(b) An application for
authorization to revise discharge limits must include the following
information:
(1) A list of pollutants proposed
for discharge limit revisions.
(2)
Influent and effluent operational data demonstrating consistent removal or
other information, as permitted by the commissioner, that demonstrates
consistent removal of the pollutants for which a removal allowance is proposed.
These data must meet the following requirements:
(A) The data must be representative of yearly
and seasonal conditions to which the POTW is subjected for each pollutant
proposed for a discharge limit revision.
(B) The data must be representative of the
quality and quantity of normal effluent and influent flow of the system if the
data can be obtained. If the data are unobtainable, alternate data or
information may be presented for approval to demonstrate consistent
removal.
(C) The influent and
effluent operational data must be obtained through a minimum of twelve (12)
composite samples taken at approximately equal intervals throughout one (1)
calendar year and meeting the following requirements:
(i) Each composite sample must consist of
discrete, flow-proportional samples taken at equal time intervals not to exceed
two (2) hours.
(ii) The sampling
period must be a minimum of twenty-four (24) hours and each effluent sample
must be taken approximately one (1) detention time later than the corresponding
influent sample except that, if the commissioner determines that a sampling
schedule will not be representative of the actual operation of the POTW
treatment plant, an alternative sampling schedule will be required. The
detention time must be determined from the flow at the time sampling
begins.
(iii) If a particular
pollutant is measurable in the influent but not in the effluent, the effluent
level may be assumed to be the limit of quantitation, and those data may be
used by the POTW in its discretion subject to approval by the
commissioner.
(iv) If the pollutant
is not measurable in the influent, the data must not be used.
(v) If there are less than eight (8) samples
with influent concentrations equal to or above the limit of quantitation, the
commissioner may approve alternate means, such as a mass balance, for
demonstrating consistent removal. The samples must be evenly distributed over
the days of the week so as to include nonworkdays as well as workdays. If the
commissioner determines that this schedule will not be most representative of
the actual operation of the POTW, an alternative sampling schedule will be
approved.
(vi) In addition, upon
the commissioner's approval, a POTW may utilize an historical data base amassed
prior to the effective data of this rule, provided that the data meets the
requirements of this subdivision. In order for the historical data base to be
approved, it must present a statistically valid description of daily, weekly,
and seasonal sewage treatment plant loadings and performance for at least one
(1) year.
(D) Where
composite sampling is not an appropriate sampling technique, a grab sample must
be taken to obtain influent and effluent operational data and must meet the
following requirements:
(i) A grab sample is
required, for example, when the parameters being evaluated are those that may
not be held for any extended period because of biological, chemical, or
physical interactions that take place after sample collection, therefore
affecting the results.
(ii) A grab
sample is an individual sample and must be collected over a period of time not
exceeding fifteen (15) minutes.
(iii) Collection of influent grab samples
must precede collection of effluent samples by approximately one (1) detention
period.
(E) The sampling
and analysis required by clause (C) and this clause must be performed in
accordance with the following:
(i) Techniques
prescribed in one (1) of the following:
(AA)40 CFR
136 * and its amendments.
(BB) Applicable categorical standards.
(ii) Applicable
sampling and analytical procedures approved by U.S. EPA if one (1) of the
following situations exists to make the techniques listed in item (i)
inapplicable:
(AA) There is no sampling or
analytical technique for the pollutant in question.
(BB) The administrator determines that the
40 CFR
136 sampling and analytical techniques are
inappropriate for the pollutant in question.
(F) Consistent removal for a specific
pollutant must be determined as follows:
(i)
For each sample, the difference between the pollutant concentrations in the
influent and effluent must be calculated and expressed as a percentage of the
influent concentration.
(ii)
Removal for the pollutant must be calculated as the average of the lowest fifty
percent (50%) of the individual sample removal results. If the number of
samples with quantifiable results is between eight (8) and twelve (12), the
removal must be calculated as the average of the lowest six (6) sample
results.
(iii) All sample data
obtained for the measured pollutant according to clause (C) must be reported
and used in calculating consistent removal.
(iv) If an alternate means is approved by the
commissioner under clause (C) for demonstrating consistent removal, then
removal must be calculated as specifically provided by the
commissioner.
(3) A list of the industrial subcategories
for which discharge limits in categorical pretreatment standards would be
revised, including the number of industrial users in each subcategory and an
identification of which of the pollutants on the list prepared under
subdivision (1) are discharged by each subcategory.
(4) The revised discharge limits proposed for
each of the subcategories of industrial users identified in subdivision (3)
calculated in the following manner:
(A) The
revised discharge limit proposed for the specified pollutant must be calculated
using the following formula:
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Where: X = Pollutant discharge limit specified in the
applicable categorical pretreatment standard (expressed in milligrams per
liter).
r = POTW's consistent removal rate for that pollutant as
established under this rule (percentage expressed as a decimal).
Y = Revised discharge limit for the specified pollutant
(expressed in milligrams per liter).
(B) In the case of a POTW that either has
combined sewers or has bypassed untreated wastewater into the receiving water
at least once annually, and that claims consistent removal of a pollutant under
section 1(c)(1) of this rule, the revised discharge limits proposed for the
specific pollutant must be calculated using the following formula:
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Where: rm = POTW's consistent removal
rate for a specific pollutant.
rc = Removal corrected by the overflow
factor.
Z = Hours per year that overflow occurred between the
industrial user and the POTW treatment plant, the hours either to be shown in
the POTW's current NPDES permit application or the hours, as demonstrated by
verifiable techniques, that a particular industrial user's discharge overflows
between the industrial user and the POTW treatment plant.
(5) Data showing the
concentrations and amounts of the pollutants in a POTW's sludge that are
proposed for discharge limit revisions, and for which sludge disposal or use
criteria applicable to the POTW's current method of sludge use or disposal have
been published by U.S. EPA or the department must meet the following
requirements:
(A) The data must be obtained
through a composite sample taken during each of the sampling periods selected
to measure consistent removal in accordance with the requirements of
subdivision (2)(C). Each composite sample must contain a minimum of twelve (12)
discrete samples taken at equal time intervals over a twenty-four (24) hour
period. Where a composite sample is not an appropriate sampling technique, grab
samples must be taken.
(B) Sampling
and analysis of the samples referred to in clause (A) must be performed in
accordance with the sampling and analytical techniques described in subdivision
(2)(E).
(6) A specific
description of the following:
(A) The POTW's
current method of use or disposal of its sludge.
(B) Data certifying that the current sludge
use or disposal methods comply and will continue to comply with section 1(d) of
this rule.
(7) A
certification that the POTW has an approved POTW pretreatment program or
qualifies for the exception to this requirement found at section 1(c) of this
rule.
(8) A certification that the
granting of removal credits will not cause a violation of the POTW's NPDES
permit limits or conditions.