What is true regarding the temperature of well water?

The statement that the deeper the well, the warmer the water can be understood through the principles of geothermal gradient and groundwater movement. In many geographic areas, as you go deeper underground, the temperature generally increases due to geothermal heating, which is the result of the heat from the Earth's core. This is a natural phenomenon where the temperature increases approximately 1°F to 2°F for every 100 feet of depth below the Earth's surface.

Additionally, deeper wells often tap into aquifers that are insulated from surface temperature fluctuations, leading to a stable, often warmer temperature compared to shallower wells that are more susceptible to seasonal changes in air temperature. While it's important to consider variations based on local geology and environmental conditions, the general trend holds true in many regions.

Understanding this gradient helps water operators anticipate the temperature profiles of water extracted from wells and can influence operational decisions regarding water treatment and distribution.