Section 611.240  Disinfection

a)         This subsection (a) corresponds with the first sentence of 40 CFR 141.72, pertaining to unfiltered system suppliers using a surface water source not providing filtration treatment. These no longer exist in Illinois.  This statement maintains structural consistency with USEPA regulations.

b)         This subsection (a) corresponds with the second sentence of 40 CFR 141.72, pertaining to unfiltered system suppliers using groundwater source under the direct influence of surface water not providing filtration treatment. These no longer exist in Illinois.  This statement maintains structural consistency with USEPA regulations.

c)         Upon determining that a supplier must apply filtration, the Agency may issue a SEP requiring the supplier to comply with interim disinfection requirements before installing filtration.

d)         A supplier using a surface water source and providing filtration treatment must provide the disinfection treatment Section 611.242 specifies.

e)         A supplier using a groundwater source under the direct influence of surface water and providing filtration treatment must provide the disinfection treatment Section 611.242 specifies beginning when the supplier installs filtration.

f)         Failing to comply with Section 611.242 before the Agency requires in a SEP is a treatment technique violation.

BOARD NOTE:  This Section derives from 40 CFR 141.72 preamble.

(Source:  Amended at 47 Ill. Reg. 16486, effective November 2, 2023)