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)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(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)4.
4. Per capita sewage contribution expressed as an average and as a maximum value;
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(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)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)(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.
NR 110.13(1)(d)2.
2. Sanitary sewers shall be located with a minimum separation distance of 15 meters (50 feet) from private water system wells or any other wells subject to ch.
NR 812.
NR 110.13(1)(d)3.
3. Horizontal and vertical separation of sewers from public water mains shall comply with the requirements of s.
NR 811.67. Horizontal and vertical separation of sewer from private water laterals shall comply with the requirements of s.
SPS 382.40 (8) (b).
NR 110.13(1)(d)4.
4. Cross-connections with public and private water supply systems are prohibited.
NR 110.13(2)(a)1.1. Conventional gravity sewer may not be less than 20 centimeters (8 inches) in diameter.
NR 110.13(2)(a)2.
2. Gravity sewers with diameters less than 20 centimeters (8 inches) which are intended to transport septic tank effluent will be evaluated on a case-by-case basis.
NR 110.13(2)(b)
(b) Depth. Sewers shall be designed deep enough to prevent freezing and, where economically feasible, to provide gravity basement drainage for sanitary wastes.
NR 110.13(2)(c)1.1. Conventional gravity sewers shall be laid with uniform slope between manholes. All sewers shall be designed and constructed to give average velocities of not less than 60 centimeters per second (2.0 feet per second) when flowing full. The minimum slopes shown in Table 1 shall be provided. Slopes less than 0.4% may be permitted for 20 centimeter (8 inch) sewers. In such cases, however, the slope may not be less than 0.3%. The department will approve these sewers only when the owner demonstrates that physical circumstances warrant the lesser slope. Furthermore, approval will not be granted until the department has received written assurance from the operating authority that the authority will provide the additional maintenance which may result from the sedimentation due to decreased velocities.
NR 110.13(2)(c)2.
2. Gravity sewers with a diameter less than 20 centimeters (8 inches) shall be laid at uniform slopes between manholes and shall be designed to provide sufficient flow velocities to prevent sedimentation of septic tank solids.
NR 110.13(2)(d)1.1. Sewers with diameters less than 91 centimeters (36 inches) shall be laid with straight alignment between manholes.
NR 110.13(2)(d)2.
2. The department may approve curvilinear sewers with diameters of 91 centimeters (36 inches) or larger on a case-by-case basis.
NR 110.13(2)(e)
(e) Increasing size. When a sewer joins a larger one, the invert of the smaller sewer shall be laid at the elevation necessary to maintain the same energy gradient.
NR 110.13(2)(f)
(f) Velocity. Where velocities of greater than 4.6 meters per second (15 feet per second) are attained, special provision shall be made to protect against displacement or erosion.
NR 110.13(2)(g)
(g) Anchoring. Sewers on slopes of 20% or greater shall be anchored securely with concrete anchors or the equivalent, spaced as follows:
NR 110.13(2)(g)1.
1. Not over 11 meters (36 feet) center to center on grades 20% to 35%;
NR 110.13(2)(g)2.
2. Not over 7.3 meters (24 feet) center to center on grades 35% to 50%; and
NR 110.13(2)(g)3.
3. Not over 4.9 meters (16 feet) center to center on grades greater than 50%.
NR 110.13(2)(h)
(h) Trench width. The width of the trench shall be sufficient to allow the pipe to be laid and jointed properly and to allow the backfill to be placed and compacted as needed. The trench sides shall be kept as nearly vertical as possible. When wider trenches are dug, appropriate bedding class and pipe strength shall be used. Ledge rock, boulders, and large stones shall be removed to provide a minimum clearance of 10 centimeters (4 inches) below and on each side of the pipe.
NR 110.13(2)(i)1.1. Bedding classes A, B, or C, as described in ASTM C12-09 shall be used for all rigid pipe provided the proper strength pipe is used with the specified bedding to support the anticipated load.
NR 110.13(2)(i)2.
2. Bedding classes I, II, or III, as described in ASTM D2321-09 shall be used for all flexible pipe provided the proper strength pipe is used with the specified bedding to support the anticipated load.
NR 110.13(2)(j)
(j) Backfill. Debris, frozen material, large clods or stones, organic matter, or other unstable materials may not be used for backfill within 60 centimeters (2 feet) of the top of the pipe. Backfill shall be placed in such a manner as not to disturb the alignment of the pipe.
NR 110.13(2)(k)1.1. Groundwater infiltration into sanitary sewer systems shall be minimized. Tests for infiltration shall be specified in the construction specifications. This may include appropriate water or low pressure air testing. The leakage outward or inward (exfiltration or infiltration) may not exceed 0.19 cubic meters per centimeter pipe diameter per kilometer per day (200 gallons per inch of pipe diameter per mile per day) for any section of the system. An exfiltration or infiltration test shall be performed with a minimum positive head of 60 centimeters (2 feet). The air test, if used, shall, at a minimum, conform to the test procedure described in ASTM C828-06 for clay pipe, ASTM C924-02 (2009) for concrete pipe, or ASTM F1417-92 (2005) for plastic pipe. The testing methods selected should take into consideration the range in groundwater elevations projected and the situation during the test.
