Ohio Administrative Code › Title 3745 - Ohio Environmental Protection Agency › Chapter 3745-2 - Attainment and Protection of Surface Water Quality Standards (WQS) › Section 3745-2-02 - Definitions

Current through all regulations passed and filed through July 1,
			 2024
(A) Acronyms and
			 abbreviations used in this chapter are
			 defined as listed below.
BAF
Bioaccumulation factor
BCC
Bioaccumulative chemical of concern
BCF
Bioconcentration factor
BSAF
Bioto-sediment accumulation factor
C.F.R.
Code of federal regulations
D.O.
Dissolved oxygen
DMT
Dissolved metal translator
FAV
Final acute value
HMQ
Harmonic mean flow
IC
Inhibition concentration
IMZM
Inside mixing zone maximum
LAMP
Lakewide management plan
LOEC
Lowest observed effect concentration
LA
Load allocation
LC
Lethal concentration
NOEC
No observed effect concentration
NPDES
National pollutant discharge elimination system
OMZM
Outside mixing zone maximum
PQL
Practical quantification level
PEL
Preliminary effluent limit
PEQ
Projected effluent quality
POTW
Publicly owned treatment works
Q
Flow, as in 7Q10
RAP
Remedial action plan
SDR
Stream-to-discharge ratio
TCDD
Tetrachloro-dibenzo dioxin
TMDL
Total maximum daily load
TUa
Acute toxic unit
TUc
Chronic toxic unit
U.S.C.
United States Code
U.S. EPA
United States environmental protection agency
WLA
Wasteload allocation
WQBEL
Water quality based effluent limit
WET
Whole effluent toxicity
(B)
			 Technical words used in this chapter shall be
			 defined as follows:
(1) "1Q10," see stream
			 design flow.
(2) "30Q10," see
			 stream design flow.
(3) "7Q10," see
			 stream design flow.
(4) "90Q10,"
			 see stream design flow.
(5) "Act"
			 means the federal Water Pollution Control Act (commonly referred to as the
			 "Clean Water Act"),
			 33 U.S.C.
			 1251 to
			 1274 as
			 amended through July 1, 2017.
[Comment: The Water Pollution Control
				Act can generally be found in public libraries, and can be viewed
				electronically online at
http://www.gpo.gov/fdsys
and purchased through: "U.S. Government Publishing Office
				Bookstore, 701 North Capital Street N.W., Washington, DC 20401."]
(6) "Ambient water
			 temperature" means the spatial (longitudinal, lateral and vertical) and
			 temporal water temperature measured in the receiving body of water prior to a
			 specific waste heat discharge, and is outside the influence of any thermal
			 mixing zone.
(7) "Ambient screening values" mean numbers that
			 estimate the concentration of a pollutant in a receiving water required to
			 protect humans from non-carcinogenic health effects and aquatic life from acute
			 and chronic effects. These numbers are used to determine the necessity of
			 developing a tier II value for a pollutant.
(8) "Analytical
			 detection limit" means the detection limit applied during the laboratory
			 analysis for a specific measurement or set of
			 measurements.
[Comment: Ohio EPA prefers reporting of
				any concentrations above the method detection limit, even if the concentrations
				are considered estimated. Federal regulations at
				40
				C.F.R. 122.21(e)(3) and
				122.44(i)(1)(iv)
				require NPDES applicants and permittees to use sufficiently sensitive test
				methods when quantifying the presence of pollutants in a discharge as part of
				an application and for the analysis of pollutants under the permit. Applicants
				and permittees are required to use analytical methods that are capable of
				detecting and measuring the pollutants at, or below, the respective water
				quality criteria or permit limits. The regulations address when a method is
				sufficiently sensitive.]
(9) "Average
			 criteria" means all numeric criteria and tier II values expressed on an average
			 basis contained in Chapter 3745-1 of the Administrative Code.
(10)
			 "Background" means all pollutants that flow from waters into the water body
			 segment for which a TMDL, or a PEL determined in the absence of a TMDL, is
			 being developed unless a load allocation is established for that
			 source.
(11) "Bioaccumulation" means the net accumulation of a
			 substance by an organism as a result of uptake from all environmental
			 sources.
(12) "Bioaccumulative chemical of concern" or "BCC"
			 has the same meaning as in rule
			 3745-1-02 of the
			 Administrative Code.
(13) "Carcinogen"
			 means a substance, for the purpose of calculating additivity, for which a
			 cancer criterion exists as identified in or calculated pursuant to, Chapter
			 3745-1 of the Administrative Code.
(14)
			 "Conservative pollutant" means a persistent pollutant for which a TMDL, or a
			 PEL determined in the absence of a TMDL, is being developed that is assumed to
			 not decay or transform within the water body segment.
(15)
			 "Criteria" means numeric criteria and tier II values established pursuant to
			 Chapter 3745-1 of the Administrative Code.
(16) "Critical low
			 depth for lakes" means the minimum depth reasonably expected for the lake at
			 the discharge point based on historical records, release schedules, or other
			 pertinent information.
(17) "Daily average
			 temperature" means the arithmetic mean of multiple temperature measurements to
			 be taken at least once per hour during a twenty-four -hour day.
(18) "Design
			 conditions" means the receiving water and effluent conditions applied in the
			 determination of a TMDL, or a WLA in the absence of a TMDL, that represent the
			 conditions most critical to protection of the applicable use designations.
			 These conditions include, but are not limited to, stream design flow, effluent
			 design flow, temperature, hardness, and pH.
(19) "Dilution ratio"
			 means the ratio of receiving water to effluent for a given volume of
			 water.
(20) "Director" means the director of Ohio
			 environmental protection agency.
(21) "Discharge port"
			 means the final outlet for effluent in a discharge pipe. This terminology is
			 usually associated with outfall structures with multiple outlets designed to
			 mix effluent rapidly with the receiving water.
(22)
			 "Discharge" means the addition of any pollutant to waters of the state from
			 a point source.
(23) "Dissolved metal translator" or "DMT" means the
			 ratio between the total recoverable and dissolved concentrations of a metal in
			 a receiving water, discharge, or a mixture of both that is expected to occur
			 under the design conditions applicable to that metal.
(24)
			 "Endangered or threatened species", see threatened or endangered
			 species.
(25) "Endangered Species Act" means Endangered Species
			 Act,
			 16
			 U.S.C. sections 1531 to
			 1544,
			 as amended through July 1, 2017.
[Comment: The Endangered Species Act
				can generally be found in public libraries, and can be viewed electronically
				online at
http://www.gpo.gov/fdsys
and purchased through: "U.S. Government Publishing Office
				Bookstore, 701 North Capital Street N.W., Washington, DC 20401."]
(26) "Flowing receiving water" means a body of water
			 that exhibits a primarily unidirectional flow at the point of
			 discharge.
(27) "Group X", see reasonable potential.
(28)
			 "HMQ", see stream design flow.
(29) "IC25" means the
			 inhibition concentration twenty-five; the toxicant concentration that would
			 cause a twenty-five per cent reduction in a non-quantal biological measurement
			 such as reproduction or growth in the test population (as opposed to lethality
			 which is a quantal or "all-or-none" response).
(30) "Inside mixing
			 zone maximum criteria" means the criteria that cannot be exceeded within the
			 mixing zone. It is identical to final acute value (FAV), as defined in Chapter
			 3745-1 of the Administrative Code.
(31) "Lake Erie
			 drainage basin" means all the streams, rivers, lakes, and other bodies of water
			 within the drainage basin of lake Erie and within the United States.
(32)
			 "Lake Erie Lakewide Management Plan" or "Lake Erie LAMP" means the management
			 plan to restore and protect the beneficial uses of lake Erie developed in
			 accordance with the Great Lakes Water Quality Agreement as amended in 1987, and
			 the Great Lakes Critical Programs Act of 1990,
			 Pub.
			 L. No. 101-596, 104 Stat. 3000 (Nov. 16, 1990).
			 The geographic scope of the lake Erie LAMP includes the open lake waters, the
			 near shore area, embayments, river mouths and the lake effect zone of lake Erie
			 tributaries. This document is available on the internet
			 at  https://www.epa.gov/greatlakes/lake-erie-lamps.
(33) "LC50", for
			 whole effluent toxicity tests, means the median lethal concentration; the per
			 cent by volume effluent concentration that kills fifty per cent of exposed
			 organisms during a specified exposure period.
(34) "Lowest observed
			 effect concentration" or "LOEC" means the lowest measured concentration
			 (expressed as a per cent by volume) of an effluent or a toxicant that causes a
			 statistically significant effect on a test organism during a specified exposure
			 period.
(35) "Load allocation" or "LA" is the portion of a
			 receiving water's loading capacity that is attributed to one of its existing or
			 future nonpoint sources.
(36) "Loading
			 capacity" is the greatest loading of a pollutant that a water body can receive
			 without violating water quality standards under specific flow conditions; also
			 referred to as assimilative capacity.
(37) "Maximum
			 criteria" means all numeric criteria and tier II values expressed as maximum
			 pursuant to Chapter 3745-1 of the Administrative Code.
(38)
			 "Method 1669: Sampling Ambient Water for Trace Metals at EPA Water Quality
			 Criteria Levels" means "Method 1669: Sampling Ambient Water for Trace Metals at
			 EPA Water Quality Criteria Levels, U.S. EPA
			 821R96011, 1996". This document is available on the internet at
http://www3.epa.gov/caddis/pdf/Metals_Sampling_EPA_method_1669.pdf
.
(39)
									"Method
			 detection limit" means the minimum measured concentration of a substance that
			 can be reported with ninety-nine per cent confidence that the measured
			 concentration is distinguishable from method blank results.
(40)
			 "Mixing zone" means an area of a water body contiguous to a discharge. This
			 discharge is in transit and progressively diluted from the source concentration
			 to the receiving system concentration. The mixing zone shall be considered a
			 place where wastewater and receiving water mix and not as a place where wastes
			 are treated.
(41) "Natural conditions" mean those conditions that
			 are measured outside the influence of human activities.
(42)
			 "New discharge", for the purposes of implementing the bioaccumulative chemical
			 of concern provisions in this chapter, means any of the
			 following:
(a) A discharge of
			 pollutants to a water body from a building, structure, facility or
			 installation, the construction of which commences after December 30,
			 2002.
(b) A
			 new discharge from an existing discharger that commences after December 30,
			 2002.
(c) An expanded discharge from an
			 existing discharger that commences after December 30, 2002, except for those
			 expanded discharges resulting from changes in loadings of any BCC within the
			 existing capacity and processes (e.g., normal operational variability, changes
			 in intake water pollutants, increasing the production hours of the facility or
			 adding additional shifts, or increasing the rate of production), and that are
			 covered by the existing Ohio NPDES permit.
Not included within the definition of "new discharge" are new
				or expanded discharges of BCCs from a publicly owned treatment works when such
				discharges are necessary to prevent a public health threat to the community
				(e.g., a situation where a community with failing septic systems is connected
				to a POTW to avert a potential public health threat from these failing
				systems), unless there is increased loadings of BCCs
				due to the collection of wastewater from a significant industrial user and,
				based on the industry's raw materials and processes, the wastewater is expected
				to have quantifiable concentrations of the BCC significantly above levels
				typically associated with domestic wastewater and non-industrial storm
				water. These and all other discharges of BCCs are defined as existing
				discharges.
(43) "No observed
			 effect concentration" or "NOEC" means the highest tested concentration
			 (expressed as a per cent by volume) of an effluent or a toxicant that causes no
			 statistically significant observed effects on a test organism during a
			 specified exposure period.
(44) "Non-flowing
			 waters" means water bodies that do not exhibit a natural unidirectional flow at
			 the point of discharge.
(45) "Nonpoint
			 source" means any source of pollutants other than those defined or designated
			 as point sources.
(46) "Ohio river drainage basin" means all the
			 streams, rivers, lakes, and other bodies of water within the drainage basin of
			 the Ohio river.
(47) "Point source" means any discernible, confined or
			 discrete conveyance from which a pollutant is or may be discharged to the
			 surface waters of the state.
(48) "Pollutant"
			 means sewage, industrial waste, or other waste as defined by divisions (B) to
			 (D) of section 6111.01 of the Revised
			 Code.
(49) "Pollution prevention alternatives assessment"
			 means an analysis that identifies any cost-effective pollution prevention
			 alternatives and techniques that are available to the discharger, and that
			 would reduce the extent to which the increased loading results in a lowering of
			 water quality. A pollution prevention alternatives analysis shall demonstrate a
			 good faith effort by the discharger to review equipment or technology
			 modifications, process or procedure modifications, reformulation or redesign of
			 products, substitution of raw materials and improvements to housekeeping. The
			 discharger is not required to implement a pollution prevention alternative if
			 it is not technically or economically feasible.
(50) "Practical
			 quantification level" or "PQL" means a concentration of a pollutant that is
			 five times the method detection limit for the most sensitive available
			 analytical procedure currently approved under 40 C.F.R. 136 for a pollutant,
			 unless the director, by rules adopted in accordance with Chapter 119. of the
			 Revised Code, establishes a different practical quantification level for the
			 pollutant that is consistent with, and no more
			 stringent than, the appropriate national
			 consensus standard or other generally accepted standard.
(51)
			 "Preliminary effluent limit" or "PEL" means the most stringent applicable WLA
			 expressed as both an average and a maximum. The average PEL is the lowest WLA
			 to maintain chronic criteria and the maximum PEL is the lowest WLA to maintain
			 acute criteria.
(52) "Projected effluent quality" or "PEQ" means the
			 estimated level of a pollutant in an effluent.
(53) "Publicly owned
			 treatment works" or "POTW" means any device or system used in the treatment
			 (including recycling and reclamation) of domestic sewage or industrial waste of
			 a liquid nature that is owned by a municipality, county, or state entity or any
			 public body created under state law that has authority over disposal of
			 sewage.
(54) "Ranked ninety-fifth percentile" means the data
			 value in a set of data that is greater than ninety-five per cent of the other
			 data values as determined by ranking the data values from lowest to
			 highest.
(55) "Reasonable potential" means the likelihood of a
			 pollutant to cause or contribute to an excursion of a water quality standard.
			 For chemical-specific determinations, a grouping system for assessing whether
			 to establish WQBELs as limits in NPDES permits consists of five categories that
			 rank the reasonable potential.
(a) "Group one"
			 pollutants have no applicable criteria and the director has determined that
			 data are
			 insufficient to calculate criteria or values. The reasonable potential for
			 pollutants in this group cannot be determined.
(b) "Group two" pollutants have little
			 potential based on water quality data to cause or contribute to a water quality
			 excursion; permit requirements may not be warranted based solely on water
			 quality considerations.
(c) "Group
			 three" pollutants have some potential based on water quality data to cause or
			 contribute to a water quality excursion; permit requirements may not be
			 warranted based solely on water quality considerations.
(d) "Group four" pollutants have significant
			 potential based on water quality data to cause or contribute to a water quality
			 excursion; permit monitoring requirements are generally warranted based solely
			 on water quality considerations.
(e) "Group five" pollutants have the highest
			 potential based on water quality data to cause or contribute to a water quality
			 excursion; permit limitations are generally warranted based solely on water
			 quality considerations.
(56) "Receiving
			 water" means the water body into which point and nonpoint sources
			 flow.
(57) "Remedial action plan" or "RAP" means a
			 management plan to restore and protect beneficial uses in the Great Lakes areas
			 of concern. The areas of concern were identified by state and federal
			 government agencies with the international joint commission as the most
			 polluted sites around the Great Lakes. A RAP is prepared in accordance with the
			 Great Lakes Water Quality Agreement as amended in 1987, and the Great Lakes
			 Critical Programs Act of 1990, Public Law Number 101-596, 104 Stat. 3000 (Nov.
			 16, 1990). A RAP is prepared from a broad ecosystem perspective and with
			 considerable public involvement.
(58) "Representative
			 aquatic species" mean those organisms, either natural or introduced, which
			 presently exist or have existed in the surface waters of the state prior to
			 July 1, 1977, with the exception of those banned species outlined in rule
			 1501:31-19-01
			 of the Administrative Code. In addition, it may include any species that are
			 introduced into the surface waters of the state. Aquatic species designated as
			 representative shall satisfy one or more of the following:
(a) Species that are particularly vulnerable
			 to the existing or proposed environmental impact in question.
(b)
			 Species that are commercially or recreationally valuable.
(c) Species that are threatened, rare, or
			 endangered.
(d)
			 Species that are critical to the structure and function of the aquatic
			 community.
(e)
			 Species whose presence is causally related to the existing or proposed
			 environmental impact under examination.
(f)
			 Species that are potentially capable of becoming localized nuisance
			 species.
(g) Species that are
			 representative of the ecological, behavioral, and physiological requirements
			 and characteristics of species determined in paragraphs
			 (B)(58)(a) to (B)(58)(f)
			 of this rule, but which themselves may not be representative.
(59) "Stream design flow" means the flow in a
			 receiving water upstream from a discharge or nonpoint source that represents
			 the flow conditions that are critical for protection of an aquatic life, human
			 health, wildlife, or agricultural water supply use. Stream design flows may be
			 calculated using annual or seasonal data; where seasonal data
			 are
			 appropriate, the applicable months are specified. The following statistical
			 quantities based on stream flow data are used as stream design flows for
			 various use designations in accordance with the rules of this chapter:
(a) "1Q10" or "one-day, ten-year low flow"
			 means the lowest one-day average flow expected to occur once every ten
			 years.
(b) "7Q10" or "seven-day,
			 ten-year low flow" means the lowest seven-consecutive-day average flow expected
			 to occur once every ten years.
(c)
			 "30Q10" or "thirty-day, ten-year low flow" means the lowest
			 thirty-consecutive-day average flow expected to occur once every ten years.
(d) "90Q10" or "ninety-day,
			 ten-year low flow" means the lowest ninety-consecutive-day average flow
			 expected to occur once every ten years.
(e) "HMQ" or "harmonic mean flow" is
			 calculated as the reciprocal of the arithmetic mean of the reciprocals of the
			 individual daily flows. The HMQ is determined from a continuous record of daily
			 average flow measurements.
(60) "Technical
			 Support Document for Water Quality-based Toxics Control" means "Technical
			 Support Document for Water Quality-based Toxics Control,
			 U.S. EPA
			 505/2-90-001, 1991." This document is available on the internet at
http://www3.epa.gov/npdes/pubs/owm0264.pdf
.
(61)
			 "The Metals Translator: Guidance For Calculating A Total Recoverable Permit
			 Limit From A Dissolved Criterion" means "The Metals Translator: Guidance For
			 Calculating A Total Recoverable Permit Limit From A Dissolved Criterion,
			 U.S. EPA
			 823-B-96-007, 1996." This document is available on the internet at
http://www3.epa.gov/npdes/pubs/metals_translator.pdf
.
(62) "Threatened or
			 endangered species" or "endangered or threatened
			 species" mean those species of the state's biota that are threatened with
			 statewide extirpation or national extinction, as listed in rule
			 1501:31-23-01
			 of the Administrative Code or 50 C.F.R. 17 or that are listed as endangered or
			 threatened under section 4 of the Endangered Species Act.
(63) "Total maximum daily load" or "TMDL" means the
			 sum of the existing or projected point source, nonpoint source, and
			 background loads for a pollutant to a specified watershed, water body, or water
			 body segment. A TMDL sets and allocates the maximum amount of a pollutant that
			 may be introduced into the water and still ensures attainment and maintenance
			 of water quality standards.
(64) "Waste heat
			 discharge" means a point source discharge through which excess heat is
			 discharged into the surface waters of the state.
(65) "Wasteload
			 allocation" or "WLA" means the portion of a receiving water's loading capacity
			 that is allocated to one of its existing or future point sources of pollution.
			 In the absence of a TMDL or TMDL assessment and remediation plan, a WLA is the
			 allocation for an individual point source that ensures that the level of water
			 quality to be achieved by the point source is derived from and complies with
			 all applicable water quality standards.
(66) "Water bodies"
			 or "waters of the state" mean all streams, lakes, ponds, marshes, watercourses,
			 waterways, wells, springs, irrigation systems, drainage systems, and all other
			 bodies or accumulations of water, surface and underground, natural or
			 artificial, regardless of the depth of the strata in
			 which underground water is located, that are situated wholly or partly
			 within, or border upon, this state, or are within its jurisdiction, except
			 those private waters that do not combine or effect a junction with natural
			 surface or underground waters.
(67) "Water quality
			 based effluent limit" or "WQBEL" means an effluent limitation determined on the
			 basis of water quality standards set forth in Chapter 3745-1 of the
			 Administrative Code or wasteload allocation procedures contained in this
			 chapter.
(68) "Water quality standards" means the standards set
			 forth in Chapter 3745-1 of the Administrative Code.
(69) "Wet weather
			 point source" means any discernible, confined and discrete conveyance from
			 which pollutants are, or may be, discharged as the result of a wet weather
			 event. Discharges from wet weather point sources include only: discharges of
			 storm water from a municipal separate storm sewer as defined in
			 40
			 C.F.R. 122.26(b)(8); storm
			 water discharges associated with industrial activity as defined in
			 40
			 C.F.R. 122.26(b)(14);
			 discharges of storm water and sanitary wastewaters (domestic, commercial, and
			 industrial) from a combined sewer overflow; or any other storm water discharge
			 for which a permit is required under section 402 (p) of the act. All storm
			 water discharges associated with industrial activity that are mixed with
			 process wastewater shall not be considered a wet weather point
			 source.
(70) "Whole effluent toxicity" or "WET" means the
			 aggregate toxic effect of an effluent measured
			 directly by a toxicity test where the
			 test results are based on acute (lethal) or chronic (lethal and sublethal)
			 endpoints.
(71) As used in this chapter "40 C.F.R." means Title
			 40 of the Code of Federal Regulations effective July 1, 2017 and "50 C.F.R."
			 means Title 50 of the Code of Federal Regulations effective
			 October
			 1, 2017.
[Comment: The Code of Federal Regulations can generally be
				found in public libraries, and can be viewed electronically online at
http://www.gpo.gov/fdsys/
and
				purchased through: "U.S. Government Publishing
				Office Bookstore, 701 North Capital Street N.W., Washington, DC
				20401."]