South Carolina Code of Regulations › Chapter 61 - DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL › Subchapter 61-68 - Water Classifications and Standards › Section 61-68.B - DEFINITIONS

Current through Register Vol. 48, No. 6, June 28, 2024
1. The definition
			 of any word or phrase employed in this regulation shall be the same as given in
			 the South Carolina Pollution Control Act, S.C. Code Sections
			 48-1-10, et seq., hereafter
			 referred to as the Act. Words or phrases which are not defined in the Act are
			 defined as follows:
2.
7Q10
means the annual minimum seven (7)-day average flow rate that
			 occurs with an average frequency of once in ten (10) years as published or
			 verified by the U. S. Geological Survey (USGS) or an estimate extrapolated from
			 published or verified USGS data.
3.
30Q5
means the annual minimum thirty (30)-day average flow rate
			 that occurs with an average frequency of once in five (5) years as published or
			 verified by the U.S. Geological Survey (USGS) or an estimate extrapolated from
			 published or verified USGS data.
4.
Acute
means a stimulus severe enough to rapidly induce an effect;
			 in aquatic toxicity tests, an effect observed in ninety-six (96) hours or less
			 typically is considered acute. When referring to aquatic toxicology or human
			 health, an acute effect is not always measured in terms of lethality.
5.
Acute-to-chronic ratio
(ACR)
			 means the ratio of the acute toxicity of an effluent or a toxicant to its
			 chronic toxicity. It is used as a factor for estimating chronic toxicity on the
			 basis of acute toxicity data, or for estimating acute toxicity on the basis of
			 chronic toxicity data.
6.
Agricultural
means the use of water for stock watering,
			 irrigation, and other farm purposes.
7.
Annual average flow
means the
			 annual mean flow rate of a stream at a specific point as published or verified
			 by the U.S. Geological Survey (USGS) or an estimated annual mean flow rate
			 extrapolated from published or verified USGS data.
8.
Aquaculture
means a defined
			 managed water area which uses discharges of pollutants into that designated
			 area for the maintenance or production of harvestable freshwater, estuarine, or
			 marine plants or animals.
9.
Aquatic farm
means the cultivation, production, or marketing of
			 domestic aquatic organisms which are any fish, aquatic invertebrates, or
			 aquatic plants that are spawned, produced, or marketed as a cultivated crop in
			 the waters of the State.
10.
Aquatic toxicity test
mean laboratory experiments that measure the
			 biological effect (e.g., growth, survival, and reproduction) of effluents or
			 receiving waters on aquatic organisms.
11.
Aquifer
means a geologic
			 formation, group of formations, or part of a formation that contains sufficient
			 saturated permeable material to yield significant quantities of ground water to
			 wells or springs.
12.
Balanced indigenous aquatic community
means a natural, diverse
			 biotic community characterized by the capacity to sustain itself through cyclic
			 seasonal changes, presence of necessary food chain species, and by a lack of
			 domination by pollutant tolerant species.
13.
Best management practice
(BMP) means a practice or combination of practices that are the most effective,
			 practical ways of controlling or abating pollution from widespread or localized
			 sources.
14.
Bioaccumulation
means the process by which a compound is taken up
			 and retained by an aquatic organism, both from water and through
			 food.
15.
Bioavailability
means a measure of the physiochemical access that
			 a toxicant has to the biological processes of an organism. The less the
			 bioavailability of a toxicant, the less its toxic effect on an
			 organism.
16.
Bioconcentration
means the process by which a compound is
			 absorbed from water through gills or epithelial tissues and is concentrated in
			 the body.
17.
Bioconcentration factor
(BCF) means the ratio of a substance's
			 concentration in tissue versus its concentration in water, in situations where
			 the food chain is not exposed or represents equilibrium partitioning between
			 water and organisms.
18.
Biological assessment
means an evaluation of the biological
			 condition of a waterbody using biological surveys and other direct measurements
			 of resident biota in surface waters and sediments.
19.
Biological criteria
, also
			 known as biocriteria, mean narrative expressions or numeric values of the
			 biological characteristics of aquatic communities based on appropriate
			 reference conditions. Biological criteria serve as an index of aquatic
			 community health.
20.
Biological monitoring
, also known as biomonitoring, means a
			 description of the living organisms in water quality surveillance used to
			 indicate compliance with water quality standards or permit effluent limits and
			 to document water quality trends. Methods of biological monitoring may include,
			 but are not limited to, toxicity testing such as ambient toxicity testing,
			 whole effluent toxicity testing, and ambient assessment of the resident
			 biological community.
21.
Chlorophyll
a
means a photosynthetic pigment
			 present in all types of green plants. It is used as a measure of algal biomass
			 and is an indicator of nutrient enrichment.
22.
Chronic
means a stimulus
			 that lingers or continues for a relatively long period of time, often one-tenth
			 of the life span or more. Chronic should be considered a relative term
			 depending on the life span of an organism. The measurement of a chronic effect
			 can be reduced growth, reduced reproduction, etc., in addition to
			 lethality.
23.
Classified
			 uses
mean those uses specified in Section G for surface waters and
			 Section H for ground waters, whether or not those uses are being
			 attained.
24.
Concentrated
			 aquatic animal production facility
means a hatchery, fish farm, or other
			 facility related to aquatic animal production which is not located in waters of
			 the State and is subject to a National Pollutant Discharge Elimination System
			 (NPDES) permit.
25.
Conventional treatment as applying to potable water supplies
means
			 treatment including at least flocculation, sedimentation, filtration, and
			 disinfection.
26.
Criterion
			 continuous concentration
(CCC) means the highest instream concentration
			 of a toxicant or an effluent to which the organisms can be exposed to protect
			 against chronic (long-term) effects. EPA derives chronic criteria from longer
			 term (often greater than twenty-eight (28) days) tests that measure survival,
			 growth, reproduction, and, in some cases, bioconcentration.
27.
Criterion maximum
			 concentration
(CMC) means the highest instream concentration of a
			 toxicant or an effluent to which the organisms can be exposed for a brief
			 period of time without causing an acute effect. EPA derives acute criteria from
			 forty-eight (48) to ninety-six (96) hour tests of lethality or
			 immobilization.
28.
Daily
			 average
means the average of all samples taken during any twenty-four
			 (24)-hour period.
29.
Daily
			 maximum
(for bacterial indicators only) means the highest arithmetic
			 average of bacterial samples collected [for each of the bacterial indicator
			 species (i.e.,
E. coli
, enterococci, and/or fecal coliform)]
			 in any twenty-four (24) hour period during a calendar month.
30.
Deleterious substances
mean
			 those substances which in sufficient concentrations or levels have a harmful
			 effect on classified or existing water uses.
31.
Department
means the S.C.
			 Department of Health and Environmental Control.
32.
Ecoregions
mean areas of
			 general similarity in ecosystems and in the type, quality, and quantity of
			 environmental resources and are designed to serve as a spatial framework for
			 the research, assessment, management, and monitoring of ecosystems and
			 ecosystem components. The EPA has published a document that outlines the Level
			 III ecoregions (please refer to U.S. Environmental Protection Agency. 1999.
			 Level III ecoregions of the continental United States (revision of Omernik,
			 1987). Corvallis, Oregon, U.S. E.P.A.-National Health and Environmental Effects
			 Research Laboratory, Map M-1.) The following are South Carolina Level III
			 ecoregions: Blue Ridge Mountains, Piedmont, Southeastern Plains, and Middle
			 Atlantic Coastal Plains.
33.
EPA
means the U.S. Environmental Protection Agency.
34.
Ephemeral streams
mean
			 streams that generally have defined natural watercourses that flow only in
			 direct response to rainfall or snowmelt and in which discrete periods of flow
			 persist no more than twenty-nine (29) consecutive days per event.
35.
Existing uses
mean those
			 uses actually being attained in or on the water, on or after November 28, 1975,
			 regardless of the classified uses.
36.
Fishing
means the taking,
			 harvesting, or catching of finfish or crustaceans for human
			 consumption.
37.
Full pool
			 elevation
means the maximum lake level attained before water releases
			 over a fixed weir, spillway, or other discharge structure. In larger lakes and
			 reservoirs, the full pool elevation is the maximum level established for
			 management.
38.
Groundwater
means water below the land surface in a zone of saturation.
39.
Hydrograph controlled release
(HCRs) means the onsite storage or holding of treated wastewater or the
			 use of an alternative discharge option contained in Section D.2.a. of this
			 regulation, during specified critical streamflow conditions and then
			 discharging the treated wastewater to the stream when streamflow is sufficient
			 to assimilate the wastewater.
40.
Intermittent streams
mean streams that generally have defined
			 natural watercourses which do not flow year around, but flow beyond periods of
			 rainfall or snowmelt.
41.
Lake
means any water of the State that is a freshwater pond,
			 reservoir, impoundment, or similar body of water located wholly or partially
			 within the State.
42.
LC50
means the concentration of a toxicant
			 at which lethality occurs to fifty percent (50%) of the test organisms during a
			 specified exposure time period.
43.
Mixing zone
means:
a. For
			 surface waters, an area where a discharge undergoes initial dilution and is
			 extended to cover the secondary mixing in the ambient waterbody. A mixing zone
			 is an allocated impact zone where water quality criteria can be exceeded as
			 long as acutely toxic conditions are prevented (except as defined within a Zone
			 of initial dilution) and public health and welfare are not
			 endangered.
b. For ground waters, a
			 hydrogeologically controlled three-dimensional flow path in the subsurface
			 which constitutes the pathway for waste constituents to migrate from a
			 source.