327 IAC 5-2-11.6 - Great Lakes system dischargers establishment of water quality-based effluent limitations (WQBELs)
Authority: IC 13-14-8; IC 13-14-9; IC 13-15-1-2; IC 13-15-2-1; IC 13-18-3
Affected: IC 13-11-2; IC 13-18-4
Sec. 11.6.
(a) The
NPDES permit shall include conditions necessary to achieve water quality
standards established under 327 IAC 2-1.5, including narrative water quality
criteria. The numeric water quality criteria set forth in
327 IAC
2-1.5-8 and
327
IAC 2-1.5-16 and Tier I criteria and Tier II values
established under
327 IAC
2-1.5-11 through
327
IAC 2-1.5-16 shall not be enforceable against any
point source discharger until translated into effluent limitations that are
incorporated in NPDES permits in accordance with this article.
(b) TMDLs and WLAs developed under section
11.4 of this rule shall provide the basis for numeric water quality-based
effluent limitations (WQBELs) established in NPDES permits for point sources
discharging to waters within the Great Lakes system. If a variance has been
granted from a water quality criterion under
327
IAC 2-1.5-17 and
327
IAC 5-3-4.1, WQBELs for the pollutant that is the
subject of the variance shall be calculated on the basis of the variance rather
than the water quality criterion.
(c) The following procedure shall be used to
calculate WQBELs using the WLAs developed under section 11.4 of this rule:
(1) This subsection assumes that effluent
data follow a log-normal distribution. If a discharger is able to demonstrate
that the effluent data for a pollutant does not follow a log-normal
distribution and provides an alternate distribution that more accurately
describes the data, this alternate distribution may be used instead of the
procedures in this subsection.
(2)
For the equations contained within this subsection, the following apply:
(A) Z99 = 2.326 (99th
percentile probability basis).
(B)
CV = coefficient of variation = ratio of the standard deviation to the mean. A
value of six-tenths (0.6) will be used for the CV unless the discharger
demonstrates that an alternate CV is more representative of the variability of
the pollutant in the effluent.
(3) The first step in this procedure is to
calculate a long term average (LTA) for each WLA determined for the pollutant
under section 11.4 of this rule. These LTAs are calculated as follows:
(A) The LTAA
protective of acute aquatic life effects shall be calculated as follows:
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| Where: | [SIGMA]2 | = | ln(CV2 + 1). |
| WLAA | = | WLA determined under section 11.4 of this rule using the acute aquatic life criterion or value. This WLA is expressed as a one (1) day maximum. |
(B)
The LTAC protective of chronic aquatic life effects
shall be calculated as follows:
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| Where: | [SIGMA]42 | = | ln(CV2/4 + 1). |
| WLAC | = | For chloride, sulfate, total dissolved solids, fluoride, and dissolved iron, the more stringent WLA determined under section 11.4 of this rule using the criterion for the pollutant under 327 IAC 2-1.5-8(j), if applicable, or the chronic aquatic life criterion or value. For other pollutants, the WLA determined under section 11.4 of this rule using the chronic aquatic life criterion or value. This WLA is expressed as a four (4) day average. |
(C)
The LTAH protective of human health effects shall be
calculated as follows:
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| Where: | [SIGMA]302 | = | ln(CV2/30 + 1). |
| WLAH | = | The most stringent WLA determined under section 11.4 of this rule using a criterion or value for the protection of human health. This WLA is expressed as a thirty (30) day average. |
(D)
The LTAW protective of wildlife effects shall be
calculated as follows:
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| Where: | [SIGMA]302 | = | ln(CV2/30 + 1). |
| WLAW | = | WLA determined under section 11.4 of this rule using the WC or WV. This WLA is expressed as a thirty (30) day average. |
(4) Daily maximum and monthly average WQBELs
are determined using the lowest LTA calculated in subdivision (3) as follows:
(A) The daily maximum WQBEL is calculated as
follows:
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| Where: | [SIGMA]2 | = | ln(CV2 + 1). |
(B)
The monthly average WQBEL is calculated as follows:
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| Where: | [SIGMA]n2 | = | ln(CV2/n + 1). |
| z95 | = | 1.645 (95th percentile probability basis). | |
| n | = | Number of samples per month. A value of ten (10) will be used unless the discharger demonstrates that an alternate value is more appropriate. |
(C)
The monthly average WQBEL shall not exceed the most stringent WLA developed
under section 11.4 of this rule unless calculated using the following:
(i) A CV calculated using facility-specific
effluent monitoring data that is representative of the variability of the
pollutant in the effluent.
(ii) A
value for n based on the monitoring frequency in the NPDES permit to be
issued.
(d) Notwithstanding subsection (c), WQBELs
for whole effluent toxicity (WET) and WQBELs for the criteria listed in section
11.4(d) of this rule shall be developed as follows:
(1) For WET, WQBELs shall be developed using
the WLAs for acute and chronic WET developed under section 11.4 of this rule as
follows:
(A) The commissioner shall ensure
that the WQBELs for WET established under this subdivision attain the acute and
chronic WET criteria in
327 IAC
2-1.5-8 under the receiving waterbody flows and
outside the mixing zones used to develop the WLAs for acute and chronic WET
under section 11.4 of this rule.
(B) The commissioner shall determine, on a
case-by-case basis, the following:
(i)
Whether to develop a WQBEL for only acute or chronic WET or WQBELs for both
acute and chronic WET.
(ii) The
number of species required for WET testing.
(iii) The particular species required for WET
testing.
(C) In making
the determination in clause (B), the commissioner shall take into consideration
available information about the discharge and receiving waterbody, including,
but not limited to, the following:
(i) The
ACR of the effluent.
(ii) The
sensitivity of the test species to the toxicity in the effluent.
(iii) The WLAs developed for acute and
chronic WET under section 11.4 of this rule.
(D) When the commissioner determines that it
is necessary to develop a WQBEL for acute WET, the WQBEL shall be set equal to
the WLA developed for acute WET under section 11.4 of this rule and shall be
established in an NPDES permit as a daily maximum limit.
(E) When the commissioner determines that it
is necessary to develop a WQBEL for chronic WET, the WQBEL shall be set equal
to the WLA developed for chronic WET under section 11.4 of this rule and shall
be established in an NPDES permit as a monthly average limit.
(2) For the criteria listed in
section 11.4(d) of this rule, WQBELs shall be developed to be consistent with
the models used in that subsection.
(e) WQBELs in an NPDES permit for a metal
calculated from a water quality criterion expressed in the form of dissolved
metal that is:
(1) contained in 327 IAC
2-1.5; or
(2) subsequently
developed under the procedures contained in 327 IAC 2-1.5;
shall be expressed in the permit as total recoverable metal unless all approved analytical methods for the metal inherently measure only its dissolved form, such as hexavalent chromium.
(f) WQBELs for cyanide, calculated from a
criterion for free cyanide contained in 327 IAC 2-1.5, shall be limited in the
permit as free cyanide and monitored in the effluent using the "Cyanides
Amenable to Chlorination" (CATC) method ( 40 CFR 136, Method 4500-CN G) or
another method approved by the commissioner. The commissioner may include
additional monitoring, limitations, or other requirements in a permit, on a
case-by-case basis, if the additional requirements are necessary to ensure that
water quality standards will be attained.
(g) Whenever a WQBEL is developed, unless
otherwise provided in subdivision (3), the WQBEL in the NPDES permit shall be
expressed as both a concentration value and a corresponding mass loading rate
as follows:
(1) Both mass and concentration
limits shall be based on the same permit averaging periods, such as daily, or
monthly averages, or in other appropriate permit averaging periods.
(2) The mass loading rates shall be
calculated using effluent flow rates that are the same as those used in
establishing the concentration-based WQBELs.
(3) For pollutants or parameters that cannot
appropriately be expressed in terms of mass (such as pH, temperature,
radiation, bacteria, or dissolved oxygen) mass limits are not
required.
(4) A discharger may
request tiered mass limits for a discharge that increases as a result of wet
weather flow. As used in this subdivision, "tiered mass limits" consists of two
(2) sets of mass limits. One (1) set shall be based on the dry-weather effluent
flow determined under section 11.4(a)(9) of this rule and the stream design
flow under section 11.4(b) of this rule. The second set shall be based on an
effluent flow and stream flow under wet weather conditions. For each mass limit
developed under this subdivision, the NPDES permit shall include a
corresponding concentration limit.
(h) When a WQBEL for a pollutant is
calculated to be less than the LOQ, the following conditions apply:
(1) The calculated WQBEL shall be established
as the limit in the NPDES permit.
(2) The analytical method, LOD, and LOQ shall
be specified as follows:
(A) The commissioner
shall specify in the permit the most sensitive, applicable, analytical method,
specified in or approved under 40 CFR 136 or by the commissioner, to be used to
monitor for the presence and amount in an effluent of the pollutant for which
the WQBEL is established and shall specify in accordance with clause (B), the
LOD and LOQ that can be achieved by use of the specified analytical
method.
(B) The LOD and LOQ shall
be determined as follows:
(i) The MDL shall be
used as the LOD unless the permittee demonstrates that a higher LOD is
appropriate because of effluent-specific matrix interference.
(ii) The LOQ shall be the ML specified in or
approved under 40 CFR 136 for the method for that pollutant. If no such ML
exists, or if the method is not specified or approved under 40 CFR 136 or by
the commissioner, the LOQ shall be calculated by multiplying the LOD by three
and eighteen-hundredths (3.18). The commissioner may specify a higher LOQ if
the permittee demonstrates that a higher LOQ is appropriate because of
effluent-specific matrix interference. Other methods for deriving an LOQ may be
approved by the commissioner if the method is scientifically
defensible.
(3) Compliance with the WQBELs for the
pollutant shall be determined as follows:
(A)
When a daily maximum WQBEL is less than the LOD specified in the permit,
effluent levels:
(i) of the pollutant less
than the LOD are in compliance with the maximum WQBEL; and
(ii) greater than the LOD but less than the
LOQ are in compliance with the maximum WQBEL, except when confirmed by a
sufficient number of analyses of multiple samples and use of appropriate
statistical techniques.
(B) When a daily maximum WQBEL is greater
than the LOD specified in the permit but less than the LOQ specified in the
permit, effluent levels of the pollutant less than the LOQ are in compliance
with the WQBEL.
(C) To determine
compliance with a WQBEL expressed as a daily maximum mass limitation, the LOD
and LOQ shall each be converted to a mass value, using appropriate conversion
factors and the same effluent flow used to determine the mass-based WQBEL,
before applying the provision of clauses (A) and (B).
(D) When a monthly or weekly average WQBEL is
less than the LOQ specified in the permit, a monthly or weekly average effluent
level less than or equal to the respective monthly or weekly average WQBEL is
in compliance with the monthly or weekly average WQBEL. Daily effluent values
that are less than the LOQ, used to determine the monthly or weekly average
effluent levels less than the LOQ, may be assigned a value of zero (0), unless,
after considering the number of monitoring results that are greater than the
LOD, and applying appropriate statistical techniques, a value other than zero
(0) is warranted.
(4)
When a WQBEL is less than the LOD, the commissioner may require a period of
accelerated monitoring in a permit, when the measured effluent level is between
the LOD and LOQ, for the purpose of collecting additional data to apply the
statistical analysis referenced in subdivision (3)(A) and (3)(D).
(5) When a WQBEL is less than the LOQ,
special conditions may be included in the permit to better quantify the levels
of pollutant present in the discharge. These special conditions may include,
but are not limited to, the following:
(A)
Fish tissue sampling.
(B)
Caged-biota studies.
(C) WET
tests.
(D) Limits on internal
wastestreams.
(E) Monitoring
requirements on internal wastestreams.
(F) Development of a more sensitive
analytical procedure.
(G)
Monitoring for surrogate parameters.
(H) Waterbody bioassessment.
(6) The permit shall contain
reopener clauses authorizing modification or revocation and reissuance of the
permit to:
(A) include more stringent
monitoring requirements or conditions if new information generated as a result
of accelerated monitoring conducted in accordance with subdivision (4), or
special conditions included in the permit in accordance with subdivision (5)
indicates the likely presence of the pollutant in the discharge at levels above
the WQBEL; and
(B) specify the use
of a different analytical method if a more sensitive analytical method has been
specified in or approved under 40 CFR 136 or approved by the commissioner to
monitor for the presence and amount in the effluent of the pollutant for which
the WQBEL is established and shall specify in accordance with subdivision
(2)(B), the LOD and LOQ that can be achieved by use of the specified analytical
method.
(7) The
commissioner shall include a condition in the permit requiring the permittee to
develop and conduct a pollutant minimization program (PMP) for each pollutant
with a WQBEL below the LOQ in accordance with the following:
(A) The goal of the PMP shall be to maintain
the effluent at or below the WQBEL. The PMP shall include, but is not limited
to, the following:
(i) Submission of a
control strategy designed to proceed toward the goal.
(ii) Implementation of appropriate
cost-effective control measures consistent with the control strategy.
(iii) Monitoring necessary to monitor the
progress toward the goal. This shall include, but is not limited to, the
following:
(AA) Semiannual monitoring of
potential sources of the pollutant.
(BB) Quarterly monitoring for the pollutant
in the influent of the wastewater treatment system.
(iv) An annual status report that shall be
sent to the commissioner, including the following:
(AA) All PMP monitoring results for the
previous year.
(BB) A list of
potential sources of the pollutant.
(CC) A summary of all actions taken to reduce
or eliminate the identified sources of the pollutant.
(v) A PMP may include the submittal of
pollution prevention strategies that use changes in production process
technology, materials, processes, operations, or procedures to reduce or
eliminate the source of the pollutant.
(B) No PMP is required if the permittee
demonstrates that the discharge of a pollutant with a WQBEL below the LOQ is
reasonably expected to be in compliance with the WQBEL at the point of
discharge into the receiving water. This demonstration may include, but is not
limited to, the following:
(i) Treatment
information, including information derived from modeling the destruction or
removal of the pollutant in the treatment process.
(ii) Mass balance information.
(iii) Fish tissue studies or other biological
studies.
(C) In
determining appropriate cost-effective control measures to be implemented in a
PMP, the following factors may be considered:
(i) Significance of sources.
(ii) Economic and technical
feasibility.
(iii)
Treatability.
(D) The
permit shall contain a reopener clause authorizing modification or revocation
and reissuance of the permit to revise (such as more or less frequent
monitoring) or remove the requirements of this subdivision if supported by
information generated as a result of this subdivision.
(i) The determinations under this
subsection regarding the consideration of intake pollutants, as defined under
section 11.5(b)(4)(A) of this rule, shall be made on a pollutant-by-pollutant,
outfall-by-outfall basis. This subsection applies only when the concentration
of the pollutant of concern upstream of the discharge, as determined under
section 11.4(a)(8) of this rule, exceeds the most stringent applicable water
quality criterion or value for that pollutant. In addition, this subsection
applies only in the absence of an EPA-approved TMDL applicable to the
discharge, or in the absence of an assessment and remediation plan submitted
and approved in accordance with section 11.4(a)(2) of this rule. The following
procedures shall be used in the consideration of intake pollutants in
establishing WQBELs:
(1) When an intake
pollutant is from the same body of water, as defined under section
11.5(b)(4)(B) of this rule, and the discharge and the facility meet the
conditions in section 11.5(b)(4)(C)(i)(BB) through 11.5(b)(4)(C)(i)(EE), the
following procedures apply:
(A) The
commissioner may establish effluent limitations allowing the facility to
discharge a mass and concentration of the pollutant that are no greater than
the mass and concentration of the pollutant identified in the facility's intake
water (no net addition limitations). The permit shall specify how compliance
with mass and concentration limitations shall be assessed. No permit may
authorize no net addition limitations that are effective after March 23, 2007.
After that date, WQBELs shall be established in accordance with section 11.5(d)
of this rule.
(B) Where proper
operation and maintenance of a facility's treatment system results in removal
of a pollutant, the commissioner may establish limitations that reflect the
lower mass or concentration, or both, of the pollutant achieved by such
treatment, taking into account the feasibility of establishing such
limits.
(C) For pollutants
contained in intake water provided by a water system, the concentration of the
intake pollutant shall be determined at the point where the raw water supply is
removed from the same body of water, except that it shall be the point where
the water enters the water supplier's distribution system where the water
treatment system removes any of the identified pollutants from the raw water
supply. Mass shall be determined by multiplying the concentration of the
pollutant by the volume of the facility's intake flow received from the water
system.
(2) Where the
pollutant in a facility's discharge originates from a water of the state that
is not the same body of water as the receiving water, as determined in
accordance with section 11.5(b)(4)(B) of this rule, WQBELs shall be established
based upon the most stringent applicable water quality criterion or value for
that pollutant.
(3) Where a
facility discharges intake pollutants that originate in part from the same body
of water, and in part from a different body of water, the commissioner may
apply the procedures of subdivisions (1) and (2) to derive an effluent
limitation reflecting the flow-weighted average of each source of the
pollutant, provided that adequate monitoring to determine compliance can be
established and is included in the permit.
Notes
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