Groundwater - found below the ground where it accumulated in between soil and rocks. The volume of water can range from small to very large similar to above ground creeks, rivers and lakes.
What is Safe Drinking Water? (High School)
Total Chlorine for High School Operation Water Drop
Studies have shown that when total chlorine levels drop below recommendations, several water quality problems can occur. With regard to public health, bacteria and selected viruses, called bacteriophages, are able to multiply in water that is not properly disinfected and, depending on the species, could potentially cause waterborne illnesses