§ 51.01 DEFINITIONS.

   For the purpose of this subchapter, the following definitions shall apply, unless the context clearly indicates or requires a different meaning.

   APPROVING AUTHORITY. The City Council of Preston, Fillmore County, Minnesota, or its duly authorized committee, agent or representative.

   BIOCHEMICAL OXYGEN DEMAND or BOD. The quantity of oxygen utilized in the biochemical oxidation of organic matter in five days at 20°C, expressed as milligrams per liter. Quantitative determination of BOD shall be made in accordance with procedures set forth in Standard Methods.

   BUILDING DRAIN. That part of the lowest horizontal piping of a drainage system which receives the discharge from soil, waste, and other drainage pipes inside the walls of the building and conveys it to the building sewer.

   BUILDING SEWER. The extension from the building drain to the public sewer or other place of disposal beginning outside the inner face of the building wall.

   CHLORINE REQUIREMENTS. The amount of chlorine in milligrams per liter which must be added to sewage to produce a specified residual chlorine content in accordance with procedures set forth in Standard Methods.

   COMPATIBLE POLLUTANTS. Biochemical oxygen demand, suspended solids, phosphorus, pH, or fecal coliform bacteria, plus additional pollutants identified in the NPDES permit for the publicly- owned treatment works receiving the pollutants, if the works were designed to treat the additional pollutants to a substantial degree.

   DEBT SERVICE CHARGE. Shall include all costs associated with the repayment of debts incurred for the construction and/or rehabilitation of the wastewater collection system and treatment plant. A portion of the debt service may be budgeted by levying an ad valorem tax in accordance with state statutes.

   FLOATABLE OIL. Oil, fat, or grease in a physical state such that it will separate by gravity from wastewater by treatment in an approved pretreatment facility. A wastewater shall be considered free of floatable fat if it is properly pretreated and the wastewater does not interfere with the collection system.

   GARBAGE. The residue from the preparation, cooking, and dispensing of food, and from the handling, storage, and sale of food products and produce.

   GARBAGE, GROUND. The residue from the preparation, cooking, and dispensing of food that has been shredded to such degree that all particles will be carried freely in suspension under the flow conditions normally prevailing in public sewers with no particle greater than ½-inch in any dimension.

   INCOMPATIBLE POLLUTANTS. Wastewater with pollutants that will adversely affect or disrupt the quality of wastewater treatment if discharged to a wastewater treatment facility.

   INDUSTRIAL WASTE. The wastewater from industrial process, trade, or business, as distinct from sanitary sewage, including cooling water and discharge from sewage pretreatment facilities.

   MAY is permissible.

   NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM or NPDES. Any permit or equivalent document or requirements issued by the Environmental Protection Agency administration, or, where appropriate, by the Minnesota Pollution Control Agency, after enactment of the Federal Water Pollution Control Amendment of 1972, to regulate the discharge of pollutants pursuant to Section 402 of the Act.

   NATURAL OUTLET. Any outlet, including storm sewers and combined sewer overflows, into a watercourse, pond, ditch, lake, or other body of surface water or groundwaters.

   NORMAL DOMESTIC STRENGTH WASTEWATER. Wastewater with concentrations of BOD5 and suspended solids no greater than 200 and 250 milligrams per liter (mg/l) respectively.

   OPERATION AND MAINTENANCE COSTS. All costs associated with the operation and maintenance of the wastewater collection and treatment facilities, as well as the costs associated with periodic equipment replacement necessary for maintaining capacity and performance of wastewater collection and treatment facilities.

   PARTS PER MILLION. A weight-to-weight ratio; the parts per million value multiplied by the factor 8.344 shall be equivalent to pounds per million gallons of water.

   PERSON. Any and all person, including any individual, firm, company, municipal or private corporation, association, society, institution, enterprise, governmental agency, or other entity.

   pH. The logarithm of the reciprocal of the hydrogen ion concentration. The concentration is the weight of hydrogen ion, in grams per liter of solution. Neutral water, for example, has a pH value of 7, and a hydrogen ion concentration of 10 exp(-7).

   PUBLIC SEWER.  Any sewer provided by a subject to the jurisdiction of the city. It shall also include sewers within or outside the corporate boundaries that serve one or more persons and ultimately discharge into the city sanitary sewer system, even though those sewers may not have been constructed with the city fund.

   REPLACEMENT COSTS. All costs associated with establishing a fund to accumulate the necessary resources to replace equipment as required to maintain capacity and performance during the design life of the plant.

   SANITARY SEWAGE. A combination of liquid and water-carried wastes discharged from toilets and/or sanitary plumbing facilities, together with any ground, surface, and storm waters as may be present.

   SANITARY SEWER.  A sewer that carries liquid and water-carried wastes from residences, commercial buildings, industrial plants, and institutions, together with minor quantities of ground, storm, and surface waters that are not admitted intentionally.

   SEWAGE.  The spent water of a community. Spent water shall be referred to as wastewater.

   SEWER SERVICE CHARGE. A service charge levied on users of the wastewater collection and treatment facilities for payment of use-related capital expenses, as well as the operation and maintenance costs, including replacement of the facilities.

   SHALL is mandatory.

   SHOCK. Any discharge of sewage or industrial wastewater which, in concentration of any given constituent, or in quantity of flow, exceeds the following.

      (1)   Four times the allowable average hourly rate, as set forth in the table below, for a period of 15 minutes during a given sampling day, as determined by the average concentration measured in consecutive, flow-proportionally composited grab samples taken at 15-minute intervals over a 15- minute period; or samples automatically collected in proportion to flow over a 15-minute period.

      (2)   Three times the allowable average hourly rate, as set forth in the table below, for a period of 30 minutes during a given sampling day, as determined by the average concentration measured in consecutive, flow-proportionally composited grab samples over a 30-minute period; or samples automatically collected in proportion to flow over a 30-minute period.

      (3)   Two times the allowable average daily rate, as set forth in the table below, for a period of 60 minutes during a given sampling day, as determined by the average concentration measured in consecutive, flow-proportionally composited grab samples taken at 15-minute intervals over a 60-minute period, or samples automatically collected in proportion to flow over a 60-minute period.

      (4)   One and one-half times the allowable average hourly rate, as set forth in the table below, for a period of two hours during a given sampling day, as determined by the average concentration measured in consecutive, flow-proportionally composited grab samples taken at 15-minute intervals over a two-hour period, or samples automatically collected in proportion to flow over a two-hour period.

      (5)   One and three-tenths times the allowable average hourly rate, set forth in the table below, for any period exceeding two hours and less than 24 hours in length, during a given sampling day, as determined by the average concentration measured in consecutive, flow-proportionally composited grab samples taken at 15-minute intervals over the defined period, or samples automatically collected in proportion to flow over the defined period

Allowable Daily Increase in Industrial Wastewater BOD5 Discharges
Previous Sampling Day’sAllowable AverageAllowable Average
Actual Discharge Daily Rate Hourly Rate
BOD5BOD5/DayBOD5/Hour

   0 - 100   200   8.3
   100 - 200   325   13.5
   200 - 300   450   18.7
   300 - 400   575   24.0
   400 - 500   700   29.2
   500 - 600   825   34.4
   600 - 700   950   39.6
   700 - 800   1075   44.8
   800 - 900   1200   50.0
   900 - 1000   1325   55.2
   1000 - 1100   1450   60.4
   1100 - 1200   1575   65.6
   1200 - 1300   1700   70.8

   STANDARD METHODS. The examination and analytical procedures set forth in the most recent edition of Standard Methods for the Examination of Water, Sewage, and Industrial Wastes published jointly by the American Public Health Association, the American Water Works Association, and the Federation of Sewage and Industrial Wastes Associations.

   STORM DRAIN or STORM SEWER. A drain or sewer for conveying water, groundwater, subsurface water, or unpolluted water from any source.

   STORM WATER RUNOFF. That portion of the rainfall that is drained into the sewers.

   SUSPENDED SOLIDS. Solids that either float on the surface of, or are in suspension in water, wastewater, or other liquids, and that are removable by laboratory filtering as prescribed in Standard Methods for Examination of Water and Wastewater, and is referred to as nonfilterable residue.

   UNPOLLUTED WATER. Water of quality equal to or better than the effluent criteria in effect or water that would not cause violation of receiving water quality standards, and would not be benefitted by discharge to the sanitary sewers and wastewater treatment facilities provided.

   USER CHARGE. A charge levied on users of the wastewater collection and treatment facilities as a part of the sewer service charge for payment of operation and maintenance and replacement costs of the facilities.

   USER CLASSES. The various users of the sewer system shall be divided into the following classifications.

      (1)   COMMERCIAL USER.  A user whose contributions to the wastewater treatment works consist only of normal domestic strength waste originating from an office, store, or other work place constituting a business, institution or commercial enterprise.

      (2)   INDUSTRIAL USER. A user whose contributions to the wastewater treatment works result from a manufacturing, processing, or other industrial operation, as distinct from domestic use, and discharges an equivalent to 25,000 (gpd).

      (3)   RESIDENTIAL USER. A user whose contributions to the wastewater treatment works consist only of normal domestic strength waste originating from a dwelling, house, apartment, flat or other living quarters occupied by a person or persons constituting a distinct household.

   WASTEWATER. The spent water of a community. From the standpoint of source, it may be a combination of the liquid and water-carried wastes from residences, commercial buildings, industrial plants, and institutions, together with any groundwater, surface water, and storm water that may be present.

   WASTEWATER FACILITIES. The structures, equipment, and processes required to collect, carry away, and treat domestic and industrial wastes and dispose of the effluent.

   WASTEWATER TREATMENT WORKS. An arrangement of devices and structures for treating wastewater, industrial wastes, and sludge. Sometimes used as synonymous with waste treatment.

   WATERCOURSE. A natural or artificial channel for the passage of water, either continuously or intermittently.

(Ord. 170, passed 8-10-1981)