Section 310.112  Significant Industrial User

a)         Except as provided in subsections (b) and (c), the term "significant industrial user" means the following:

1)         An industrial user subject to any of the categorical pretreatment standards under Sections 310.220 through 310.222, 310.230, 310.232, and 310.233 and 35 Ill. Adm. Code 307; and

2)         Any other industrial user that: discharges an average of 25,000 gallons per day or more of process wastewater to the POTW (excluding sanitary, noncontact cooling, and boiler blowdown wastewater); contributes a process wastestream which makes up five percent or more of the average dry weather hydraulic or organic capacity of the POTW treatment plant; or is designated as such by the Control Authority on the basis that the industrial user has a reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard or requirement (in accordance with Section 310.510(f)).

b)         The Control Authority may determine that an industrial user subject to categorical pretreatment standards under Sections 310.220 through 310.222, 310.230, 310.232, and 310.233 and 35 Ill. Adm. Code 307 is a non-significant categorical industrial user, rather than a significant industrial user, on a finding that the industrial user never discharges more than 100 gallons per day (gpd) of total categorical wastewater (excluding sanitary, noncontact cooling, and boiler blowdown wastewater, unless specifically included in the pretreatment standard), and the industrial user meets the following conditions:

1)         Prior to the Control Authority's finding, the industrial user has consistently complied with all applicable categorical pretreatment standards and requirements;

2)         The industrial user annually submits the certification statement required in Section 310.636 together with any additional information necessary to support the certification statement; and

3)         The industrial user never discharges any untreated concentrated wastewater.

c)         Upon a finding that an industrial user meeting the criteria in subsection (a)(2) has no reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standards or requirement, the Control Authority may at any time, on its own initiative or in response to a petition from an industrial user or POTW, and in accordance with Section 310.510(f), determine that such industrial user is not a significant industrial user.

BOARD NOTE:  Derived from 40 CFR 403.3(v) (2005), as renumbered and amended at 70 Fed. Reg. 60134 (Oct. 14, 2005).

(Source:  Amended at 47 Ill. Reg. 5083, effective March 23, 2023)