Section 611.800  General Requirements and Applicability

a)         Scope of This Subpart S.  The requirements of this Subpart S constitute NPDWRs.

b)         Applicability.  This Subpart S applies to all PWS suppliers that use groundwater, except that it does not apply to public water systems that combine all of their groundwater with surface water or with groundwater under the direct influence of surface water prior to treatment under Subpart B.  For the purposes of this Subpart S, "GWS" is defined as any PWS that meets this applicability statement, including a consecutive system receiving finished groundwater.

c)         General Requirements.  A supplier subject to this Subpart S must comply with the following requirements:

1)         Sanitary survey information requirements for all GWS suppliers, as described in Section 611.801.

2)         Microbial source water monitoring requirements for GWS suppliers that do not treat all of their groundwater to at least 99.99 percent (4-log) treatment of viruses (using inactivation, removal, or an Agency-approved combination of 4-log virus inactivation and removal) before or at the first customer, as described in Section 611.802.

3)         Treatment technique requirements, described in Section 611.803, that apply to GWS suppliers that have fecally contaminated source waters, as determined by source water monitoring conducted under Section 611.802, or which have significant deficiencies that are identified by the Agency, by a SEP, or which are identified by USEPA under SDWA section 1445 (42 USC 300j-4).  A GWS supplier with fecally contaminated source water or with significant deficiencies subject to the treatment technique requirements of this Subpart S must implement one or more of the following corrective action options:  correct all significant deficiencies; provide an alternate source of water; eliminate the source of contamination; or provide treatment that reliably achieves at least 4-log treatment of viruses (using inactivation, removal, or an Agency-approved combination of 4-log virus inactivation and removal) before or at the first customer.

4)         A GWS supplier that provides at least 4-log treatment of viruses (using inactivation, removal, or an Agency-approved combination of 4-log virus inactivation and removal) before or at the first customer is required to conduct compliance monitoring to demonstrate treatment effectiveness, as described in Section 611.803(b).

5)         If requested by the Agency, a GWS supplier must provide the Agency with any existing information that will enable the Agency to perform a hydrogeologic sensitivity assessment.

BOARD NOTE:  The Board moved the definition of "hydrogeologic sensitivity assessment" to the definitions provision of this Part:  Section 611.101.

d)         This subsection (d) corresponds with 40 CFR 141.400(d), which recites past effective dates.  This statement maintains structural consistency with the corresponding federal provision.

BOARD NOTE:  Derived from 40 CFR 141.400.

(Source:  Amended at 44 Ill. Reg. 6996, effective April 17, 2020)