How Much Water Is My Well Producing? Static Water Level
In the United States, there are over 43 million people who rely on private well water for their drinking water supply. These wells rely on an adequate, dependable supply of groundwater, replenished throughout the year by rain and snowmelt to provide homeowners with the water they need. Drought and other weather-related and man-made factors can affect the amount of groundwater in your well.
The resting level of your well water is called the static water level. What follows is information on measuring your wells static water level to help determine the health of your home's water supply.
What Exactly is Static Water Level?
The static water level is the level of water under normal, undisturbed conditions. To determine static water level, it is best to conduct any testing when the well has not been pumped for several hours. If your well was recently pumped and your replenishment rate is not accounted for, you may get a false reading when conducting a test.
How Static Well Water Level is Measured
Your water well professional has several different methods for measuring the static water level of your well. These include:
- electric sounder of electric depth gauge
- wetted tape
- an air line
Each of these methods can accurately measure static water level. The method used depends upon the type and depth of the well being tested.
Electric Sounder or Electric Depth Gauge
Using either an electric sounder or electric gauge to measure static water levels is the most practical method. It consists of using a weight suspended on an insulated wire with depth markings and an ammeter to indicate a closed circuit. When the end of the wire touches the water's surface, a current flows through the circuit. Current is supplied by a small battery.
To determine a reading, the operator lowers the line until the needle deflects then reads the distance from the top of the water to the top of the casing on the line. He then uses a tape measure to measure the distance between marks on the line.
This method is best for measuring shallower wells. It's accurate up to about 90 feet. To use this method you need to know the approximate depth of the water in your well.
This method uses a 100-foot steel measuring tape with a lead weight attached to the end. Eight to ten feet of the tape is dried and covered with carpenters chalk before each measurement. The tape is lowered into the well until a portion of the chalk is below the waterline. The person taking the measurement will align and mark an even foot mark on the tape at the top of the casing. Then the tape is pulled to the surface to read the mark where the line is wet. The wetted mark is subtracted from the mark at the casing to determine the actual depth of the water table.
This method is appropriate for repeated testing of deep wells over 300 feet in depth.
In this method, a small pipe or tube long enough to reach from the top of the wellhead to a point about 20 feet below the lowest anticipated water level is used. Air is pumped into the line and excess air is forced out the end equalizing the pressure in the line with the water outside of the line. Typically ¼ inch brass, copper, or steel tubing is used, although plastic tubing can also be used.
The exact length of the air line is measured as it is lowered into the well. The airline is kept airtight by hanging it vertically, making sure that it doesn't spiral inside the well casing. This is usually accomplished by securing the line to a known point on the pump column. The end of the line is attached low enough so it is submerged when the pump is operated at full discharge.
By noting the pipe joints, the depth of the air line can be determined. The top of the line is then fitted with a pressure gauge and a valve with a hand pump attached. The air is then pumped out of the line until the gauge levels off indicating all the water has been forced out of the line. The resulting pressure supports the column of water from the water level in the well to the bottom of the tube. The water column pressure is equal to the amount of air submerged. Using a mathematical formula (lbs pressure X 2.31 = Feet) the pressure is converted to feet and deducted from the known length of the air line to determine the well water depth.
The static water level is an important measure of the health of your water well. It is a determining factor when choosing the proper pump and depth to place the pump and is also an indicator of the health of your aquifer and if there are sufficient supplies of groundwater available to meet your families needs.
The best option for determining the static water level of your well is to contact Skillings and Sons and speak with a well water professional. They will have the tools and expertise to determine this important measurement and can analyze and advise you on exactly what this means for your well health.