WATER, ENGLAND AND WALES Citation and commencement 1 These Regulations may be cited as the Trade Effluents (Prescribed Processes and Substances) Regulations 1989 and shall come into force on 1st September 1989. Interpretation 2 In these Regulations – “the 1989 Act ” means the Water Act 1989; “asbestos” means any of the fibrous silicates, namely, crocidolite, actinolite, anthophyllite, chrysotile, amosite and tremolite; and “background concentration”, in relation to any substance, means such concentration of the substance as would, but for anything done on the premises in question, be present in the effluent discharged from those premises; and without prejudice to the generality of the foregoing, includes such concentrations of the substance as are present – in water supplied to the premises; in water abstracted for use in the premises; and in precipitation onto the site within which the premises are situated. Trade effluent containing prescribed substances 3 Section 74 of the 1989 Act (control of exercise of trade effluent functions in certain cases) shall apply to trade effluent in which any of the substances listed in Schedule 1 to these Regulations is present in a concentration greater than the background concentration. Trade effluent derived from prescribed processes 4 Section 74 of the 1989 Act shall apply to trade effluent deriving from a process of a description mentioned in Schedule 2 to these Regulations if either asbestos or chloroform is present in that effluent in a concentration greater than the background concentration. Variation of existing consents 5 1 A sewerage undertaker shall, in the circumstances referred to in paragraph (2), notify the Secretary of State of its proposal to vary, by direction under section 60(1) of the Public Health Act 1961 , the conditions attached to a consent having effect as if given by the undertaker under the Public Health (Drainage of Trade Premises) Act 1937 (consent to the discharge of trade effluent into a public sewer). 2 The circumstances mentioned in paragraph (1) are that – a the consent has not been reviewed by the Secretary of State in accordance with paragraph 2 of Schedule 9 to the 1989 Act; and b if the proposed variation were made, the consent would authorise the discharge of effluent containing a concentration of a substance referred to in Schedule 1 to these Regulations in excess of the background concentration. 3 A notification under paragraph (1) shall be treated as a reference to the Secretary of State under paragraph 1 of the said Schedule 9 of the question whether the relevant operations should be prohibited; and paragraphs 3 and 4 of that Schedule shall have effect accordingly. 4 Where the undertaker has notified the Secretary of State in accordance with paragraph (1) – a it shall inform the owner or occupier of the trade premises in question of that notification; and b it shall not vary the consent unless the Secretary of State has given such a notice as is described in paragraph 3(2)(c) of the said Schedule 9. 5 The requirements imposed on a sewerage undertaker by this regulation shall be enforceable under section 20 of the 1989 Act by the Secretary of State. Signed by authority of the Secretary of State Michael Howard Minister for Water and Planning, Department of the Environment 6th July 1989 Peter Walker Secretary of State for Wales 6t July 1989