Farm dugouts typically contain a lot of organic matter because they aren’t in a flowing river or lake with an inlet and outlet. Runoff feeding the farm dugout often comes from high organic sources such as cultivated land or pasture.
Although there is no firm number documenting how many rural residents depend on dugout water, a good guess can be made by studying maps showing drilled wells that produced water or did not produce water. The maps provide a sketch of where well water was not available.
“From my own research and from talking to people in the water industry, my best guess is that roughly 20 percent of the water source comes from surface water for farms.” says Brian Tennant
Added a study published by West Virginia University: “When chlorine is added to water with organic material, such as algae, river weeds, and decaying leaves, trihalomethanes (THM) are formed.
“Residual chlorine molecules react with this harmless organic material to form a group of chlorinated chemical compounds called THMs. They are tasteless and odorless, but harmful and potentially toxic.
“At what levels are THMs present in water? The byproduct concentration is mainly determined by the amount of organic material in the source water. Water facilities that draw water from surface water such as lakes, rivers and reservoirs produce water with higher levels.”