Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 611 - PRIMARY DRINKING WATER STANDARDS
Subpart B - FILTRATION AND DISINFECTION
Section 611.250 - Filtration
Current through Register Vol. 48, No. 38, September 20, 2024
A supplier using a surface water source or a groundwater source under the direct influence of surface water must provide both disinfection treatment, as Section 611.242 specifies, and filtration treatment complying with subsection (a), (b), (c), (d), or (e) within 18 months after the Agency issues a SEP requiring the supplier to apply filtration treatment. Failing to apply filtration treatment before the time the Agency provides in a SEP violates a treatment technique.
a) Conventional Filtration Treatment or Direct Filtration
b) Slow Sand Filtration
c) Diatomaceous Earth Filtration
d) Other Filtration Technologies. The Agency may issue a SEP allowing a supplier to use a filtration technology not included in subsections (a) through (c) if the supplier demonstrates, using pilot plant studies or other means, that the alternative filtration technology, in combination with disinfection treatment complying with Section 611.242, consistently achieves 99.9 percent removal or inactivation of Giardia lamblia cysts and 99.99 percent removal or inactivation of viruses. Subsection (b) applies to a supplier making this demonstration. A supplier serving 10,000 or more persons must comply with Section 611.743(b). A supplier serving fewer than 10,000 people must comply with Section 611.955.
BOARD NOTE: This Section derives from 40 CFR 141.73.