New Jersey Administrative Code › Title 7 - ENVIRONMENTAL PROTECTION › Chapter 14A - NEW JERSEY POLLUTANT DISCHARGE ELIMINATION SYSTEM › Subchapter 13 - EFFLUENT LIMITATIONS FOR DSW PERMITS › Section 7:14A-13.5 - Determination of the reasonable potential to cause an excursion above the SWQS as a basis for requiring inclusion of water quality based effluent limitations

Current through Register Vol. 56, No. 14, July 15, 2024
(a) Water quality
				based effluent limitations shall control all pollutants or pollutant parameters
				(either conventional, nonconventional, or toxic pollutants, including whole
				effluent toxicity) which are or may be discharged at a level which will cause,
				have the reasonable potential to cause, or contribute to an excursion above the
				Surface Water Quality Standards.
(b) When determining whether a discharge
				causes, has the reasonable potential to cause, or contributes to an instream
				excursion above any Surface Water Quality Standard the Department shall
				evaluate and consider existing controls on point and nonpoint sources of
				pollution, the variability of the pollutant or pollutant parameter in the
				effluent, the sensitivity of the test species to toxicity testing (when
				evaluating whole effluent toxicity), and, where appropriate, the available
				dilution of the effluent in the receiving water.
(c) The dilution of the effluent in the
				receiving water shall be determined in accordance with
				7:9B-1.5(h).
(d) A separate determination of reasonable
				potential shall be made for each pollutant or pollutant parameter of interest
				(either conventional, nonconventional, or toxic pollutants, including acute and
				chronic whole effluent toxicity) that is or may be discharged from the
				facility. These determinations shall be based on a WLA or site specific
				allocation.
(e) The discharge shall
				be determined to cause an excursion above the Surface Water Quality Standards
				if the maximum reported effluent concentration, considering the criteria
				averaging period, for the pollutant of interest is greater than the WLA or the
				site specific allocation for that pollutant.
(f) The discharge shall be determined to
				contribute to an excursion above the Surface Water Quality Standards if the
				maximum reported effluent concentration, considering the criteria averaging
				period, for the pollutant of interest when considered collectively with other
				discharges to the receiving water is greater than the WLA determined for that
				pollutant.
(g) The discharge shall
				be determined to have the reasonable potential to cause an excursion above the
				Surface Water Quality Standards if the maximum projected effluent concentration
				is greater than the WLA or site specific allocation determined for that
				discharge for that pollutant or pollutant parameter. The maximum projected
				effluent concentration shall be calculated in accordance with the USEPA TSD, as
				amended and/or supplemented, unless the permittee demonstrates for a given
				pollutant of interest that none of the methods in the TSD are applicable and
				that an alternative statistical method more accurately estimates the maximum
				projected effluent concentration.
(h) Where an effluent concentration is
				directly caused by a documented facility upset, or other unusual event which
				has been identified and appropriately remedied by the permittee, data collected
				during the period of upset may be eliminated when making a determination of
				reasonable potential. Data no longer representative of effluent quality because
				of process modification or pollution prevention activities undertaken shall not
				be used when making a determination of reasonable potential.
(i) (Reserved)
(j) (Reserved)
(k) When the Department determines that a
				discharge does not cause, have reasonable potential to cause, or contribute to
				an excursion above the water quality standards for a specific pollutant or
				pollutant parameter; or that data are insufficient to make such a
				determination:
1. Except as specified in
				(k)1i through iii below, water quality based effluent limitations shall not be
				required for that pollutant or pollutant parameter.
i. Where the discharge is in compliance with
				an existing water quality based effluent limitation and the permittee provides
				treatment for the limited pollutant or pollutant parameter , the reissued
				permit shall include a water quality based effluent limitation for the affected
				pollutant or pollutant parameter unless the permittee demonstrates to the
				satisfaction of the Department that a water quality based limitation is no
				longer required and that the existing effluent quality is anticipated to be
				maintained.
ii. When the Department
				determines in accordance with (k)1i above that a water quality based effluent
				limitation is not required for the reissued permit, the fact sheet for the
				reissued permit shall include a summary of effluent data for the pollutant or
				pollutant parameter, a justification for eliminating the effluent limitation,
				and a determination that eliminating the effluent limitation is not anticipated
				to cause or contribute to an exceedance of the surface water quality
				standards.
iii. When the Department
				determines in accordance with (k)1i above that a water quality based effluent
				limitation is not required for the reissued permit, the discharge permit shall
				be reopened and modified to include water quality based effluent limitations if
				the effluent quality changes so as to cause, contribute, or have the reasonable
				potential to cause or contribute to an excursion above the Surface Water
				Quality Standards.
iv. The
				Department shall consider the following factors when making a determination
				regarding reasonable potential for discharges with existing water quality based
				effluent limitations:
(1) The permit
				compliance history for the facility, including the compliance history for the
				specific pollutant or pollutant parameter and any permit conditions related to
				the pollutant or pollutant parameter;
(2) The reliability of the treatment process;
				and
(3) The ratio between the
				permitted or actual effluent flow and the base flow of the receiving
				water;