Section 611.220  General Requirements

a)         This Subpart B constitutes NPDWRs.  This Subpart B establishes criteria for filtration as a treatment technique for PWSs using a surface water source or groundwater source under the direct influence of surface water.  This Subpart B also establishes treatment techniques in lieu of MCLs for specific contaminants:  Giardia lamblia, viruses, HPC bacteria, Legionella, and turbidity.  A supplier using a surface water source or a groundwater source under the direct influence of surface water must treat that source water and comply with these treatment techniques.  The treatment techniques comprise installing and properly operating water treatment processes that reliably achieve specific objectives:

1)         At least 99.9 percent (3-log) removal or inactivation of Giardia lamblia cysts between a point where the raw water is not subject to recontamination by surface water runoff and a downstream point before or at the first customer; and

2)         At least 99.99 percent (4-log) removal or inactivation of viruses between a point where the raw water is not subject to recontamination by surface water runoff and a downstream point before or at the first customer.

b)         A supplier using a surface water source or a groundwater source under the direct influence of surface water complying with Section 611.250 (filtration) and Section 611.241 (disinfection) complies with subsection (a).

c)         A supplier using a surface water source or groundwater source under the direct influence of surface water must have a certified operator under 35 Ill. Adm. Code 603.103 and the Public Water Supply Operations Act [415 ILCS 45].

d)         Additional Requirements for PWSs Serving 10,000 or More Persons.  In addition to this Subpart B, a PWS serving 10,000 or more persons must also comply with Subpart R.

e)         Additional Requirements for Systems Serving Fewer Than 10,000 People.  In addition to this Subpart B, a supplier serving fewer than 10,000 people must also comply with Subpart X.

BOARD NOTE:  This Section derives from 40 CFR 141.70.  The Public Water Supply Operations Act applies only to CWSs, which the Agency regulates.  It does not apply to non-CWSs, which Public Health regulates. Public Health has its own requirements for personnel operating water supplies, e.g., 77 Ill. Adm. Code 900.40(e). The Board removed provisions for unfiltered system suppliers.  A supplier in Illinois using a surface water source or groundwater under the direct influence of surface water must apply filtration treatment and disinfection to water it provides to the public.

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