Organic compounds can be of many types and can have many origins.
Some organics in drinking water can be caused by the decay of naturally occurring vegetation. These decay compounds are called lignins or tannins. The presence of these compounds, dissolved in water, would be part of the natural environment of that water resource. A much larger group of organic contaminants are the thousands of manmade organic chemicals that have been created in the last 50 years. The MCL concentrations for the organics regulated by the SDWA are shown on pages 4 and 5.