Ohio Administrative Code
Title 3745 - Ohio Environmental Protection Agency
Chapter 3745-2 - Attainment and Protection of Surface Water Quality Standards (WQS)
Section 3745-2-06 - Application of preliminary effluent limitations
Universal Citation: OH Admin Code 3745-2-06
Current through all regulations passed and filed through September 16, 2024
(A) General provisions.
(1) The average preliminary effluent
limitation (PEL) is the lowest wasteload allocation (WLA) based on chronic
criteria, and the maximum PEL is the lowest WLA based on acute criteria,
calculated pursuant to rule
3745-2-05 of the Administrative
Code.
(2) A water quality-based
effluent limitation (WQBEL) or monitoring requirement for a pollutant shall be
determined by the reasonable potential of that pollutant to cause or contribute
to an excursion of any applicable water quality standard established in or
developed under Chapter 3745-1 of the Administrative Code.
(3) Except as provided in paragraph (C) of
this rule and paragraph (A) of rule
3745-33-07 of the Administrative
Code, the determination of reasonable potential shall be based on the
comparison of the average or the maximum projected effluent quality (PEQ) to
the average or the maximum PEL, respectively, and on other site-specific
factors in accordance with paragraph (B) of this rule. This comparison will
result in the assignment of the pollutant to a group with an associated water
quality-based permit condition recommendation. Final permit conditions shall be
established by Ohio EPA in accordance with rule
3745-33-07 of the Administrative
Code.
(B) Pollutant assessment.
(1) WQBELs shall be recommended
for any group five pollutant. A pollutant shall be assigned to group five if
any of the following conditions apply:
(a)
The average PEQ is greater than or equal to the average PEL or the maximum PEQ
is greater than or equal to the maximum PEL.
(b) The average or maximum PEQ is greater
than or equal to seventy-five per cent of the average or maximum PEL,
respectively, and any of the following conditions apply:
(i) The total load of a pollutant in the
receiving water at a point downstream of the discharge is greater than or equal
to seventy-five per cent of the loading capacity of the receiving water at that
point, where, for the purpose of this determination:
(a) The total load of a pollutant is
determined as the sum of the background load and the load associated with the
PEL for that discharge. If multiple discharges were included in determination
of the PEL, the load associated with the PEL for each upstream discharge shall
also be added. Other upstream pollutant loads included in determination of the
PEL shall also be included.
(b) The loading capacity is determined as the
highest pollutant load in the receiving water that will maintain the numeric
criteria applied in determination of the PEL at a receiving water flow equal to
the sum of effluent flow and one hundred per cent of the stream design flow
used in determination of the PEL. If other upstream pollutant sources were
included in determination of the PEL, the flows applied to those sources in
determination of the PEL shall also be included.
(c) Background load is the load based on the
background concentration and one hundred per cent of the stream design flow
used in determination of the PEL.
(ii) The PEQ value is believed to be an
underestimation of effluent quality due to factors such as, but not limited to,
a small data set, data inaccuracies, or projected changes in effluent quality
that are not accounted for in current effluent data.
(iii) It is uncertain whether a PEL will be
sufficient to achieve or maintain the designated uses of the receiving water
for reasons such as, but not limited to, any of the
following:
(a) The PEL is based on
alternative modeling methods pursuant to rule
3745-2-05 of the Administrative
Code.
(b)
Discharge-specific or project-area dissolved metal translators were used in
determination of the PEL.
(c) The
PEL exceeds the applicable inside mixing zone maximum criteria.
(d) Ohio EPA determines that the PEL will
achieve or maintain the designated uses.
(iv) Evidence suggests that the
designated use of the receiving water is impaired or threatened, or that there
is bioaccumulation of the pollutant or pollutants of concern in aquatic
organisms.
(2) A monitoring requirement shall be
recommended for any group four pollutant. A pollutant shall be assigned to
group four if any of the following conditions apply:
(a) The average PEQ is greater than or equal
to fifty per cent of the average PEL and paragraph (B)(1) of this rule does not
apply.
(b) The maximum PEQ is greater
than or equal to fifty per cent of the maximum PEL and paragraph (B)(1) of this
rule does not apply.
(c) The
pollutant is expected to be present but has not been adequately
quantified.
(3) A
tracking requirement in accordance with rule
3745-33-07 of the Administrative
Code shall be recommended for any pollutant for which the average PEQ is more
than seventy-five per cent of the average PEL or the maximum PEQ is more than
seventy-five per cent of the maximum PEL and paragraph (B)(2) of this rule
applies.
(4) A monitoring
requirement evaluation shall be recommended for any group three pollutant. A
pollutant shall be assigned to group three if the average PEQ is less than
fifty per cent of the average PEL and the maximum PEQ is less than fifty per
cent of the maximum PEL and paragraph (B)(5) of this rule does not
apply.
(5) A monitoring requirement
shall not be recommended for any group two pollutant. A pollutant shall be
assigned to group two if a WLA was not required for one of the following
reasons:
(a) Because the maximum PEQ is less
than twenty-five per cent of the lowest applicable maximum criteria and the
average PEQ is less than twenty-five per cent of the lowest applicable average
criteria, in accordance with paragraphs (A)(1) and (A)(2) of rule
3745-2-04 of the Administrative
Code.
(b)
Because all available effluent data for the pollutant are below the analytical
detection levels applied to that data, in accordance with paragraph (B)(1) of
rule 3745-2-04 of the Administrative
Code.
(6) A pollutant
shall be assigned to group one if a WLA could not be calculated because
available data is insufficient to develop numeric criteria.
(a) For discharges in the lake Erie basin, if
WLAs are determined based on ambient screening values as required by paragraph
(C)(2) of rule
3745-2-04 of the Administrative
Code, Ohio EPA shall generate or require the discharger to generate the data
necessary to derive numeric criteria under the following conditions:
(i) If the maximum PEQ is greater than or
equal to the WLA based on the ambient screening value to protect aquatic life
from acute effects, data shall be generated to derive an acute aquatic life
criterion for that pollutant.
(ii)
If the average PEQ is greater than or equal to the WLA based on the ambient
screening value to protect aquatic life from chronic effects, data shall be
generated to derive a chronic aquatic life criterion for that
pollutant.
(iii) If the average PEQ
is greater than or equal to the WLA based on the ambient screening value to
project humans from health effects other than cancer, data shall be generated
to derive a human health criterion for that pollutant.
(b) After data has been generated, as
required by paragraph (B)(6)(a) of this rule, Ohio EPA shall develop numeric
criteria for that pollutant in accordance with Chapter 3745-1 of the
Administrative Code. Ohio EPA shall then reevaluate WLAs for that pollutant in
accordance with Chapter 3745-2 of the Administrative Code.
(c) Ohio EPA shall establish any requirements
for the discharger to collect the data required by paragraph (B)(6)(a) of this
rule in the discharger's permit, in accordance with Chapter 3745-33 of the
Administrative Code.
(7)
Ohio EPA may exclude design parameters indicative of treatment plant
performance from paragraphs (A) and (B) of this rule.
(C) Pollutants in the intake water. The determination of reasonable potential of intake pollutants shall be made on a pollutant-specific and an outfall-specific basis. An intake pollutant is a pollutant that is present in waters of the state at the time it is withdrawn from such waters by a discharger or other facility (e.g., public water supply) supplying the discharger with intake water.
(1) Paragraph (C) of this rule applies only
in the absence of a TMDL implementation plan applicable to the discharge
developed pursuant to rule
3745-2-12 of the Administrative
Code. Paragraph (C) of this rule does not alter the conditions established in
paragraph (A) of rule
3745-2-04 of the Administrative
Code for determining the necessity of calculating WLAs.
(2) The director may determine that an intake
pollutant does not have reasonable potential where a discharger demonstrates to
the director's satisfaction all of the following:
(a) The discharger withdraws one hundred per
cent of the intake water containing the pollutant from the same body of water
into which the discharge is made.
(b) The
discharger does not contribute any additional mass of the identified intake
pollutant to its wastewater. In cases where the discharge is a combination of
process wastewater and noncontact cooling water, and the process wastewater is
limited separately from the noncontact cooling water, the director may consider
application of paragraph (C) of this rule to the discharge of process
wastewater and noncontact cooling water separately.
(c) The discharge does not alter the
identified intake pollutant chemically or physically in a manner that would
cause adverse water quality impacts to occur that would not occur if the
pollutants were left instream.
(d) The
discharge does not increase the identified intake pollutant concentration at
the edge of the mixing zone, or at the point of discharge if a mixing zone is
not allowed, as compared to the pollutant concentration in the intake water,
unless the increased concentration does not cause or contribute to an excursion
of an applicable water quality standard.
(e) The timing and location of the discharge
would not cause adverse water quality impacts to occur that would not occur if
the identified intake pollutant were left instream.
(3) Upon a finding by the director under
paragraph (C)(2) of this rule that a pollutant in the discharge does not have
reasonable potential, the director shall not be required to include a WQBEL for
the identified intake pollutants in the discharger's NPDES permit, provided
the
following:
(a) The NPDES permit fact
sheet or statement of basis includes a specific determination that there is no
reasonable potential for the discharge of an identified intake pollutant and
the fact sheet or statement of basis references appropriate supporting
documentation included in the administrative record.
(b) The NPDES permit requires all influent,
effluent and ambient monitoring deemed necessary by the director to demonstrate
that the conditions that led to the determination under paragraph (C)(2) of
this rule are maintained during the term of the NPDES permit.
(c) The NPDES permit contains a reopener
clause authorizing modification or revocation and reissuance of the NPDES
permit if new information demonstrates changes in the conditions that led to
the determination under paragraph (C)(2) of this rule.
(4) Absent a finding by the director that an
intake pollutant in the discharge does not have reasonable potential in
accordance with paragraph (C)(2) of this rule, the director shall use the
procedures set forth in paragraphs (A) and (B) of this rule to determine the
reasonable potential of that pollutant.
(5) Same body of water. An intake pollutant
is considered to be from the same body of water as the discharge if the intake
pollutant would have reached the vicinity of the outfall in the receiving water
within a reasonable period of time had it not been removed by the discharger.
This finding may be established if all of the following conditions apply:
(a) The background concentration of the
pollutant in the receiving water is similar to that in the intake water.
(b) There is a direct hydrological connection
between the intake and discharge points.
(c) Water quality characteristics (e.g.,
temperature, pH, hardness) are similar in the intake and receiving
waters.
(6) The director
may also consider other site-specific factors relevant to the transport and
fate of the pollutant to make the finding in a particular case that a pollutant
would or would not have reached the vicinity of the outfall in the receiving
water within a reasonable period of time had it not been removed by the
discharger.
(7) The director may
consider an intake pollutant from groundwater to be from the same body of water
if the pollutant would have reached the vicinity of the outfall in the
receiving water within a reasonable period of time had it not been removed by
the discharger. Such a pollutant shall not be considered to be from the same
body of water if the groundwater contains the pollutant partially or entirely
due to human activity, such as industrial, commercial, or municipal operations,
disposal actions, or treatment processes.
(D) Other applicable conditions.
In the lake Erie drainage basin, if the geometric mean of a pollutant in fish tissue samples collected from a waterbody exceeds the tissue basis of a tier I criterion or tier II value, after consideration of the variability of the pollutant's bioconcentration and bioaccumulation in fish, each facility that discharges detectable levels of such pollutant to that water has the reasonable potential to cause or contribute to an excursion above a tier I criteria or a tier II value and the director shall establish a WQBEL for such pollutant in the NPDES permit for such facility.
Disclaimer: These regulations may not be the most recent version. Ohio may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.
