Paragraph 6
England and Wales
(1)
The revivable total colony count of the water at source, determined according to sub-paragraph (2), shall conform to the normal viable colony count of that water and shall not show that the source of that water is contaminated.
(2)
The colony count is that determined per ml of water—
(a)
at 20 to 22 oC in 72 hours on agar-agar or an agar-gelatine mixture; and
(b)
at 37 oC in 24 hours on agar-agar.