For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
ABSORPTION AREA. The areas below a mound that is designed to absorb sewage tank effluent.
ADDITIVE, INDIVIDUAL SEWAGE TREATMENT SYSTEM. A product which is added to the wastewater or to the system to improve the performance of an individual sewage treatment system.
AEROBIC TANK. Any sewage tank which uses the principle of oxidation to decompose sewage by introducing air into the sewage.
ALTERNATIVE SITE. The portion of real property that is designated by a licensed individual sewage treatment system (ISTS) professional and approved by the city to be protected from all vehicular traffic, construction, and other disturbances. The site must be maintained in its original, natural soil condition so a future individual sewage treatment system or device may be constructed which meets all requirements when the original ISTS malfunctions, becomes nonrepairable, or when it fails to comply with the regulations.
ALTERNATIVE SYSTEM. An individual sewage treatment system employing the methods and devices presented in § 157.39.
AS-BUILT. Drawings and documentation specifying the final in-place location, size, and type of all system components. These records identify the results of materials testing and describe the conditions during construction. AS-BUILT also contains a certified statement.
AT-GRADE SYSTEMS. A pressurized soil treatment system where sewage tank effluent is dosed to a drainfield rock bed which is constructed on original soil at the ground surface and covered by loamy soil materials.
BAFFLE. A device installed in a septic tank for proper operation of the tank and to provide maximum retention of solids, and includes vented sanitary tees and submerged pipes in addition to those devices that are normally called BAFFLES.
BEDROCK. The layer of parent material which is consolidated and unweathered. BEDROCK also includes layers of which greater than 50% by volume consists of unweathered in-place consolidated BEDROCK fragments.
BEDROOM. Any room or unfinished area within a dwelling that might reasonably be used as a sleeping room.
BUILDING. Any structure, either temporary or permanent, having a roof and used or built for the shelter or enclosure of any person, animal, or property of any kind. For purpose of this chapter, BUILDING includes any structure whose foundation could be damaged and structural integrity jeopardized by the seepage of sewage or sewage tank effluent.
BUILDING DRAIN. The part of the lowest piping of the draining system which receives the sewage discharge inside the walls of the building and conveys it to the building sewer beginning at least 1 foot outside the building footings.
BUILDING SEWER. The part of the drainage system which extends from the end of the building drain and conveys its discharge to an individual sewage treatment system.
CERTIFIED STATEMENT. A statement signed by a licensed installer or qualified employee certifying that work was completed in accordance with applicable requirements.
CESSPOOL. An underground pit or seepage tank into which raw household sewage or other untreated liquid waste is discharged and from which the liquid seeps into the surrounding soil, bedrock, or other soil materials.
CHAMBERED SYSTEM. A soil treatment system where sewage tank effluent is discharged to a buried structure creating an enclosed open space with the original solid surface to act as a surface for the infiltration of sewage tank effluent.
CLEAN SAND. A soil texture composed of weight of at least 25% very coarse, coarse, and medium sand varying in size from 2.00 millimeters (sieve size 10) to 0.25 millimeters (sieve size 60), less than 40% fine or very fine sand ranging in size between 0.25 millimeters and 0.05 millimeter (sieve size 270), and no more than 10% smaller than 0.05 millimeters and no larger than 2.00 millimeters. CLEAN SAND also means a soil texture which meets American Society for Testing and Materials (ASTM) specifications C-33 (Fine Aggregate for Concrete) or Minnesota Department of Transportation (MNDOT) specification 3126 (Fine Aggregate for Portland Cement Concrete). The ASTM specification is found in the 1994 Annual Book of ASTM Standards, volume 4.02, which is incorporated by reference. This document is provided by the American Society for Testing and Materials located at 100 Bar Harbor Drive, West Conshohocken, PA 19428-2959. The MNDOT specifications is found in the MNDOT Standard Specifications for Construction, 1988 edition, and the May 2, 1994, Supplemental Specifications which are incorporated by reference. These documents are provided by the Minnesota Department of Transportation located at 395 John Ireland Boulevard, St. Paul, MN 55155. All references can be found at the Minnesota State Law Library, Judicial Center, 25 Constitution Avenue, St. Paul, MN 55155. These documents are not subject to frequent change.
COMPLIANCE INSPECTION. Any evaluation, investigation, inspection, or other such process to make conclusions, recommendations, or statements regarding an individual sewage treatment system to reasonably assure an individual sewage treatment system is in compliance with regulations.
DEPARTMENT. The City Building Department.
DISCLOSURE. Any conclusions or statements regarding an ISTS made by the owner of a property with or served by an ISTS to fulfill the requirements of M.S. § 115.55, Subd. 6, as it may be amended from time to time.
DISTRIBUTION BOX. A device designed to concurrently and equally distribute sewage tank effluent by gravity to a soil treatment system.
DISTRIBUTION DEVICE. A device used to receive and transfer effluent from a supply pipe to distribution pipes or down slope supply pipes, or both. These devices may also be known as drop boxes, valve boxes, distribution boxes, or manifolds.
DISTRIBUTION MEDIUM. The material used to distribute the sewage tank effluent within a soil treatment system. This medium includes drainfield rock, gravel-less drainfield pipe in a geotextile wrap or a chambered system.
DISTRIBUTION PIPES. Perforated pipes that are used to distribute sewage tank effluent into a distribution medium.
DNR. The Minnesota Department of Natural Resources.
DOMESTIC WASTE. See definition of Sewage.
DOSING CHAMBER or PUMP PIT or WET WELL. A tank or separate compartment following the sewage tank which serves as a reservoir for the dosing device.
DOSING DEVICE. A pump, siphon, or other device that discharges sewage tank effluent from the dosing chamber to the soil treatment system.
DRAINFIELD ROCK. Igneous rock, or similar insoluble, durable, and decay-resistant material between 3/4 inch and 2-1/2 inches in size with no more than 5% by weight passing a 3/4-inch sieve and no more than 1% by weight passing a number 200 sieve. Materials greater than 2-1/2 inches in size shall not exceed 5% by weight.
DROP BOX. A distribution device used for the serial gravity application of sewage tank effluent to a soil treatment system.
DWELLING. Any building or place used or intended to be used by human occupants as single- family or 2-family residence.
EXPERIMENTAL SYSTEM. Any system which is considered new technology with limited data on reliability.
FAILING SYSTEM. Any system that discharges sewage to a seepage pit, cesspool, drywell, or leaching pit and any system with less than 3 feet of soil or sand between the bottom of the distribution medium and the saturated soil level or bedrock. In addition, any system posing an imminent threat to public health or safety shall be considered FAILING.
GAS DEFLECTING BAFFLE. An obstructing device on the septic tank outlet that limits the escape of solids that are carried by septic tank gases.
GRAVEL-LESS DRAINFIELD PIPE. A distribution medium consisting of a corrugated distribution pipe encased in a geotextile wrap installed in a trench.
GREY WATER. Sewage that does not contain toilet waste. Liquid waste from a dwelling or other establishment produced by bathing, laundry, culinary operation, and from floor drains associated with these sources is considered GREY WATER.
HAZARDOUS WASTE. Any substance which, when discarded, meets the definition of hazardous waste in Minn. Rules Chapter 7045, as it may be amended from time to time.
HOLDING TANK. A watertight tank for storage of sewage until it can be transported to a point of approved treatment and disposal.
IMMINENT THREAT TO PUBLIC HEALTH OR SAFETY. Situations with the potential to immediately and adversely impact or threaten public health or safety. At a minimum, cesspools, ground surface or surface water discharges and systems causing sewage backup into a dwelling or other establishment shall constitute an IMMINENT THREAT.
INDIVIDUAL SEWAGE TREATMENT SYSTEM. A sewage treatment system, or part thereof, serving a dwelling or other establishment, or group thereof, and using sewage tanks or advanced treatment followed by soil treatment and disposal.
INVERT. The lowest point of a channel inside a pipe.
LIQUID CAPACITY. The liquid volume of a sewage tank below the invert of the outlet pipe.
MOTTLING. A zone of chemical and reduction activity, appearing as splotchy patches of red, brown, or gray in the soil. In subsoils with a color value of 4 or more, the term MOTTLING also includes soils having matrix colors with a chroma of 2 or less as described in Keys to Soil Taxonomy, 5th Edition, 1992 Soil Management Support Services, Technical Monograph No. 19, which is incorporated by reference. This document is provided by the Agency for International Development, United States Department of Agriculture Soil Conservation Service, and Soil Management Support Services. The document was printed by Pocahontas Press, Inc., P.O. Drawer F, Blacksburg, Virginia 24063-1020. It can be found at the Minnesota State Law Library, Judicial Center, 25 Constitution Avenue, St. Paul, MN 55155. This document is not subject to frequent change.
MOUND SYSTEM. A system where the soil treatment area is built above the natural elevation of the soil to overcome limits imposed by proximity to saturated soil or bedrock, or by rapidly or slowly permeable soils.
NEW CONSTRUCTION. Installing or constructing a new individual sewage treatment system in its entirety; or altering, extending, or adding capacity to an existing individual sewage treatment system.
NOTICE OF NONCOMPLIANCE. A document written and signed by a qualified employee or licensee after a compliance inspection which gives notice that an individual sewage treatment system is not in compliance with these regulations.
ORDINARY HIGH WATER LEVEL. The boundary of water basins, watercourses, public waters and wetlands, and:
(1) An elevation delineating the highest water level that has been maintained for a sufficient period of time to leave evidence upon the landscape, commonly the point where the natural vegetation changes from predominantly aquatic to predominantly terrestrial;
(2) For watercourses, the elevation of the top of the bank of the channel; and
(3) For reservoirs and flowage, the operating elevation of the normal summer pool.
ORIGINAL SOIL. Naturally occurring, inorganic soil that has not been moved, smeared, compacted, nor manipulated with construction equipment.
OTHER ESTABLISHMENT. Any public or private structure other than a dwelling which generates sewage.
OWNER. Any person having possession of, control over, or title to property with an individual sewage treatment system.
PERCOLATION RATE. The time rate of drop of a water surface in a test hole as specified in § 157.20(I).
PERMITS. A building, construction, sanitary, planning, zoning, or other such PERMIT issued for new construction, replacement, repair, alteration, or extension of an individual sewage treatment system. PERMIT also means a permit issued for the addition of a bedroom or bathroom on property served by an individual sewage treatment system.
PERMITTEE. Any person who is named on a permit issued pursuant to these regulations.
PERMITTING AUTHORITY. Any unit of government, state agency, or any authorized representative who administers or enforces these regulations through permitting.
PLASTIC LIMIT. A soil moisture content below which the soil may be manipulated for purposes of installing a soil treatment system, and above which manipulation will cause compaction and puddling. The soil moisture content at the PLASTIC LIMIT can be measured by American Society for Testing and Materials (ASTM) Test Number D4318-84.
PREVIOUSLY DEVELOPED SITE. Land already containing a dwelling or other establishment.
PRIVY. An above-ground structure with an underground cavity meeting the requirements of § 157.39(E), which is used for the storage or treatment and disposal of toilet waste, specifically excluding water for flushing and grey water.
PUBLIC HEALTH NUISANCE. Any activity or failure to act that adversely affects the public health.
PUBLIC WATER. Any PUBLIC WATERS or wetlands as defined in M.S. § 103G.005, Subds. 15 and 19, as it may be amended from time to time, or identified as PUBLIC WATERS or wetlands by the inventory prepared pursuant to M.S. § 103G.201, as it may be amended from time to time.
QUALIFIED EMPLOYEE. An employee of the Department who meets the minimum criteria for employment as an ISTS professional and who conducts site evaluations or inspects individual sewage treatment system as part of employment duties.
REPLACEMENT. The replacement of an existing sewage tank, holding tank, dosing chamber, artificial drainage, privy, collector system, or soil treatment system.
RESTAURANTS. Any place where food is prepared and intended for individual portion service, regardless of whether consumption is on or off the premises or whether there is a charge for the food. This definition does not include private homes.
SATURATED SOIL. The highest elevation in the soil where periodically depleted oxygen levels occur because of soil void being filled with water. SATURATED SOIL is evidenced by presence of soil mottling or other information.
SEEPAGE BED. An excavated area larger than 36 inches in width which contains drainfield rock and has more than 1 distribution pipe.
SEEPAGE PIT or LEACHING PIT or DRY WELL. An underground pit into which sewage tank discharges effluent and from which the liquid seeps into the surrounding soils.
SEPTAGE. Solids and liquids removed during periods maintenance of an individual sewage treatment system, or solids and liquids which are removed from toilet waste treatment devices or a holding tank.
SEPTIC TANK. Any watertight, covered receptacle designed and constructed to receive the discharge of sewage from a building sewer, separate solids from liquids, digest organic matter, and store liquids through a period of detention, and allow the clarified liquids to discharge to a soil treatment system.
SEWAGE. Any water-carried domestic waste, exclusive of footing and roof drainage and chemically treated hot tub or pool water, from any industrial, agricultural, or commercial establishment, or any dwelling or other structure. Domestic waste includes liquid waste produced by toilets, bathing, laundry, culinary operations, and the floor drains associated with these sources. Animal waste and commercial or industrial waste are not considered domestic waste.
SEWAGE FLOW. Flow as determined by measurement of actual water use or, if actual measurements are not available, by the best available data provided.
SEWAGE TANK. A watertight tank used in the treatment of sewage and includes but is not limited to septic tanks and aerobic tanks.
SEWAGE TANK EFFLUENT. The liquid which flows from a septic or aerobic tank under normal operation.
SHORELAND. Land located within the following distance from public waters: 1,000 feet from the ordinary high water mark of a lake, pond, or flowage; and 300 feet from a river or stream or the landward extent of a floodplain designated by ordinance on the river or streams, whichever is greater.
SITE. The area bounded by the dimensions required for the property location of the soil treatment system.
SLOPE. The ratio of the vertical rise or fall to horizontal distance.
SOIL CHARACTERISTICS, LIMITING. Those soil characteristics which preclude the installation of a standard system, including evidence of water table or bedrock and percolation rates faster than 1/10 or slower than 60 minutes per inch.
SOIL TEXTURAL CLASSIFICATION. Soil particle sizes or textural classifications as specified in the Soil Survey Manual, Handbook No. 18, United States Department of Agriculture, 1993, incorporated by reference.
SOIL TREATMENT AREA. The area of trench, at-grade rock bed, or seepage bed bottoms which is in direct contact with the distribution medium of the soil treatment system. For mounds, that area to the edges of the required absorption widths and extending 5 feet beyond the ends of the rock layer.
SOIL TREATMENT SYSTEM. A system where sewage tank effluent is treated and disposed of into the soil by percolation and filtration, and includes trenches, seepage beds, drainfields, at-grade systems, and mound systems.
ST. CROIX RIVER LAND USE DISTRICT. Those lands designated by the Commissioner of the Department of Natural Resources as the protected land corridor along the St. Croix River.
STANDARD SYSTEM. An individual sewage treatment system employing a building sewer, sewage tank, and the soil treatment system consisting of trenches, seepage beds, or mounds.
SUPPLY PIPE. Any nonperforated pipe whose purpose is the transport of sewage tank effluent. SUPPLY PIPES must meet or exceed the requirements established in these regulations.
SURFACE WATER FLOODING. The 100-year floodplain along rivers and streams as defined by the DNR, or in the absence of such data, as defined by the largest flood of record; on lakes, high water levels as determined or recorded by the DNR or, in the case of no DNR record, by local records or experience. Other SURFACE WATER FLOODING or high water areas will be determined based on local information.
TEN-YEAR FLOOD. The flood which can be expected to occur, on an average, of once in 10 years; or the elevation to which floodwaters have a 10% change of rising in any given year.
TOILET WASTE. Waste commonly disposed of in toilets including fecal matter, urine, toilet paper, and any water used for flushing, and specifically excluding sanitary napkins, tampons, and disposable diapers.
TOILET WASTE TREATMENT DEVICES. Privies and other devices including incinerating, composting, biological, chemical, recirculating, or holding toilets.
TRENCH. An area excavated from 18 to 36 inches in width which contains drainfield rock or other distribution medium.
VALVE BOX. A watertight structure designed for alternate distribution of effluent to a soil treatment system.
WATER TABLE. The highest elevations in the soil where all voids are filled with water, as evidenced by presence of water or soil mottling or other information.
WATERTIGHT. A device constructed so that no water can get into or out of the device except through designed inlets and outlets.
(Prior Code, Ch. 506 § 2.1)