Ill. Admin. Code tit. 35, § 611.161 - Case-by-Case Reduced Subpart Y Monitoring for Wholesale and Consecutive Systems

The Agency may, by a SEP, reduce the monitoring requirements of Subpart Y as they apply to a wholesale system or a consecutive system, otherwise than by use of the provisions of Section 611.500 subject to the following limitations:

a) The Agency must consider the following system-specific knowledge in making its determination:

1) The amount and percentage of finished water provided;

2) Whether finished water is provided seasonally, intermittently, or full-time;

3) Improved DBP occurrence information based on IDSE results;

4) Significant changes in the supplier's raw water quality, treatment, or distribution system after completion of the IDSE; and

5) Such other considerations as would bear on the occurrence of DBP in the distribution system and the ability of the reduced monitoring to detect DBP in the supplier's distribution system.

b) Any reduced monitoring allowed under this Section must require a minimum of one compliance monitoring location for each supplier.

c) The supplier must report any changes in its raw water quality, treatment, or distribution system or any other factors that come to its attention after the issuance of a SEP that allows reduced monitoring under this Section that would bear on the occurrence of DBP in the distribution system and the ability of the reduced monitoring to detect DBP in the supplier's distribution system.

d) The Agency may allow the reduced monitoring provided by this Section only after USEPA has approved the State program revisions involving Subparts W and Y.

Notes

Ill. Admin. Code tit. 35, § 611.161

Added at 31 Ill. Reg. 11757, effective July 27, 2007

Amended at 43 Ill. Reg. 8206, effective 7/26/2019

BOARD NOTE: Derived from 40 CFR 142.16(m) and the preamble discussion at 71 Fed. Reg. 388, 430-31 (Jan. 4, 2006). USEPA stated that it will allow the State to elect to authorize reduced monitoring according to a procedure devised by the State. The Board borrowed from the special primacy requirements applicable to the Subpart Y provisions and the accompanying preamble discussion to derive the procedure set forth in this Section.