Alaska Administrative Code
Title 18 - Environmental Conservation
Chapter 72 - Wastewater Treatment and Disposal
Article 7 - General Provisions
18 AAC 72.990 - Definitions and abbreviations

Universal Citation: 18 AK Admin Code 18 AAC 72.990

Current through November 28, 2024

In this chapter,

(1) "5-wide" means a conventional soil absorption system that is five feet wide, contains one line of distribution piping, and has at least 18 inches but not more than four feet of distribution medium measured from the springline of the distribution pipe to the bottom of the distribution media; the absorption area is calculated using the bottom area and sidewalls;

(2) "above-ground storage tank" means a tank system with 100 percent of its volume above ground;

(3) "absorption field" means the portion of a soil absorption system, excluding sand liners, that contains the distribution medium;

(4) "alternative onsite wastewater system"

(A) means a method of wastewater storage, treatment, and disposal that
(i) receives only domestic wastewater;

(ii) is located wholly on property owned by a single individual or entity who also has ownership of the dwellings, buildings, or structures it serves; and

(iii) does not discharge to surface water;

(B) does not include a conventional wastewater system;

(5) "alternative soil absorption system"

(A) means a method of soil absorption treatment and disposal other than a conventional soil absorption system, including any system utilizing soil located above original grade for treatment;

(B) does not include composting, incineration, pit privies, or other nonwater-carried disposal methods;

(6) "alternative wastewater system" means a method of treatment and disposal other than a conventional wastewater system, including

(A) advanced treatment units, package plants, holding tanks, or other methods of storage and treatment;

(B) a final disposal system not located on property owned or operated by the same individual or entity;

(7) "approved" and "approval" mean approved by, or the approval of, the department by means of written letter, electronic mail, or facsimile transmission;

(8) "bed" or "bed system" means a conventional soil absorption system that is a level excavation wider than five feet, using an absorption area calculated based on the bottom area only;

(9) "biochemical oxygen demand" means the amount, in milligrams per liter, of oxygen used in the biochemical oxidation of organic matter in five days at 20° Celsius;

(10) "cesspool" means a subsurface pit that receives untreated sewage;

(11) "cleanout" means an appurtenance on a sewer line designed to provide access for the purpose of removing deposited or accumulated materials;

(12) "collection and pumping system" or "collection system"

(A) means a system of pumps, conduits, or both that transports wastewater from the facility where the wastewater is generated to a wastewater treatment works, and consists of
(i) gravity, pressure, and vacuum sewer lines, including associated appurtenances such as manholes and cleanouts;

(ii) pump or collection stations;

(iii) a sewer main, regardless of ownership of the land on which it is installed; and

(iv) other pumps or conduits that serve a similar function;

(B) does not include a sewer service line or private sewer line;

(13) "commissioner" means the commissioner of environmental conservation or the commissioner's designee;

(14) "community sewer line" means that portion of a collection system serving two or more

(A) private residences;

(B) mobile homes, trailer park spaces, or recreational vehicle connection points;

(C) buildings not associated with a private residence; or

(D) any combination of two or more of the structures listed in (A) - (C) of this paragraph;

(15) "construction observation" or "observing construction" means visual observation of or visually observing the quality of construction, and the equipment and materials used for construction so that the observing engineer, or a person under the observing engineer's responsible charge, has the information necessary to provide a professional opinion regarding the system's conformance to approved construction documents, AS 46.03, and this chapter;

(16) "construction supervision" or "supervising construction" means providing oversight and direction during construction such that the supervising engineer, or a person under the supervising engineer's responsible charge

(A) can validate that the system was constructed in accordance with the requirements of this chapter and conforms to department publicly identified best management practices, protective of public health, public and private water systems, and the environment; and

(B) has the information necessary to prepare accurate record documents;

(17) "conventional onsite wastewater system" means a conventional wastewater system that

(A) receives only domestic wastewater; and

(B) is located wholly on property owned by the person or entity who also has ownership of the dwellings, buildings, and structures that the system serves;

(18) "conventional soil absorption system" means a wastewater treatment and disposal system that

(A) receives wastewater that, at a minimum, has received primary treatment;

(B) is of a typical 5-wide, shallow trench, deep trench, bed, or seepage pit design;

(C) uses natural subsurface undisturbed soils, with or without a sand liner, for treatment above a limiting condition;

(D) utilizes pressurized or non-pressurized distribution pipe; and

(E) has distribution media located as follows:
(i) has all distribution media located below original grade for absorption fields using sidewalls for the infiltrative surface; or

(ii) has the bottom of the distribution medium below original grade for absorption fields using the bottom area only for the infiltrative surface;

(19) "conventional wastewater system" means a wastewater treatment and disposal system that, with or without pumps and lift stations, uses a septic tank followed by disposal into a conventional soil absorption system;

(20) "daily peak capacity" means the maximum daily flow of wastewater, measured in gallons per day, that a treatment system is designed to process;

(21) "deep trench" means a conventional soil absorption system that

(A) is at least four feet deep but not more than 12 feet deep, with distribution media depth measured from the springline of the distribution pipe to the bottom of the distribution media;

(B) is at least 12 inches wide with one line of distribution piping; and

(C) has the absorption area calculated based on the area of the two vertical sidewalls along the length of the trench;

(22) "department" means the Department of Environmental Conservation;

(23) "design criteria" includes

(A) engineering guidelines that specify construction details and materials;

(B) objectives, results, or limits that a facility, structure, or process must meet in the performance of its intended function;

(C) flow rates, organic and hydraulic loading rates, and other information, numerical data, and parameters upon which a specific facility design is based;

(24) "director" means the director of the department's division assigned to water;

(25) "disinfect" means to treat by means of chlorination, ozonation, application of ultraviolet light, sterilization, or another chemical, physical, or other process designed to reduce or eliminate pathogenic organisms and produce an effluent with the following characteristics:

(A) an arithmetic mean of the values for a minimum of five effluent samples collected in 30 consecutive days that does not exceed 200 fecal coliform per 100 milliliters; and

(B) an arithmetic mean of the values for effluent samples collected in seven consecutive days that does not exceed 400 fecal coliform per 100 milliliters;

(26) "disposal sewer" means a pipeline or conduit that transports wastewater from a treatment works, providing at least primary treatment, to a disposal system;

(27) "disposal system" means a system that provides a method of final disposal of wastewater to the environment;

(28) "distribution medium" means sewer rock, polystyrene beads, chambers, gravelless pipe or another material used to provide void space in a soil absorption system, through which effluent flows and is stored before infiltration into the surrounding soils;

(29) "distribution pipe" means perforated pipe used to distribute effluent from a treatment process to the distribution medium within a soil absorption system;

(30) "distribution tank" means a manufactured tank with equal sized and spaced perforations used to distribute effluent from a pretreatment process to the distribution medium in a seepage pit;

(31) "domestic wastewater"

(A) means
(i) waterborne human wastes or graywater derived from dwellings, commercial buildings, institutions, or similar structures; or

(ii) the contents of individual removable containers used to collect and temporarily store human wastes;

(B) does not include
(i) liquid or solid material removed from a septic tank, cesspool, or similar treatment works if those facilities receive nondomestic wastewater; or

(ii) grease removed from a grease trap at a restaurant;

(32) "domestic wastewater disposal system" includes an injection well, soil absorption system, pit, crevice, sinkhole, depression, outfall, percolating stabilization pond, land irrigation system, sewer, treatment works, or other device, structure, or formation used to dilute, dispose, or discharge domestic wastewater;

(33) "domestic wastewater treatment works" includes a septic tank, package plant, stabilization pond, soil absorption system, activated sludge treatment plant, trickling filter, rotating biological contactor plant, membrane biological reactor, or other plant, device, structure, or other works designed to treat, neutralize, or stabilize domestic wastewater or sludges;

(34) "drain"

(A) means a line in or beneath a building that receives and carries sewage to the sewer service line or private sewer line;

(B) does not include a line in or beneath a building when it meets the definition of a sewer main or community sewer line;

(35) "duplex" means a single structure designed to house two single-family dwelling units;

(36) "emergency" means an unforeseen event that

(A) causes damage to or disrupts normal operations of a wastewater collection, storage, treatment, or disposal system; and

(B) requires immediate action for the system to perform the major functions for which it was designed, and to protect public health and the environment;

(37) "engineering plans" means a set of plans, prepared for construction, signed, sealed, and dated by an engineer registered in this state;

(38) "EPA" means the United States Environmental Protection Agency;

(39) "equalize" means to dampen daily fluctuations of the flow, quality, or amount of wastewater, in order to distribute surges over a period of time;

(40) "facility" means a building or structure, or multiple buildings and structures operated as a single institution, business, or entity;

(41) "force main" means a pressurized sewer main through which sewage is pumped;

(42) "geotechnical study" means a report or study analyzing sufficient subsurface information necessary to evaluate the effect of permafrost degradation on the structural integrity and operational performance of the proposed wastewater system;

(43) "gpd" means gallons per day;

(44) "graywater" means wastewater that

(A) is from a laundry, kitchen, sink, shower, bath, or other domestic source; and

(B) does not contain excrement, urine, or stormwater;

(45) "groundwater" means the subsurface water permanently or seasonally occupying the zone in which the voids in the rock or soil are filled with water at a pressure equal to or greater than atmospheric;

(46) "holding tank"

(A) means a watertight vessel or tank for the temporary storage or wastewater, urine, or excrement;

(B) includes a vault privy;

(C) does not include a pit privy;

(47) "hydroelectric project" means a project that generates electricity by converting the energy of running water;

(48) "impermeable strata" means bedrock, clay or other soil strata with a percolation rate slower than 120 minutes per inch;

(49) "land surface disposal system"

(A) means a system that disposes of treated wastewater onto the surface of the land in areas suitable for that purpose;

(B) does not include the land application of sewage solids or biosolids for an agricultural purpose regulated under 18 AAC 60;

(50) "limiting condition" includes a seasonal high water table, bedrock, permafrost, other impermeable or unsuitable soil strata, or another soil or site characteristic that reduces efficacy of soil treatment and thus restricts design options for a system;

(51) "marine outfall" means a discharge pipe used for the final disposal of wastewater extending from a wastewater treatment works to the point of discharge in marine waters, including equipment or appurtenances used for diffusing treated effluent to the marine environment;

(52) "modify" means to alter, renovate, improve, or replace a system component;

(53) "multi-family dwelling" means a single structure housing more than two single-family units;

(54) "nondomestic wastewater" means liquid or water-carried wastes other than domestic wastewater, including wastes resulting from

(A) a manufacturing, food processing, or production enterprise;

(B) an industrial establishment;

(C) the development of natural resources;

(D) the construction of a manufacturing, production, or industrial facility; or

(E) stormwater runoff;

(55) "nondomestic wastewater disposal system" means a device or structure designed to dilute, dispose, or discharge nondomestic wastewater;

(56) "nondomestic wastewater treatment works" means a plant, device, structure, or other works designed to treat, neutralize, or stabilize nondomestic wastewater or sludges;

(57) "nonpercolating stabilization pond" means a stabilization pond that

(A) is designed to contain wastewater; and

(B) prevents subsurface leakage at a rate greater than 500 gallons per acre per day at a water depth of six feet;

(58) "observed percolation rate" means the rate at which water will pass through a soil as measured by a person certified under 18 AAC 72.405 or a registered engineer during a percolation test conducted in accordance with standard practice or a best management practice publicly identified by the department under 18 AAC 72.070;

(59) "observed soil texture" and "observed soil type" mean the soil texture or soil type as observed by a person certified under 18 AAC 72.405 or a registered engineer;

(60) "observing construction" means construction observation;

(61) "package plant"

(A) means an alternate wastewater system that is a transportable modular treatment unit for domestic wastewater;

(B) does not include septic or holding tanks;

(62) "percolating stabilization pond" means a stabilization pond designed to contain wastewater and to allow subsurface leakage at a rate greater than 500 gallons per acre per day at a water depth of six feet;

(63) "pit privy"

(A) means a subsurface excavation that
(i) receives urine and excrement that is not waterborne; and

(ii) is the final disposal site and not a temporary storage facility;

(B) does not include a vault privy;

(64) "point source" has the meaning given in 18 AAC 83.990;

(65) "potable water system" has the meaning given in 18 AAC 80.1990;

(66) "primary treatment" means wastewater treatment that

(A) will subsequently discharge wastewater to land or waters that are not waters of the United States and
(i) removes substantially all floating and settleable solids; or

(ii) uses fine screens with 0.04-inch or smaller openings; or

(B) will subsequently discharge wastewater to waters of the United States and uses
(i) screening, sedimentation, and skimming adequate to remove at, least 30 percent of the biochemical oxygen demanding material and of the suspended solids in the treatment works influent; and

(ii) disinfection, where appropriate;

(67) "private residence"

(A) means a single residential lot that is developed as a primary habitation for not more than two families and has a total maximum design flow of not more than 1,500 gallons per day of domestic wastewater;

(B) includes one or more support buildings used only by the residents of the property, including a workshop, home office, greenhouse, or garage;

(C) does not include a commercial development open to the public or that produces a product available for human consumption;

(68) "private sewer line" means a pipeline or conduit carrying wastewater from a service connection to a community sewer line or treatment works;

(69) "private water line" has the meaning given in 18 AAC 80.1990;

(70) "private water system" has the meaning given in 18 AAC 80.1990;

(71) "public water system" has the meaning given in 18 AAC 80.1990;

(72) "publicly owned treatment works" has the meaning given in 18 AAC 83.990;

(73) "record documents" includes record drawings, specifications, construction submittals, photographs, diaries, daily reports, and test reports;

(74) "record drawings" means the engineering plans prepared for construction and revised to reflect how the system was constructed or installed;

(75) "registered engineer" means a professional engineer registered to practice in this state under AS 08.48;

(76) "residential dwelling" means a building or part of a structure used as a primary residence;

(77) "routine maintenance"

(A) means activity normally required to maintain the system components in good working order, including the replacement of 40 feet or less of pipe, a valve, a pump, or other minor components with a similar component that does not affect the system's configuration, material, treatment, or capacity;

(B) does not include replacement of a tank, soil absorption system, or other major system components;

(78) "sealed" means prepared by a registered engineer or a person under that engineer's direct supervision, and bearing the signature and seal of that engineer as required under AS 08.48.221 and 12 AAC 36.185;

(79) "secondary treatment" means a method of removal of dissolved and colloidal materials that produces an effluent with the following characteristics:

(A) for the five-day measure of biochemical oxygen demand from a source other than a stabilization pond,
(i) an arithmetic mean of the values for effluent samples collected in 30 consecutive days that does not exceed 30 milligrams per liter;

(ii) an arithmetic mean of the values for effluent samples collected in seven consecutive days that does not exceed 45 milligrams per liter; and

(iii) an arithmetic mean of the values for effluent samples collected in a 24-hour period that does not exceed 60 milligrams per liter;

(B) for the five-day measure of biochemical oxygen demand at a stabilization pond,
(i) an arithmetic mean of the values for effluent samples collected in 30 consecutive days that does not exceed 45 milligrams per liter and a percent removal that is not less than 65 percent by weight; and

(ii) an arithmetic mean of the values for effluent samples collected in seven consecutive days that does not exceed 65 milligrams per liter;

(C) for the measure of suspended solids from a source other than a stabilization pond,
(i) an arithmetic mean of the values for effluent samples collected in 30 consecutive days that does not exceed 30 milligrams per liter;

(ii) an arithmetic mean of the values for effluent samples collected in seven consecutive days that does not exceed 45 milligrams per liter; and

(iii) an arithmetic mean of the values for effluent samples collected in a 24-hour period that does not exceed 60 milligrams per liter;

(D) for the measure of suspended solids at a stabilization pond, an arithmetic mean of the values for effluent samples collected in 30 consecutive days that does not exceed 70 milligrams per liter; and

(E) for the measure of effluent pH, between 6.0 and 9.0 unless
(i) inorganic chemicals are not added to the waste stream as part of the treatment process; and

(ii) contributions from industrial sources do not cause the pH of the effluent to be less than 6.0 or greater than 9.0;

(80) "seepage pit" means a conventional soil absorption system that uses a perforated tank to distribute septic tank effluent to a distribution medium of clean sewer rock, with the absorption area calculated based on the area of the sidewalls only;

(81) "sensitive receiving environment" means

(A) fresh or marine water that supports anadromous fish;

(B) fresh or marine water used for drinking or food processing;

(C) water susceptible to eutrophication;

(D) a stream with low or intermittent flow;

(E) tundra; or

(F) land that permits exposure of wastewater to the public;

(82) "septage" means liquid or solid material removed from a septic tank, cesspool, portable toilet. Type III marine sanitation device, or similar domestic wastewater treatment or storage system that receives only domestic wastewater;

(83) "septic tank" means a watertight, covered receptacle designed and built to

(A) treat sewage;

(B) separate floating and settleable solids from the liquid;

(C) anaerobically digest organic matter;

(D) store digested solids through a period of detention; and

(E) allow clarified liquids to discharge for additional treatment and final disposal;

(84) "service connection" means a private residence or single building not associated with a private residence, including a single structure designed to accept or collect sewage for conveyance through a sewer service line;

(85) "sewage" means domestic or nondomestic wastewater;

(86) "sewer" or "sewer line"

(A) means a pipeline, conduit, or other constructed conveyance that carries domestic or nondomestic wastewater;

(B) does not include
(i) a private sewer line or sewer service line;

(ii) an open ended culvert or unlined ditch that conveys stormwater only;

(87) "sewer main" means a sewer line that is used as a common receiver of sewage from more than one sewer service line and carries wastewater to a treatment works;

(88) "sewer service line" means a pipeline or conduit that services a single service connection and carries sewage to a sewer main;

(89) "sewerage" means sewer lines, sewage pumping stations, force mains, and related structures, devices, and appliances used to carry domestic or nondomestic wastewater to a point of final treatment or disposal;

(90) "shallow trench" means a conventional soil absorption system that does not exceed five feet in width, with the absorption area calculated using the bottom area only;

(91) "slough" means a swamp, bog, or marsh, especially one that is part of an inlet or backwater;

(92) "sludge" means a solid, semisolid, or liquid waste that contains at least five percent solids by weight, and that is generated at a municipal, commercial, or industrial wastewater treatment plant, a septic tank, a water supply treatment plant, or an air pollution control facility, including similar material accumulated in and removed from a collection system, storage tank, or surface impoundment containing grit, sediment, oil, industrial liquid waste, acid, chemicals, or another similar substance;

(93) "small commercial facility"

(A) means a single commercial, institutional, or industrial building with an expected peak design flow of 500 gallons per day or less of domestic wastewater only;

(B) does not include a building or portion of a building that contains a residential dwelling;

(94) "soil absorption system"

(A) means a constructed system using soil for the treatment and disposal of effluent from a treatment process;

(B) does not include a cesspool;

(95) "springline" means the line of greatest horizontal dimension of the end cross-section of a pipe, the horizontal centerline of the pipe;

(96) "stabilization pond" means a shallow body of liquid or sludge contained in an earthen basin and designed to treat wastewater or septage sludge;

(97) "standard designated regulatory services" has the meaning given in AS 37.10.058;

(98) "stormwater" has the meaning given in 18 AAC 83.990;

(99) "stormwater pollution prevention plan" means a facility's plan to prevent or control the discharge of pollutants in stormwater runoff, as required by a permit required under 33 U.S.C. 1342(p) (Clean Water Act, Sec. 402(p)) and 18 AAC 83.990;

(100) "supervising construction" means construction supervision;

(101) "toxic substance" has the meaning given in 18 AAC 70.990;

(102) "treatment works" means the central portion of a wastewater system that contains the various treatment processes, exclusive of the collection system;

(103) "treatment works with individual marine outfall" means

(A) a treatment system located on one lot, or shared by adjacent lots, from which treated wastewater is discharged through a single outfall extending to marine waters; or

(B) multiple treatment works located on separate lots and owned by separate entities that discharge treated wastewater to a common collector that extends to marine waters;

(104) "vacuum sewer" means a collection system using a vacuum and high scour velocities to convey wastewater;

(105) "vault privy" means a holding tank with a seat or seats, or other appurtenances attached, that allows for excretion of human wastes directly into the tank;

(106) "wastewater" means domestic or nondomestic wastewater;

(107) "wastewater utility" has the meaning given in 3 AAC 52.749;

(108) "water table" means the upper surface of a zone of saturated soil, including normal seasonal fluctuations, but excluding fluctuations caused by heavy rainfall or rapid snow-melt; the water table is indicated by the level at which water stands in a well that

(A) is open along its length; and

(B) penetrates the surficial deposits just deeply enough to encounter standing water in the bottom;

(109) "waters of the United States" has the meaning given in 18 AAC 83.990;

(110) "wetlands" has the meaning given in 18 AAC 83.990.

Statutory definitions that apply to this chapter are found at AS 46.03.900.

Authority:AS 44.46.020

AS 46.03.020

AS 46.03.050

AS 46.03.100

AS 46.03.110

AS 46.03.710

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