Letter: Call for a two-tier system

FRED PEARCE neglected to mention a simple and cheap solution to the supply of clean water 'Counting the cost of cleaner water', 20 September).

Most water is flushed down the toilet or used for washing, so why do we purify it? We could supply the water we use for drinking and cooking separately, at a nominal fee, via retail outlets, or have it arrive with the morning's milk. The cost benefits of having to purify only a small fraction of the supply would be enormous, reducing, not increasing, water costs overall.

David Lacey

London W5