Wisconsin Legislature: SPS 382.35(5)(a)2.c.

d. The distance from a manhole to a cleanout located upstream is not more than 300 feet.

2. Private interceptor main sewers 6″ or larger in diameter shall be provided with a manhole at:

a. The most upstream point of the private interceptor main sewer;

b. Every horizontal change in direction of more than 45 degrees where the change in direction is created within a distance of less than 10 feet,

c. Every change in pipe diameter where both connections are 6 inches or larger, and

d. Intervals of not more than 400 feet.

(e) Junction of building drain and building sewer. A cleanout shall be provided near the junction of a building drain and a building sewer.

1. The cleanout shall be located within 5 feet of where the building drain and the building sewer connect. The cleanout may be located either inside or outside the building.

2. A cleanout in a drain stack may serve as the cleanout at the junction of the building drain and building sewer, if the stack is within 5 feet of where the building drain and building sewer connect.

(f) Stacks. Where a cleanout is provided in a drain stack, the cleanout shall be located not more than 60 inches above the lowest floor penetrated by the stack.

(g) Branches.

1. Except as provided in subd. 2., cleanouts shall be provided in connection with batteries of fixtures at such points that all parts of the branch drain may be accessible for cleaning or removal of stoppages. For the purposes of this requirement, removable fixture traps may serve as cleanout openings.

2. A cleanout shall not be required for a branch drain when the fixtures on the branch include one floor outlet fixture and any fixtures discharging into an accompanying wet vent.

(h) Greasy wastes. Drain pipes carrying greasy wastes shall be provided with cleanouts located not more than 40 feet apart and at all changes in direction of more than 45°.

(i) Double sanitary tees. A cleanout shall be provided immediately above or below a double sanitary tee drain fitting which is installed in a vertical drain pipe of less than 3” in diameter, unless a stack cleanout is provided in accordance with par. (f).

(j) Traps and fixture drains.

1. All traps shall be constructed or installed so that stoppages may be removed from the traps and the horizontal portions of fixture drains.

2. If a trap is not accessible for removal or does not contain a removable dip, a cleanout or a removable inlet shall be installed to enable cleaning of the trap passageway and the horizontal portions of the fixture drain.

(k) Conductors. Where a cleanout is provided in a conductor, the cleanout shall be located 28 to 60” above the lowest floor penetrated by the conductor.

(L) Sampling manholes. Municipalities or sanitary sewage districts by ordinance or rule may require the installation of sampling manholes for periodic sewage monitoring.

Note: The installation of sampling manholes may be needed for the monitoring of industrial wastes under chs. NR 200 to 299. See ch. SPS 382 Appendix for further explanatory material.

(m) Catch basins and interceptors. The fixture drain from all interceptors designed in accordance with s. SPS 382.34 (4) (a) 2. shall be provided with an accessible cleanout located outside of the basin and not more than 15 inches from the weir of the trap.

(4) Direction of flow. Every cleanout shall be installed so as to open in the direction of the waste flow or at a right angle thereto.

(5) Accessibility. Cleanout plugs shall not be covered with cement, plaster, or any other similar permanent finishing material.

(a) Underground piping. Cleanouts installed in underground drain piping shall be extended vertically to or above the finish grade.

1. All interior and exterior cleanouts where the vertical distance between the horizontal drain pipe being served and the top of the cleanout opening exceeds 18 inches in length, shall connect to the drain piping through a fitting as specified in Table 382.30–4.

2. A cleanout located outside of a building shall be provided with a frost sleeve.

a. The frost sleeve shall be of a material approved for building sewers in accordance with s. SPS 384.30 (2) (c).

b. Where a cleanout is located in an area subject to vehicular traffic the top of the frost sleeve shall terminate in a concrete pad at least 4” thick and extending at least 9” from the sleeve on all sides, sloping away from the sleeve.

c. The bottom of the frost sleeve shall terminate 6” to 12” above the top of the drain piping or at least 6” below the predicted frost depth in accordance with s. SPS 382.30 Table 382.30-6.

d. The frost sleeve shall have a removable watertight top of sufficient thickness and strength to sustain the weight of anticipated traffic.

Note: See ch. SPS 382 Appendix for further explanatory material.

(b) Concealed piping. Cleanout access for drain piping located in concealed spaces shall be provided by either extending the cleanout to at least the surface of a wall or floor or by providing access panels of a sufficient size to permit removal of the cleanout plug and proper cleaning of the pipe.

(6) Cleanout size.

(a) Cleanouts and cleanout extensions shall be sized in accordance with Table 382.35, except as provided in par. (b).

(b) The replacement or repair of a non-public 6-inch sanitary sewer may be served by an existing 4-inch extension within the building.

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(7) Prohibited use of cleanout openings. Cleanout openings shall not be used for the installation of fixtures or floor drains, except where another cleanout of equal access and capacity is provided.

(8) Manholes.

(a) Diameter. The minimum diameter of manholes shall be 42 inches. A manhole shall have a minimum access opening of 23 inches.

(b) Materials. Manholes shall be constructed of approved materials in accordance with ch. SPS 384 and in accordance with the design provisions of s. NR 110.13.

Note: The provisions of s. NR 110.13 regarding the manhole’s flow channel, watertightness, and drop pipe indicate the following specifications:

—The flow channel through manholes shall be made to conform to the shape and slope of the sewer.

—Solid watertight manhole covers are to 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 are to 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.

—An outside drop pipe is to be provided for a sewer entering a manhole where the invert elevation of the entering sewer is 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.

Note: See ch. SPS 382 Appendix for further explanatory material.

History: Cr. Register, February, 1985, No. 350, eff. 3-1-85; am. (3) (i), r. and recr. (3) (j), Register, May, 1988, No. 389, eff. 6-1-88; am. (5) (a) 2. a., Register, August, 1991, No. 428, eff. 9-1-91; r. and recr. (3) (j) and (5) (a) 2. c., Register, February, 1994, No. 458, eff. 3-1-94; CR 02-002: am. (3) (a) and (d) 1. (intro.), renum. (3) (g) to be (3) (g) 1. and am., cr. (3) (g) 2. and (m), r. and recr. (5) (a) 1. Register April 2003 No. 568, eff. 5-1-03; CR 08-055: r. and recr. (3) (a), am. (3) (b) 2. a., b., (c) 2. a., b., (d) 2. b., c., (5) (a) 1. and Table 82.35 Register February 2009 No. 638, eff. 3-1-09; correction in (2), (3) (m), (5) (a) 1., 2. a., c., (6), (8) (b) made under s. 13.92 (4) (b) 7., Stats., Register December 2011 No. 672; CR 23-006: am. (3) (a) (intro.), (f), r. and recr. (6), am. (8) (a) Register September 2023 No. 813, eff. 10-1-23.; correction in (6) (b) made under s. 35.17, Stats, Register September 2023 No. 813.

SPS 382.36 Stormwater and clearwater plumbing systems.

(1) Scope. The provisions of this section set forth the requirements for the design, installation and maintenance of piping, conveyance, venting, detention and treatment of stormwater and clearwater in plumbing systems.

Note: Refer to ch. NR 151 for stormwater management requirements.

(2) Materials. All stormwater and clearwater plumbing systems shall be constructed of approved materials in accordance with s. SPS 384.30 (3).

(3) Design of stormwater plumbing systems.

(a) Plumbing systems upstream of detention shall be designed, at a minimum, based on the 10-year, 24-hour storm event.

(b) Plumbing detention systems and plumbing systems located downstream of detention shall be designed based on anticipated flows and volumes.

(d) Tank access shall comply with all the following:

1. Each compartment of a detention tank used for the reduction of total suspended solids shall be provided with a manhole opening. For compartments with multiple inlets or outlets a manhole or a cleanout, as determined under s. SPS 382.35 (6) Table 382.35, shall be provided at all additional inlets and outlets.

2. The distance between manhole openings serving the same compartment may not exceed 50 feet.

3. A manhole opening shall be not less than 23 inches in the least dimension.

4. A manhole shall terminate at or above ground surface and be of approved materials. Steel tanks shall have a minimum 2-inch collar for the manhole extensions permanently welded to the tank. The manhole extension on fiberglass tanks shall be of the same material as the tank and an integral part of the tank. The collar shall have a minimum height of 2 inches.

5. Manhole risers shall be provided with a substantial, fitted, watertight cover of concrete, steel, cast iron, or other approved material.

6. Manhole covers shall terminate at or above grade and shall have an approved locking device.

7. Tanks shall conform to provisions of s. SPS 384.25.

(e) Tank labeling shall comply with all the following:

1. Covers for all tank openings larger than 8 inches in diameter shall be provided with a permanent warning label indicating the dangers of entering the tank, in accordance with this paragraph.

2. The warning label shall be securely attached and made of a noncorrosive metal or plastic bearing the legend “DO NOT ENTER WITHOUT PROPER EQUIPMENT” or “DANGEROUS GASES EXIST IN TANK” or similar language.

3. The label shall be rectangular in shape with minimum dimensions of 4 by 5 inches.

4. The wording on the label shall be a minimum of 1/2 inch in height and be either indented or raised.

Note: For a listing of best management practices (BMPs) refer to ch. SPS 382 Appendix A-382.36 (3)-1.

Note: Where local discharge requirements are more stringent, stormwater plumbing systems may provide detention and treatment to comply with the local stormwater management plan.

(4) Discharge and connections.

(a) Discharge points. The discharge points for stormwater and clearwater shall be as specified in Table 382.38-1.

(b) Segregation of wastewater.

1. Except as provided in subd. 2., stormwater or clearwater piping may not connect to a sanitary drain system.

2. Where a combined sanitary-storm sewer system is available, stormwater, clearwater and sanitary wastewater may be combined in the building sewer.

3. Stormwater gravity drains shall not be combined with clearwater drains prior to discharging to the storm building drain except where approved by the department.

Note: See also Table SPS 382.38-1 which limits clearwater discharges to sanitary sewer at 50 gpd.

Note: For the use of stormwater or reuse of clearwater, refer to the appropriate requirements in ss. SPS 382.30, 382.34, 382.40, 382.41, 382.70 and this section.

Note: For further explanatory material regarding the rational method, other methods and runoff co-efficients, see ch. SPS 382 Appendix A-382.36 (4).

(5) Input calculations.

(a) Peak flow. The peak flow of stormwater influent to a plumbing system shall be calculated using any of the following methods:

1. ‘Area method.’ For sizing of conveyance piping, when calculating stormwater peak flow based on the tributary area, the area in square feet shall be divided by the following applicable divisors:

a. For roofs the divisor is 26 square feet/gpm.

b. For paved or graveled ground surfaces the divisor is 32.5 square feet/gpm.

c. For lawns, parks and similar land surfaces the divisor is 104 square feet/gpm.

Note: For example, 10,000 square feet of roof area/26 square feet/gpm = 385 gpm or 0.85 cubic feet/second.

2. ‘Rational method.’ For calculating peak flow, the intensity shall be determined using the time of concentration for the tributary area.

Note: For the equation procedure for runoff coefficients for use with the rational method, refer to ch. SPS 382 Appendix A-382.36 (5)-1.

3. ‘Engineering analysis method.’ An engineering analysis shall be based on an analysis provided by a Wisconsin registered architect, registered professional engineer, or permitted designer of engineering systems - plumbing, or an approved alternate standard per s. SPS 381.20 (2) based on the peak flow calculated in accordance with sub. (3) (a).