Contaminant: Any physical, chemical, biological, or radiological substance or matter that has an adverse effect
on air, water, or soil.   

EPA Office of Drinking Water seems to be the only department that knows contaminants actually cause human
health problems at very low parts per million (ppm) or even at parts per billion (ppb)

Inorganic contaminants (pollutants) -- short and long term health effects.
Synthetic Organics and pesticides (pollutants)  -- short and long term health effects.
Volatile Organic contaminants (pollutants) -- short and long term health effects.
Microbe contaminants  

Contamination: Introduction into water, air, and soil of microorganisms, chemicals, toxic substances, wastes, or
wastewater in a concentration that makes the medium unfit for its next intended use. Also applies to surfaces of
objects, buildings, and various household and agricultural use products.

It is the accepted and false notion that the gram negative bacteria family referred to as coliform and fecal coliform
(E. coli)  are not disease causing organisms because some may have resided in the gut at one time. They are
now all disease causing pathogens.

Coliform -- Total coliform

Fecal coliform

5. What is EPA doing about suppression of Aeromonas during fecal coliform test?
Because these bacteria are common in natural waters and because it is generally accepted that some strains of
Aeromonas can be pathogenic to humans, the U.S. EPA conducted occurrence monitoring for Aeromonas
bacteria in selected drinking water utilities in 2003. Currently, the U.S. EPA is evaluating the data received from
this monitoring and is identifying the species of Aeromonas isolated throughout this monitoring period. This
information will be used in a risk assessment evaluation to determine whether Aeromonas bacteria should be
proposed for regulation in drinking water.

Unregulated contaminants are those for which EPA has not established drinking water standards. The purpose of
unregulated contaminant monitoring is to assist EPA in determining the occurrence of unregulated contaminants
in drinking water and whether future regulation is warranted.

5411---no person (includes city) shall discharge sewage or other waste, or the effluent of treated sewage or other
waste, in any manner which will result in contamination, pollution, or nuisance

Toxic Pollutants