The following words and terms when used in this chapter shall have the following meanings unless the context clearly indicates otherwise:
"Assimilative capacity" means the greatest amount of loading that a water can receive without violating water quality standards, significantly degrading waters of existing high quality, or interfering with the beneficial use of state waters.
"Best management practices (BMP)" means a schedule of activities, prohibition of practices, maintenance procedures and other management practices to prevent or reduce the pollution of state waters. BMPs include treatment requirements, operating and maintenance procedures, schedule of activities, prohibition of activities, and other management practices to control plant site runoff, spillage, leaks, sludge or waste disposal, or drainage from raw material storage.
"Best practicable control technology currently available (BPT)" means control measures required of point source discharges (other than POTWs) as determined by the EPA pursuant to § 304(b)(1) of the CWA (33 USC § 1251 et seq.) as of 1987.
"Board" means the State Water Control Board (SWCB).
"Chesapeake Bay Watershed" means the following Virginia river basins: Potomac River Basin (9VAC25-260-390 and 9VAC25-260-400), James River Basin (9VAC25-260-410, 9VAC25-260-415, 9VAC25-260-420, and 9VAC25-260-430), Rappahannock River Basin (9VAC25-260-440), Chesapeake Bay and small coastal basins (9VAC25-260-520, Sections 2 through 3g), and the York River Basin (9VAC25-260-530).
"Clean Water Act or Act (CWA)" means 33 USC § 1251 et seq. as amended, as of 1987.
"Delivery factor" means an estimate of the number of pounds of total nitrogen or total phosphorus delivered to tidal waters for every pound discharged from a permitted facility, as determined by the specific geographic location of the permitted facility, to account for attenuation that occurs during riverine transport between the permitted facility and tidal waters. Delivery factors shall be calculated using the Chesapeake Bay Program watershed model.
"Discharge" means when used without qualification, a discharge of a pollutant or any addition of any pollutant or combination of pollutants to state waters or waters of the contiguous zone or ocean or other floating craft when being used for transportation.
"Effluent limitation" means any restriction imposed by the board on quantities, discharge rates or concentrations of pollutants that are discharged from point sources into state waters.
"Effluent limitation guidelines" means a regulation published by EPA under the Act and adopted by the board.
"Effluent limited segment (EL)" means a stream segment where the water quality does and probably will continue to meet state water quality standards after the application of technology-based effluent limitations required by §§ 301(b) and 306 of the CWA (33 USC § 1251 et seq.) as of 1987.
"Environmental Protection Agency (EPA)" means the United States Environmental Protection Agency.
"Equivalent load" means 2,300 pounds per year of total nitrogen and 300 pounds per year of total phosphorus at a flow volume of 40,000 gallons per day; 5,700 pounds per year of total nitrogen and 760 pounds per year of total phosphorus at a flow volume of 100,000 gallons per day; and 28,500 pounds per year of total nitrogen and 3,800 pounds per year of total phosphorus at a flow volume of 500,000 gallons per day.
"Load or loading" means the introduction of an amount of matter or thermal energy into a receiving water. Loading may be either man-caused (pollutant loading) or natural (background loading).
"Load allocation (LA)" means the portion of a receiving water's loading capacity attributable either to one of its existing or future nonpoint sources of pollution or to natural background sources. Load allocations are best estimates of the loading, which may range from accurate estimates to gross allotments, depending on the availability of data and appropriate techniques for predicting the loading. Wherever possible, natural and nonpoint source loads should be distinguished.
"Nonpoint source" means a source of pollution, such as a farm or forest land runoff, urban storm water runoff, mine runoff, or salt water intrusion that is not collected or discharged as a point source.
"Point source" means any discernible, defined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock vessel or other floating craft, from which pollutants are or may be discharged. This term does not include return flows from irrigated agricultural land.
"Pollutant" means any substance, radioactive material, or heat that causes or contributes to, or may cause or contribute to, pollution. It does not mean:
1. Sewage from vessels; or
2. Water, gas, or other material that is injected into a well to facilitate production of oil, dry gas, or water derived in association with oil or gas production and disposed of in a well, if the well is used either to facilitate production or for disposal purposes if approved by the Department of
Mines, Minerals and Energy unless the board determines that such injection or disposal will result in the degradation of ground or surface water resources.
"Pollution" means such alteration of the physical, chemical or biological properties of any state waters as will or is likely to create a nuisance or render such waters (i) harmful or detrimental or injurious to the public health, safety or welfare, or to the health of animals, fish or aquatic life; (ii) unsuitable with reasonable treatment for use as present or possible future sources of public water supply; or (iii) unsuitable for recreational, commercial, industrial, agricultural, or other reasonable uses; provided that: (a) an alteration of the physical, chemical, or biological property of state waters, or a discharge or deposit of sewage, industrial wastes or other wastes to state waters by any owner, which by itself is not sufficient to cause pollution, but which, in combination with such alteration of or discharge or deposit to state waters by other owners is sufficient to cause pollution; (b) the discharge of untreated sewage by any owner into state waters; and (c) contributing to the contravention of standards of water quality duly established by the board, are "pollution" for the terms and purposes of this water quality management plan.
"Publicly owned treatment works (POTW)" means any sewage treatment works that is owned by a state or municipality. Sewers, pipes, or other conveyances are included in this definition only if they convey wastewater to a POTW providing treatment.
"Significant discharger" means (i) a point source discharger to the Chesapeake Bay watershed with a design capacity of 0.5 million gallons per day or greater, or an equivalent load; (ii) a point source discharger to the Chesapeake Bay watershed downstream of the fall line with a design capacity of 0.1 million gallons per day or greater, or an equivalent load; (iii) a planned or newly expanding point source discharger to the Chesapeake Bay watershed that is expected to be in operation by 2010 with a permitted design of 0.5 million gallons per day or greater, or an equivalent load; or (iv) a planned or newly expanding point source discharger to the Chesapeake Bay watershed downstream of the fall line with a design capacity of 0.1 million gallons per day or greater, or an equivalent load, that is expected to be in operation by 2010.
"State waters" means all waters, on the surface and under the ground and wholly or partially within or bordering the Commonwealth or within its jurisdiction, including wetlands.
"Surface water" means all waters in the Commonwealth except ground waters as defined in § 62.1-255 of the Code of Virginia.
"Total maximum daily load (TMDL)" means the sum of the individual waste load allocations (WLAs) for point sources, load allocations (LAs) for nonpoint sources, natural background loading and usually a safety factor. TMDLs can be expressed in terms of either mass per time, toxicity, or other appropriate measure. The TMDL process provides for point versus nonpoint source trade-offs.
"Toxic pollutant" means any agent or material including, but not limited to, those listed under § 307(a) of the CWA (33 USC § 1251 et seq. as of 1987), which after discharge will, on the basis of available information, cause toxicity.
"Toxicity" means the inherent potential or capacity of a material to cause adverse effects in a living organism, including acute or chronic effects to aquatic life, detrimental effects on human health or other adverse environmental effects.
"Virginia Pollution Discharge Elimination System (VPDES) permit" means a document issued by the board, pursuant to 9VAC25-31, authorizing, under prescribed conditions, the potential or actual discharge of pollutants from a point source to surface waters.
"Waste load allocation (WLA)" means the portion of a receiving water's loading or assimilative capacity allocated to one of its existing or future point sources of pollution. WLAs are a type of water quality-based effluent limitation.
"Water quality limited segment (WQL)" means any stream segment where the water quality does not or will not meet applicable water quality standards, even after the application of technology-based effluent limitations required by §§ 301(b) and 306 of the CWA (33 USC § 1251 et seq. as of 1987).
"Water quality management plan (WQMP)" means a state- or area-wide waste treatment management plan developed and updated in accordance with the provisions of §§ 205(j), 208 and 303 of the CWA (33 USC § 1251 et seq. as of 1987).
"Water quality standards (WQS)" means narrative statements that describe water quality requirements in general terms, and of numeric limits for specific physical, chemical, biological or radiological characteristics of water. These narrative statements and numeric limits describe water quality necessary to meet and maintain reasonable and beneficial uses such as swimming and, other water based recreation, public water supply and the propagation and growth of aquatic life. The adoption of water quality standards under the State Water Control Law is one of the board's methods of accomplishing the law's purpose.