Current through Register Vol. 56, No. 24, December 18, 2024
(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.
