Chapter NR 110

NR 110.03(7m) (7m) “Combined sewer system” has the meaning specified under s. NR 210.03 (3p).

NR 110.03 Note Note: Section NR 210.03 (3p) reads: “Combined sewer system” means a wastewater collection system owned by a municipality that conveys domestic, commercial, and industrial wastewater and storm water runoff through a single pipe system to a publicly owned treatment works.

NR 110.03(7s) (7s) “Combined sewer treatment facility” means all the structures, pipes and other equipment that constitute the various treatment processes and treatment units employed to reduce pollutants in wastewater from combined sewer systems.

NR 110.03(9) (9) “Controlled diversion” has the meaning specified under s. NR 205.03 (9m).

NR 110.03 Note Note: Section NR 205.03 (9m) and Note reads: “Controlled diversion” means the routing of untreated or partially treated wastewater around any treatment unit within a sewage or wastewater treatment facility which is then recombined with undiverted wastewater prior to the effluent sampling location and prior to effluent discharge.

NR 110.03 Note Note: Controlled diversions at a sewage treatment facility do not include blending and may occur only in compliance with s. NR 205.07 (1) (v).

NR 110.03(11) (11) “Cost-effective analysis” means a systematic comparison of alternative means of meeting state water quality standards, effluent limitations or other treatment standards in order to identify the alternative which will minimize the total resources costs over the planning period. These resources costs include monetary costs and environmental as well as other non-monetary costs.

NR 110.03(12) (12) “Department” means the department of natural resources.

NR 110.03(12g) (12g) “Design flow” means the anticipated wastewater discharge rate to a sewerage system component, which is used to design the sewerage system component to provide compliance with WPDES permit limits and other performance objectives, during the most critical operating conditions anticipated within the design planning period. Specific design flow terms used in this chapter, include the following:

NR 110.03(12g)(a) (a) “Average daily base flow” means the average of the daily flow volumes anticipated to occur for a continuous 12-month period, less infiltration and inflow, and expressed as a daily average.

NR 110.03(12g)(b) (b) “Average design flow” means the average of the daily flow volumes anticipated to occur for a continuous 12-month period, expressed as a daily average.

NR 110.03(12g)(c) (c) “Maximum month design flow” means the largest volume of flow anticipated to occur during a continuous 30-day period, expressed as a daily average.

NR 110.03(12g)(d) (d) “Maximum week design flow” means the largest volume of flow anticipated to occur during a continuous 7-day period, expressed as a daily average.

NR 110.03(12g)(e) (e) “Maximum day design flow” means the largest volume of flow anticipated to occur during a one-day period, expressed as a daily average.

NR 110.03(12g)(f) (f) “Maximum hour design flow” means the largest volume of flow anticipated to occur during a one-hour period, expressed as a daily or hourly average.

NR 110.03(12g)(g) (g) “Peak instantaneous design flow” means the maximum anticipated instantaneous flow.

NR 110.03(12g)(h) (h) “Peak design flow” and “maximum design flow” mean the largest volume of flow anticipated to occur on an infrequent basis, expressed as a daily average. The “peak design flow” or “maximum design flow” may be equal to any one of the design flows defined in pars. (c) to (g).

NR 110.03(12m) (12m) “Design management zone” or “DMZ” means a 3-dimensional area, bounded by a set horizontal distance from the application or containment area, as specified in Table 4, ch. NR 140, and by variable vertical distance which extends from the land surface downward through all saturated formations.

NR 110.03 Note Note: The size of the DMZ may be altered by the department based on the criteria in s. NR 140.22 (3).

NR 110.03(13) (13) “Dry land access” means a sewage treatment facility service road which has a minimum elevation of at least one foot above the regional flood elevation.

NR 110.03(13c) (13c) “Excessive infiltration/inflow” means the quantities of infiltration/inflow which can be economically eliminated from a sewerage system by rehabilitation, as determined in a cost-effectiveness analysis that compares the cost of correcting the infiltration/inflow conditions to the total costs for transportation and treatment of the infiltration/inflow.

NR 110.03(13e) (13e) “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.

NR 110.03(13t) (13t) “Highest anticipated groundwater elevation” means the sum of the calculated mounding effects of the disposal discharge and the seasonal high groundwater level.

NR 110.03(14e) (14e) “Hydraulic application rate” means the average daily volume of effluent discharged to a designed acreage of the land application system during a calendar month or other period of time specified in a WPDES permit. The rate is calculated by dividing the total discharge volume for the month or period of time by the acreage of land and by the number of days in the month or period of time, usually expressed in units of gallons per acre per day. For overland flow systems, the hydraulic application rate is expressed as a flow rate per unit width of slope per day.

NR 110.03(14t) (14t) “Hydrogeologist” means a person who is a graduate of an accredited institution of higher education and who has successfully completed 30 semester hours or 45 quarter hours of course work in geology. At least 6 semester hours or 9 quarter hours of the geology course work must be in hydrogeology, geohydrology or groundwater geology. This person shall also have acquired through education and actual field experience the ability to direct the drilling of borings, and the installation and development of wells; describe and classify geology samples and evaluate and interpret geologic and hydrogeologic data in accordance with the requirements of chs. NR 110 and 206.

NR 110.03(15) (15) “Industrial user” means:

NR 110.03(15)(a) (a) Any nongovernmental, nonresidential user of a municipally owned sewerage system which discharges more than the equivalent of 25,000 gallons per day (gpd) of sanitary wastes and which is identified in the Standard Industrial Classification Manual, 1972, United States Office Management and Budget, as amended and supplemented as of October 1, 1978 under one of the following divisions:

Division A. Agriculture, Forestry, and Fishing
Division B. Mining
Division D. Manufacturing
Division E. Transportation, Communications, Electric,
    Gas, and Sanitary Services
Division I. Services.

NR 110.03(15)(a)1. 1. In determining the amount of a user’s discharge, domestic wastes or discharges from sanitary conveniences may be excluded.

NR 110.03(15)(a)2. 2. After applying the sanitary waste exclusion in subd. 1., discharges in the above divisions that have a volume exceeding 25,000 gpd or the weight of biochemical oxygen demand (BOD) or suspended solids (SS) equivalent to that weight found in 25,000 gpd of sanitary waste are considered industrial users. Sanitary wastes, for purposes of this calculation of equivalency, are the wastes discharged from residential users. The municipality shall, with the department’s approval, define the strength of the residential waste discharges in terms of parameters including biochemical oxygen demand (BOD) and suspended solids (SS) per volume of flow as a minimum. Dischargers with a volume exceeding 25,000 gpd or the weight of BOD or SS equivalent to that weight found in 25,000 gpd of sanitary waste are considered as industrial users.

NR 110.03(15)(b) (b) Any nongovernmental user of a municipally owned sewerage system which discharges wastewater to the sewerage system which contains toxic pollutants or poisonous solids, liquids, or gases in sufficient quantity either singly or by interaction with other wastes, to contaminate the sludge of any municipal system, or injure or interfere with any sewage treatment process, constitutes a hazard to humans or animals, creates a public nuisance, or creates any hazard in or has an adverse effect on the waters receiving any discharge from the treatment works;

NR 110.03(15)(c) (c) All commercial users of an individual system constructed with grant assistance under s. 281.57, Stats.

NR 110.03(16) (16) “Infiltration” means water other than wastewater that enters a sewerage system (including sewer service connections) from the ground through such sources as defective pipes, pipe joints, connections, or manholes. Infiltration does not include, and is distinguished from, inflow.

NR 110.03(17) (17) “Inflow” means water other than wastewater that enters a sewerage system (including sewer service connections) from sources such as roof leaders, cellar drains, yard drains, area drains, foundation drains, sump pumps, drains from springs and swampy areas, manhole covers, cross connections between storm sewers and sanitary sewers, catch basins, cooling towers, storm waters, surface runoff, street wash waters, or drainage. Inflow does not include, and is distinguished from, infiltration.

NR 110.03(18) (18) “Interceptor sewer” means a sewer whose primary purpose is to transport wastewaters from collector sewers to a treatment facility.

NR 110.03(18m) (18m) “Intermediate sludge storage” means the storage of sludge for a period of more than 24 hours and no more than 3 months.

NR 110.03(19) (19) “Lagoon” means those sewage treatment facilities where the wastewater or sludge containment structure is constructed primarily of earthen materials.

NR 110.03(19m) (19m) “Long-term sludge storage” means the storage of sludge for a period exceeding 3 months.

NR 110.03(21) (21) “Municipality” means any city, town, village, county, utility district, town sanitary district, public inland lake protection and rehabilitation district or metropolitan sewage district.

NR 110.03(22) (22) “NEC” means the NFPA 70 National Electrical Code. Copies of the National Electrical Code are available for inspection at the offices of the department of natural resources, the secretary of state’s office, and the legislative reference bureau. Copies may be obtained for personal use from the National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02169-7471.

NR 110.03(23) (23) “Owner” means the state, county, town, town sanitary district, city, village, firm, company, institution, association, utility district, school district, metropolitan sewerage district, or individual owning or operating a sewerage system.

NR 110.03(25) (25) “Planning area” means that area under study as part of a facilities plan.

NR 110.03(26) (26) “Planning period” means the period over which sewerage system alternatives are evaluated for cost-effectiveness. The planning period begins with the initiation of the operation of the proposed facilities.

NR 110.03(26m) (26m) “Private interceptor main sewer” means a sewer serving two or more buildings and not part of the municipal sewer system.

NR 110.03 Note Note: This is the same definition as contained in s. SPS 381.01 (193).

NR 110.03(27) (27) “Reviewable project” means any construction or installation project for which department approval is required, pursuant to s. 281.41, Stats., including any new sewerage system; and, any improvements, extensions, or alterations of existing sewerage systems which may effect the quality or quantity of effluent or the location of any outfall.

NR 110.03(27e) (27e) “Sanitary sewer overflow” has the meaning specified under s. NR 210.03 (10).

NR 110.03 Note Note: Section NR 210.03 (10) reads: “Sanitary sewer overflow” means a release of wastewater from a sewage collection system or an interceptor sewer directly into a water of the state or to the land surface.

NR 110.03(27m) (27m) “Sanitary sewer overflow structure” means the physical structure, hydraulic mechanisms, and piping specifically constructed to convey a sanitary sewer overflow.

NR 110.03(27s) (27s) “Satellite sewage collection system” has the meaning specified under s. NR 205.03 (31r).

NR 110.03 Note Note: Section NR 205.03 (31r) reads: “Satellite sewage collection system” means a municipally owned or a privately owned sewage collection system that conveys wastewater to another satellite sewage collection system or to another sewerage system that provides wastewater treatment and discharges under a separate WPDES permit.

NR 110.03(28) (28) “Sewage collection system” means the common sanitary sewers, interceptor sewers, and appurtenant equipment, such as lift stations, within a sewerage system which are primarily installed to receive wastewaters directly from facilities which convey wastewater from individual structures or from private property, and which include service connection “Y” fittings designed for connection with those facilities. The facilities which convey wastewater from individual structures, such as building sewers and private interceptor sewers, from private property to the public sanitary sewer, or its equivalent, are specifically excluded from the definition of “sewage collection system”; except that pumping units and pressurized lines for individual structures or groups of structures are included as part of a “sewage collection system” when such units are cost effective and are owned and maintained by the sewerage system owner.

NR 110.03(29) (29) “Sewage treatment facility” means all the structures, pipes, and other equipment that constitute the various treatment processes and treatment units employed to reduce pollutants in sewage.

NR 110.03(29d) (29d) “Sewage treatment facility overflow” has the meaning specified under s. NR 210.03 (13).

NR 110.03 Note Note: Section NR 210.03 (13) reads: “Sewage treatment facility overflow” means a release of wastewater from a location within a sewage treatment facility, other than permitted effluent outfall structures, directly to a water of the state or to the land surface. A sewage treatment facility overflow does not include blending, controlled diversions or discharges from permitted combined sewage treatment facility effluent outfall structures.

NR 110.03(29h) (29h) “Sewage treatment facility overflow structure” means the physical structure, hydraulic mechanisms, and piping specifically constructed to convey a sewage treatment facility overflow.

NR 110.03(29m) (29m) “Sewer extension” means installation of a sewer or interceptor sewer, or extension thereof, to provide additional conveyance capacity and service to development within the existing or proposed tributary area of the extension. Alterations or modifications of existing sewerage systems designed to replace inadequate existing structures or installed because of inadequate hydraulic sewer capacity and that do not extend sanitary sewer service to areas previously not served are not sewer extensions.

NR 110.03(29t) (29t) “Sewer service area” means that area served or anticipated to be served by a sewage collection system.

NR 110.03(30) (30) “Sewerage system” means all structures, conduits and pipes, by which sewage is collected, treated, and disposed of, except plumbing inside and in connection with buildings served, and service pipes, from building to street main.

NR 110.03(31c) (31c) “Short-term sludge storage” means the storage of sludge for a period of no more than 24 hours.

NR 110.03(31e) (31e) “Sludge storage” means the retention of sludge at a treatment plant or at an approved off-site facility.

NR 110.03(32) (32) “Staging period” means the period of time during which reserve capacity will be provided in the sewerage system for future domestic, commercial, and industrial flows.

NR 110.03(32g) (32g) “Treatment process” means a physical, biological or chemical action that is applied to wastewater to remove or reduce pollutants. A treatment process may consist of multiple individual treatment units. “Treatment process” includes screening, chemical treatment, sedimentation, biological treatment, filtration, disinfection, and sludge digestion.

NR 110.03(32i) (32i) “Treatment unit” means individual structures or equipment within a sewage or wastewater treatment facility that are part of a treatment process. Typical treatment units are screens, clarifiers, aeration tanks, filters, digesters, and lagoons.

NR 110.03(32m) (32m) “Water table observation well” means any groundwater monitoring well whose screen intersects the water, which is installed for the specific purpose of determining either the elevation of the water table or the physical, chemical, biological, or radiological properties of groundwater at the water table, or both.

NR 110.03(34) (34) “WPDES permit” means the Wisconsin pollutant discharge elimination system permit issued by the department under ch. 283, Stats., for the discharge of pollutants.

NR 110.03 History History: Cr. Register, November, 1974, No. 227, eff. 12-1-74; r. and recr. Register, December, 1978, No. 276, eff. 1-1-79; cr. (20), Register, August, 1981, No. 308, eff. 9-1-81; renum. (3) to (20) to be (11), (12), (14) to (18), (21), (23), (25) to (32) and (34) and am. (29) and (34), cr. (4) to (10), (13), (19), (20), (22), (24) and (33), Register, February, 1983, No. 326, eff. 3-1-83; cr. (6m), (12m), (13e), (13t), (14e), (14t), (18m), (19m), (31e), (31t) and (32m), am. (19), Register, November, 1990, No. 419, eff. 12-1-90; corrections in (2), (27), and (34) were made under s. 13.93 (2m) (b) 7., Stats., Register, May, 2001, No. 545; corrections in (3), (4), (6), (22) and (33) made under s. 13.92 (4) (b) 6., Stats., Register February 2010 No. 650; CR 09-123: r. (3), (5), (20), (24) and (33), r. and recr. (4) and (6), am. (9) and (22), cr. (12g) Register July 2010 No. 655, eff. 8-1-10; CR 12-027: renum. (6m) to (6e), cr. (6m), (6s), r. and recr. (7), cr. (7e), (7m), (7s), r. (8), r. and recr. (9), r. (10), am. (17), cr. (26m), (27e), (27m), (27s), am. (28), r. and recr. (29), cr. (29d), (29h), (30p), renum. (31) to (29t), cr. (32g), (32r) Register July 2013 No. 691, eff. 8-1-13; renum. (14), (30p), (31t), (32r) to (13c), (29m), (31c), (32i) under s. 13.92 (4) (b) 1., Stats., Register July 2013 No. 691; correction in (15) (c) made under s. 13.92 (4) (b) 7., Stats., Register June 2020 No. 774.

NR 110.04 NR 110.04 Alternative requirements.

NR 110.04(1) (1) If the owner of a proposed reviewable project feels that compliance with the design requirements of this chapter is impracticable, the reasons therefor shall be fully communicated in writing to the department prior to the submission of final plans. This communication must set forth alternative requirements for which department approval is sought and all pertinent facts, data, reports and studies supporting the imposition of such alternative requirements.

NR 110.04(2) (2) If the department determines that compliance with the design requirements of this chapter would be impracticable in specific cases, it may approve alternative requirements which, in its opinion, are in substantial compliance with the requirements of this chapter.

NR 110.04 History History: Cr. Register, November, 1974, No. 227, eff. 12-1-74.

NR 110.05 NR 110.05 Sewer extensions.

NR 110.05(1) (1) Purpose. The purpose of this section is to insure that department approval of applications for sanitary sewer extensions are consistent with and enhance the policy of the state to restore and maintain the chemical, physical and biological integrity of its waters to protect public health, safeguard fish and aquatic life and scenic and ecological values and enhance the domestic, municipal, recreational, industrial, agricultural and other uses of water.

NR 110.05(3) (3) Permissive approvals related to permitted effluent limitations.

NR 110.05(3)(a) (a) Unless an approval would be contrary to the purpose of this section, applications for sanitary sewer extensions that comply with all applicable requirements of this chapter shall be approved if the sewer will be tributary to a sewage treatment facility in compliance with the monthly average effluent limitations for biochemical oxygen demand (BOD) and total suspended solids contained in its WPDES permit.

NR 110.05(3)(b) (b) In the event that the WPDES permit for a sewage treatment facility currently discharging an effluent in accordance with ch. NR 210 establishes a compliance schedule for achievement of any more stringent water quality related effluent limitations for biochemical oxygen demand and total suspended solids applicable to such treatment facility, compliance with the schedule of compliance in the discharge permit will be deemed to be compliance with the applicable water quality related effluent limitations.

NR 110.05(3)(c) (c) In determining whether a discharged effluent is in compliance with the monthly average effluent limitations for biochemical oxygen demand (BOD) and total suspended solids contained in a WPDES permit, the following procedure shall apply:

NR 110.05(3)(c)1. 1. Compliance shall be determined by department review of the previous 12 months of discharge monitoring data. If 12 months of data are not available, the review shall be based on the data that are available.

NR 110.05(3)(c)2. 2. More than a total of 3 months of violations of the monthly average limitations for either BOD or total suspended solids or both in the previous 12 months (or the equivalent ratio for the number of months of data available) shall cause denial, subject to the following additional considerations:

NR 110.05(3)(c)2.a. a. Recognition of the inherent inaccuracy of the BOD and total suspended solids tests shall be given by multiplying the monthly average effluent limitations as specified in the permit by a factor of 1.3 for BOD and 1.2 for total suspended solids for purposes of determining whether monthly average effluent results are in compliance.

NR 110.05(3)(c)2.b. b. The department may grant approval if it determines that, due to a demonstrable action by the permittee, the sewage treatment facility has been in compliance for four or more consecutive months, thus demonstrating a trend toward better operation.

NR 110.05(3)(c)2.c. c. The department may grant approval in those instances where the permittee demonstrates that noncompliance with the effluent limitations has been caused by algae growth in a sewage treatment facility utilizing lagoons as the principal treatment process.

NR 110.05(3)(c)2.d. d. The department may grant approval if it determines that noncompliance with the effluent limitations has been caused by operating difficulties associated with startup for those sewage treatment facilities which have recently been constructed or undergone major modification or expansion. The period described as startup may be no longer than 12 consecutive months.

NR 110.05(4) (4) Denial related to permitted effluent limitations.

NR 110.05(4)(a) (a) Taking into account the factors in sub. (3) (c), applications for sanitary sewer extensions shall be denied if the sewer will be tributary to a sewage treatment facility not in compliance with the monthly average effluent limitations for biochemical oxygen demand (BOD5) and total suspended solids contained in its WPDES permit.

NR 110.05(4)(b) (b) If the WPDES permit for a sewage treatment facility establishes a compliance schedule for achievement of any more stringent water quality related effluent limitations for biochemical oxygen demand and total suspended solids applicable to such treatment plant, compliance with the schedule of compliance in the discharge permit shall be deemed to be compliance with the applicable water quality related effluent limitations.

NR 110.05(5) (5) Exceptions. Sewer extensions otherwise prohibited by sub. (4) may be granted by the department upon the determination of any of the following:

NR 110.05(5)(a) (a) That construction of the subdivision, commercial establishment, institutional facility or industrial plant had commenced prior to May 24, 1976, as evidenced by the issuance of a building permit;

NR 110.05(5)(b) (b) That the area to be served was developed prior to May 24, 1976, and that the sewer extension will eliminate use of existing private sewage systems which pose a threat to the public health or safety, provided that connections to the sewer are allowed only for the existing development;