(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:
(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.
(b) A transportation facility
construction site that has undergone final stabilization within 2 years after
October 1, 2002.
(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.
(c) Reconditioning or resurfacing of a
highway.
(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.
(e) A redevelopment
transportation facility with no increase in exposed parking lots or
roads.
(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.
Note: Projects that consist of only the
construction of bicycle paths or pedestrian trails generally meet this
exception as these facilities have minimal connected
imperviousness.
(g)
Protective area requirements under sub. (6) do apply to actions described in s.
NR 151.20(2).
(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.
(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.
(j) Routine maintenance for transportation
facilities if performed to maintain the original line and grade, hydraulic
capacity or original purpose of the facility.
(2) PLAN. A written plan shall be developed
and implemented for each transportation facility and shall incorporate the
requirements of subs. (3) to (10).
(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:
(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.
(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.
(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.
Note: 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.
(4) PEAK DISCHARGE.
(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.
Note: 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.
(b) This subsection
does not apply to:
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.
Note: Hydraulic models such as HEC-RAS or
another methodology may be used to determine the change in surface water
elevations.
2. A highway
reconstruction site.
3. A
transportation facility that is part of a redevelopment project.
Note: The intent of sub. (4) is to minimize
streambank erosion under bank full conditions.
(5) INFILTRATION.
(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:
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.
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.
(b) Pre-development condition shall be the
same as specified in sub. (4) (a).
Note: 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.
(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.
Note: 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.
(d) The following are
prohibited from meeting the requirements of this subsection:
1. Areas associated with tier 1 industrial
facilities identified in s.
NR 216.21(2)
(a), including storage, loading, rooftop and
parking.
2. Storage and loading
areas of tier 2 industrial facilities identified in s.
NR 216.21(2)
(b).
Note: Runoff from tier 2 parking and rooftop
areas may be infiltrated but may require pretreatment.
3. Fueling and vehicle maintenance
areas.
4. Areas within 1000 feet
upgradient or within 100 feet downgradient of karst features.
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.
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.
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.
8. Areas
where contaminants of concern, as defined in s.
NR 720.03(2), are present in the soil
through which infiltration will occur.
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:
a. At least a 3-foot soil layer with 20%
fines or greater.
b. At least a
5-foot soil layer with 10% fines or greater.
c. Where the soil medium within the
infiltration system does not provide an equivalent level of protection.
Note: The areas listed in par. (d) are
prohibited from infiltrating runoff due to the potential for groundwater
contamination.
(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:
1. Areas where the infiltration rate of the
soil is less than 0.6 inches/hour measured at the bottom of the infiltration
system.
2. Parking areas and access
roads less than 5,000 square feet for commercial and industrial
development.
3. Redevelopment
post-construction sites.
4. In-fill
development areas less than 5 acres.
5. Infiltration areas during periods when the
soil on the site is frozen.
6.
Roads in commercial, industrial and institutional land uses, and arterial
residential roads.
7.
Highways.
(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.
(g)
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.
2. Notwithstanding
subd.1., the discharge from BMPs shall remain below the enforcement standard at
the point of standards application.
(6) PROTECTIVE AREAS.
(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.
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.
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.
3. For lakes, 50 feet.
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.
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.
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.
7.
For concentrated flow channels with drainage areas greater than 130 acres, 10
feet.
(b)
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.
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.
Note: It is recommended that seeding of
non-aggressive vegetative cover be used in the protective areas. Vegetation
that is flood and drought tolerant and can provide long-term bank stability
because of an extensive root system is preferable. Vegetative cover may be
measured using the line transect method described in the university of
Wisconsin-extension publication number A3533, titled "Estimating Residue Using
the Line Transect Method".
3. Best management practices such as filter
strips, swales or wet detention basins, that are designed to control pollutants
from nonpoint sources may be located in the protective width area.
Note: Other regulations, such as ch. 30,
Stats., and chs.
NR 103, 115, 116 and 117 and their
associated review and approval process may apply in the protective
area.
4. This subsection
does not apply to:
a. Non-highway
transportation redevelopment sites.
b. Transportation facilities that cross or
access surface waters, such as boat landings, bridges and culverts.
c. Structures constructed in accordance with
s.
59.692(1v),
Stats.
d. Transportation facilities
from which runoff does not enter the surface water, except to the extent that
vegetative ground cover is necessary to maintain bank stability.
Note: A vegetated protective area to filter
runoff pollutants from transportation facilities described in subd. 4. d. is
not necessary since runoff is not entering the surface water at that location.
Other practices necessary to meet requirements of this section, such as a swale
or basin, will need to be designed and implemented to reduce runoff pollutants
prior to runoff entering a surface water of the state.
(7) FUELING
AND VEHICLE MAINTENANCE AREAS. Fueling and vehicle maintenance areas shall, to
the maximum extent practicable, have BMPs designed, installed and maintained to
reduce petroleum within runoff, such that the runoff that enters waters of the
state contains no visible petroleum sheen.
Note: A combination of the following BMPs may
be used: oil and grease separators, canopies, petroleum spill cleanup
materials, or any other structural or non-structural method of preventing or
treating petroleum in runoff.
(8) LOCATION. To comply with the standards
required under this section, BMPs may be located on-site or off-site as part of
a regional storm water device, practice or system, but shall be installed in
accordance with s.
NR 151.003.
(9) TIMING. The BMPs required under this
section shall be installed before the construction site has undergone final
stabilization.
(10) SWALE
TREATMENT.
(a)
Applicability. Except as provided in par. (b), transportation
facilities that use swales for runoff conveyance and pollutant removal meet all
of the requirements of this section, if the swales are designed to the maximum
extent practicable to do all of the following:
1. Be vegetated. However, where appropriate,
non-vegetative measures may be employed to prevent erosion or provide for
runoff treatment, such as rock riprap stabilization or check dams.
Note: It is preferred that tall and dense
vegetation be maintained within the swale due to its greater effectiveness at
enhancing runoff pollutant removal.
2. Carry runoff through a swale for 200 feet
or more in length that is designed with a flow velocity no greater than 1.5
feet per second for the peak flow generated using either a 2-year, 24-hour
design storm or a 2-year design storm with a duration equal to the time of
concentration as appropriate. If a swale of 200 feet in length cannot be
designed with a flow velocity of 1.5 feet per second or less, the flow velocity
shall be reduced to the maximum extent practicable.
Note: Check dams may be included in the swale
design to slow runoff flows and improve pollutant removal. Transportation
facilities with continuous features such as curb and gutter, sidewalks or
parking lanes do not comply with the design requirements of this subsection.
However, a limited amount of structural measures such as curb and gutter may be
allowed as necessary to account for other concerns such as human safety or
resource protection.
(b)
Exemptions.
1. Notwithstanding par. (a), the department
may, consistent with water quality standards, require other provisions of this
section, in addition to swale treatment, be met on a transportation facility
with an average daily traffic rate greater than 2500 and where the initial
surface water of the state that the runoff directly enters is any of the
following:
a. An outstanding resource
water.
b. An exceptional resource
water.
c. Waters listed in section
303 (d) of the federal clean water act that are identified as impaired in whole
or in part, due to nonpoint source impacts.
d. Waters where targeted performance
standards are developed pursuant to s.
NR 151.004.
2. The transportation facility authority
shall contact the department's regional storm water staff or the department's
liaison to the department of transportation to determine if additional BMPs
beyond a water quality swale are needed under this paragraph.
