Replies

1. 
   Guest_ | Aug 05, 1999 05:45am | #1

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   One way, of course, is to call a well and pump service company. Another way is to securely tie a small rounded piece of wood to some nylon string. The block does not have to be very heavy but it should have some heft so you can sense when it starts floating. Drop the block down the well. Some wells have spacers that hold the pipe off the side of the casing. Even so, you should be able to work the line down. When the block hits water mark the string, draw it out, and get a measurement. This will be the current static level. From the driller's log you can get the static level at the time the well was drilled. From this you can tell if there has been a change in the water table. A significant change can signal a need for additional drilling and/or repositioning of the pump. From the log you can also find out how deep the pump is set. The water in the casing above the pump is your reserve. At this point, drop the wooden block back down the well. Open a yard hydrant and let it run for ten minutes or so. If the current static level does not change then the well is recovering as fast as it is being pumped. More likely, you will see some drawdown. Record the amount. Close the hydrant and measure the time it takes for the water in the well to return to its current static level. From this you should be able to compute your reserve, your drawdown rate, and your recovery rate. If any of these numbers give you concern then you need to talk to a well professional.

2. 
   Rebeccah_ | Aug 05, 1999 12:00pm | #2

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   Very similar measurement method to what we used when I worked for the state Water Survey one summer., mapping out the piezometric surface of the water table. We used a steel tape measure on a reel, chalked it up, and if you could keep it from sticking to the side of the well pipe drawing it up again, you could read the water level where the chalk got wet and subtract from how much you had let down. Of course, the steel tape (about 1/4 or 3/8" wide by 300 or 350' long) is much more expensive than a piece of wood on a string. Can you really sense when you've hit water at that depth? With the tape, sometimes you can hear the "plunk" .

3. 
   Guest_ | Aug 06, 1999 02:03am | #3

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   Rebeca. The answer is yes. You can also hear a "splash" up the casing at times. You want a block of wood small enough to pass down without hanging up on the pipe and cable. The more heft in the block the greater the ease off in the string when the block starts to float. 300 foot steel tape? Not your usual home improvement store tool rack item.

4. 
   Larry_N._Smith | Aug 10, 1999 12:13am | #4

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   I would also reccommend measuring a static water level, a pumping water level, and recovery measurements. If a block of wood doesn't work for some reason, a good sized metal washer also can serve well, you measure the water level by hearing the "plink" at the water surface. I never put much faith in a driller's reported water level (at least here in Montana), since most wells are drilled with air, and I've met very few drillers that have a water level probe on their rig.
   To get technical, we usually record the static and pumping water levels after pumping 30 minutes, and report the drawdown in gallons per minute per foot of drawdown, something known as "specific capacity" of the well. This is only useful if you are comparing one well to another... since the amount of drawdown will depend on the rate it is being pumped.
   Another this is really useful in times of drought: Compare the depth that the pump is set to the pumping water level(!!) You never want to pump the well all the way down, since you can burn out the pump doing so!

5. 
   Dan_Bittner | Aug 13, 1999 12:28am | #5

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   The lack of rain here in the Northeast has got many communities on water emergency restrictions and there have been stories in the local papers of wells going dry for the first time in 30+ years.Many of my customers are in rural areas and rely on well water, anywhere from 160 to 400 feet deep. Is there anyway to determine what a wells recovery rate is? Many of the flow rates are in the 6-10 GPM range, but how can one be sure that that 6-10 is being replenished, and ifso how quickly?

6. 
   Guest_ | Oct 01, 1999 07:39am | #6

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   I bought a 300 foot tape (Empire brand for less than $30) and attached a 1/2- 3/4 full plastic bottle of drinking water. The bottle was a 16 oz size, so it was fairly slender (about 2 inches in diameter). It provided sufficient heft so you could easily tell when you hit the water level and it started to float. You could do the same thing with a 50 or 100 foot tape by extending it a known distance. For instance on a 250 foot well, add a 200 foot length of cord and then tie it to the 100 foot tape. Unless you have a 50 gallon per minute well that you only pump at 5 gallons per minute you will get some draw down. In some areas the well casing is used as a reservoir and the pumps are equiped with shut-offs if the water level drops below a certain point.