Chapter NR 110

NR 110.10(1)(k)1. 1. Design period.

NR 110.10(1)(k)2. 2. Population densities per acre and total population served.

NR 110.10(1)(k)3. 3. Area served by proposed sewers in acres.

NR 110.10(1)(k)4. 4. Per capita sewage contribution expressed as an average and maximum value, include basis for this determination.

NR 110.10(1)(k)5. 5. Infiltration.

NR 110.10(1)(k)6. 6. Industrial waste contribution.

NR 110.10(1)(k)7. 7. Design flow rates as expressed as average and maximum values.

NR 110.10(1)(k)8. 8. Size of pipe, grade, velocity and maximum capacity.

NR 110.10(1)(L) (L) Environmental analysis. The department may require the submittal of an environmental analysis meeting the requirements of s. NR 110.09 (3) for large or complex sewer projects, for those projects which are proposed to be constructed in environmentally sensitive areas, or for projects which involve significant public controversy.

NR 110.10(2) (2) Staging of interceptors.

NR 110.10(2)(a) (a) Since the location and length of interceptors will influence growth, interceptor routes and staging of construction shall be planned carefully and shall be consistent with approved areawide waste treatment management plans, growth management plans and other environmental laws.

NR 110.10(2)(b) (b) The staging period for interceptor construction and interceptor pipe sizes shall be cost-effective. A 20 year staging period shall be analyzed. Other staging periods, not to exceed 40 years, may also be evaluated. The cost-effectiveness analysis shall consider the following factors:

NR 110.10(2)(b)1. 1. Cost.

NR 110.10(2)(b)1.a. a. Capital cost (present and future).

NR 110.10(2)(b)1.b. b. Operation and maintenance cost.

NR 110.10(2)(b)1.c. c. Salvage value.

NR 110.10(2)(b)2. 2. Primary environmental impacts.

NR 110.10(2)(b)2.a. a. Short-term disruption of traffic, business and other activities.

NR 110.10(2)(b)2.b. b. Destruction of flora and fauna.

NR 110.10(2)(b)2.c. c. Noise, erosion and sedimentation.

NR 110.10(2)(b)2.d. d. Destruction of, or impact on, wetlands and floodplains.

NR 110.10(2)(b)3. 3. Secondary impacts.

NR 110.10(2)(b)3.a. a. Pressure to rezone or otherwise stimulate unplanned development.

NR 110.10(2)(b)3.b. b. Pressure to accelerate growth for quicker recovery of the nonfederal share of the interceptor investments.

NR 110.10(2)(b)3.c. c. Effects on air quality and environmentally sensitive areas by cultural changes.

NR 110.10(2)(b)4. 4. Other nonmonetary impacts including implementation capability, operability, performance reliability and flexibility.

NR 110.10(2)(c) (c) The estimation of peak flows in interceptors shall be based upon the following considerations:

NR 110.10(2)(c)1. 1. Daily and seasonal variations of pipe flows, the timing of flows from the various parts of the tributary area and pipe storage effects.

NR 110.10(2)(c)2. 2. The feasibility of off-pipe storage to reduce peak flows.

NR 110.10(2)(c)3. 3. The use of an appropriate peak flow factor that decreases as the average daily flow to be conveyed increases.

NR 110.10(3) (3) Construction plans and specifications for sewer projects. In addition to the requirements of ch. NR 108 and ss. NR 110.06 and 110.07 plans and specifications for proposed sewer projects shall include a plan and profile view of all proposed construction. The plans and profiles shall show:

NR 110.10(3)(a) (a) Location. The location of existing or proposed streets and sewers;

NR 110.10(3)(b) (b) Streams and water surfaces. The location and 100 year flood elevation of all streams and water surfaces relevant to the project;

NR 110.10(3)(c) (c) Elevations. The line of the ground surface, the invert and surface elevation at each manhole and the grade of the sewer between each adjacent manhole. Basement elevations shall be noted on the plans or the designing engineer shall state that all sewers are sufficiently deep to serve adjacent basements except where otherwise noted on the plans. Where gravity basement drainage to the proposed sewer will not be possible for existing buildings, the buildings’ owners shall be so advised prior to construction of the sewers;

NR 110.10(3)(d) (d) Pipe size and material. The pipe size, material, pipe strength and bedding class shall be shown on the plans or in the specifications;

NR 110.10(3)(e) (e) Manhole spacing. The length of sewer between the manholes shall be shown on the plans;

NR 110.10(3)(f) (f) Special features. The locations of all special features including inverted siphons, concrete encasements, elevated sewers, and other features as appropriate;

NR 110.10(3)(g) (g) Existing structures. The location of all known existing structures and utilities which might interfere with the proposed construction, particularly all water mains, gas mains, storm drains, and other pertinent structures;

NR 110.10(3)(h) (h) Special drawings. Special detail drawings made to a scale to clearly show the nature of the design shall be furnished to show the following:

NR 110.10(3)(h)1. 1. Stream crossings with elevations of the stream bed and of normal and extreme high and low water levels;

NR 110.10(3)(h)2. 2. Details of all special sewer joints and cross-sections;

NR 110.10(3)(h)3. 3. Details of all sewer appurtenances such as manholes, lampholes, inspection chambers, inverted siphons and elevated sewers.

NR 110.10(4) (4) System evaluation and capacity assurance plan. A system evaluation and capacity assurance plan shall include all the following:

NR 110.10(4)(a) (a) An evaluation of those portions of the sewage collection system that may contribute to sewage treatment facility overflows or other noncompliance at a sewage treatment facility, or that are experiencing or contributing to a sanitary sewer overflow caused by excessive infiltration and inflow or a system hydraulic deficiency. The evaluation must provide estimates of peak flows, including the amount from sanitary sewer overflows and sewage treatment facility overflows, provide estimates of the capacity of key system components, identify hydraulic deficiencies, and identify the sources (including private property sources) of infiltration and inflow that contribute to the peak flows associated with sanitary sewer overflow or sewage treatment facility overflow occurrences.

NR 110.10(4)(b) (b) An analysis to identify actions that will eliminate sanitary sewer overflows and sewage treatment facility overflows or abate their occurrence and effects on public health and the environment to the extent technically and economically feasible. The analysis shall consider alternatives such as providing improved operation and maintenance, infiltration and inflow reduction, and removal from all sources, wastewater equalization or storage facilities, sewer and lift station replacement or rehabilitation, the treatment of overflows, peak flow treatment schemes at sewage treatment facilities, expansion of sewage treatment facility capacity, and any other construction of new or modified sewerage system components.

NR 110.10 Note Note: When evaluating feasibility of alternatives, the department may consider factors such as technical achievability, the relationship between the control of storm water and the control of infiltration/inflow into the sewage collection system, costs and affordability of implementation, and risks to public health, the environment, and welfare of the community served by the sewage collection system.

NR 110.10(4)(c) (c) Identification of specific short and long term corrective actions. Schedules for implementation shall be established giving greatest priority to those actions that will protect public health and minimize environmental risk. The department may establish compliance schedules in WPDES permits to implement specific actions identified under this paragraph.

NR 110.10 Note Note: Portions of a system evaluation and capacity analysis plan may include results from an infiltration/inflow analysis or a sewer system evaluation survey under s. NR 110.09 (5) or s. NR 110.09 (6), respectively.

NR 110.10 History History: Cr. Register, November, 1974, No. 227, eff. 12-1-74; r. and recr. Register, December, 1978, No, 276, eff. 1-1-79; r. and recr. (2), Register, February, 1983, No. 326, eff. 3-1-83; CR 12-027: r. and recr. (1) (h), cr. (4) Register July 2013 No. 691, eff. 8-1-13; CR 13-022: am. (1) (L) Register March 2014 No. 699, eff. 4-1-14.

NR 110.11 NR 110.11 Sewage lift stations.

NR 110.11(1) (1) Facilities plans for sewage lift stations. The facilities plan shall include the following:

NR 110.11(1)(a) (a) Contributory area. A description of the extent of the existing and proposed contributory area with reference to a general system map as well as description of the areas of probable future expansion of the contributory area.

NR 110.11(1)(b) (b) Location. The location of the proposed lift station, force main and point of discharge to the existing sewer system. In addition the report shall discuss the capacity available in the existing downstream sewer to handle the additional flow.

NR 110.11(1)(c) (c) Flooding. A statement indicating whether the proposed lift station is in a floodway or floodplain as defined in ch. NR 116. All projects shall conform to the requirements of ch. NR 116.

NR 110.11(1)(d) (d) Basis for design. The design data for the proposed project including the following:

NR 110.11(1)(d)1. 1. Design period;

NR 110.11(1)(d)2. 2. Population densities per acre and total population served;

NR 110.11(1)(d)3. 3. Area served in acres;

NR 110.11(1)(d)4. 4. Per capita sewage contribution expressed as an average and as a maximum value;

NR 110.11(1)(d)5. 5. Infiltration and inflow;

NR 110.11(1)(d)6. 6. Industrial waste contributions;

NR 110.11(1)(d)7. 7. Design flow rates expressed as average and maximum values; and

NR 110.11(1)(d)8. 8. Design head conditions.

NR 110.11(1)(e) (e) Essential features. A description of the essential features of construction and operation of the proposed stations.

NR 110.11(1)(f) (f) Costs. Discussion of the estimated capital costs, estimated annual maintenance cost, and estimated annual cost to the average user of the system;

NR 110.11(1)(g) (g) Environmental analysis. The department may require the submittal of an environmental analysis meeting the requirements of s. NR 110.09 (3) for large or complex lift station projects, for those projects constructed in environmentally sensitive areas or for projects which could involve significant public controversy.

NR 110.11 Note Note: Facilities plans for sewage lift stations may include results from a system evaluation and capacity assurance plan under s. NR 110.10 (4).

NR 110.11(2) (2) Construction plans and specifications for sewage lift stations. In addition to the requirements of ch. NR 108 and ss. NR 110.06 and 110.07, the following requirements shall be adhered to for submission of construction plans and specifications for sewage lift stations:

NR 110.11(2)(a) (a) Location plan. A location plan shall be submitted showing the tributary area, the municipal boundaries within the tributary area and the location of the lift station and force main, and all pertinent elevations;

NR 110.11(2)(b) (b) Detailed plans. The detailed lift station plans shall show the following, where applicable:

NR 110.11(2)(b)1. 1. The location and the topography (using a contour map) of the property to be used;

NR 110.11(2)(b)2. 2. The station details and all appurtenant equipment including pumps, sump pumps, heaters, ventilation equipment, valving, access ladder, intermediate landings, and wet well;

NR 110.11(2)(b)3. 3. The elevation of high water at the site, including the maximum elevation of sewage in the collection system in the event of power failure at the station.

NR 110.11 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 12-027: am. (1) (d) 5. Register July 2013 No. 691, eff. 8-1-13; CR 13-022: am. (1) (g) Register March 2014 No. 699, eff. 4-1-14.

NR 110.12 NR 110.12 Owner approval requirement. If the engineer submitting plans to the department for approval is not an employee of or has not been retained by the owner of the sewerage system for which the plans are submitted, written acceptance of the final plans by the owner shall be required prior to submission of the plans to the department.

NR 110.12 Note Note: For example, if an engineer is retained by a developer to design sewer extensions which will be connected to a municipal system and which will eventually be owned by the municipality, the plans must be accepted by the municipality before the department issues an approval.

NR 110.12 History History: Cr. Register, November, 1974, No. 227, eff. 12-1-74.

NR 110.13 NR 110.13 Sewer design criteria.

NR 110.13(1) (1) General design considerations.

NR 110.13(1)(a) (a) Separation of sewers. New systems, or extensions to existing systems, which will serve presently unsewered areas shall be designed to exclude storm and other clear water sources from the sanitary sewer system.

NR 110.13(1)(b) (b) Design basis.

NR 110.13(1)(b)1. 1. Sewage collection systems, exclusive of interceptors, shall be designed in accordance with s. NR 110.10 (1).

NR 110.13(1)(b)2. 2. Interceptors shall be designed in accordance with s. NR 110.10 (2) (a).

NR 110.13(1)(b)3. 3. Extensions to existing sewage collection systems may be designed assuming an average design flow rate of 378 liters (100 gallons) per capita per day.

NR 110.13(1)(c) (c) Design capacity. Sewers shall be designed to carry, when running full, the peak design flows expected from domestic, commercial, industrial and other sources, and infiltration and inflow. Peak design flow shall be established using existing sewage flow or water use records, and records of infiltration and inflow. Where peak flow records are not available, the peak design flow shall be determined by applying one of the following peak flow factors to the average design flow:

NR 110.13(1)(c)1. 1. 250% of the average design flow for interceptors, main (trunk) sewers, and sewage outfall pipes; or,

NR 110.13(1)(c)2. 2. 400% of average design flow for submain and branch sewers.

NR 110.13(1)(d) (d) Protection of water supplies.

NR 110.13(1)(d)1. 1. Sanitary sewers shall be located with a minimum separation distance of 60 meters (200 feet) from any community water system well in accordance with ch. NR 811. A lesser separation distance may be allowed where the sanitary sewer main is constructed of water main materials and joints and pressure tested in accordance with ch. NR 811 requirements. When sanitary sewers are proposed to be laid within 60 meters (200 feet) of a community water system well the location of the well shall be shown on the design plans. The separation distance between a community water system well and a sanitary sewer main may not be less than 50 feet.