Chapter NR 110

NR 110.09(5) (5) Content of an infiltration/inflow analysis.

NR 110.09(5)(a) (a) The infiltration/inflow analysis shall demonstrate whether or not excess infiltration/inflow exists in the sewer system. The analysis shall identify the presence, flow rate, and type of infiltration/inflow conditions, which exist in the sewer systems.

NR 110.09(5)(b) (b) For determination of the possible existence of excessive infiltration/inflow, the analysis shall include an estimate of the cost of eliminating the infiltration/inflow conditions. These costs shall be compared with estimated total costs for transportation and treatment of the infiltration/inflow. This determination shall be made at several levels of infiltration/inflow removal.

NR 110.09(5)(c) (c) If the infiltration/inflow analysis demonstrates the existence or possible existence of excessive infiltration/inflow and the specific sources of excessive infiltration/inflow have not been adequately identified, a sewer system evaluation survey shall be conducted in accordance with sub. (6). A detailed plan for the sewer system evaluation survey shall be included in the infiltration/inflow analysis. The plan shall outline the tasks to be performed in the survey and their estimated costs.

NR 110.09(5)(d) (d) The department may waive the requirements of pars. (a) through (c) if the owner can demonstrate to the department’s satisfaction the obvious existence or nonexistence of excessive infiltration or inflow, or both. The information necessary for this demonstration may include infiltration and inflow estimates, per capita design flows, ratio of total flow to dry weather flow, cubic meters of infiltration per centimeter diameter per kilometer of pipe per day (gallons of infiltration per inch diameter per mile per day), bypassing, and other hydrological and geological factors. The department may require the information be expanded to meet the requirements of pars. (a) through (c) if this demonstration is inconclusive.

NR 110.09(6) (6) Content of a sewer system evaluation survey.

NR 110.09(6)(a) (a) The sewer system evaluation survey shall determine the location, estimated flow rate, method of rehabilitation and cost of rehabilitation versus cost of transportation and treatment for each defined source of infiltration/inflow.

NR 110.09(6)(b) (b) The report shall summarize the results of the sewer system evaluation survey. In addition, the report shall include:

NR 110.09(6)(b)1. 1. A justification for each sewer section cleaned and internally inspected; and

NR 110.09(6)(b)2. 2. A proposed rehabilitation program for the sewer system to eliminate all defined excessive infiltration/inflow.

NR 110.09(7) (7) Construction plans and specifications for sewage treatment plant projects. 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 plans for sewage treatment plants.

NR 110.09(7)(a) (a) Overall plan. A plan shall be submitted which shows the sewage treatment plant in relation to the remainder of the system. Sufficient topographic features shall be included to indicate its location with respect to streams and the point of discharge of treated effluent.

NR 110.09(7)(b) (b) Layout. A general layout plan shall be submitted which includes:

NR 110.09(7)(b)1. 1. A contour map of the site;

NR 110.09(7)(b)2. 2. The size and location of plant structures;

NR 110.09(7)(b)3. 3. A schematic flow diagram indicating the various plant units;

NR 110.09(7)(b)4. 4. Piping details including piping arrangements for bypassing individual units;

NR 110.09(7)(b)5. 5. The materials handled and the direction of flow through each pipe;

NR 110.09(7)(b)6. 6. The hydraulic profiles for sewage and sludge flows;

NR 110.09(7)(b)7. 7. Soil conditions at the site.

NR 110.09(7)(c) (c) Detailed plans. Detailed construction plans shall be submitted which include:

NR 110.09(7)(c)1. 1. The location, dimensions, elevations and details of all existing and proposed plant units;

NR 110.09(7)(c)2. 2. The elevation of high and low water level in the receiving stream;

NR 110.09(7)(c)3. 3. An adequate description of all features not covered in the specifications.

NR 110.09(8) (8) Additional facility planning requirements for land disposal system alternatives.

NR 110.09(8)(a) (a) General requirements. In addition to the requirements of sub. (1), a report including a soil investigation and a hydrogeologic evaluation shall be submitted as part of the facilities plan for a land disposal discharge alternative. The report shall detail the soil types, characteristics, variability and permeability, topography, groundwater conditions and quality, and other characteristics of the disposal site. Soil boring and test pit logs and soil analyses shall be provided. Wastewater characteristics which may influence the design of the disposal system shall also be discussed. Water supply quality, local groundwater use, and potential impacts of the facility on groundwater quality shall be included.

NR 110.09(8)(b) (b) Hydrogeological investigation.

NR 110.09(8)(b)1. 1. A hydrogeological investigation shall be included as part of the facilities plan. The analysis of the hydrogeological information shall be done by a hydrogeologist, or other qualified person. The investigation shall include both regional and site-specific hydrogeological information.

NR 110.09 Note Note: The skills and knowledge required of a hydrogeologist making submittals under this chapter include: the ability to apply hydrogeologic principles and practices to the siting, design and operation of land disposal systems; knowledge of contaminants associated with land disposal of wastewater, their transport mechanisms and fate in the environment; familiarity standards; and proficiency in the design of groundwater monitoring systems for defining the physical and chemical characteristics of groundwater flow. A soil scientist or other environmental scientist who can demonstrate the above skills and knowledge, as reflected in submittals made under this chapter, shall be deemed a “qualified person”.

NR 110.09(8)(b)2. 2. The following site-specific groundwater information may be required as part of the facilities plan for land disposal facilities:

NR 110.09(8)(b)2.a. a. Depth to highest anticipated groundwater elevation.

NR 110.09(8)(b)2.b. b. Groundwater flow directions and rates of flow.

NR 110.09(8)(b)2.c. c. Vertical and horizontal gradients.

NR 110.09(8)(b)2.d. d. Groundwater quality.

NR 110.09(8)(b)2.e. e. Presence of groundwater divides and barriers.

NR 110.09(8)(b)2.f. f. Presence and extent of perched groundwater.

NR 110.09(8)(b)2.g. g. Mounding calculations.

NR 110.09(8)(c) (c) Soil investigation. The soil evaluation may be performed in conjunction with the hydrogeological evaluation; however, each evaluation shall be performed by a person who is qualified to perform the evaluation. The following site-specific soil information shall be submitted as a part of the facilities plan for land disposal systems;

NR 110.09(8)(c)1. 1. Soil borings and sampling performed in accordance with ss. NR 110.24 (3) (d) and 110.24 (4) (d), and test pit analyses. The one boring per acre minimum of s. NR 110.24 (3) (d) 4. does not apply to spray irrigation, ridge and furrow, or overland flow systems. A soil analysis may be required on a case-by-case basis for land disposal systems. The USDA soil classification system shall be used for spray irrigation systems, ridge and furrow, and overland flow systems.

NR 110.09(8)(c)2. 2. Soil descriptions, including soil profile, stratification, slope, soil moisture content, continuity, structure, texture, relative density and depth to groundwater and bedrock.

NR 110.09(8)(c)3. 3. Soil analyses shall be performed on the zone of soil which will provide treatment of the wastewater. The department may require that the analyses include any or all of the following: grain size analyses, hydrometer analyses, field and laboratory horizontal and vertical permeabilities, Atterberg limits, soil pH, cation exchange capacity, bulk density and relative density, porosity, soil nutrient content, and organic matter content.

NR 110.09(8)(c)4. 4. In-field infiltration rates (measured at the proposed elevation of application).

NR 110.09(8)(c)5. 5. A description of the soil testing methods used.

NR 110.09(8)(c)6. 6. Depth to bedrock.

NR 110.09(8)(c)7. 7. Type and nature of bedrock.

NR 110.09 History History: Cr. Register, November, 1974, No. 227, eff. 12-1-74; r. and recr. Register December, 1978, No. 276, eff. 1-1-79; am. (1) (b) 4. and (2) (h), cr. (2) (n) to (q) and (5) (d), Register, February, 1983, No. 326, eff. 3-1-83; am. (2) (h) 5. and 6., cr. (2) (r) and (8), Register, November, 1990, No. 419, eff. 12-1-90; am. (2r), Register, April, 1994, No. 460, eff. 5-1-94; am. (2) (r), Register, March, 1995, No. 471, eff. 4-1-95; correction in (1) (j) 2. made under s. 13.93 (2m) (b) 1., Stats., Register, September, 1995, No. 477; corrections in (2) (f), (j) 1., 4. (intro.), and (4) (c) 1., were made under s. 13.93 (2m) (b) 7., Stats., Register, May, 2001, No. 545; CR 09-123: am. (2) (j) 2., 3. b., 4. b. and (8) (b) 2. Register July 2010 No. 655, eff. 8-1-10; CR 13-022: am. (3) (title), (intro.) Register March 2014 No. 699, eff. 4-1-14.

NR 110.10 NR 110.10 Sewage collection system projects.

NR 110.10(1) (1) Facilities plans for sewer projects. For sewer projects the facilities plan shall include the following information:

NR 110.10(1)(a) (a) Description. A brief description of the project; including its geographic location and any necessary reference maps or exhibits.

NR 110.10(1)(b) (b) Topography. A brief description of the topography of the general area with specific reference to the area serviced by the proposed sewer.

NR 110.10(1)(c) (c) Soil investigations. A description of the extent of soil investigations, including information on rock likely to be encountered. In addition, that portion of the proposed sewer which is below high ground water level shall be indicated.

NR 110.10(1)(d) (d) Flooding. A designation of any portion of the proposed sewer which is located within the floodway or floodplain as defined in ch. NR 116. All projects shall conform to the requirements of ch. NR 116.

NR 110.10(1)(e) (e) Wetlands. A statement indicating whether the proposed sewer will pass through a wetlands area, and the approximate acreage of the wetland.

NR 110.10(1)(f) (f) Population. Population growth rate (annual) based on the most recent data for the municipality.

NR 110.10(1)(g) (g) Sewer service area. If the sewer project is tributary to a treatment plant for which a service area that has been delineated as a part of an approved areawide waste treatment management plan, indicate the location of the sewer on a map of the service area.

NR 110.10(1)(h) (h) Downstream overflows. A description of the number and location of sanitary sewer overflow structures and a description of the occurrence of sanitary sewer overflow events at any location within the sewerage system.

NR 110.10(1)(i) (i) Description of treatment facilities. A brief description of the type of treatment facility indicating the ability of the facility to handle the sewage of the proposed project during both wet and dry weather conditions.

NR 110.10(1)(j) (j) Costs. A discussion of the estimated capital costs and where an entire sewerage system is being installed, the estimated annual cost to the user of the system.

NR 110.10(1)(k) (k) Basis of design. The following data shall be provided for the proposed project:

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.