Most undesirable metal in drinking water is:

Undesirable metal in drinking water: iron, manganese, zinc, copper, aluminum, lead MOST undesirable metal in drinking water: Lead. Lead was earlier seen in drinking water when water was being supplied through lead pipes. Undesirable salts in drinking water: chloride, fluorides, nitrites, nitrates, calcium, magnesium. Undesirable gases in drinking water: ammonia, hydrogen sulphide, methane.