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 110.12NR 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 NoteNote: 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 110.13(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)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)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.