NR 151.23(4)(4) Pre-January 1, 2011 requirements. The design plan required under sub. (3) shall include the following: NR 151.23(4)(a)(a) BMPs that, by design, achieve, to the maximum extent practicable, a reduction of 80% of the sediment load carried in runoff, on an average annual basis, as compared with no sediment or erosion controls, as specified in s. NR 151.22 (1) (a) or (3), until the construction site has undergone final stabilization. No person shall be required to exceed an 80% sediment reduction to meet the requirements of this paragraph. Erosion and sediment control BMPs may be used alone or in combination and shall be installed according to any associated implementation plan to meet the requirements of this paragraph. Credit toward meeting the sediment reduction shall be given for limiting the duration or area, or both, of land disturbing construction activity, or other appropriate mechanism. NR 151.23 NoteNote: Soil loss prediction tools that estimate the sediment load leaving the construction site under varying land and management conditions, or methodology identified in subch. V., may be used to calculate sediment reduction.
NR 151.23(4)(b)(b) Notwithstanding par. (a), if BMPs cannot be designed and implemented to reduce the sediment load by 80%, based on an average annual rainfall, the design plan shall include a written and site-specific explanation why the 80% reduction goal is not attainable and the sediment load shall be reduced to the maximum extent practicable. NR 151.23(4)(c)(c) Where appropriate, the design plan shall include sediment controls to do all of the following to the maximum extent practicable: NR 151.23(4)(c)1.1. Prevent tracking of sediment from the construction site onto roads and other paved surfaces. NR 151.23(4)(c)3.3. Protect the separate storm drain inlet structure from receiving sediment. NR 151.23(4)(d)(d) The use, storage and disposal of chemicals, cement and other compounds and materials used on the construction site shall be managed during the construction period to prevent their transport by runoff into waters of the state. However, projects that require the placement of these materials in waters of the state, such as constructing bridge footings or BMP installations, are not prohibited by this paragraph. NR 151.23(4m)(4m) Post-January 1, 2011 requirements. The design plan required under sub. (3) shall meet all of the following: NR 151.23(4m)(a)(a) Erosion and sediment control practices. Erosion and sediment control practices at each site where land disturbing construction activity is to occur shall be used to prevent or reduce all of the following: NR 151.23(4m)(a)2.2. The discharge of sediment from disturbed areas into on-site storm water inlets. NR 151.23(4m)(a)3.3. The discharge of sediment from disturbed areas into adjacent waters of the state. NR 151.23(4m)(a)6.6. The discharge of sediment eroding from soil stockpiles existing for more than 7 days. NR 151.23(4m)(a)7.7. The discharge of sediment from erosive flows at outlets and in downstream channels. NR 151.23(4m)(a)8.8. The transport by runoff into waters of the state of chemicals, cement and other building compounds and materials on the construction site during the construction period. However, projects that require the placement of these materials in waters of the state, such as constructing bridge footings or BMP installations, are not prohibited by this subdivision. NR 151.23(4m)(a)9.9. The transport by runoff into waters of the state of untreated wash water from vehicle and wheel washing. NR 151.23 NoteNote: Wastewaters, such as from concrete truck washout, need to be properly managed to limit the discharge of pollutants to waters of the state. A separate permit may be needed from the department where a wastewater discharge has the potential to adversely impact waters of the state. The appropriate department regional wastewater specialist should be contacted to determine if wastewater permit coverage is needed where wastewater will be discharged to waters of the state.
NR 151.23(4m)(b)(b) Sediment performance standards. In addition to the erosion and sediment control practices under par. (a), the following erosion and sediment control practices shall be employed: NR 151.23(4m)(b)1.1. For transportation facility construction sites for which the department received a notice of intent for the construction project in accordance with subch. III of ch. NR 216 within 2 years after January 1, 2011, BMPs that, by design, achieve a reduction of 80 percent, or to the maximum extent practicable, of the sediment load carried in runoff, on an average annual basis, as compared with no sediment or erosion controls, until the construction site has undergone final stabilization. NR 151.23(4m)(b)2.2. For transportation facility construction sites for which the department received a notice of intent for the construction project in accordance with subch. III of ch. NR 216, 2 years or more after January 1, 2011, BMPs that, by design, discharge no more than 5 tons per acre per year, or to the maximum extent practicable, of the sediment load carried in runoff from initial grading to final stabilization. NR 151.23(4m)(b)3.3. The department may not require any person to employ more BMPs than are needed to meet a performance standard in order to comply with maximum extent practicable. Erosion and sediment control BMPs may be combined to meet the requirements of this paragraph. The department shall give credit toward meeting the sediment performance standard of this paragraph for limiting the duration or area, or both, of land disturbing construction activity, or for other appropriate mechanisms. NR 151.23(4m)(b)4.4. Notwithstanding subd. 1. or 2., if BMPs cannot be designed and implemented to meet the sediment performance standard, the plan shall include a written, site-specific explanation of why the sediment performance standard cannot be met and how the sediment load will be reduced to the maximum extent practicable. NR 151.23 NoteNote: The department of natural resources has developed guidance document no. 3800-2017-03 to assist with compliance with the 5 tons per acre sediment performance standard.
NR 151.23 NoteNote: In accordance with subch. V, the department has developed technical standards to help meet the construction site performance standards. These technical standards are available from the department at dnr.wi.gov.
NR 151.23(4m)(c)(c) Preventive measures. The plan shall incorporate all of the following: NR 151.23(4m)(c)1.1. Maintenance of existing vegetation, especially adjacent to surface waters, whenever possible. NR 151.23(4m)(c)3.3. Minimization of land disturbing construction activity on slopes of 20% or more. NR 151.23(5)(5) Location. BMPs shall be located so that treatment occurs before runoff enters waters of the state. NR 151.23 NoteNote: While regional treatment facilities are appropriate for control of post-construction pollutants, they should not be used for construction site sediment removal.
NR 151.23(6)(6) Implementation. The BMPs used to comply with this section shall be implemented as follows: NR 151.23(6)(a)(a) Erosion and sediment control practices shall be constructed or installed before land disturbing construction activities begin and in accordance with the plan developed under sub. (3). NR 151.23(6)(b)(b) Erosion and sediment control practices shall be maintained until final stabilization. NR 151.23(6)(c)(c) Final stabilization activity shall commence when land disturbing activities cease and final grade has been reached on any portion of the site. NR 151.23(6)(d)(d) Temporary stabilization activity shall commence when land disturbing construction activities have temporarily ceased and will not resume for a period exceeding 14 calendar days. NR 151.23(6)(e)(e) BMPs that are no longer necessary for erosion and sediment control shall be removed by the responsible party. NR 151.23 HistoryHistory: CR 00-027: cr. Register September 2002 No. 561, eff. 10-1-02; CR 09-112: am. (title), (1), (3) (a), (4) (title), (5), cr. (2) (cm), (4m), (6) Register December 2010 No. 660, eff. 1-1-11. NR 151.24NR 151.24 Post–construction performance standard. NR 151.24(1)(1) Applicability. This section applies to a transportation facility that is or was subject to the construction performance standards of s. NR 151.23, except any of the following: NR 151.24(1)(a)(a) A transportation construction site where the department has received a notice of intent for the construction project in accordance with subch. III of ch. NR 216 within 2 years after October 1, 2002. NR 151.24(1)(b)(b) A transportation facility construction site that has undergone final stabilization within 2 years after October 1, 2002. NR 151.24(1)(bm)(bm) A transportation post-construction site for which the department received a notice of intent for the construction project in accordance with subch. III of ch. NR 216 on or after January 1, 2011. Transportation post-construction sites for which the department received a notice of intent for the construction project, in accordance with subch. III of ch. NR 216, on or after January 1, 2011, shall meet the performance standards of ss. NR 151.242 to 151.249. NR 151.24(1)(d)(d) Minor reconstruction of a highway. Notwithstanding the exemption under this paragraph, the protective areas requirements in sub. (6) apply to minor reconstruction of a highway. NR 151.24(1)(e)(e) A redevelopment transportation facility with no increase in exposed parking lots or roads. NR 151.24(1)(f)(f) A transportation facility with less than 10% connected imperviousness based on complete development of the transportation facility, provided the cumulative area of all parking lots and rooftops is less than one acre. NR 151.24 NoteNote: Projects that consist of only the construction of bicycle paths or pedestrian trails generally meet this exception as these facilities have minimal connected imperviousness.
NR 151.24(1)(h)(h) A transportation facility, the construction of which involves activity described in s. NR 151.23 (1) (a) 2. but that has less than one acre of land disturbing construction activity. NR 151.24(1)(i)(i) Transportation facility construction projects that are part of a larger common plan of development, such as a residential or industrial development, that are in compliance with the performance standards of subch. III. NR 151.24(1)(j)(j) Routine maintenance for transportation facilities if performed to maintain the original line and grade, hydraulic capacity or original purpose of the facility. NR 151.24(2)(2) Plan. A written plan shall be developed and implemented for each transportation facility and shall incorporate the requirements of subs. (3) to (10). NR 151.24(3)(3) Total suspended solids. Best management practices shall be designed, installed and maintained to control total suspended solids carried in runoff from the transportation facility as follows: NR 151.24(3)(a)(a) For new transportation facilities, by design, reduce to the maximum extent practicable, the suspended solids load by 80%, based on an average annual rainfall, as compared to no runoff management controls. No person shall be required to exceed an 80% total suspended solids reduction to meet the requirements of this paragraph. NR 151.24(3)(b)(b) For highway reconstruction and non-highway redevelopment, by design, reduce to the maximum extent practicable, the total suspended solids load by 40%, based on an average annual rainfall, as compared to no runoff management controls. No person shall be required to exceed a 40% total suspended solids reduction to meet the requirements of this paragraph. NR 151.24(3)(c)(c) Notwithstanding pars. (a) and (b), if the design cannot achieve the applicable total suspended solids reduction specified, the design plan shall include a written and site-specific explanation why that level of reduction is not attained and the total suspended solids load shall be reduced to the maximum extent practicable. NR 151.24 NoteNote: Pollutant loading models such as SLAMM, P8 or equivalent methodology may be used to evaluate the efficiency of the design in reducing total suspended solids. Information on how to access SLAMM and P8 is available from the storm water coordinator in the runoff management section of the bureau of watershed management at dnr.wi.gov.
NR 151.24(4)(a)(a) By design, BMPs shall be employed to maintain or reduce the peak runoff discharge rates, to the maximum extent practicable, as compared to pre-development site conditions for the 2-year, 24-hour design storm applicable to the transportation facility. Pre-development conditions shall assume “good hydrologic conditions” for appropriate land covers as identified in TR-55 or an equivalent methodology. The meaning of “hydrologic soil group” and “runoff curve number” are as determined in TR-55. However, when pre-development land cover is cropland, rather than using TR-55 values for cropland, the runoff curve numbers in Table 2 of subch. III shall be used. NR 151.24 NoteNote: The curve numbers in Table 2 represent mid-range values for soils under a good hydrologic condition where conservation practices are used and are selected to be protective of the resource waters.
NR 151.24(4)(b)1.1. A transportation facility where the change in hydrology due to development does not increase the existing surface water elevation at any point within the downstream receiving surface water by more than 0.01 of a foot for the 2-year, 24-hour storm event. NR 151.24 NoteNote: Hydraulic models such as HEC-RAS or another methodology may be used to determine the change in surface water elevations.
NR 151.24(4)(b)3.3. A transportation facility that is part of a redevelopment project. NR 151.24 NoteNote: The intent of sub. (4) is to minimize streambank erosion under bank full conditions.
NR 151.24(5)(a)(a) Except as provided in pars. (d) to (g), BMPs shall be designed, installed and maintained to infiltrate runoff to the maximum extent practicable in accordance with one of the following: NR 151.24(5)(a)1.1. Infiltrate sufficient runoff volume so that the post-development infiltration volume shall be at least 60% of the pre-development infiltration volume, based on an average annual rainfall. However, when designing appropriate infiltration systems to meet this requirement, no more than 2% of the project site is required as an effective infiltration area. NR 151.24(5)(a)2.2. Infiltrate 10% of the post-development runoff volume from the 2-year, 24-hour design storm with a type II distribution. Separate curve numbers for pervious and impervious surfaces shall be used to calculate runoff volumes and not composite curve numbers as defined in TR-55. However, when designing appropriate infiltration systems to meet this requirement, no more than 2% of the project site is required as an effective infiltration area. NR 151.24 NoteNote: A model that calculates runoff volume, such as SLAMM, P8 or an equivalent methodology may be used. Information on how to access SLAMM and P8 is available from the storm water coordinator in the runoff management section of the bureau of watershed management at dnr.wi.gov.
NR 151.24(5)(c)(c) Before infiltrating runoff, pretreatment shall be required for parking lot runoff and for runoff from new road construction in commercial, industrial and institutional areas that will enter an infiltration system. The pretreatment shall be designed to protect the infiltration system from clogging prior to scheduled maintenance and to protect groundwater quality in accordance with par. (g). Pretreatment may include, but is not limited to, oil/grease separation, sedimentation, biofiltration, filtration, swales or filter strips. NR 151.24 NoteNote: To minimize potential groundwater impacts it is desirable to infiltrate the cleanest runoff. To achieve this, a design may propose greater infiltration of runoff from low pollutant sources such as roofs, and less from higher pollutant source areas such as parking lots.
NR 151.24(5)(d)(d) The following are prohibited from meeting the requirements of this subsection: NR 151.24 NoteNote: Runoff from tier 2 parking and rooftop areas may be infiltrated but may require pretreatment.
NR 151.24(5)(d)4.4. Areas within 1000 feet upgradient or within 100 feet downgradient of karst features. NR 151.24(5)(d)5.5. Areas with less than 3 feet separation distance from the bottom of the infiltration system to the elevation of seasonal high groundwater or the top of bedrock. NR 151.24(5)(d)6.6. Areas with runoff from industrial, commercial and institutional parking lots and roads and residential arterial roads with less than 5 feet separation distance from the bottom of the infiltration system to the elevation of seasonal high groundwater or the top of bedrock. NR 151.24(5)(d)7.7. Areas within 400 feet of a community water system well as specified in s. NR 811.16 (4) or within 100 feet of a private well as specified in s. NR 812.08 (4) for runoff infiltrated from commercial, industrial and institutional land uses or regional devices for residential development.
