SECTION 312.8. General Definitions

The following words and terms, when used in this chapter, have the following meanings, unless the context clearly indicates otherwise.

(1) 25-year, 24-hour rainfall event--The maximum rainfall event with a probable recurrence interval of once in 25 years, with a duration of 24 hours as defined by the National Weather Service in Technical Paper Number 40, Rainfall Frequency Atlas of the United States, May 1961, and subsequent amendments, or equivalent regional or state rainfall information developed from it.

(2) Active disposal unit--A disposal unit that has not closed and/or is still receiving sewage sludge, biosolids, domestic septage, or water treatment residuals.

(3) Aerobic digestion--The biochemical decomposition of organic matter in sewage sludge into carbon dioxide, water, and other by-products by microorganisms in the presence of free oxygen.

(4) Agricultural land--Land on which a food crop, a feed crop, or a fiber crop is grown. This includes range land and land used as pasture.

(5) Agricultural management unit--A portion of a land application area contained within an identifiable boundary, such as a river, fence, or road, where the area has a known crop or land use history.

(6) Agronomic rate--The whole application rate (dry weight basis) designed:

(A) to provide the amount of nitrogen needed by the crop or vegetation grown on the land; and

(B) to minimize the amount of nitrogen that passes below the root zone of the crop or vegetation to the groundwater.

(7) Anaerobic digestion--The biochemical decomposition of organic matter in sewage sludge into methane gas, carbon dioxide, and other by-products by microorganisms in the absence of free oxygen.

(8) Annual metal loading rate--The maximum amount of a metal (dry weight basis) that can be applied to a land application unit during a 365-day period.

(9) Annual whole application rate--The maximum amount of biosolids, domestic septage, or water treatment residuals that can be applied to a land application unit during a 365-day period.

(10) Applied uniformly--Land application conducted in such a way that the agronomic rate is not exceeded anywhere in the land application unit.

(11) Aquifer--A geologic formation, group of geologic formations, or a portion of a geologic formation capable of yielding groundwater to wells or springs.

(12) Base flood--A flood that has a 1% chance of occurring in any given year.

(13) Beneficial use--The land application of biosolids or domestic septage in a manner that complies with the requirements of Subchapter B of this chapter (relating to Land Application and Storage of Biosolids and Domestic Septage), or the land application of water treatment residuals in a manner that complies with the requirements of Subchapter F (relating to Land Application, Storage, and Disposal of Water Treatment Residuals) and does not exceed the agronomic rate for a food, fiber, feed, or turf crop, or any metal or toxic constituent limitations that the food, fiber, feed, or turf crop may have. Land application of biosolids, water treatment residuals, or domestic septage at a rate below the optimal agronomic rate will be considered a beneficial use.

(14) Beneficial use site--An area of land that contains one or more land application units.

(15) Biosolids--Sewage sludge that has been treated or processed to meet Class A, Class AB, or Class B pathogen standards under this chapter for beneficial use.

(16) Bulk biosolids--Biosolids that are not sold or given away in a bag or other container for land application.

(17) Certified nutrient management specialist--An organization in Texas or an individual who is currently certified as a nutrient management specialist through a United States Department of Agriculture-Natural Resources Conservation Service recognized certification program.

(18) Class A biosolids--Biosolids meeting the metal limits in §312.43(b)(1) and (3) of this title (relating to Metal Limits) and the pathogen reduction requirements in §312.82(a)(1)(B) of this title (relating to Pathogen Reduction).

(19) Class AB biosolids--Biosolids meeting the metal limits in §312.43(b)(1) and (3) of this title (relating to Metal Limits) and the pathogen reduction requirements in §312.82(a)(1)(A) of this title (relating to Pathogen Reduction).

(20) Class B biosolids--Biosolids meeting the metal limits in §312.43(b)(1) of this title (relating to Metal Limits) and one of the pathogen reduction requirements in §312.82(b) of this title (relating to Pathogen Reduction).

(21) Contaminate an aquifer--To introduce a substance that causes the maximum contaminant level for nitrate in 40 Code of Federal Regulations (CFR) §141.11, as amended, 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 already exceeds the maximum contaminate level for nitrate in 40 CFR §141.11, as amended.

(22) Cover--Soil or other material used to cover sewage sludge, biosolids, domestic septage, or water treatment residuals placed on an active disposal unit.

(23) Cover crop--Grasses or small grain crop, such as oats, wheat, or barley, not grown for harvest.

(24) Cumulative metal loading rate--The maximum amount of an inorganic pollutant (dry weight basis) that may be applied to a land application unit.

(25) Debris--Solid material such as rubber, plastic, glass, or other trash that may pass through a wastewater treatment process or sewage sludge or biosolids process. Also, material that may be collected with domestic septage. This solid material is visibly distinguishable from sewage sludge, biosolids, and domestic septage. This material does not include grit or screenings removed during the preliminary treatment of domestic sewage at a treatment works, nor does it include grit trap waste.

(26) Density of microorganisms--The number of microorganisms per unit mass of total solids (dry weight basis) in the sewage sludge or biosolids.

(27) Displacement--The relative movement of any two sides of a fault measured in any direction.

(28) Disposal--The placement of sewage sludge, biosolids, domestic septage, or water treatment residuals on the land for any purpose other than beneficial use. Disposal does not include placement onto the land where the activity has been approved by the executive director or commission as storage or temporary storage and it occurs only for the period of time expressly approved.

(29) Disposal unit--Land that only sewage sludge or biosolids is placed for disposal. A sewage sludge or biosolids unit must be used for sewage sludge and biosolids. This does not include land that sewage sludge and biosolids is either stored or treated.

(30) Disposal unit boundary--The outermost perimeter of a surface disposal site.

(31) Domestic septage--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 or chemical toilet waste.

(32) Domestic sewage--Waste and wastewater from humans or household operations that is discharged to a wastewater collection system or otherwise enters a treatment works.

(33) Dry weight basis--Calculated based on having been dried at 105 degrees Celsius until reaching a constant mass (i.e., essentially 100% solids content).

(34) Experimental use--Non-routine beneficial use land application or reclamation projects where sewage sludge or biosolids are added to the soil for research purposes, in pilot projects, feasibility studies, or similar projects.

(35) Facility--Includes all contiguous land, structures, other appurtenances, and improvements on the land used for surface disposal, land application, or incineration.

(36) Fault--A fracture or zone of fractures in any materials along which strata, rocks, or soils on one side are displaced with respect to strata, rocks, or soil on the other side.

(37) Feed crops--Crops produced primarily for consumption by domestic livestock, such as swine, goats, cattle, horses, sheep, or poultry.

(38) Fiber crops--Crops such as flax and cotton.

(39) Final cover--The last layer of soil or other material placed on a sludge or biosolids unit at closure.

(40) Floodway--A channel of a river or watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the surface elevation more than one foot.

(41) Food crops--Crops consumed by humans. These include, but are not limited to, fruits, vegetables, and tobacco.

(42) Forest--Land densely vegetated with trees and/or underbrush.

(43) Grease trap waste--Material collected in and from a grease interceptor in the sanitary sewer service line of a commercial, institutional, or industrial food service or processing establishment, including the solids resulting from dewatering processes.

(44) Grit trap--A unit/chamber that allows for the sedimentation of solids from an influent liquid stream by reducing the flow velocity of the influent liquid stream. In a grit trap, the inlet and the outlet are both located at the same vertical level, at, or very near, the top of the unit/chamber; the outlet of the grit trap is connected to a sanitary sewer system. A grit trap is not designed to separate oil and water.

(45) Grit trap waste--Waste collected in a grit trap. Grit trap waste includes waste from grit traps placed in the drains prior to entering the sewer system at maintenance and repair shops, automobile service stations, car washes, laundries, and other similar establishments. The term does not include material collected in an oil/water separator or in any other similar waste management unit designed to collect oil.

(46) Groundwater--Water below the land surface in the saturated zone.

(47) Harvesting--Removal of a food, fiber, feed or turf crop from a land application unit by the means of cutting, picking, drying, baling, or gathering. The act of cutting and leaving vegetative material on the land application unit is not considered harvesting.

(48) Holocene time--The most recent epoch of the Quaternary period, extending from the end of the Pleistocene Epoch to the present. Holocene time began approximately 10,000 years ago.

(49) Incinerator--An apparatus for burning sewage sludge or biosolids at high temperatures until it is reduced to ash.

(50) Incorporation--Mixing the applied material evenly through the top three inches of soil.

(51) Industrial wastewater--Wastewater generated in a commercial or industrial process.

(52) Institution--An established organization or corporation, especially of a public nature or where the public has access, such as child care facilities, public buildings, or health care facilities.

(53) Irrigation conveyance canal--A canal that is constructed to convey water from the source of supply to one or more farms.

(54) Lagoon--A surface impoundment that is authorized under a permit issued by the commission for the storage of sewage sludge or biosolids. Any other type of impoundment must be considered an active disposal unit.

(55) Land application or land apply or land applied--The spraying or spreading of biosolids, domestic septage, or water treatment residuals onto the land surface; the injection of biosolids, domestic septage, or water treatment residuals below the land surface; or the incorporation of biosolids, domestic septage, or water treatment residuals into the soil to either condition the soil or fertilize crops or vegetation grown in the soil.

(56) Land application unit--An area where materials are applied onto or incorporated into the soil surface for beneficial use or for treatment and disposal, where the disposal occurs within five feet of the surface of the land. The term does not include manure spreading operations.

(57) Land with a high potential for public exposure--Land that the public uses frequently and/or is not provided with a means of restricting public access.

(58) Land with a low potential for public exposure--Land that the public uses infrequently and/or is provided with a means of restricting public access.

(59) Leachate collection system--A system or device installed immediately above a liner that is designed, constructed, maintained, and operated to collect and remove leachate from a disposal unit.

(60) Licensed professional geoscientist--A geoscientist who maintains a current license through the Texas Board of Professional Geoscientists in accordance with its requirements for professional practice.

(61) Liner--Soil or synthetic material that has a hydraulic conductivity of 1 x 10^-7 centimeters per second or less. Soil liners must be of suitable material with more than 30% passing a number 200 sieve, have a liquid limit greater than 30%, a plasticity index greater than 15, compaction of greater than 95% Standard Proctor at optimum moisture content, and will be at least two feet thick placed in six-inch lifts. Synthetic liners must be a membrane with a minimum thickness of 20 mils and include an underdrain leak detection system.

(62) Lower explosive limit for methane gas--The lowest percentage of methane in air, by volume, that propagates a flame at 25 degrees Celsius and atmospheric pressure.

(63) Major sole-source impairment zone--A watershed that contains a reservoir that is used by a municipality as a sole source of drinking water supply for a population of more than 140,000, inside and outside of its municipal boundaries; and into which at least half of the water flowing is from a source that, on September 1, 2001, is on the list of impaired state waters adopted by the commission as required by 33 United States Code, §1313(d), as amended, at least in part because of concerns regarding pathogens and phosphorus, and for which the commission at some time prepared and submitted a total maximum daily load standard.

(64) Metal limit--A numerical value that describes the amount of a metal allowed per unit amount of sewage sludge, biosolids, or water treatment residuals (e.g., milligrams per kilogram of total solids); the amount of a metal that can be applied to or disposed onto a land application unit (e.g., kilograms per hectare); or the volume of a material that can be applied to a land application unit (e.g., gallons per acre).

(65) Monofill--A landfill or landfill trench in which sewage sludge, biosolids, or water treatment residuals are the only type of solid waste placed.

(66) Municipality--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 or biosolids management; or a designated and approved management agency under federal Clean Water Act, §208, as amended. The definition includes a special district created under state law, such as a water district, sewer district, sanitary district, or an integrated waste management facility as defined in federal Clean Water Act, §201(e), as amended, that has as one of its principal responsibilities the treatment, transport, use, or disposal of sewage sludge or biosolids.

(67) Off-site--Property that cannot be characterized as "on-site."

(68) On-site--The same or contiguous property owned, controlled, or supervised by the same person. If the property is divided by public or private right-of-way, the access must be by crossing the right-of-way or the right-of-way must be under the control of the person.

(69) Operator--The person responsible for the overall operation of a facility, land application unit, or surface disposal site.

(70) Other container--Either an open or closed receptacle, including, but not limited to, a bucket, box, or a vehicle or trailer with a load capacity of one metric ton (2,200 pounds) or less.

(71) Owner--The person who owns a facility or part of a facility.

(72) Pasture--Land that animals feed directly on for feed crops such as legumes, grasses, grain stubble, forbs, or stover.

(73) Pathogenic organisms--Disease-causing organisms including, but not limited to, certain bacteria, protozoa, viruses, and viable helminth ova.

(74) Person who prepares sewage sludge or biosolids--Either the person who generates sewage sludge or biosolids during the treatment of domestic sewage in a treatment works or the person who derives a material from sewage sludge or biosolids.

(75) Place or placed sewage sludge or biosolids--Disposal of sewage sludge or biosolids on a surface disposal site.

(76) Pollutant--An organic or inorganic substance, 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 executive director, 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.

(77) Precipitation--Deposit on the land of rain, mist, hail, sleet, or snow that falls on the ground under the action of gravitational force.

(78) Process or processing--For the purposes of this chapter, these terms shall have the same meaning as "treat" or "treatment."

(79) Public contact site--Land with a high potential for contact by the public. This includes, but is not limited to, public parks, ball fields, cemeteries, plant nurseries, turf farms, and/or golf courses.

(80) Range land--Open land with indigenous vegetation.

(81) Reclamation site--Drastically disturbed land that is reclaimed using sewage sludge, biosolids, or water treatment residuals. This includes, but is not limited to, strip mines, borrow areas, and\or construction sites.

(82) Runoff--Rainwater, leachate, or other liquid that drains overland on any part of a land surface and runs off of the land surface.

(83) Seismic impact zone--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.

(84) Sewage sludge--Solid, semi-solid, or liquid residue generated during the treatment of domestic sewage in 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 material derived from sewage sludge. Sewage sludge does not include ash or grit and screenings generated during preliminary treatment of domestic sewage in a treatment works.

(85) Sole-source surface drinking water supply--A body of surface water that is identified as a public water supply in §307.10 of this title (relating to Appendices A - G) and is the sole source of supply of a public water supply system, exclusive of emergency water connections.

(86) Source-separated organic material--As defined in §332.2 of this title (relating to Definitions).

(87) Specific oxygen uptake rate--The mass of oxygen consumed per unit time per unit mass of total solids (dry weight basis).

(88) Stabilization--Biological or chemical treatment processes that minimize subsequent complications due to biodegradation of organic compounds, biologically by reducing organic content and chemically by retarding the degradation of organic materials.

(89) Staging--Temporary holding of sewage sludge, biosolids, domestic septage, or water treatment residuals, at a land application unit, for up to a maximum of seven calendar days per each staging location, prior to land application.

(90) Store or storage--The placement of sewage sludge, biosolids, domestic septage, or water treatment residuals on land or in an enclosed vessel for longer than seven days.

(91) Surface disposal site--An area of land that contains one or more active disposal units.

(92) Surface impoundment--A facility or part of a facility that is a natural topographic depression, human-made excavation, or diked area formed primarily of earthen materials (although it may be lined with man-made materials), that is designed to hold an accumulation of liquid wastes or wastes containing free liquids, and that is not an injection well. Examples of surface impoundments include: holding, storage, settling, and aeration pits, ponds, and lagoons.

(93) Temporary storage--Storage of waste regulated under this chapter by a transporter, which has been approved in writing by the executive director, in accordance with §312.147 of this title (relating to Temporary Storage).

(94) Three hundred-sixty-five-day period--A running total that covers the period between land application to a site and the nutrient uptake of the feed, food, fiber, or turf crop.

(95) Total solids--The amount of solids in a material that remain as residue when the material is dried at 103 degrees Celsius to 105 degrees Celsius.

(96) Transporter--Any person who collects, conveys, or transports sewage sludge, biosolids, water treatment residuals, grit trap waste, grease trap waste, chemical toilet waste, or domestic septage by roadway, ship, rail, or other means.

(97) Treat or treatment--The preparation of sewage sludge, biosolids, domestic septage, or water treatment residuals for final use or disposal. This includes, but is not limited to, thickening, stabilization, initial alkali addition for pathogen or vector control, and dewatering. This term does not include storage of sewage sludge, biosolids, domestic septage, or water treatment residuals, or subsequent alkali addition for pathogen or vector control.

(98) Treatment works--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, located at an authorized wastewater treatment plant.

(99) Turf crop--Grass and the surface layer of earth held together by its roots that is grown and harvested as sod, sprigs, or plugs, primarily for the establishment of lawns.

(100) Unstabilized solids--Organic materials in sewage sludge or biosolids that have not been treated in either an aerobic or anaerobic treatment process.

(101) Unstable area--Land subject to natural or human induced forces that may damage the structural components of an active disposal unit or land application unit. This includes, but is not limited to, land that the soils are subject to mass movement.

(102) Vector attraction--The characteristic of sewage sludge, biosolids, and domestic septage that attracts rodents, flies, mosquitoes, or other organisms capable of transporting infectious agents.

(103) Volatile solids--The amount of the total solids in a material that is lost when the material is combusted at 550 degrees Celsius in the presence of excess oxygen.

(104) Waste pile--Any noncontainerized accumulation of solid, nonflowing waste that is used for treatment or storage.

(105) Water treatment residuals--Material generated during the treatment of either surface water or groundwater for potable use, which is not an industrial solid waste as defined in §335.1 of this title (relating to Definitions).

(106) Wetlands--Those areas that are inundated or saturated by surface water or groundwater at a frequency and duration to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas.

Source Note: The provisions of this §312.8 adopted to be effective October 13, 1995, 20 TexReg 7840; amended to be effective September 1, 2003, 28 TexReg 6300; amended to be effective October 2, 2003, 28 TexReg 8346; amended to be effective October 20, 2005, 30 TexReg 6743; amended to be effective October 2, 2014, 39 TexReg 7756; amended to be effective April 23, 2020, 45 TexReg 2542