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.
NR 110.13(2)(k)2.
2. Deflection tests shall be performed for all polyvinyl chloride pipe installations. The deflection test shall be performed using a rigid ball or mandrel, and shall be performed without mechanical pulling devices. If deflection testing occurs within 30 days of placement of the final backfill, deflection may not exceed 5%. Maximum deflection may not exceed 7.5% when testing occurs more than 30 days after placement of the final backfill.
NR 110.13(3)(a)(a) Location. Manholes shall be installed at the end of each line, at all changes in grade, size or alignment, and at all pipe intersections.
NR 110.13(3)(b)1.1. Manholes shall be located at intervals not greater than 120 meters (400 feet) for sewers with diameters of 38 centimeters (15 inches), or less, and not greater than 150 meters (500 feet) for sewers with diameters of 46 centimeters (18 inches) to 76 centimeters (30 inches). Distances up to 180 meters (600 feet) may be approved in cases where the sewer system owner has cleaning equipment which can reach this length.
NR 110.13(3)(b)2.
2. Manhole spacing for sewers with a diameter greater than 76 centimeters (30 inches) shall be determined on a case-by-case basis.
NR 110.13(3)(c)
(c) Drop pipe. An outside drop pipe shall be provided for a sewer entering a manhole where the invert elevation of the entering sewer is 60 centimeters (2 feet) or more above the spring line of the outgoing sewer. The entire drop connection shall be encased in the concrete. Inside drop connection may be approved on a case-by-case basis.
NR 110.13(3)(d)
(d) Diameter. The minimum diameter of manholes shall be 1.1 meters (42 inches).
NR 110.13(3)(e)
(e) Construction. Manholes shall be constructed of precast concrete, monolithic concrete, brick or block, or other approved materials. Fiberglass manholes may be approved on a case-by-case basis. Fiberglass manholes may be approved for use in high traffic areas provided the top section of the manhole is not made of fiberglass.
NR 110.13(3)(f)
(f) Flow channel. The flow channel through manholes shall be made to conform to the shape and slope of the sewers.
NR 110.13(3)(g)
(g) Water tightness. Solid watertight manhole covers shall be used wherever the manhole tops may be flooded by street runoff or high water. Where groundwater conditions are unfavorable, manholes of brick or block shall be waterproofed on the exterior with plastic coatings supplemented by a bituminous waterproof coating or other approved coatings. Inlet and outlet pipes shall be joined to the manhole with a gasketed flexible watertight connection or any watertight connection arrangement that allows differential settlement of the pipe and manhole wall to take place.
NR 110.13(3)(h)
(h) Cleanouts. For sewers with diameters 20 centimeters (8 inches), or greater, cleanouts and lampholes may not be used as substitutes for manholes. The department may allow cleanout instead of manholes when the sewer diameter is less than 20 centimeters (8 inches).
NR 110.13(3)(i)
(i) Manholes for sewers with diameters less than 20 centimeters (8 inches). Manholes shall be located at pipe intersections. The spacing of these manholes shall be determined on a case-by-case basis.
NR 110.13(4)
(4)
Inverted siphons. Inverted siphons may not have less than 2 barrels with a minimum pipe size of 15 centimeters (6 inches) and shall be provided with the necessary appurtenances for convenient flushing and maintenance. The manholes shall have adequate clearance for rodding. Sufficient head shall be provided and pipe sizes selected to secure velocities of at least 91.5 centimeters per second (3.0 feet per second) at average flows. The inlet and outlet details shall be arranged so that the normal flow is diverted to one barrel, and so that either barrel may be removed from service for cleaning.
NR 110.13(5)
(5)
Material specifications for sewer construction. NR 110.13(5)(a)
(a) Materials. Materials used in the construction of sanitary sewers shall be restricted to the following: concrete, vitrified clay, steel, ductile iron, polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene (ABS) composite, fiberglass reinforced-PVC composite, and high density polyethylene (HDPE) pipe. Other pipe material will be considered on its merit and may be approved by the department. Where an approval is issued for a restricted or experimental use, the department may require a construction inspection report and annual reports including television inspection of the system as a condition of its approval.
NR 110.13(5)(b)
(b) Quality. All material used for sanitary sewer construction shall be free from defects that impair service.
NR 110.13(5)(c)
(c) Labeling. Each length of pipe and fitting used in a sanitary sewer shall be stamped or indelibly marked with the manufacturer's name or mark.
NR 110.13(5)(d)
(d) Material selection. Pipe material selection shall recognize the design conditions of the sewer installation. Factors which shall be considered include depth of cover, soil types, loading on pipe, and corrosivity.
NR 110.13(5)(e)
(e) Nonpressure pipe. All nonpressure sewer pipe shall have sufficient strength to withstand the loads which will exist. The following are minimum standards for nonpressure pipe:
NR 110.13(5)(e)1.
1. Concrete pipe shall meet the requirements of ASTM C14-07, C76-10, or C655-09;
NR 110.13(5)(e)2.
2. Vitrified clay pipe shall meet the requirements of ASTM C700-09;
NR 110.13(5)(e)4.
4. Ductile iron pipe and fittings shall meet the requirements of ASTM A746-09;
NR 110.13(5)(e)5.
5. Polyvinyl chloride sewer pipe shall meet the requirements of D3034-08 or ASTM F679-08;
NR 110.13(5)(e)6.
6. ABS composite sewer pipe shall meet the requirements of ASTM D2680-01(2009).
NR 110.13(5)(f)
(f) Joints for nonpressure pipe. The method of making joints and the materials used shall be included in the specifications and meet the minimum standards in subds.
1. to
5. Sewer joints shall be designed to minimize infiltration and to prevent the entrance of roots. Joint material shall be of such a composition as not to be adversely affected by the sewage.
NR 110.13(5)(f)1.
1. Rubber gasket joints for concrete sewer pipe shall meet ASTM C443-05ae1.
NR 110.13(5)(f)2.
2. Resilient joints for vitrified clay sewer pipe shall meet ASTM C425-04 (2009).
NR 110.13(5)(f)4.
4. Polyvinyl chloride sewer pipe shall be joined by solvent weld joints or by elastomeric joints which have been approved by the department.
NR 110.13(5)(f)5.
5. ABS composite sewer pipe shall be joined by solvent weld joints or by type OR mechanical–seal joints meeting the requirements of ASTM D2680-01 (2009).
NR 110.13(5)(g)
(g) Pressure sewer pipe and joints. All pressure sewer pipe 10 centimeters (4 inches) or larger shall meet the following minimum requirements:
NR 110.13(5)(g)1.
1. Ductile iron pipe and joints shall meet the requirements of AWWA C151.
NR 110.13(5)(g)2.
2. Steel pipe and joints shall meet the requirements of AWWA C200-05.
NR 110.13(5)(g)3.
3. Concrete pipe and joints shall meet the requirements of AWWA C300-04.
NR 110.13(5)(g)4.
4. Polyvinyl chloride pipe and joints shall meet the requirements of AWWA C900-07 (minimum class 150) or ASTM D2241-09 (minimum class 250). Solvent weld joints may not be used.
NR 110.13(5)(g)5.
5. Fiberglass reinforced–polyvinyl chloride composite pipe and joints shall meet the requirements of AWWA C950-07 (minimum class 250). Eight and 10–inch pipe shall have minimum category 3 stiffness as defined in ASTM D2996-01 (2007) e1. Four and 6–inch pipe shall have a minimum category 2 stiffness as defined in ASTM D2996-01 (2007).
NR 110.13(5)(h)
(h) Small diameter pressure sewer pipe and joints. All pipe and joints 8 centimeters (3 inches) in diameter or smaller to be used in grinder pumps shall meet the following minimum requirements:
NR 110.13(5)(h)1.
1. Polyethylene pipe and joints which meet the requirements of ASTM D2239-03 (minimum class 160) may be approved on a case–by–case basis depending on the expected system pressure relative to the pipe working strength. Solvent weld, butt fusion, or elastomeric joints will be acceptable.
NR 110.13(5)(h)2.
2. For ABS pipe, solvent weld or elastomeric joints will be acceptable.
NR 110.13(5)(h)3.
3. Polyvinyl chloride pipe and joints shall meet the requirements of ASTM D2241-09 (minimum class 160). Solvent weld or elastomeric joints will be acceptable.
NR 110.13(6)
(6)
Sanitary sewer overflow structures. Sanitary sewer overflows structures may be provided as measures to manage and mitigate the effects of sanitary sewer overflow discharges that may occur under extreme conditions. Sanitary sewer overflow structures shall be designed in accordance with all the following requirements:
NR 110.13(6)(a)
(a) The overflow may be activated either manually or automatically. If automatically activated, a monitoring system shall be provided to detect the initiation time of the overflow and to provide an alarm signal to the sewage collection system operator or other responsible authority.
NR 110.13(6)(b)
(b) The overflow structure shall be designed to discharge only those wastewater flows greater than the peak flow conveyance capacity within the sewage collection system.
NR 110.13(6)(c)
(c) Equipment shall be provided to measure the flow and, if practicable, sample the wastewater discharged from the structure.
NR 110.13 Note
Note: A department approval of a sanitary sewer overflow structure does not eliminate or alleviate the requirement that prohibits sewage treatment facility overflows in s.
NR 210.21.
NR 110.13 History
History: Cr.
Register, November, 1974, No. 227, eff. 12-1-74; am. (2),
Register, December, 1978, No. 276, eff. 1-1-79; r. and recr.
Register, February, 1983, No. 326, eff. 3-1-83; corrections in (1) made under s. 13.93 (2m) (b) 7., Stats.,
Register, September, 1995, No. 477; corrections in (1) (d) 2. and 3. were made under s. 13.93 (2m) (b) 7., Stats.,
Register, May, 2001, No. 545;
CR 09-123: am. (1) (d) 1., 2., (2) (i), (k) 1., (5) (a) and (e) to (h)
Register July 2010 No. 655, eff. 8-1-10; correction in (1) (d) 3. made under s. 13.92 (4) (b) 7., Stats.,
Register January 2012 No. 673;
CR 12-027: cr. (6)
Register July 2013 No. 691, eff. 8-1-13.
NR 110.14
NR 110.14 Sewage lift stations design criteria. NR 110.14(1)(a)(a) Applicability. Lift stations may be approved when gravity sewers are not feasible or economical to transport the same design quantities of sewage.
NR 110.14(1)(b)
(b) Design report. A design report shall be submitted with plans and specifications for all new sewage lift stations as well as the major rehabilitation of existing lift stations. Major lift station rehabilitation may include, but is not limited to, replacing pumps with larger units or changing the type of lift stations. The design report shall comply with the facilities planning requirements of s.
NR 110.11, and shall contain the detailed design calculations for the lift station design capacity.
NR 110.14(2)(a)2.
2. Where practical, lift stations shall be located off the traffic way of streets and alleys.
NR 110.14(2)(a)3.
3. Lift stations shall be located with a minimum separation distance of 60 meters (200 feet) from community water system well, and a minimum separation distance of 30 meters (100 feet) from a private water well or any other well subject to ch.
NR 812. A lesser separation distance from a community water system well may be approved if hydrogeologic information is provided to the department to indicate the lesser separation distance would provide adequate protection of a well from contamination. When a lift station is proposed within 60 meters (200 feet) of a community water system well, or 30 meters (100 feet) of private water wells or any other well subject to ch.
NR 812, the location of the well shall be shown on the engineering plans. Gravity or pressure sewers connecting to lift stations shall be separated from water supply wells in accordance with s.
NR 110.13 (1) (d).
NR 110.14(2)(b)1.1. Pumping rates for lift stations integral to collection systems shall be determined in the same manner as the flows for the sewers contributory to the lift station and in accordance with the provisions of s.
NR 110.11 (1) (d).
NR 110.14(2)(b)2.
2. Pumping rates for lift stations which operate as part of sewage treatment facilities shall be determined in the same manner as the design flow for the treatment facility in accordance with s.
NR 110.15 (4) (c).
NR 110.14(2)(b)3.
3. Where possible, the pumping rate shall be designed to approximate the peak hour influent design flow rate to the lift station. For main lift stations or lift stations associated with treatment facilities, or in cases where large fluctuations of flow are known to occur, the use of variable speed pumps, or multiple constant speed pumps may be required by the department.
NR 110.14(3)(a)
(a) Type. Sewage lift stations in general use fall into 7 types: wet well/dry well, submersible, suction lift, screw pump, pneumatic ejector, grinder pump and septic tank effluent pump.
NR 110.14(3)(b)1.1. Dry wells, including their superstructure, shall be completely separated from wet wells. Common walls shall be gas tight.
