HL Deb 27 February 1963 vol 247 c183WA
LORD CLITHEROE

asked Her Majesty's Government:

What is the permitted level of chlorine in water supplied in this country by statutory water undertakings, and what, if any, other poisons may be legally used.

THE JOINT PARLIAMENTARY SECRETARY, MINISTRY OF HOUSING AND LOCAL GOVERNMENT (LORD HASTINGS)

The treatment of water, to render it wholesome for domestic use, must vary considerably according to the character of the water and the nature of its source. It is therefore inappropriate, and would be exceedingly difficult, to impose any limit by law upon the level of chlorine. Waterworks techniques ensure that a safe and acceptable water is put into supply. The law does not prescribe any list of substances, which may be used in water treatment.