Section 930.40  Treatment Plant Maintenance

a)         Slow sand filtration treatment plants shall be maintained as follows:

1)         Cleaning.  Whenever the design flow can no longer be achieved the filter must be cleaned.  In order to clean the filter, the water level must be lowered to 2 to 3 inches below the top of the sand.  The filter must not be drained.  The accumulated mud and slime along with ½ inch of the top of the sand surface must be removed.

2)         Proper Filter Depth.  After 6 inches of sand has been removed due to repeated cleaning, additional sand which shall comply with the design criteria specified in Section 930.20(c) must be added so the filter is restored to the original depth of 3 feet.

b)         Cartridge filtration treatment plants shall be maintained as follows:

1)         Cartridge filters shall be cleaned or replaced according to the manufacturer’s recommendation.

2)         Replacement cartridges shall be equal to the original equipment.

c)         Ultraviolet disinfection equipment shall be maintained as follows:

1)         The ultraviolet equipment lamp shall be cleaned or replaced when the equipment has a lamp intensity failure.  The lamp shall be replaced when the equipment has a lamp failure.

2)         The ultraviolet lamp shall be replaced at intervals specified by the manufacturer, but no less often than annually.

3)         Replacement ultraviolet equipment lamps shall be equal to the original equipment.

(Source:  Amended at 27 Ill. Reg. 15998, effective October 1, 2003)