If process wastewater is mixed prior to treatment with
wastewaters other than those generated by the regulated process, the Control
Authority (or the industrial user with the written concurrence of the Control
Authority) must derive fixed alternative discharge limits. When it is deriving
alternative categorical limits, the Control Authority must calculate both an
alternative daily maximum value using the daily maximum values specified in the
appropriate categorical pretreatment standards and an alternative consecutive
sampling day average value using the average monthly values specified in the
appropriate categorical pretreatment standards. The industrial user must comply
with the alternative daily maximum and average monthly limits fixed by the
Control Authority until the Control Authority modifies the limits or approves
an industrial user modification request. Modification is authorized whenever
there is a material or significant change in the values used in the calculation
to fix alternative limits for the regulated pollutant. An industrial user must
immediately report any such material or significant change to the Control
Authority. If appropriate, the Control Authority must calculate new alternative
categorical limits within 30 days.
a)
Alternative Limit Calculation. For these formulas, the "average daily flow"
means a reasonable measure of the average daily flow for a 30-day period. For
new sources, flows must be estimated using projected values. The Control
Authority must derive the alternative limit for a specified pollutant by the
use of either of the following formulas:
1)
Alternative Concentration Limit
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here to view image
where
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C
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=
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The alternative concentration limit for the combined
waste stream.
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Ci
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=
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The categorical pretreatment standard concentration
limit for a pollutant in the regulated stream i.
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Fi
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=
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The average daily flow (at least a 30-day average) of
stream i to the extent that it is regulated for such pollutant.
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"[SIGMA]Gi"
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The sum of the results of calculation G for streams i
= 1 to i = N.
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N
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=
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The total number of regulated streams.
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T
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=
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The average daily flow (at least a 30-day average)
through the combined pretreatment facility (includes Fi,
D and unregulated streams.
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D
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=
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The average daily flow (at least a 30-day average)
from:
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A) Boiler
blowdown streams, non-contact cooling streams, stormwater streams, and
demineralizer backwash streams, subject to the proviso of subsection
(d);
B) Sanitary waste streams if
such waste streams are not regulated by a categorical pretreatment standard;
and
C) From any process waste
streams that were or could have been entirely exempted from categorical
pretreatment standards as specified in subsection (e).
2) Alternative Mass Limit
Click
here to view image
where
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M
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=
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The alternative mass limit for a pollutant in the
combined waste stream.
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Mi
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=
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The categorical pretreatment standard mass limit for
a pollutant in the regulated stream i (the categorical pretreatment mass limit
multiplied by the appropriate measure of production).
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Fi
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=
|
The average daily flow (at least a 30-day average) of
stream i to the extent that it is regulated for such pollutant.
|
|
"[SIGMA]Gi"
|
|
means the sum of the results of calculation G for
streams i = 1 to i = N.
|
|
N
|
=
|
The total number of regulated streams.
|
|
T
|
=
|
The average daily flow (at least a 30-day average)
through the combined pretreatment facility (includes Fi,
D and unregulated streams.
|
|
D
|
=
|
The average daily flow (at least a 30-day average)
from:
|
A) Boiler
blowdown streams, non-contact cooling streams, stormwater streams and
demineralizer backwash streams, subject to the proviso of subsection
(d);
B) Sanitary waste streams if
such waste streams are not regulated by a categorical pretreatment standard;
and
C) From any process waste
streams that were or could have been entirely exempted from categorical
pretreatment standards, as specified in subsection (e).
b) Alternative Limits Below
Detection. An alternative pretreatment limit must not be used if the
alternative limit is below the analytical detection limit for any of the
regulated pollutants.
c)
Self-monitoring. Self-monitoring required to ensure compliance with the
alternative categorical limit must be as follows:
1) The type and frequency of sampling,
analysis, and flow measurement must be determined by reference to the
self-monitoring requirements of the appropriate categorical pretreatment
standards.
2) If the
self-monitoring schedules for the appropriate standards differ, monitoring must
be done according to the most frequent schedule.
3) If flow determines the frequency of
self-monitoring in a categorical pretreatment standard, the sum of all
regulated flows (Fi) is the flow that must be used to
determine self-monitoring frequency.
d) Proviso to Subsections (a)(1) and (a)(2).
If boiler blowdown, non-contact cooling streams, stormwater streams, and
demineralizer backwash streams contain a significant amount of a pollutant, and
the combination of such streams, prior to pretreatment, with the industrial
user's regulated process waste streams will result in a substantial reduction
of that pollutant, the Control Authority, upon application of the industrial
user, must determine whether such waste streams should be classified as diluted
or unregulated. In its application to the Control Authority, the industrial
user must provide engineering, production, sampling, and analysis and such
other relevant information so the Control Authority can make its
determination.
e) Exemptions from
Categorical Pretreatment Standards. Process waste streams were or could have
been entirely exempted from categorical pretreatment standards pursuant to
paragraph 8 of the NRDC v. Costle consent decree, incorporated by reference in
Section
310.107, for one or more of the
following reasons (see appendix D to 40 CFR
403, incorporated by reference in
Section 310.107):
1) The pollutants of
concern are not detectable in the discharge from the industrial user;
2) The pollutants of concern are present only
in trace amounts and are neither causing nor are likely to cause toxic
effects;
3) The pollutants of
concern are present in amounts too small to be effectively reduced by
technologies known to USEPA;
4) The
waste stream contains only pollutants that are compatible with the
POTW.
f) If a treated
regulated process waste stream is combined prior to treatment with wastewaters
other than those generated by the regulated process, the industrial user may
monitor either the segregated process waste stream or the combined waste stream
to determine compliance with applicable pretreatment standards. If the
industrial user chooses to monitor the segregated process waste stream, it must
apply the applicable categorical pretreatment standard. If the user chooses to
monitor the combined waste stream, it must apply an alternative discharge limit
calculated using the combined waste stream formula as provided in this Section.
The industrial user may change monitoring points only after receiving approval
from the Control Authority. The Control Authority must ensure that any change
in an industrial user's monitoring point or points will not allow the user to
substitute dilution for adequate treatment to achieve compliance with
applicable standards.
