Section 500. Definitions

In addition to the definitions given in Part I (9VAC25-31-10 et seq.) of this chapter, the following definitions apply to Part VI (9VAC25-31-420 et seq.) of this chapter. Where the same term is defined in both parts, the definition of Part VI of this chapter applies to the use of the term in Part VI of this chapter.

"Active sewage sludge unit" means a sewage sludge unit that has not closed.

"Aerobic digestion" means the biochemical decomposition of organic matter in sewage sludge into carbon dioxide and water by microorganisms in the presence of air.

"Agricultural land" means land on which a food crop, a feed crop, or a fiber crop is grown. This includes range land and land used as pasture.

"Agronomic rate" means the whole sludge application rate (dry weight basis) designed: (i) to provide the amount of nitrogen needed by the food crop, feed crop, fiber crop, cover crop, or vegetation grown on the land and (ii) to minimize the amount of nitrogen in the biosolids that passes below the root zone of the crop or vegetation grown on the land to the groundwater.

"Anaerobic digestion" means the biochemical decomposition of organic matter in sewage sludge into methane gas and carbon dioxide by microorganisms in the absence of air.

"Annual pollutant loading rate " or "APLR" means the maximum amount of a pollutant that can be applied to a unit area of land during a 365-day period.

"Annual whole sludge application rate" or "AWSAR" means the maximum amount of biosolids (dry weight basis) that can be applied to a unit area of land during a 365-day period.

"Apply biosolids" or "biosolids applied to the land" means land application of biosolids.

"Aquifer" means a geologic formation, group of geologic formations, or a portion of a geologic formation capable of yielding groundwater to wells or springs.

"Base flood" means a flood that has a one percent chance of occurring in any given year (i.e., a flood with a magnitude equaled once in 100 years).

"Bulk biosolids" means biosolids that are not sold or given away in a bag or other container for application to the land.

"Class I sludge management facility" means any publicly owned treatment works (POTW) required to have an approved pretreatment program under this chapter and any treatment works treating domestic sewage classified as a Class I sludge management facility by the board because of the potential for its biosolids use or sewage sludge disposal practice to affect public health and the environment adversely.

"Contaminate an aquifer" means to introduce a substance that causes the maximum contaminant level for nitrate in the Virginia Water Quality Standards or in 40 CFR 141.62(b) to be exceeded in groundwater or that causes the existing concentration of nitrate in groundwater to increase when the existing concentration of nitrate in the groundwater exceeds the maximum contaminant level for nitrate in the Virginia Water Quality Standards or 40 CFR 141.62(b).

"Cover" means soil or other material used to cover sewage sludge placed on an active sewage sludge unit.

"Cumulative pollutant loading rate" means the maximum amount of an inorganic pollutant that can be applied to an area of land.

"Density of microorganisms" means the number of microorganisms per unit mass of total solids (dry weight) in the biosolids or sewage sludge.

"Displacement" means the relative movement of any two sides of a fault measured in any direction.

"Domestic septage" means either liquid or solid material removed from a septic tank, cesspool, portable toilet, Type III marine sanitation device, or similar treatment works that receives only domestic sewage. Domestic septage does not include liquid or solid material removed from a septic tank, cesspool, or similar treatment works that receives either commercial wastewater or industrial wastewater and does not include grease removed from a grease trap at a restaurant.

"Domestic sewage" means waste and wastewater from humans or household operations that is discharged to or otherwise enters a treatment works.

"Dry tons" means dry weight established as representative of land applied biosolids and expressed in units of English tons.

"Dry weight" means the measured weight of a sample of sewage sludge or biosolids after all moisture has been removed in accordance with the standard methods of testing and often represented as percent solids.

"Dry weight basis" means calculated on the basis of having been dried at 105°C until reaching a constant mass (i.e., essentially 100% solids content).

"Exceptional quality biosolids" means biosolids that have received an established level of treatment for pathogen control and vector attraction reduction and contain known levels of pollutants, such that they may be marketed or distributed for public use in accordance with this regulation.

"Fault" means a fracture or zone of fractures in any materials along which strata on one side are displaced with respect to strata on the other side.

"Feed crops" means crops produced primarily for consumption by animals.

"Fiber crops" means crops such as flax and cotton.

"Field" means an area of land within a site where land application is proposed or permitted.

"Final cover" means the last layer of soil or other material placed on a sewage sludge unit at closure.

"Food crops" means crops produced primarily for consumption by humans. These include, but are not limited to, fruits, vegetables, and tobacco.

"Forest" means a tract of land thick with trees and underbrush.

"Groundwater" means water below the land surface in the saturated zone.

"Holocene time" means the most recent epoch of the Quaternary period, extending from the end of the Pleistocene epoch to the present.

"Industrial wastewater" means wastewater generated in a commercial or industrial process.

"Land application" means in regard to biosolids, the distribution of biosolids by spreading or spraying on the surface of the land, injecting below the surface of the land, or incorporating into the soil with a uniform application rate for the purpose of fertilizing the crops and vegetation or conditioning the soil. Sites approved for land application of biosolids in accordance with this chapter are not to be considered to be treatment works. Bulk disposal of stabilized sludge in a confined area, such as in landfills, is not land application. For the purpose of this chapter, the use of biosolids in agricultural research and the distribution and marketing of exceptional quality biosolids are not land application.

"Land application area" means, in regard to biosolids, the area in the permitted field, excluding the setback distances, where the biosolids may be applied.

"Land applier" means someone who land applies biosolids pursuant to a valid permit from the department as set forth in this chapter and 9VAC25-32-690 through 9VAC25-32-760.

"Land with a high potential for public exposure" means land that the public uses frequently. This includes, but is not limited to, a public contact site and a reclamation site located in a populated area (e.g., a construction site located in a city).

"Land with a low potential for public exposure" means land that the public uses infrequently. This includes, but is not limited to, agricultural land, forest, and a reclamation site located in an unpopulated area (e.g., a strip mine located in a rural area).

"Leachate collection system" means a system or device installed immediately above a liner that is designed, constructed, maintained, and operated to collect and remove leachate from a sewage sludge unit.

"Liner" means soil or synthetic material that has a hydraulic conductivity of 1 X 10^-7 centimeters per second or less.

"Local monitor" means a person or persons employed by a local government to perform the duties of monitoring the operations of land appliers pursuant to a local ordinance.

"Local ordinance" means an ordinance adopted by counties, cities, or towns in accordance with § 62.1-44.19:3 of the Code of Virginia.

"Lower explosive limit for methane gas" means the lowest percentage of methane gas in air, by volume that propagates a flame at 25°C and atmospheric pressure.

"Monthly average" means the arithmetic mean of all measurements taken during the month.

"Municipality" means a city, town, county, district, association, or other public body (including an intermunicipal Agency of two or more of the foregoing entities) created by or under state law; an Indian tribe or an authorized Indian tribal organization having jurisdiction over sewage sludge management; or a designated and approved management agency under § 208 of the CWA, as amended. The definition includes a special district created under state law, such as a water district, sewer district, sanitary district, utility district, drainage district, or similar entity, or an integrated waste management facility as defined in § 201(e) of the CWA, as amended, that has as one of its principal responsibilities the treatment, transport, use, or disposal of biosolids or sewage sludge.

"Odor sensitive receptor" means, in the context of land application of biosolids, any health care facility, such as hospitals, convalescent homes, etc. or a building or outdoor facility regularly used to host or serve large groups of people such as schools, dormitories, or athletic and other recreational facilities.

"Other container" means either an open or closed receptacle. This includes, but is not limited to, a bucket, a box, a carton, and a vehicle or trailer with a load capacity of one metric ton or less.

"Pasture" means land on which animals feed directly on feed crops such as legumes, grasses, grain stubble, or stover.

"Pathogenic organisms" means disease-causing organisms. These include, but are not limited to, certain bacteria, protozoa, viruses, and viable helminth ova.

"Person who prepares biosolids" means either the person who generates biosolids during the treatment of domestic sewage in a treatment works or the person who derives a material from sewage sludge.

"pH" means the logarithm of the reciprocal of the hydrogen ion concentration measured at 25° Celsius or measured at another temperature and then converted to an equivalent value at 25° Celsius.

"Place sewage sludge or sewage sludge placed" means disposal of sewage sludge on a surface disposal site.

"Pollutant" means an organic substance, an inorganic substance, a combination of organic and inorganic substances, or a pathogenic organism that, after discharge and upon exposure, ingestion, inhalation, or assimilation into an organism either directly from the environment or indirectly by ingestion through the food chain, could, on the basis of information available to the board, cause death, disease, behavioral abnormalities, cancer, genetic mutations, physiological malfunctions (including malfunction in reproduction), or physical deformations in either organisms or offspring of the organisms.

"Pollutant limit" means a numerical value that describes the amount of a pollutant allowed per unit amount of biosolids (e.g., milligrams per kilogram of total solids); the amount of a pollutant that can be applied to a unit area of land (e.g., kilograms per hectare); or the volume of a material that can be applied to a unit area of land (e.g., gallons per acre).

"Public contact site" means land with a high potential for contact by the public. This includes, but is not limited to, public parks, ball fields, cemeteries, and golf courses.

"Qualified groundwater scientist" means an individual with a baccalaureate or post-graduate degree in the natural sciences or engineering who has sufficient training and experience in groundwater hydrology and related fields, as may be demonstrated by state registration, professional certification, or completion of accredited university programs, to make sound professional judgments regarding groundwater monitoring, pollutant fate and transport, and corrective action.

"Range land" means open land with indigenous vegetation.

"Reclamation site" means drastically disturbed land that is reclaimed using biosolids. This includes, but is not limited to, strip mines and construction sites.

"Run-off" means rainwater, leachate, or other liquid that drains overland on any part of a land surface and runs off of the land surface.

"Seismic impact zone" means an area that has a 10% or greater probability that the horizontal ground level acceleration of the rock in the area exceeds 0.10 gravity once in 250 years.

"Sewage sludge" means solid, semi-solid, or liquid residue generated during the treatment of domestic sewage in a treatment works. Sewage sludge includes, but is not limited to, domestic septage; scum or solids removed in primary, secondary, or advanced wastewater treatment processes; and a material derived from sewage sludge. Sewage sludge does not include ash generated during the firing of sewage sludge in a sewage sludge incinerator or grit and screenings generated during preliminary treatment of domestic sewage in a treatment works.

"Sewage sludge unit" means land on which only sewage sludge is placed for final disposal. This does not include land on which sewage sludge is either stored or treated. Land does not include surface waters.

"Sewage sludge unit boundary" means the outermost perimeter of an active sewage sludge unit.

"Site" means the area of land within a defined boundary where an activity is proposed or permitted.

"Specific oxygen uptake rate (SOUR)" means the mass of oxygen consumed per unit time per unit mass of total solids (dry weight basis) in the sewage sludge.

"Store or storage of sewage sludge" means the placement of sewage sludge on land on which the sewage sludge remains for two years or less. This does not include the placement of sewage sludge on land for treatment.

"Surface disposal site" means an area of land that contains one or more active sewage sludge units.

"Total solids" means the materials in sewage sludge that remain as residue when the sewage sludge is dried at 103°C to 105°C.

"Treat or treatment of sewage sludge" means the preparation of sewage sludge for final use or disposal. This includes, but is not limited to, thickening, stabilization, and dewatering of sewage sludge. This does not include storage of sewage sludge.

"Treatment works" means either a federally owned, publicly owned, or privately owned device or system used to treat (including recycle and reclaim) either domestic sewage or a combination of domestic sewage and industrial waste of a liquid nature.

"Unstable area" means land subject to natural or human-induced forces that may damage the structural components of an active sewage sludge unit. This includes, but is not limited to, land on which the soils are subject to mass movement.

"Unstabilized solids" means organic materials in sewage sludge that have not been treated in either an aerobic or anaerobic treatment process.

"Use" means to manage or recycle a processed waste product in a manner so as to derive a measurable benefit as a result of such management.

"Vector attraction" means the characteristic of biosolids or sewage sludge that attracts rodents, flies, mosquitoes, or other organisms capable of transporting infectious agents.

"Volatile solids" means the amount of the total solids in sewage sludge lost when the sewage sludge is combusted at 550°C in the presence of excess air.

Historical Notes

Derived from Volume 12, Issue 20, eff. July 24, 1996; amended, Virginia Register Volume 16, Issue 25, eff. September 27, 2000; Volume 18, Issue 09, eff. February 15, 2002; Volume 28, Issue 10, eff. February 15, 2012; Volume 29, Issue 24, eff. September 1, 2013.

Statutory Authority

§ 62.1-44.15 of the Code of Virginia.