Surface water sources include lakes, rivers, streams and ponds. They are open to the environment, may be contaminated by human and animal activity and the quality of the water may change significantly with the weather (storms or heavy rain).
Surface water is not safe to use as drinking water.
It is possible to treat surface water and make it safe to drink, but treatment must deal with viruses, bacteria, parasites and with changing physical characteristics such as turbidity, chemical contaminants (oil or gasoline residue, pesticides and herbicides) and organic material. Treatment should be designed by an experienced professional to fit the source.
Effective surface water treatment can be expensive and can require constant monitoring and maintenance.
Untreated surface water should not be sampled for testing as drinking water because it is known not safe to drink. The Public Health Laboratory will reject such sample submissions.
A ground water source of drinking water such as a drilled well can supply safe water with no treatment or very little treatment. Even a dug well which draws from a shallow water table and is subject to the weather can be treated effectively with relatively simple equipment.