Wis. Admin. Code Department of Natural Resources § NR 204.03 - Definitions

Current through March 28, 2022

The following definitions are applicable to terms used in this chapter. Definitions of other terms and the meaning of abbreviations are in ch. NR 205.

(1) "Aerobic digestion" means the biochemical decomposition of organic matter in sewage sludge into carbon dioxide and water by microorganisms in the presence of air.
(2) "Agricultural land" means land on which a food crop, a feed crop or fiber crop will be grown within 12 months following sludge application. This includes range land and land used as pasture.
(3) "Agronomic rate" means the whole sludge application rate, on a dry weight basis, designed to provide the amount of nitrogen needed by the food crop, feed crop, fiber crop, cover crop or vegetation grown on the land, and designed to minimize the amount of nitrogen in the sewage sludge that passes below the root zone of the crop or vegetation grown on the land to the groundwater.
(4) "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.
(5) "Annual pollutant loading rate" means the maximum amount of a pollutant that can be applied to a unit area of land during a 365-day period.
(6) "Application rate" means the loading limits placed on a landspreading site, as established by the agronomic needs of the crop and the characteristics of the sludge, normally expressed as dry tons/acre, gallons/acre or cu yd/acre.
(7) "Available nitrogen" means the nitrogen which is present in the sludge in the NH3-N form and the nitrogen that is mineralized from the organic nitrogen in the sludge; both of which can then be absorbed and assimilated by growing plants in the cropping year.
(8) "Bag or other container" or "bagged" or "bag" means either a bag or an open or closed receptacle that has a capacity of one metric ton or less. This includes a bucket, a box, a carton and a vehicle or trailer.
(9) "Bedrock" means the rocks that underlie soil material. Bedrock may be present at the earth's surface when the weathered in-place consolidated material, larger than 2 mm in size, is greater than 50% by volume.
(10) "Bulk sewage sludge" means sewage sludge which will be applied to the land but is not bagged.
(11) "Centralized septage treatment facility" means a treatment facility which accepts septage from multiple sources and treats the septage prior to discharge or disposal.
(12) "Community well" means a public well which serves at least 15 service connections used by year-round residents or regularly serves at least 25 year- round residents. Any well serving 7 or more homes, 10 or more mobile homes, 10 or more apartment units or 10 or more condominium units shall be considered a community well unless information is available to indicate that 25 year- round residents will not be served.
(13) "Cumulative metals loading rate" means the maximum amount of an inorganic metal that can be applied to a unit area of land.
(14) "Density of microorganisms" means the number of microorganisms per unit mass of total solids, on a dry weight basis, in the sewage sludge.
(15) "Department" means the department of natural resources.
(16) "Detrimental effects" means contamination of the lands or waters of the state or making the same injurious to public health, harmful for commercial or agricultural use, or deleterious to animal or plant life.
(17) "Domestic sewage" means waste and wastewater from humans or household operations that is discharged to or otherwise enters a treatment works.
(18) "Dry run" means a drainage pathway, either natural or artificial, with definable banks, which contains confined flow during periods of natural runoff.
(19) "Exceptional quality sludge" means sludge that meets the class A requirements for pathogens, as specified in s. NR 204.07(6) (a), the high quality pollutant concentrations, as specified in s. NR 204.07(5) (c), and one of the pre-land application processes to reduce vector attraction, as specified in s. NR 204.07(7) (a) to (i).
(20) "Feed crops" means crops produced primarily for consumption for animals.
(21) "Field" means a subset of a site.
(22) "Floodplain" means the land which has been or may be covered by flood water during the regional flood as specified under s. NR 116.03(16) and (41).
(23) "Food crops" means tobacco and crops grown for human consumption.
(24) "Generator" means either the person who generates or prepares sludge during the treatment of domestic sewage in a treatment works or the person who derives a material from sludge or the person who changes the sludge characteristics either through treatment, mixing or any other process.
(25) "Geometric mean" means the average of the log values of the colony density and taking the antilog of that value, or by taking the nth root of the products of the n values, i.e., (Y10Y20Y 30.....Yn) to the 1/nth power.
(26) "Grit" means the heavy solid materials such as sand, gravel and cinders collected from the headwork of a treatment system.
(27) "Groundwater" means any of the waters of the state, as defined in ss. 281.01(18) and 283.01(20), Stats., occurring in a saturated subsurface geological formation of permeable rock or soil.
(28) "High groundwater level" means the higher of either the elevation to which the soil is saturated as observed as a free water surface in an unlined hole or the elevation to which the soil has been seasonally or periodically saturated as indicated by soil color patterns throughout the soil profile.
(29) "High quality sludge" means sludge that meets the monthly average pollutant concentration limits which are shown, as Table 3, in s. NR 204.07(5) (c).
(30) "Historical site" means any property as established under s. 44.40(2) (a), Stats.
(31) "Incorporation" means the mixing of sludge with topsoil to a minimum depth of 4 inches by such means as discing, mold-board plowing, chisel plowing, rototilling or other tillage methods.
(32) "Injection" means the subsurface placement of liquid sludge to a depth of 4 to 12 inches.
(33) "Land application" means the spraying or spreading of sludge onto the land surface, the injection of sludge below the land surface, or the incorporation of sludge into the soil. Sludge can either condition the soil or fertilize crops or vegetation grown in the soil.
(34) "Land with high potential for public exposure" means land that the public uses frequently. This includes sites such as a public contact site, a lawn or home garden, and a reclamation site located in a populated area, e.g., a construction site located in a city.
(35) "Land with low potential for public exposure" means land that the public uses infrequently. This includes agricultural land, forest and reclamation sites located in an unpopulated area.
(36) "Monthly average" means the arithmetic mean of all measurements taken during the month using analytical methodologies specified in ch. NR 219.
(37) "Municipal solid waste landfill" means a discrete area of land or an excavation that is subject to the requirements in chs. NR 500 to 538 and is licensed to receive household waste, other wastes such as commercial solid waste, nonhazardous sludge, small quantity generator waste and industrial solid waste. It does not include a land application site, surface disposal unit, surface impoundment, injection well or waste pile.
(38) "Pathogens" means disease causing organisms. This includes, but is not limited to, certain bacteria, protozoa, viruses and viable helminth ova.
(39) "PCBs" means polychlorinated biphenyls.
(40) "Permeability" means the rate of the movement of liquid through the soil expressed in inches per hour.
(41) "Person" means an individual, owner, operator, association, partnership, corporation, municipality, interstate agency, state agency or federal agency.
(42) "Person who prepares sludge" means a generator.
(43) "pH" means the logarithm of the reciprocal of the hydrogen ion concentration measured at 25° C or measured at another temperature and then converted to an equivalent value at 25° C.
(44) "POTW" or "publicly owned treatment works" means a treatment works which is owned by a public entity and any sewers that convey wastewater to the treatment works. This definition includes any device or system used by a municipality in the storage, treatment, recycling and reclamation of municipal sewage, sludge or liquid industrial waste.
(45) "Privately owned domestic wastewater treatment works" means a facility which has a permit under ch. 283, Stats., and which treats domestic wastewater or sludge and which is owned and operated by non-municipal entity or enterprise such as a mobile home park, restaurant, hotel, motel or country club.
(46) "Public contact site" means land with a high potential for contact by the public. This includes sites such as public parks, ball fields, plant nurseries, turf farms and golf courses.
(47) "Recreation area" means a designated area clearly identified for the purpose of providing an opportunity for recreational activity.
(48) "Reclamation site" means drastically disturbed land that is reclaimed using sewage sludge. This includes sites such as strip mines and construction sites.
(49) "Recycling" means the beneficial reuse of sludge through land application, composting or other approved method that returns organic matter or nutrients to the soil, or creates a useful product.
(50) "Research plots" means an area of land approved by the department and designed and operated by a qualified person to investigate questions pertaining to land application and uses of sludge.
(51) "Restricted public access" means private property or the limiting of entry, for a period of time, by means such as signs or traditional agricultural fencing or other department approved method.
(52) "School" means a public or private educational facility in which a program of educational instruction is provided to children or adults in any grade or grades from pre-school through the university level.
(53) "Screenings" means the coarse sewage solids collected from devices such as gratings, wire mesh or perforated plates.
(54) "Set aside land" or "acreage conservation reserve" means the agricultural land which is taken out of crop production on an annual basis for the purposes of conservation and to reduce the acreage planted of a particular crop.
(55) "Sewage sludge" or "sludge" or "biosolids" means the solid, semi-solid or liquid residue generated during the treatment of domestic sewage in a treatment works. Sewage sludge includes scum or solids removed in primary, secondary or advanced wastewater treatment processes and material derived from sewage sludge. Sewage sludge does not include ash generated during the firing of a sewage sludge incinerator or grit and screenings generated during preliminary treatment of domestic sewage in a treatment works.

Note: All 3 terms defined here are interchangeable and recognized by the department, as they are all in common use.

(56) "Site" means any property used for recycling, disposal or storage of sludge and may be divided into fields.
(57) "Soil" means the unconsolidated material which overlies bedrock.
(58) "Soil compaction" means the degree of compaction to a soil at which its infiltration capacity, permeability and ability to function as a medium for plant growth is impeded.
(59) "Soil conservation practice" means a measure used to retain surface water and soil on agricultural fields, including contour strip cropping, terracing, grassed waterways or plant residue management practices.
(60) "Soil pH" means the pH of the soil in the plow layer as measured in water by a pH meter with a glass electrode or by using another department approved procedure.
(61) "Specific oxygen uptake rate" or "SOUR" means the mass of oxygen consumed per unit time per unit mass of total solids on a dry weight basis.
(62) "Stabilization of sludge" means any combination of chemical, physical, thermal or biological treatment processes which result in a significant reduction in the percentage of volatile solids or the specific oxygen uptake rate in the sludge.
(63) "Surface disposal unit" means an area of land on which only sewage sludge, including exceptional quality sludge, is placed for final disposal. This does not include land or lagoons on which sewage sludge is either stored or treated, municipal solid waste landfills or land application sites.
(64) "Surface water" means those portions of Lake Michigan and Lake Superior within the boundaries of Wisconsin, all lakes, bays, rivers, streams, springs, ponds, impounding reservoirs, marshes, water courses, drainage systems and other surface water, natural or artificial, public or private within the state or under its jurisdiction, except those waters which are entirely confined and completely retained upon the property of a facility.
(65) "Threatened or endangered species" means those species defined in ch. NR 27.
(66) "Total nitrogen" means the sum of nitrite, nitrate, ammonia and organic nitrogen.
(67) "Total solids" means the materials in sewage sludge that remain as residue when the sewage sludge is dried at 103 to 105° Celsius.
(68) "Treatment works" means a publicly or privately owned treatment works, centralized septage treatment facility, and treatment works owned by federal or state government.
(69) "Unstabilized solids" means the organic materials in sewage sludge that have not been treated in either an aerobic or anaerobic treatment process.
(70) "Vector attraction" means the characteristics of sewage sludge that attract rodents, flies, mosquitos or other organisms capable of transporting infectious agents.
(71) "Volatile solids" means the amount of the total solids in sewage sludge lost when the sewage sludge is combusted at 550° Celsius in the presence of excess air.
(72) "Wetlands" means those areas where water is at, near, or above the land surface long enough to be capable of supporting aquatic or hydrophytic vegetation, and which have soils indicative of wet conditions.
(73) "Wisconsin pollutant discharge elimination system permit" or "WPDES permit" or "permit" means a permit issued by the department under ch. 283, Stats., for the discharge of pollutants.


Wis. Admin. Code Department of Natural Resources § NR 204.03
Cr. Register, December, 1995, No. 480, eff. 1-1-96; corrections made under s. 13.93(2m) (b) 7, Stats., Register, November, 1996, No. 491; correction in (37) made under s. 13.92(4) (b) 7, Stats., Register February 2010 No. 650.

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