N.J. Admin. Code § 7:14A-21.4 - Categorical standards, calculation of equivalent and/or alternative limits

(a) When the categorical pretreatment standards are expressed in terms of production, equivalent effluent limitations shall be calculated as follows:

1. When the limits in a categorical pretreatment standard are expressed only in terms of mass of pollutant per unit of production, the control authority may convert the limits to equivalent limitations expressed either as mass of pollutant discharged per day or effluent concentration for purposes of calculating effluent limitations applicable to individual indirect users.

2. A control authority calculating equivalent mass-per-day limitations under (a)1 above shall calculate such limitations by multiplying the limits in the categorical pretreatment standard by the indirect user's average rate of production. This average rate of production shall be based not upon the designed production capacity but rather upon a reasonable measure of the indirect user's actual long-term daily production, such as the average daily production during a representative year. For new sources, actual production shall be estimated using projected production.

3. A control authority calculating equivalent concentration limitations under (a)1 above shall calculate such limitations by dividing the mass limitations derived under (a)2 above by the average daily flow rate of the indirect user's regulated process wastewater. This average daily flow rate shall be based upon a reasonable measure of the indirect user's actual long-term average flow rate, such as the average daily flow rate during the representative year. For new sources, flow rate shall be estimated using projected flow rate.

(b) When the limits in a categorical pretreatment standard are expressed only in terms of pollutant concentrations, an indirect user may request that the control authority convert the limits to equivalent mass limits. The determination to convert concentration limits to mass limits is within the discretion of the control authority.

1. To be eligible for equivalent mass limits, the indirect user shall:

i. Employ, or demonstrate that it will employ, water conservation methods and technologies that substantially reduce water use during the term of its control mechanism;

ii. Currently use control and treatment technologies adequate to achieve compliance with the applicable categorical pretreatment standard, and not have used dilution as a substitute for treatment;

iii. Provide sufficient information to establish the facility's actual average daily flow rate for all wastestreams, based on data from a continuous effluent flow monitoring device, as well as the facility's long-term average production rate. Both the actual average daily flow rate and the long-term average production rate shall be representative of current operating conditions;

iv. Not have daily flow rates, production levels, or pollutant levels that vary so significantly that equivalent mass limits are not appropriate to control the discharge; and

v. Have consistently complied with all applicable categorical pretreatment standards during the period (determined by the control authority) prior to the user's request for equivalent mass limits.

2. An indirect user subject to equivalent mass limits shall:

i. Maintain and effectively operate control and treatment technologies adequate to achieve compliance with the equivalent mass limits;

ii. Continue to record the facility's flow rates through the use of a continuous effluent flow monitoring device;

iii. Continue to record the facility's production rates and notify the control authority whenever production rates are expected to vary by more than 20 percent from those production rates determined in (b)1iii above. Upon notification of a revised production rate, reassessment and revision of the equivalent mass limit will be performed by the control authority as necessary to reflect changed conditions at the facility; and

iv. Continue to employ the same or comparable water conservation methods and technologies as those implemented pursuant to (b)1ii above, so long as the indirect user discharges under an equivalent mass limit.

(c) Mass limits for the categorical pretreatment standards at 40 CFR Parts 414, 419 and 455 may be converted to concentration limits by the control authority for purposes of calculating limitations applicable to individual indirect users provided:

1. The concentrations listed in the applicable subparts of 40 CFR Parts 414, 419 and 455 are used; and

2. The user documents that dilution is not being substituted for treatment as prohibited by (g) below.

(d) Equivalent limitations calculated in accordance with (a), (b), and (c) above are deemed pretreatment standards for the purposes of section 307(d) of the Federal Act and this subchapter. Once incorporated into its control mechanism, the indirect user shall comply with the equivalent limitations in lieu of the promulgated categorical standards from which the equivalent limitations were derived.

(e) When a categorical pretreatment standard that specifies one limit for calculating maximum daily discharge limitations and a second limit for calculating maximum monthly average, or four-day average, limitations are applied, the same production or flow figure shall be used in calculating both the maximum and average equivalent limitations.

(f) Any indirect user operating under a control mechanism incorporating equivalent mass or concentration limits calculated from a production based standard shall notify the control authority within two business days after the indirect user has a reasonable basis to know that the production level will significantly change within the next calendar month. Any indirect user that does not notify the control authority of such anticipated change shall be required to meet the mass or concentration limits in its IPP permit that were based on the original estimate of the long term average production rate.

(g) Except where expressly authorized to do so by an applicable pretreatment standard or requirement, no indirect user shall increase the use of process water, or in any other way attempt to dilute a discharge as a partial or complete substitute for adequate treatment to achieve compliance with a pretreatment standard or requirement. The control authority may impose mass limitations on indirect users which are using dilution to meet applicable pretreatment standards or requirements, or in other cases where the imposition of mass limitations is appropriate.

(h) Where process effluent is mixed prior to treatment with wastewaters other than those generated by the regulated process, fixed alternative categorical limits shall be derived by the control authority or by the indirect user with the written concurrence of the control authority. These alternative categorical limits shall be applied to the mixed effluent. When deriving alternative categorical limits, the control authority or indirect user shall calculate both an alternative daily maximum value using the daily maximum value(s) specified in the appropriate categorical pretreatment standard(s) and an alternate monthly or consecutive sampling day average value using the monthly or consecutive sampling day average value(s) specified in the appropriate categorical pretreatment standard(s). The indirect user shall comply with the alternative categorical daily maximum and monthly average or consecutive sampling day limits fixed by the control authority, in the indirect user's permit. Modification is authorized whenever there is a material or significant change in the values used in the calculation to fix alternative categorical limits for the regulated pollutant. An indirect user shall immediately report any such material or significant change to the control authority. Where appropriate, alternative categorical limits shall be re-calculated within 30 days of being informed of changes by the indirect user.

1. For purposes of these formulas, the average daily flow means a reasonable measure of the average daily flow for a 30-day period. For new sources, flows shall be estimated using projected values. The alternative limit for a specified pollutant shall be derived by the use of either of the following formulas:

i. Alternative concentration limit.

ii. Alternative mass limit:

Data in image

2. An alternative pretreatment limit shall not be used if such alternative limit is below the analytical detection limit for any of the regulated pollutants.

3. The indirect user shall monitor, to ensure compliance with the alternative categorical limits, in accordance with the requirements of N.J.A.C. 7:14A-21.3(g).

4. Where a treated regulated process wastestream is combined prior to treatment with wastewaters other than those generated by the regulated process, the indirect user may monitor either the segregated process wastestream or the combined wastestream for the purpose of determining compliance with applicable pretreatment standards. If the indirect user monitors the segregated process wastestream, it shall apply the applicable categorical pretreatment standard. If the indirect user chooses to monitor the combined wastestream, it shall apply an alternative discharge limit calculated using the combined wastestream formula as provided in this section. The indirect user may change monitoring points only after receiving approval from the control authority. The control authority shall ensure that any change in an indirect user's monitoring point(s) will not allow the indirect user to substitute dilution for adequate treatment to achieve compliance with applicable standards.

(i) Categorical pretreatment standards may be adjusted to reflect the presence of pollutants in the indirect user's intake water. Any indirect user wishing to obtain credit for intake pollutants shall submit a written request to the control authority. Upon such request, the applicable standard will be calculated on a "net" basis (that is, adjusted to reflect credit for pollutants in the intake water) if the requirements of (i)1 below are met.

1. Categorical pretreatment standards may be adjusted to reflect the presence of pollutants in the indirect user's intake water provided either:

i. The applicable categorical pretreatment standards contained in 40 CFR subchapter N specifically provide that they shall be applied on a net basis; or

ii. The indirect user demonstrates that the control system it proposes or uses to meet applicable categorical pretreatment standards would, if properly installed and operated, meet the standards in the absence of pollutants in the intake waters.

2. Credit for generic pollutants such as biochemical oxygen demand (BOD), total suspended solids (TSS), and oil and grease shall not be granted unless the indirect user demonstrates that the constituents of the generic measure in the indirect user's effluent are substantially similar to the constituents of the generic measure in the intake water or unless appropriate additional limits are placed on process water pollutants either at the outfall or elsewhere.

3. Credit shall be granted only to the extent necessary to meet the applicable categorical pretreatment standard(s), up to a maximum value equal to the influent value. Additional monitoring may be necessary to determine eligibility for credit and compliance with standard(s) adjusted under this section.

4. Credit shall be granted only if the indirect user demonstrates that the intake water is drawn from the same body of water as that into which the local agency's treatment works discharges. The control authority may waive this requirement if it finds that no environmental degradation will result.

Notes

N.J. Admin. Code § 7:14A-21.4

Amended by R.2009 d.7, effective 1/5/2009.
See: 40 N.J.R. 1478(a), 41 N.J.R. 142(a).
Added new (b) and (c); recodified former (a)4 through (a)6 as (d) through (f); in (d), updated the internal references and substituted "Once incorporated into its control mechanism, the indirect user" for "Indirect users"; in (e), substituted "the maximum and average" for "types of"; recodified former (b) through (d) as (g) through (i); and rewrote (i).