DEFINITION

DEFINITION Generally Contaminated land refers generally to land which contains contaminants in sufficient quantities to harm people, animals, the environment or structures. There is now a statutory definition of ‘contaminated land’ contained within Part IIA of the Environmental Protection Act. Contaminants comprise hazardous substances (solids, liquids or gases) that are not naturally occurring in the site. They arise from previous site usage, although sites can be affected by pollutants arising from adjoining sites through the movement of water and air. A contaminated site can similarly pose a risk to surrounding land by off site migration of contaminants. Contaminated sites can be sold on, although the new owner would take on the responsibility for the contamination and would obviously take this into account in the offered price. The extent of remediation works required to address contamination varies dependent on the intended future use of the site – with industrial uses calling for a lower level of work than if the site were intended to be used for residential or agricultural purposes. In a commercial world, expenditure on decontaminating the land would usually need to be balanced against the release of the latent site value – unless of course the contamination contravened statutory limits. Hazardous contaminants fall into three broad categories: … Chemical contamination of land or water

… Biological contamination of land or water (e.g. samples containing pathological bacteria potentially

harmful to health) … Contamination of a physical nature (e.g. radioactive material, unsuitable fill materials, flammable gas or

combustible material e.g. wood dust) These can also be listed in the following sub-groups: … Gases Toxic, flammable and explosive gases

e.g. hydrogen cyanide

hydrogen sulphide

Flammable and explosive gases

e.g. methane

… Liquids Flammable liquids and solids Fuels, oils and other hydrocarbons

Solvents

… Combustible materials Timber Ash

Coal residue

… Heavy metals Arsenic, lead, mercury, cadmium, chromium … Corrosive substances Acids

Alkalis

… Toxic substances Hydrocarbons Inorganic salts

… Asbestos

DEFINITION - continued Generally - continued … Substituted aromatic compounds PCBs

Dioxins

Furans

… Biological agents Anthrax Tetanus

BSE

Genetically modified organisms

The following is a brief list of some of the main industrial sectors and their potential contaminants. Sector Contaminant type Example

… Gasworks Coal tar Polyaromatic hydrocarbons (PAH’s) Phenol

Cyanide Free / complex

Sulphur Sulphide / sulphate

Metals Lead, cadmium, mercury

Aromatic hydrocarbons Benzene

… Iron + Steel works Metals Copper, nickel, lead Acids Sulphuric, hydrochloric

Mineral oils -

Coking works residues (As for gasworks )

… Metal finishing Metals Cadmium, chromium, copper, nickel, zinc Acids Sulphuric, hydrochloric

Plating salts Cyanide

Aromatic hydrocarbons Benzene

Chlorinated hydrocarbons Trichloroethane

… Non ferrous metal processing Metals Copper, cadmium, lead, zinc Impurity metals Antimony, arsenic

Other wastes Battery cases, acids

… Oil refineries Hydrocarbons Various fractions Acids, alkalis Sulphuric, caustic soda

Lagging, insulation Asbestos

Spent catalysts Lead, nickel, chromium

… Paints Metals Lead, cadmium, barium Alcohols Toluol, xylol

Chlorinated hydrocarbons Methylene chloride

Fillers, extenders Silica, titanium dioxide, talc

… Petrochemical plants Acids, alkalis Sulphuric, caustic soda

Metals Copper, cadmium, mercury

Reactive monomers Styrene, acrylate, VCM

Cyanide Toluene di-isocyanate

Amines Analine

Aromatic hydrocarbons Benzene, toluene

… Petrol stations Metals Copper, cadmium, lead, nickel, zinc Aromatic hydrocarbons Benzene

Octane boosters Lead, MTBE

Mineral oil -

Paint, plastic residues Barium, cadmium, lead

… Rubber processing Metals Zinc, lead Sulphur compounds Sulphur, thiocarbonate

Reactive monomers Isoprene, isobutylene

Acids Sulphuric. hydrochloric

Aromatic hydrocarbons Xylene, toluene

… Semi-conductors Metals Copper, nickel, cadmium Metalloids Arsenic, antimony, zinc

Acids Nitric, hydrofluoric

Chlorinated hydrocarbons Trichloroethylene

Alcohols Methanol

Aromatic hydrocarbons Xylene, toluene

… Tanneries Acids Hydrochloric Metals Trivalent chromium

Salts Chlorides, sulphides

Solvents Kerosene, white spirit

Cyanide Methyl isocyanate

Degreasers Trichloroethylene

Dyestuff residues Cadmium, benzidine

… Textiles Metals Aluminium, tin, titanium, zinc Acids, alkalines Sulphuric, caustic soda

Salts Sodium hypochlorite

Chlorinated hydrocarbons Perchloroethylene

Aromatic hydrocarbons Phenol

Pesticides Dieldrin, aldrin, endrine

Dyestuff residues Cadmium, benzedrine

… Wood processing Coal tar based preservatives Creosote Chlorinated hydrocarbons Pentachlorophenol

Metalloids / metals Arsenic, copper, chromium

… Hat making Mercury