If you just want to measure the depth of the water in your well, you could use a water level tape like this one . Usually these are lowered down into test holes that don’t have other pipes and cords hanging in the way, but it might work. All it is is a conductivity meter on the end of a tape measure that beeps once it hits the water table. Then you read off the measurement on the tape. As far as price goes, you might want to just get a well drilling company to let you borrow it or measure the well for you – they’ll definitely have this type of equipment. There are cheaper models too though.
If you want to know the depth of your water table, that may require drilling some test holes or measuring the depths of your neighbours drawing from the same source as you, then comparing that to your well report from when it was first drilled to see how the water level now compares to that of when it was drilled… keeping in mind the seasonal fluctuations in ground water level. If it’s 2 feet off, yeah big deal. If it’s 50 feet lower, uh oh :eek:.
Lastly if you want to check your wells’ performance to see whether it may need redevellopment or to find out some other stuff, there are four main methods to do so (although these are usually used when first develloping a well to determine what it should be able to produce.
A bailing test is where you measure the depth down to the water from the top of the well casing, then pump out a given quantity of water (50, 100 gal), measure the new lowered depth, and time how long it take the water level to return to normal.
A slug test is where you again measure the depth down to the water in the casing, then add a given quantity of water, and similarly record how high it goes and how long it takes to return to normal.
These first two tend to tell you more the hydraulic efficiency of the well; how well water flows through the sand pack, but not much about the volume of water down there.
Better tests for this are:
A step drawdown test, in which you:
- measure water depth (usually you have a few observation wells too), then start pumping at a given rate for say an hour, monitoring the water level drop.
- then up the rate, and do the same thing.
- keep doing this 5-8 times always upping the pumping rate.
This tells you what rate you can pump at and how fast the water table drops to determine your optimum pumping rate, and lets you calculate the transmissivity and storage coefficient of your aquifer where your well is once you plot the results on logrythmic graph paper and do some math.
Then you could do a constant rate pumping test, in which you:
- again measure the water depth in your (test) well/s, and start pumping at a steady rate for 1-7 days, monitoring the drop in water height all the time. Again you can calculate transmissivity and coefficient of storage, which tells you how well the water flows through the bed material where you’re drawing from, and how much water is available to you.
Now just knowing these values (let me know if you want the formulas for calculating them; you can’t quite do them in your head :D) won’t tell you if you’re going dry. For that you’d need some historical data on your well, and hopefully whoever put it in way back when did these tests. If you hire a crew to come out and test your well, they’ll most likely do these same things and compare them to the values taken at the same time of year from previous tests.
As Crafter_Man was wondering, determining the recorvery rate of a well is usually more important from a functional view than the volume of water down there, although that’s important too. You can have a ton of water, but if your frac sand is plugged up with silt, or the bed material is fine sand or silty, the water won’t be able to flow back into your well and you’ll only be able to produce a trickle of water, if you don’t run the pump dry and detsroy it first. The pump size or power is factored in when you measure how much water you’re pumping out and how long it takes to refill.
Pumping out 2 GMP for an hour will remove 120 gal, and say it takes an hour to recover.
Now using a bigger pump you suck 10 GPM for an hour, removing 600 gal - which may then take 5 hours to recover. As long as you know your pump rate, it doesn’t matter what size pump you use (unless you run the well dry in 30 seconds, or have a pathetic little pump that isn’t capable of pulling hardly any water at all out.
There are other factors such as vertical leakage and confined aquifers which may scew the results, but these are not the pump’s fault unless it is again drastically under or over-sized.
and is 475 ft :p) so I don’t have much to say in terms of experence but do know something about aquifers and well drawdowns and the like.
). and takes apx muddy for a few days. If you start getting less then 200 gal or it’s taking longer then a few days your water level has dropped.