Substance and pollutant

Inorganic or organic water pollutant of sufficient toxicity for inhibiting the development and/or activity of aquatic organisms. The measurement unit is equitox (eq) and kilo equitox (keq or ket).

Oxygen consumption by strong chemical oxidants to oxidize organic and inorganic substances in water. The chemical oxygen demand (COD) is used to assess the pollution load of wastewater.

Amount of oxygen required to oxidize organic matter (biodegradable) with a biological process (oxidation of biodegradable organic matter by bacteria). The biological oxygen demand (BOD) is an index of water pollution that assesses the biodegradable fraction of the carbonaceous pollution load in wastewater, and is usually calculated after 5 days at 20°C and in darkness: it is then called BOD5.

Process by which a biotope - and (or) a population or an entire community - is exposed to a chemical or radioactive pollutant.

Soil containing dangerous substances of exogenous origin at abnormally high levels, exceeding the contamination levels (thresholds set out in the simplified assessment grid of polluted sites established by the Ministry for the Environment). Exceeding these thresholds requires further investigation.

Polluted site for which the people responsible of the pollution are either not identified or found, or either insolvent or refuse to meet their responsibilities.

Site where the soil or subsoil or groundwater has been polluted by former waste deposits or by the infiltration of pollutants; this pollution being likely to cause a nuisance or a permanent

Pollution by toxic substances which may, depending on their content, seriously and/or on a long-term basis, affect living organisms. These substances can lead to a deferred or immediate death, to reproductive disorders, or significant disruption of biological functions (e.g. reproductive disorders). The main toxic substances encountered in the environment during chronic or acute pollution are generally heavy metals …

As opposed to "non-point source pollution", it is a pollution from an identified site, e.g. an effluent discharge point.

Pollution coming from several or many point sites. The dispersed pollution is all the more detrimental as the number of sites involved is high.