B4.2 Water Definitions continued (2)
Indirect Discharge:
“The introduction into groundwater of any substance in list I or II after percolation through the ground or subsoil.”
Pollution:
“The discharge by man, directly or indirectly, of substances or energy into groundwater, the results of which are such as to endanger human health or water supplies, harm living resources and the aquatic ecosystem or interfere with other legitimate uses of water.”
List I Substances:
Substances listed in Schedule 1 of the Groundwater Regulations. A substance is in list I if it belongs to one of the following families or groups of substances:
(a) Organohalogen compounds and substances which may form such compounds in the aquatic environment.
(b) Organophosphorus compounds.
(c) Organotin compounds.
(d) Substances which possess carcinogenic, mutagenic or teratogenic properties in or via the aquatic environment (including substances which have those properties which would otherwise be in list II).
(e) Mercury and its compounds.
(f) Cadmium and its compounds.
(g) Mineral oils and hydrocarbons.
(h) Cyanides.
A substance is not in list I if it has been determined by the Agency to be inappropriate to list I on the basis of a low risk of toxicity, persistence and bioaccumulation.
List II Substances:
Substances listed in Schedule 2 of the Groundwater regulations. A substance is in list II if it could have a harmful effect on groundwater and it belongs to one of the following families or groups of substances:
a) the following metalloids and metals and their compounds:
| Zinc | Chromium | Tin |
| Copper | Lead | Barium |
| Nickel | Selenium | Beryllium |
| Boron | Arsenic | Cobalt |
| Uranium | Antimony | Thallium |
| Vanadium | Molybdenum | Tellurium |
| Titanium | Silver |
b) Biocides and their derivatives not appearing in list I.
c) Substances which have a deleterious effect on the taste or odour of groundwater, and compounds liable to cause the formation of such substances in such water and to render it unfit for human consumption.
d) Toxic or persistent organic compounds of silicon, and substances which may cause the formation of such compounds in water, excluding those which are biologically harmless or are rapidly converted in water into harmless substances.
e) Inorganic compounds of phosphorus and elemental phosphorus.
f) Fluorides.
g) Ammonia and nitrites.
A substance is also in list II if it has been determined by the Agency to be inappropriate to list I and it has been determined by the Agency to be appropriate to list II having regard to toxicity, persistence and bioaccumulation.