Section 327IAC2-1.3-4. Exemptions from the antidegradation demonstration requirements and the water quality improvement project or payment to the OSRW improvement fund requirements

   (a) For an ONRW or OSRW inside the Great Lakes basin, an exemption from the antidegradation demonstration requirements included in section 5 of this rule and the water quality improvement project or payment to the OSRW improvement fund requirements included in section 7 of this rule shall be allowed for new or increased loadings of mercury and non-BCCs if the following conditions are met:

(1) All reasonable methods for minimizing or preventing the new or increased loading have been taken.

(2) The discharge will last less than twelve (12) months or three hundred sixty-five (365) days.

(3) A person applies for and receives authorization from the commissioner.

(4) The discharge will result only in a short-term, temporary (not to exceed twelve (12) months) lowering of water quality.

(5) The discharge complies with the antidegradation standards contained in section 3 of this rule.

  (b) For an HQW except an ONRW or OSRW inside the Great Lakes basin, an exemption from the antidegradation demonstration requirements included in section 5 of this rule and the water quality improvement project or payment to the OSRW improvement fund requirements included in section 7 of this rule shall be allowed for new or increased loadings if the following conditions are met:

(1) All reasonable methods for minimizing or preventing the new or increased loading have been taken.

(2) The discharge will last less than twelve (12) months or three hundred sixty-five (365) days.

(3) A person applies for and receives authorization from the commissioner.

(4) The discharge will result only in a short-term, temporary (not to exceed twelve (12) months) lowering of water quality.

(5) The discharge complies with the antidegradation standards contained in section 3 of this rule.

  (c) For an HQW except an ONRW, a new or increased loading of a regulated pollutant resulting from the following is exempt from the antidegradation demonstration requirements included in section 5 of this rule and the water quality improvement project or payment to the OSRW improvement fund requirements included in section 7 of this rule:

(1) A new or increased loading of a non-BCC that is a demonstrated de minimis lowering of water quality as shown by the submission of sufficient information that allows the commissioner to verify the de minimis as determined according to the following:

(A) Calculation considerations according to the following:

(i) The proposed net increase in the loading of a regulated pollutant is less than or equal to ten percent (10%) of the available loading capacity determined at the time of the specific proposed new or increased loading of the regulated pollutant. The available loading capacity shall be established at the time of each request for a new or increased loading of a regulated pollutant.

(ii) The benchmark available loading capacity is equal to ninety percent (90%) of the available loading capacity established at the time of the request for the initial increase in the loading of a regulated pollutant.

(iii) For every request after the time of the request for the initial increase in the loading of a regulated pollutant, the available loading capacity remaining after the net increase in the loading of a regulated pollutant must be greater than or equal to the benchmark available loading capacity.

(B) For heat, except for loadings to Lake Michigan, the following conditions must be satisfied:

(i) The new or increased loading will not result in an increase in temperature in a stream or an inland lake, outside of the designated mixing zone, where applicable.

(ii) The new or increased loading will not result in an increase in waste heat of an amount in a stream greater than the amount determined by calculating the number of British thermal units (BTUs) required to raise the temperature of the stream design flow of the receiving stream by one (1) degree Fahrenheit.

(C) For loadings to Lake Michigan, relative to temperature and heat, the following conditions must be satisfied:

(i) The new or increased loading will not result in an increase in temperature as allowed in 327 IAC 2-1.5-8(c)(4)(D)(iv), at the edge of a one thousand (1,000) foot arc inscribed from a fixed point adjacent to the loading.

(ii) The new or increased loading will not result in an increase in waste heat in an amount greater than five-tenths (0.5) billion BTUs per hour.

(2) A new or increased loading that results from one (1) of the following activities that does not require the submission of information beyond what is required to comply with the discharger's existing applicable permit:

(A) A change in loading of a regulated pollutant within the existing capacity and processes that are covered by an existing applicable permit, including, but not limited to, the following:

(i) Normal operational variability, including, but not limited to, intermittent increased loadings due to wet weather conditions.

(ii) A change in intake water pollutants not caused by the discharger.

(iii) Increasing the production hours of the facility, for example, adding a second shift.

(iv) Increasing the rate of production.

(v) A change at an internal outfall that does not directly discharge to a surface water of the state.

(vi) A change in the applicable effluent limitation guideline based on a change in production.

(B) A bypass not prohibited by 327 IAC 5-2-8(11).

(C) A new limit for a regulated pollutant for an existing permitted discharger that will not allow an increase in either the mass or concentration of the regulated pollutant discharged, including a new limit that is a result of one (1) of the following:

(i) New or improved:

(AA) monitoring data; or

(BB) analytical methods.

(ii) New or modified:

(AA) water quality criteria; or

(BB) effluent limitation guidelines, pretreatment standards, or control requirements for POTWs.

(D) An increased loading of a regulated pollutant at an existing outfall discharging to a water of the state due to increasing the sewered area, connection of new sewers and users, or acceptance of trucked-in wastes, such as septage and holding tank wastes, by a POTW, provided the following are true:

(i) There is no increase in the existing NPDES permit limits.

(ii) There is no increase beyond the treatment capacity of the facility.

(iii) There is no significant change expected in the characteristics of the wastewater discharged.

(iv) There is no increased loading of BCCs from nondomestic wastes.

(Water Pollution Control Division; 327 IAC 2-1.3-4; filed May 29, 2012, 3:19 p.m.: 20120627-IR-327080764FRA)