The alkalinity of a waterbody is influenced by the soils and bedrock minerals found in its watershed and by the amount of contact the water has had with them. For example, lakes in limestone regions, which are rich in calcium carbonate, often tend to have higher values for alkalinity. Those in sandy soil regions, which are poor in calcium carbonate, often tend to have lower values.

Alkalinity (and its opposite, acidity) can also be influenced significantly by the presence of several different substances, for example:

• phosphorus (in phosphatic soils and rocks);
• nitrogen (from ammonia);
• silica (from silicates);
• organic acids (like humic acids); and
• gases (specifically carbon dioxide and hydrogen sulfide).

The Role of Alkalinity in Waterbodies
Total alkalinity is a major determinant of the acid neutralizing capacity (ANC) of waterbodies. High alkalinity waters are often more biologically productive than low alkalinity waters. Consequently, total alkalinity was once used as an indirect measure of a lake's productivity. In recent years, research has shown that waterbodies with low alkalinity levels are more susceptible to the effects of acidic water inputs such as acid rain.

In Florida
Waterbodies in the Florida LAKEWATCH database have total alkalinity concentrations ranging from 0 to over 300 mg/L as CaCO₃. Over 75% of these waterbodies had total alkalinity concentrations less than 35 mg/L as CaCO₃.

The location of a waterbody has an especially strong influence on its total alkalinity concentration. For example, lakes in the Okefenokee Plains lake region in north Florida (Baker, Columbia, and Hamilton counties) tend to have total alkalinity values of 0 mg/L as CaCO₃, while lakes in the Tsala Apopka lake region in central Florida (Citrus, Sumter, and Marion counties) tend to have values above 40 mg/L as CaCO₃.

Health Concerns
There is no known level of total alkalinity in Florida waterbodies that indicates a threat to human health.