N.J. Admin. Code § 7:9C-1.9

Current through Register Vol. 56, No. 21, November 4, 2024

Section 7:9C-1.9 - Constituent standard modifications and practical quantitation levels

(a) When constituents at background water quality exceed the criteria in 7:9C-1.7, the Department shall consider the following modifications in the development of constituent standards in the context of applicable regulatory programs:

1. For discharges that derive their source water from directly upgradient of the discharge, the constituent standards shall not be more stringent than the background water quality (that is, the source water quality);

2. For other discharges:

i. In areas where the criteria for the constituent are exceeded within the area due to natural quality, the constituent standards shall be established as the background water quality.

ii. In other areas, the constituent standards shall be established such that the volume and concentration of ground water exceeding the criteria are not increased by discharges.

(b) The Department may define Classification Exception Areas as provided for in 7:9C-1.6 within which the provisions of 7:9C-1.7, 1.8, and (a) above do not apply regarding specified constituents.

(c) Where a constituent standard (the criterion as adjusted by the antidegradation policy and applicable criteria exceptions) is of a lower concentration than the relevant PQL (in Appendix Table 1), the Department shall not (in the context of an applicable regulatory program) consider the discharge to be causing a contravention of that constituent standard so long as the concentration of the constituent in the affected ground water is less than the relevant PQL.

1. Where interim specific criteria are derived by the Department, interim PQLs shall also be derived for those constituents as appropriate.

2. Specific PQLs are not provided for interim generic ground water criteria. The numeric interim generic ground water criteria shall be used as the constituent standard unless a PQL applicable for an interim generic criteria is approved by the Department and published with the interim generic criteria in accordance with (c)3 below.

3. Selection and derivation of PQLs shall be as follows:

i. PQLs shall be rounded to one significant figure using standard methods.

ii. PQLs listed in Appendix Table 1 were, and additional PQLs shall be, derived or selected for each constituent using the most sensitive analytical method providing positive constituent identification from (c)3ii(1) and (2) below, in that order of preference:

(1) PQLs derived from Method Detection Limit (MDL) data from the New Jersey Department of Health and Senior Services Laboratory (DHSS) multiplied by 5;

(2) PQLs derived from laboratory performance data that has been evaluated by the Department using the method of Sanders, Lippincott and Eaton (See Sanders, P. et at., "Determining Quantitation Levels for Regulatory Purposes." J. Amer. Water Works Assoc., 1996, March pp. 104-114).

iii. The Department may approve an alternative PQL. An alternative PQL shall be approved when the evidence (in the context of an applicable regulatory program) establishes that:

(1) Based upon site-specific ground water matrix considerations, a PQL listed in Appendix Table 1 for a constituent is not valid;

(2) An alternative PQL is more appropriate for that constituent with regard to compliance with this chapter;

(3) The alternative PQL has been determined through rigorous laboratory analysis using methods appropriate to the site-specific ground water matrix and constituent(s), including, without limitation, the derivation of an MDL using the methodology specified by Appendix B of 40 CFR Part 136; and

(4) The alternative PQL does not result in nondetection of any target constituent due to masking effects of other target constituents, non-target constituents, or natural substances.

iv. The approval of an alternative PQL shall be applicable to the regulation of ground water quality affected by the discharge for which it is derived, and its approval and utilization shall be subject to the same procedural requirements as any other aspect of the regulatory decision.

4. Where ground water pollutants affect surface water quality within the meaning of 7:9C-1.7(g), more sensitive analytical techniques such as bioassays or bioaccumulation assays may be required by the Department.

N.J. Admin. Code § 7:9C-1.9

Recodified from N.J.A.C. 7:9-6.9 by R.2005 d.368, effective 11/7/2005.
See: 36 New Jersey Register 4374(b), 37 New Jersey Register 4226(b).
Rewrote (c).