Well Water Flow Rate

[dfeck]

My wife and I purchased a new home that has a well. The owners did a potability test. Here is an excerpt from the test.

"The test was done from an outside spigot and the average flow was 9.5GPM. Under pumping conditions the water level in the well nearly stabilized between pumping cycles at a depth of 63.75 feet (8.59 feet of drawdown) within 10 minutes. A total of approximately 95 gallons were removed from the well during the test. Based on this flow test on this date, this well is also capable of at least 13,680 gallons per day."

The well was dug a couple years ago and is 120 feet deep lined with a 6" pipe. Since I'm new to wells do these numbers indicate a "good" well? There were also no signs of eColi and Coliform.

Thanks

 

[_RaT_]

Wells are a whole new thing for me. I would think though that if the main purpose of the well is provide for domestic water and not irrigation, the figures look good. Most domestic needs only flow a few gallons per minute with the exceptions being when filling a bath tub, a washing machine that have higher GPM rates then showers, toilets, sinks etc.

 

[KubotaSteve]

When I had my well drilled, the guy told me that 5 to 6 gallon per minute is what they like to see and anything higher is better. However, he said that a well only doing 2 gal per minute can still be adequate, you just may need to drill the well deeper to have a makeshift resevoir at the bottom. The 2 gal. per minute is provided that you aren't trying to fill any swimming pools, water lawns, etc.

 

[_RaT_]

I was talking to a geologist the other day. I mentioned we would like to get our well water tested. She said they get expensive but it should be done. I mentioned for the pesticide, bacterial, ph, etc test we would pay $250. She said expect a good test to be around $800. I thought what the heck are they testing and she went on to say that it is very important to test for metals in the water as granite etc have metals in them. She was basically telling me that her gut feeling was that it may well explain or contribute to the number of alzheimer etc. Now I'm left wondering which way to go. I think maybe bottled water. /forums/images/graemlins/confused.gif

 

[HomeBrew2]

We have similar well geometry. As I pioneered my place, I don't have any well tests sebsequent to the drilling. My well log shows 100 GPM "by air test" which is the V12 air compressor on the well rig pushing it out. Of course I'm thrilled with that but was not about to install a pump big enough to handle all that capacity. I have a nominal 20GPM submersible pump which is good for household and landscaping use, though not all simultaneously. (common cheap rainbirds are around 5GPM)
So, what I'm getting at is your well production seems fine for reasonable residential use. Additionally, you may want to research 2 things: How deep is your pump set (hopefully about 110' - this would give you an idea of your reserve capacity) and how much water is the well (aquafir) really capable of producing (probably shown on your well log and/or a much more expensive test - this would identify the possibility of using a larger pump if you wanted to irrigate)

 

[dmccarty]

dfect,

There are plenty of homes in my area that have wells that produce 2-3 GPMs. One well is at the 2-3 GPM rate. There is another well withing 300-400 feet that produces 30+GPM. My well which is up hill and maybe 1000 feet away produces 15 GPM.

The wells in our area are are down around 200 feet or more.

I think my pump only moves 5-10 GPM which means in theory I can not run the well dry. Not that I'll ever try. /forums/images/graemlins/grin.gif Since our wells are kinda deep that means we have a pretty good "tank" of water. A shallow well will not have as much storage.

Sounds like a good well from a GPM measurement. How the water tastes and smells is another matter. And if it is clean. We have good tasting water and it does not smell.

Later,
Dan

 

[ByronBob]

Your water level in your well is 63 feet deep. If it's 120 feet in depth then you have 60 feet of water head. At a 9.5 GPM refill rate as long as your well pump is below 75 feet you should never run more water through your pump than the well can refill.
All these numbers are very good. You have nothing to worry about.

 

[MarkLeininger]

</font><font color="blue" class="small">( I mentioned we would like to get our well water tested )</font>
Rat,
We go through our local farm bureau for well testing. About twice a year they contract with a university lab to do the tests in bulk so it's much cheaper. We did the test for metals, organics, nitrates and everything else they offered and the total cost was only about $300. If you have a farm bureau near you look into that. You have to collect the samples on a given day and get it to them by close of business because they all get sent in together. I'm glad we did it because we found slightly elevated levels of alachlor (spelling?), which is a common herbicide used by farmers and municipalities to clear vegetation along the highway. It's easy to remove with charcoal, so we put in a charcoal filter under the sink.

 

[SPIKER]

I agree with others, that is a GOOD well: as for testing for other non dilutable metals ect that CAN be done, is it required? no but do like mark L said if you can. also a good filter will take care of 99.9% of the stuff IN the water. remember a prefilter for the house and then a fine charcoal or RO filter for drinking! cloranation should not be required since it already tested good for the common contaminates.

testing is always a good thing but sometims not really required.

MarkM
/forums/images/graemlins/smile.gif

 

[Currmudgeon]

That's 9-1/2 gallons a minute. I'd say that's pretty good. Are you planning on using more than 13,680 gallons a day?

For planning purposes, we figure 100-120 gallons per capita day with a dishwasher and washing machine, but without lawn irrigation.

With the 8-1/2 feet of drawdown, you have about fifty feet of water left, so the well looks good from that POV, too.

How does the water taste? Mine is horrible.