Details of all sewer appurtenances such as manholes, lampholes, inspection chambers, inverted siphons and elevated sewers.
NR 110.10 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.
Facilities plans for sewage lift stations.
The facilities plan shall include the following:
(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.
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.
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
(d) Basis for design.
The design data for the proposed project including the following:
Per capita sewage contribution expressed as an average and as a maximum value;
(e) Essential features.
A description of the essential features of construction and operation of the proposed stations.
Discussion of the estimated capital costs, estimated annual maintenance cost, and estimated annual cost to the average user of the system;
(g) Environmental assessment.
The department may require the submittal of an environmental assessment 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.
(2) Construction plans and specifications for sewage lift stations.
In addition to the requirements of ch. NR 108
and ss. NR 110.06
, the following requirements shall be adhered to for submission of construction plans and specifications for sewage lift stations:
(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;
(b) Detailed plans.
The detailed lift station plans shall show the following, where applicable:
The location and the topography (using a contour map) of the property to be used;
The station details and all appurtenant equipment including pumps, sump pumps, heaters, ventilation equipment, valving, access ladder, intermediate landings, and wet well;
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
Cr. Register, November, 1974, No. 227
, eff. 12-1-74; r. and recr. Register, December, 1978, No. 276
, eff. 1-1-79.
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
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.
Extensions to existing sewage collection systems may be designed assuming an average design flow rate of 378 liters (100 gallons) per capita per day.
(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:
250% of the average design flow for interceptors, main (trunk) sewers, and sewage outfall pipes; or,
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.
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
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)
Cross-connections with public and private water supply systems are prohibited.
Conventional gravity sewer may not be less than 20 centimeters (8 inches) in diameter.
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.
Sewers shall be designed deep enough to prevent freezing and, where economically feasible, to provide gravity basement drainage for sanitary wastes.
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.
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.
Sewers with diameters less than 91 centimeters (36 inches) shall be laid with straight alignment between manholes.
The department may approve curvilinear sewers with diameters of 91 centimeters (36 inches) or larger on a case-by-case basis.
(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.
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.
Sewers on slopes of 20% or greater shall be anchored securely with concrete anchors or the equivalent, spaced as follows:
Not over 11 meters (36 feet) center to center on grades 20% to 35%;
Not over 7.3 meters (24 feet) center to center on grades 35% to 50%; and
Not over 4.9 meters (16 feet) center to center on grades greater than 50%.
(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.
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.
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.
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.
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.
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.
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.
Manhole spacing for sewers with a diameter greater than 76 centimeters (30 inches) shall be determined on a case-by-case basis.
(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.
The minimum diameter of manholes shall be 1.1 meters (42 inches).
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.
(f) Flow channel.
The flow channel through manholes shall be made to conform to the shape and slope of the sewers.
(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.
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).
(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.
(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.
(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.
All material used for sanitary sewer construction shall be free from defects that impair service.
Each length of pipe and fitting used in a sanitary sewer shall be stamped or indelibly marked with the manufacturer's name or mark.
(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.
(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: