(A) The director shall include in Ohio NPDES permits the treatment and disposal standards and effluent limitations for discharges described in paragraph (C) of this rule. Effluent limitations for these discharges will be based on the requirements of this rule, or any more stringent water-quality-based limitations required by rule 3745-33-07 of the Administrative Code. The effluent limitations under this rule apply at the last point where the discharge from the applicable treatment system can be monitored, prior to both:
(1) The discharge entering waters of the state; and
(2) Dilution of the discharge by other wastewaters.
(B) If, for any limitation or standard under this rule, an applicant demonstrates to the director that site-specific conditions are fundamentally different from those considered in the development of the limitation or standard, the director may establish and include in the permit for the facility a site-specific limitation or standard instead of the limitation or standard set forth in this rule. Conditions that the director considers in development of standards and conditions under this rule may include items set forth in section 6111.42 of the Revised Code and other information relevant to the director's general supervision of the treatment and disposal of sewage and industrial wastes under section 6111.46 of the Revised Code or the setting of terms and conditions of permits under section 6111.03 of the Revised Code.
(C) Phosphorus treatment.
(1) Lake Erie basin. Any publicly owned treatment works (POTW) in the Lake Erie basin with a design flow of 1.0 million gallons per day or more, or designated as a major discharger by the director, must meet a total phosphorus discharge limit of 1.0 milligram per liter as a thirty-day average.
(2) POTW and semi-public discharges to state lakes. Any POTW or semi-public discharger with a design flow of 0.2 million gallons per day or more that discharges to a publicly owned lake or reservoir must meet a total phosphorus discharge limit of 1.0 milligram per liter (thirty-day average). This limit also applies to discharges of this magnitude to a tributary of such lake or reservoir if the discharge would contribute significant loadings of phosphorus to the reservoir. This paragraph does not apply to discharges to upground reservoirs or privately owned lakes, or to point source discharges to Lake Erie.