Section 653.116  Filtration Rates

a)         The nominal filter rate for single and multi media rapid rate gravity filters shall be 2 gal/min/sq ft.

b)         Nominal filtration rates may be increased to 3 gal/min/sq ft for single media filters and to 5 gal/min/sq ft for multi-media filters under the following conditions:

1)         continuous nephelometric turbidity monitoring and recording equipment is provided for each filter effluent individually or on a rotating basis; and

2)         surface wash equipment is provided.

c)         Filtration rates shall be reduced when finished water turbidity exceeds the standard in 35 Ill. Adm. Code 604.202.