PUMP / TANK REPLACEMENT COSTS for details.
We had a well driller drill a new well for an irrigation system that requires 40 to 50 gpm. He put in a 5" well 255' deep with 40' of screen. We had it tested and it produces 15gpm. What are our options? -Lori 10/6/12
Options to improve the service of an irrigation well include:
*120' well built 1978
*new pump, wire, pipe, check valves 1/2010. refresh rate was <2gmp
*well sat for 2 years
*turn on well and pumped pump protector shuts off pump after five secs.
put on 20 minute off-time & well pumped up overnight but tried that again and only got about 20lbs pressure.
*the pump initially draws 5amps (normal) but then drops to 3amps and the pump protector shuts off pump. it does the same thing with the pump protector not connected.
So: i'm guessing that my well is running dry, the pump screen is clogged or the well casing / screen is clogging. i'm going to have a man pull that pump next week but i'd like some suggestions on how to 'refresh' that well. i can't afford to drill another hole. - Tim 10/23/12
Tim, some of the well yield improvement companies offer a guarantee that if they cannot improve well yield you don't pay.
I am getting conflicting info regarding fracking a well that is 78' deep with the info below I am being told you can't frack such a shallow well and expect to get more GPM
Dia of Well 6"
Type of Pump Deep Well Jet
Static Level 15 ft
Pumped well at 3 GPM
Pumped well for 1 hours
to a depth of 79'
well is producing 3/4 GPM at a depth of 78' - email@example.com 10/28/12
In general I expect the well yield improvement fracking process success depends a lot on the underlying geology and hydrology of the area so I am not sure there is a single correct minimum depth requirement for well fracturing processes.
About a month ago our well pump stopped pumping water all together. I called a professional who came out and replaced our ½ HP pump with a ¾ HP pump. The new pump worked great for about 24 hours. After using the new pump for about a day it lost a great deal of it’s pressure. It was still pumping water into our house, but the pressure/volume of water at all outlets in our home were only getting about 1/4 the pressure or volume of water they had. The whole time we had low pressure the pump was running, and this low pressure continued for hours.
After a few hours of low pressure I tried turning the power to the pump off and bleeding all the water from the outlet right next to our pressure tank. After flipping the power back onto the pump I could hear the water rush back into our pipes. A short time later, maybe 15-40 seconds the pressure switch flipped off and the pump stopped running. We had good pressure for about another day or two and then the problem occurred again.
Anyway I called the pumper and explained the problem. First he replaced the pressure switch. Didn’t work. Next he dropped the well pump 10 feet, his thought was we we’re pulling the water level down below our pump. This also didn’t work. About a week ago he dropped the pump another 10 feet. We still continue to have the same problem, but it happens every 5-7 days.
I’m not sure if lowering the pump actually helped or not, but it did appear to make the problem happen less frequently. All of this sounds like what’s described under “Adding a More Powerful Well Pump Can Improve Pressure, Increase Flow Rate at Faucets ... and can Lead to Trouble“ found on the following page (WELL FLOW RATE), but I’m not sure. I would greatly appreciate any advice people are willing to offer. - Peter 12/4/2012
Bleeding water out of the water pressure tank will improve well pump short cycling by allowing an air charge to be restored in the tank, but it won't fix water pressure or flow rates.
The fact that your well contractor lowered the pump suggests that he thinks that the well has a small static head (not much water in the well).
Your description suggests that the well flow rate may no longer be able to keep up with the pump; if the pump drops water level too low in the well, and especially if it includes a pump burnout safety device or tailpiece, then when the water level in the well is low, the pump will simply stop pumping or slow pumping water out of the well.
Some additional things to check include:
I am from southern part of India. I would like to have some advice from you for my domestic well.
The well was dug in 2011 . There was plenty of water for about 1 year. After that the ground water flow reduced to a level that in summer, availability of water is hardly for one family only, if we use minimum amount of water. We never over-used water any time.
The well is full of hard rocks. We dug to about 11 meter depth and the diameter is about 1.8 meter.
We used traditional method , ie, drilling holes in the rock and filling with explosive material and crack the rock.
The interesting part was , we stopped drilling the moment water started flowing in good volume from bottom of well. Later upon inspection while cleaning the well, we found that water was flowing from a drilled hole made for explosives and it wad perpendicular to the well bottom. We left it that way since there was plenty of water flow from that hole almost like water flowing out of a 1 inch diameter pipe.
Now at present situation, we feel we should have dug the well further down at least to the depth of drilled hole from where water was coming.
Please advise me if we dig further down is there a possibility of enough water ? If so how much deep ?
I have attached a diagram of our well for you . Please give me your valuable advise? - S.V. 8/4/2014
I'm of course nervous about advising repairs for a system I don't know well and moreso about using explosives, though my older friend Paul grew up with well like yours and describes occasional use of dynamite to restore water flow.
It's reasonable to think that drilling more deeply in the same opening at the well bottom might restore water flow - most likely the aquifer level has fallen due to dry weather and falling water levels everywhere.
Improving well flow is always a lottery since there is also a chance that messing with the well can actually reduce its water flow - for example if we open a passage that drains water away rather than into the well.
If you have close neighbors who use similar wells it would be instructive to ask them what's been happening with their water supply and about the depth of their wells as well.
Still, I would try first drilling the existing hole deeper if you can do so. If that helps, try drilling additional nearby holes.
If you decide to try more explosives to deepen the well over a wider expanse please send me a follow-up email with the results and with an assurance that nobody got smacked by flying rock. Photos of the well and the procedure would be valuable to other readers as well.
(May 8, 2015) Sherwood Botsford said:
Another tidbit that may help people who are re-activating an unused well: Locally we have an iron sulfide bacteria that nibbles on iron and hydrogen sulfide in the water. One of our routines is to periodically shock chlorinate the well. In our case that means 2 gallons of 8% concentration bleach mixed with 200 gallons of water, and dropped down the bore. Then we run a garden hose to the casing, and allow full flow into the casing. This circulates the slug of chlorinated water down the bore past the screen. Once we get a chlorine smell, we turn the water off, and let it sit overnight. The next day we run each tap in the house for several minutes until we smell chlorine. Once all the taps have been run, we move that garden hose to the edge of the driveway, and let it run until the smell is gone.
We do this once a year.But what brought me here:
At present we have a 6" steel cased well with a 1/2 hp pump. The well is 140 feet deep, the pump is about 30 feet off the bottom. Static water level is 8.91 meters below the surface. Pumping at 8 gpm from a local tap using the well's pump results in the well pump running continuously. Readings over the next few minutes 9.74 9.76 9.80 9.82 9.83 9.84
Recovery 9.54 9.08 9.02 9.0 8.98 8.97 8.96 8.955
This well is used for both irrigation and for household use. During the irrigation season it runs 16-24 hours a day. Our operation is limited by the water we can pump.
I asked at the local electrical shop, who also does well wiring if it would be reasonable to replace the 1/2 horse pump with a 1 horse pump. He was willing to sell me a pump, but cautioned that some wells in the area when upgraded to a higher volume pump started moving sand in the local formations, and in the space of a couple years were reduced to 2 gpm.
I have read the logs for the section I'm in. The logs are not close to consistent. Shale, sandstone, hard sandstone, clay, coal, in any order. Subtracting the static head from the elevation is not consistent. This is in accord with my own experience of the surface 3 feet (I have a tree farm) Two auger holes 5 meters apart can produce either clay or fine sand or peat once below the A soil horizon.
How do I determine if I can safely drop a 20 gpm pump in this well?
Thanks for the comments, Sherwood. They will assist other readers.
About the well bore pumping rate, you can obtain objective data by following what well drillers do: use an adjustable flow rate pump to see what pumping rate can be sustained over 24 hours.
may be helpful.
30 May 2015 anthonyb said:
My water goes off an on for about 30mins and then goes down to nothing. So I bought a new tank and pump thinking that would take care of the problem. But now my water stays on for only 15mins and then goes down to nothing.. any thoughts?
Anthony you want to check the actual flow rate of the well. It sounds as if the in-flow rate of water into your well bore has become quite limited.
Then see WELL YIELD IMPROVEMENT
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website