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

(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:

(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.

(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:

(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:

(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."]