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. NR 151.24(5)(d)8.8. Areas where contaminants of concern, as defined in s. NR 720.03 (2), are present in the soil through which infiltration will occur. NR 151.24(5)(d)9.9. Any area where the soil does not exhibit one of the following characteristics between the bottom of the infiltration system and seasonal high groundwater and top of bedrock: NR 151.24(5)(d)9.c.c. Where the soil medium within the infiltration system does not provide an equivalent level of protection. NR 151.24 NoteNote: The areas listed in par. (d) are prohibited from infiltrating runoff due to the potential for groundwater contamination.
NR 151.24(5)(e)(e) Transportation facilities located in the following areas and otherwise subject to the requirements of this subchapter are not required to meet the requirements of this subsection: NR 151.24(5)(e)1.1. Areas where the infiltration rate of the soil is less than 0.6 inches/hour measured at the bottom of the infiltration system. NR 151.24(5)(e)2.2. Parking areas and access roads less than 5,000 square feet for commercial and industrial development. NR 151.24(5)(e)5.5. Infiltration areas during periods when the soil on the site is frozen. NR 151.24(5)(e)6.6. Roads in commercial, industrial and institutional land uses, and arterial residential roads. NR 151.24(5)(f)(f) Where alternate uses of runoff are employed, such as for toilet flushing, laundry or irrigation, such alternate use shall be given equal credit toward the infiltration volume required by this subsection. NR 151.24(5)(g)1.1. Infiltration systems designed in accordance with this subsection shall, to the extent technically and economically feasible, minimize the level of pollutants infiltrating to groundwater and shall maintain compliance with the preventive action limit at a point of standards application in accordance with ch. NR 140. However, if site specific information indicates that compliance with a preventive action limit is not achievable, then the infiltration BMP may not be installed or shall be modified to prevent infiltration to the maximum extent practicable. NR 151.24(5)(g)2.2. Notwithstanding subd.1., the discharge from BMPs shall remain below the enforcement standard at the point of standards application. NR 151.24(6)(a)(a) In this subsection, “protective area” means an area of land that commences at the top of the channel of lakes, streams and rivers, or at the delineated boundary of wetlands, and that is the greatest of the following widths, as measured horizontally from the top of the channel or delineated wetland boundary to the closest impervious surface. However, in this paragraph, “protective area” does not include any area of land adjacent to any stream enclosed within a pipe or culvert, such that runoff cannot enter the enclosure at this location. NR 151.24(6)(a)1.1. For outstanding resource waters and exceptional resource waters, and for wetlands in areas of special natural resource interest as specified in s. NR 103.04, 75 feet. NR 151.24(6)(a)2.2. For perennial and intermittent streams identified on a United States geological survey 7.5-minute series topographic map, or a county soil survey map, whichever is more current, 50 feet. NR 151.24(6)(a)4.4. For highly susceptible wetlands, 50 feet. Highly susceptible wetlands include the following types: fens, sedge meadows, bogs, low prairies, conifer swamps, shrub swamps, other forested wetlands, fresh wet meadows, shallow marshes, deep marshes and seasonally flooded basins. Wetland boundary delineation shall be made in accordance with s. NR 103.08 (1m). This paragraph does not apply to wetlands that have been completely filled in accordance with all applicable state and federal regulations. The protective area for wetlands that have been partially filled in accordance with all applicable state and federal regulations shall be measured from the wetland boundary delineation after fill has been placed. NR 151.24(6)(a)5.5. For less susceptible wetlands, 10% of the average wetland width, but no less than 10 feet nor more than 30 feet. Less susceptible wetlands include degraded wetlands dominated by invasive species such as reed canary grass. NR 151.24(6)(a)6.6. In subds. 1., 4. and 5., determinations of the extent of the protective area adjacent to wetlands shall be made on the basis of the sensitivity and runoff susceptibility of the wetland in accordance with the standards and criteria in s. NR 103.03. NR 151.24(6)(a)7.7. For concentrated flow channels with drainage areas greater than 130 acres, 10 feet. NR 151.24(6)(b)1.1. Beginning with land acquired within a protective area for a transportation facility on or after October 1, 2002, no impervious surface of a transportation facility may be constructed within a protective area, unless the transportation facility authority determines, in consultation with the department, that there is no practical alternative. If there is no practical alternative to locating a transportation facility within a protective area, the transportation facility may be constructed in the protective area only to the extent the transportation facility authority, in consultation with the department, determines is reasonably necessary, and the transportation facility authority shall state in the design plan prepared pursuant to s. NR 151.22 (1) (a), why it is necessary to construct the transportation facility within a protective area. NR 151.24(6)(b)2.2. If a transportation facility is constructed within a protective area, adequate sod or self-sustaining vegetative cover of 70% or greater shall be established and maintained in the area that is the width of the protective area, or the greatest width practical, and throughout the length of the protective area in which the transportation facility is located. The adequate sod or self-sustaining vegetative cover required under this paragraph shall be sufficient to provide for bank stability, maintenance of fish habitat and filtering of pollutants from upslope overland flow areas under sheet flow conditions. Non-vegetative materials, such as rock riprap, may be employed on the bank as necessary to prevent erosion such as on steep slopes or where high velocity flows occur.
