Monitoring water depth in a well?

[The Dougster]

if it were me, I'd contact whatever State/Federal agency that monitors groundwater in your state/area... talk to them about your concerns. Static water levels can change drastically in karst (limestone) aquifers. Determine what type aquifer your well is completed in.
In Texas, the Texas Water Development Board, does this .. they have water level monitoring wells scattered across the state and normally these wells are measured once each year.. additionally, they have automatic water level recorders that monitor the water levels year-round.
These folks can help you and if you insist on monitoring your water well, they can suggest vendors that you may talk to. Good luck..

 

[Redneck in training]

If you are worrying about the pump running dry you might measure the current draw of the pump and trip it if it is lower that the set point. When running dry the current will be much less than during normal operation.

 

[TheGoose]

If running the pump dry is a concern there are controls you can add that will prevent this. Google pumptech. It's an option.

 

[Egon]

If running the pump dry is a concern there are controls you can add that will prevent this. Google pumptech. It's an option.

This may be the simplest option.

Added to the reservoir level the local draw down cone of the well may have to be taken into account.

 

[Mickey_Fx]

Another, simple, low cost way to prevent pump running dry is to use a pressure switch with low pressure shut off. My switch turns the pump off when pressure is under ~20psi.

Amazon.com: Square D FSG2J24M4CP Water Pump Pressure Switch with Low-Pressure Cutoff: Home Improvement

 

[Highbeam]

I just don't see why you would need to know the length of tube for the bubbler option. It doesn't matter if the tube is a mile long or if it is perfectly vertical, the pressure of the water at the outlet of the bubbler will tell you exactly how much water is above the outlet. Attach the outlet to the pump and you can easily check the water depth above the pump. You can use a tire pump if you want.

The only reasons I can see fo rnot setting the pump near the bottom of the well casing are: to save materials cost for the extra drop pipe and wire, make it easier to remove the pump, and to prevent sucking mud up from the bottom of the casing.

I would tend to always set it as low as possible for the sake of water storage in the casing.

 

[tommu56]

I just don't see why you would need to know the length of tube for the bubbler option. It doesn't matter if the tube is a mile long or if it is perfectly vertical, the pressure of the water at the outlet of the bubbler will tell you exactly how much water is above the outlet. Attach the outlet to the pump and you can easily check the water depth above the pump. You can use a tire pump if you want.

The only reasons I can see fo rnot setting the pump near the bottom of the well casing are: to save materials cost for the extra drop pipe and wire, make it easier to remove the pump, and to prevent sucking mud up from the bottom of the casing.

I would tend to always set it as low as possible for the sake of water storage in the casing.

I agree with highbeam on all the points.
The only concern is to have the tube in the water length dosen't matter because with no flow no friction loss no pressure reduction.

tom

 

[The Dougster]

to calculate the water level using an airline, see the following... figure 8-4.

FM 5-484 Chptr 8 Well-Performance Testing Procedures

ya just gotta know the total length of the airline tube... ya just gotta

 

[tommu56]

I beg to differ

try this link

Level sensor - Wikipedia, the free encyclopedia



Quote from the link

Air bubbler

An air bubbler system uses a tube with an opening below the surface of the liquid level. A fixed flow of air is passed through the tube. Pressure in the tube is proportional to the depth (and density) of the liquid over the outlet of the tube.
Air bubbler systems contain no moving parts, making them suitable for measuring the level of sewage, drainage water, sewage sludge, night soil, or water with large quantities of suspended solids. The only part of the sensor that contacts the liquid is a bubble tube which is chemically compatible with the material whose level is to be measured. Since the point of measurement has no electrical components, the technique is a good choice for classified æ»´azardous Areas? The control portion of the system can be located safely away, with the pneumatic plumbing isolating the hazardous from the safe area.
Air bubbler systems are a good choice for open tanks at atmospheric pressure and can be built so that high-pressure air is routed through a bypass valve to dislodge solids that may clog the bubble tube. The technique is inherently 都elf-cleaning? It is highly recommended for liquid level measurement applications where ultrasonic, float or microwave techniques have proved undependable.

 

[The Dougster]

It's okay to disagree... I have spent most of my adult life measuring water levels in wells, and believe me, if there was an easier way to do it, I'd have known about it. Again, I don't have a dog in this fight and have only been offering my assistance.