HomeMy WebLinkAboutSD-23-10 - Supplemental - 0255 Kennedy Drive (43)Version: 4/28/2017 Project Name:
Response Attachment location
1
Plan Sheet C‐8
2
Plan Sheet C‐8
Attachment Location
Plan Sheet C‐7
Plan Sheet C‐8
Response Attachment location
5 Plan Sheet C‐8
6 Plan Sheet C‐8
7 Plan Sheet C‐8
8 Plan Sheet C‐8
9
NA
Response Attachment location
Option 1: Leave undisturbed native vegetation and soil, and protect from
compaction during construction.
Option 2: Amend existing site topsoil or subsoil in place.
Option 3: Remove and stockpile existing topsoil during grading.
Option 4: Import topsoil mix, or other materials for mixing, including compost, of
sufficient organic content and depth.
Is compost or other materials used to amend soils specified to have a C:N ratio
below 25:1?
Is it specified that compost shall meet the definition of ʺcompostʺ or meet the
contaminant standards in the Vermont Solid Waste Management Rules?
If Exceptional Quality (EQ) biosolids are used as a soil amendment, do they
comprise no more than 35% of the total volume of soil, and is it specifed that
they be well mixed before or during application?
Vegetation and Landscaping (3.3)
Hillside @ OʹBrien Farm
Does the site layout retain the duff layer and native topsoil in an undisturbed
state to the maximum extent practicable?
Is the organic matter content of the topsoil layer specified to be at least 4%?
4
Feasibility (3.1)
Have all areas that will not be disturbed and areas exempt from the Standard,
including the reason for the exemtion, been identified on a plan sheet?
Have all areas of disturbance within the site that are subject to the Post‐
Construction Soil Depth and Quality Standard been identified on a plan sheet?
This includes all disturbed areas on slopes ≤ 33% which are not covered by an
impervious surface, part of a structural stormwater treatment practice, or
engineered as structural fill once development is complete.
Which of the following methods are utilized to meet soil quality requirements for this site?
Post‐Construction Soil Depth and Quality Standard
3
Is the minimum topsoil depth specified as:
4 inches
The depth of the 0 and A horizons on the NRCS Official Soil Series Description of
the native mapped soils (provide documentation)
Treatment (3.2)
Yes No
Yes No
Yes No
Yes No
Yes No
Yes No
Yes No
Page 1 of 2
10 Plan Sheet C‐8
11 Plan Sheet C‐8
12
Plan Sheet C‐8
13
Plan Sheet C‐8
14
Plan Sheet C‐8
15 Plan Sheet C‐8
Attachment location: Indicate the specific location (i.e. appendix, page, plan sheet) where the requisite support documentation has
been provided within the application.
Includes construction details and notes on the various methods the contractor
may use to meet he Standard?
Instructions to establish dense an vigorous vegeative cover over turf areas?
Does the application include a site‐specific plan for soil management that:
Includes a statement that soil depth and quality shall be established towards
the end of construction, and once established, be protected from compaction?
Identifies all areas on the site subject to the standard?
Includes instructions for contractor verification of the Standard, including a
sampling scheme that includes nine 8‐inch deep test holes per acre of area
subject to the Standard?
Instructions that test holes shall be excavated using only a shoven driven soley
by the inspectorʹs weight and shall be at least 50 feet apart from each other?
Yes No
Yes No
Yes No
Yes No
Yes No
Yes No
Page 2 of 2
Version: 11/30/2020 Project Name:
Discharge Point:
Treatment Wetland #
Practice Drainage Area
For Permit
Coverage
Not for Permit
Coverage
Total to
Practice
1 Total Area (acres)2.060 0.000
2.060
2 1.310 0.000
1.310
3 0.000 0.000
0.000
WQV for
credit
WQV not for
credit
Total
WQV
4 WQV to practice 0.1068 0.0000 0.1068 96
5 2
6 2
Response Attachment location
7 Plan Sheet C‐6
8 Detail Sheet D‐8
9 Plan Sheet C‐6
10 Detail Sheet D‐8
11*Detail Sheet D‐8
12*Detail Sheet D‐8
13*Detail Sheet D‐8
Response Attachment location
14 Forebay, Sheet C6
↑Enter this value on the Standards
Compliance Workbook
Is outlet elevation designed such that a sub‐surface water level is maintained
in the gravel wetland?
If the gravel wetland is designed with an organic soil layer at the surface, have
vertical perforated riser pipes been provided to deliver stormwater
stormwater from the surface down to the gravel bed?
Have the outfalls and the conveyance to the discharge point been designed
and protected to avoid erosion?
Practice Type
Redeveloped Impervious
Pre‐Treatment (4.3.6.3)
Has pretreatment been provided for non‐rooftop runoff?
Discharges to Cold or
Warm Water Fishery?
Modified CN for WQ
(1.0ʺ) storm
Note: Designers may use the Practice Drainage Area Runoff Calculator (second tab) for calculation of practice‐
specific runoff volumes for other treatment standards.
Conveyance (4.3.5.2)
Are inlets stabilized to ensure that non‐erosive conditions exist for at least the
1‐year, 24 hour storm?
* Questions preceded by an asterix (*) may change based on previously entered values
Have inlet pipes been set at the permanent pool or the base of the gravel bed?
New Impervious (acres)
Hillside @ OʹBrien Farm
4
1Treatment Wetlands (4.3.5)
Has a low for orifice been provided to meet the the WQV and CPV extended
Has a liner designed in accordance with Section 4.3.5.2 been provided if the
infiltration rate exceed 0.05 inches per hour and the wetland is located above
Yes No
Yes No
No
No
Yes
Yes
NoYes
Cold
Warm
NoYes
NoYes
NoYes
Shallow surface wetland
Gravel wetland
Page 1 of 4
15
Response Attachment location
16 ft3 1320
17 ft3 2050
18 ft3 3370
19*
20*
21 72.4%Yes
22
23
24
ac‐ft Enter this on the eNOI
Response Attachment location
25 N/A
26 N/A
27 Detail SheetD‐8
28 N/A
29 Detail SheetD‐8
30 N/A
Attachment location: Indicate the specific location (i.e. appendix, page, plan sheet) where the requisite support documentation has
been provided within the application.
What is the volume stored in the forebay or other volumetric pre‐
treatment if used? (minimum 10% WQV)
What is the volume stored in the permanent pool?
What is the total WQV stored at the normal water level (pre‐
treatment + permanent pool)?
Does the pre‐treatment volume plus the permanent pool equal at least 50% of
the WQV?
Has a planting plan been prepared showing how aquatic and terrestrial areas
will be stabilized, including plant species, plant locations, sources of plant
material and any required soil amendments?
Are any donor organic soils used in the practice obtained from a source other
than natural wetlands?
Is the remaining WQV provided for by extended detention over 24 hours?
Are all deep pool areas of ≥ 4 feet depth with side slopes steeper than 4:1 (H:V)
surrounded by a safety bench with ≤6% slope extending 10 feet outward from
the normal water edge to the toe of the side slope?
Landscaping (4.3.6.5)
Treatment (4.3.6.4)
Has a minimum flow path at normal water level of 3:1 been provided?
Does the planting plan specify that no woody vegetation >2 inches in diameter
shall be planted or allowed to grow on the dam, within 15 feet of the dam or
the toe of the embankment, or within 25 of a principal spillway outlet?
What type of pretreatment is being
used?
Has an aquatic been been provided that extends at least 5 feet inward from the
normal water edge and is no more than 18 inches deep?
Has a setback been provided that extends 25 feet from the maximum design
water surface elevation of the practice?
What is the Storage Volume of the practice. Include the permanent
pool and any volume used for providing extended detention.
Swale
Filter Strip
Forebay (10% WQv)
Deep Sump Catch Basins
Proprietary
NoYes
NoYes
NoYes
Yes No
NoYes
NoYes
NoYes
NoYes
NoYes
NoYes
Page 2 of 4
Practice Drainage Area Runoff Calculator Project Name:
Discharge Point:
Treatment Wetland #
Precipitation Data NOAA Atlas 14
Storm WQ Storm 1 yr, 24 hr 10 yr, 24 hr 100 yr, 24 hr
Precipitation (inches) 1.00 1.90 3.25 4.85
Drainage Area Information
Landuse A B C D
Grass 0.000 0.000 0.000 0.000 0.000
Meadow 0.000 0.000 0.000 0.000 0.000
Woods 1.030 1.030 0.000 0.000 2.060
Pavement, roofs, and
other impervious 0.000 0.000 0.000 0.000 0.000
Total 1.030 1.030 0.000 0.000 2.060
Landuse A B C D
Grass 0.375 0.375 0.000 0.000 0.750
Meadow 0.000 0.000 0.000 0.000 0.000
Woods 0.000 0.000 0.000 0.000 0.000
Pavement, roofs, and
other impervious 0.655 0.655 0.000 0.000 1.310
Total 1.030 1.030 0.000 0.000 2.060
TV of upstream practices:0.000 ac‐ft TV credit of this practice:0.000 ac‐ft
Treatment Standard
Required
Treatment
Volume
Post
Development
Runoff
Volume
Pre‐
development
Runoff
Volume
Post
Composite CN
(to practice)
CNAdj (with TV
practice
credit)
Pre
Composite
CN
Channel Protection
(Hydrologic Condition
Method)
0.1839 0.1846 0.0007 91 91 54
Overbank Flood 0.3211 0.3439 0.0228 88 88 50
Extreme Flood 0.4711 0.5490 0.0779 85 85 46
Information for Calculating TC by the Watershed Lag Method
1 yr 10 yr 100 yr
Time of Concentration, TC (min)Hydraulic
Length, l (ft)
Average
Catchment
Slope, Y (%)
Hillside @ OʹBrien Farm
4
1
Hydrologic Soil Group
Total (acres)
This tool may be used to calculate the required treatment volumes for the area draining to an individual practice
where the practices drainage area is only a portion of of the area draining to a discharge point. Where the practice
receives runoff from the entire area to a discharge point, this calculator will give the same information as the
Standards Compliance Workbook.
* Preciptation values shall be obtained from
Pre Development Land Use (acres)
Hydrologic Soil Group
Total (acres)
Post Development Land Use (acres)
Pre Development 5.00% 350.00 12.4 13.8 15.0
Post Development,
upstream of practice 5.00% 350.00 4.1 4.7 5.3
Post Development, with
TV credit from practice
0.00% 0.00 0.0 0.0 0.0
Practice Drainage Area Runoff Calculator Project Name:
Discharge Point:
Treatment Wetland #
Precipitation Data NOAA Atlas 14
Storm WQ Storm 1 yr, 24 hr 10 yr, 24 hr 100 yr, 24 hr
Precipitation (inches) 1.00 1.90 3.25 4.85
Drainage Area Information
Landuse A B C D
Grass 0.000 0.000 0.000 0.000 0.000
Meadow 0.000 0.000 0.000 0.000 0.000
Woods 3.530 3.530 0.000 0.000 7.060
Pavement, roofs, and
other impervious 0.000 0.000 0.000 0.000 0.000
Total 3.530 3.530 0.000 0.000 7.060
Landuse A B C D
Grass 1.360 1.360 0.000 0.000 2.720
Meadow 0.000 0.000 0.000 0.000 0.000
Woods 0.000 0.000 0.000 0.000 0.000
Pavement, roofs, and
other impervious 2.170 2.170 0.000 0.000 4.340
Total 3.530 3.530 0.000 0.000 7.060
TV of upstream practices:0.000 ac‐ft TV credit of this practice:0.000 ac‐ft
Treatment Standard
Required
Treatment
Volume
Post
Development
Runoff
Volume
Pre‐
development
Runoff
Volume
Post
Composite CN
(to practice)
CNAdj (with TV
practice
credit)
Pre
Composite
CN
Channel Protection
(Hydrologic Condition
Method)
0.6097 0.6121 0.0024 90 90 54
Overbank Flood 1.0658 1.1440 0.0782 87 87 50
Extreme Flood 1.5659 1.8329 0.2670 84 84 46
Information for Calculating TC by the Watershed Lag Method
1 yr 10 yr 100 yr
Time of Concentration, TC (min)Hydraulic
Length, l (ft)
Average
Catchment
Slope, Y (%)
Hillside @ OʹBrien Farm
4
2
Hydrologic Soil Group
Total (acres)
This tool may be used to calculate the required treatment volumes for the area draining to an individual practice
where the practices drainage area is only a portion of of the area draining to a discharge point. Where the practice
receives runoff from the entire area to a discharge point, this calculator will give the same information as the
Standards Compliance Workbook.
* Preciptation values shall be obtained from
Pre Development Land Use (acres)
Hydrologic Soil Group
Total (acres)
Post Development Land Use (acres)
Pre Development 7.30% 450.00 12.5 13.9 15.2
Post Development,
upstream of practice 7.30% 450.00 4.3 4.9 5.5
Post Development, with
TV credit from practice
0.00% 0.00 0.0 0.0 0.0
Version: 11/30/2020 Project Name:
Discharge Point:
Infiltration Practice #
Practice Drainage Area
For Permit
Coverage
Not for Permit
Coverage
Total to
Practice
1 Total Area (acres)24.150 0.000
24.150
2 8.030 0.000
8.030
3 0.000 0.000
0.000
WQV for
credit
WQV not for
credit
Total
WQV
4 WQV to practice 0.7029 0.0000 0.7029 91
5 0.6173
6
1
Response Attachment location
7 Existing Practice
8*Existing Practice
9 Existing Practice
10 Existing Practice
11 Existing Practice
12 Existing Practice
13*Existing Practice
0 1
Response Attachment location
Redeveloped Impervious
Design Volume for
Infiltration (TV)
Modified CN for WQ
(1.0ʺ) storm
Note: If the practice is designed to infiltrate the WQV, then TV = WQV. Designers may use the Practice Drainage Area
Runoff Calculator (second tab) for calculation of practice‐specific runoff volumes for other treatment standards.
Sizing of the filter bed area/swale bottom need to consider the desired treatment volume (see treatment section).
Some design requirements will change based on the size of storm the practice is designed to treat.
← Tv value to enter on the Standards Compliance Workbook for this
practice
Is the seasonal high groundwater table (SHGWT) separated at least three (3)
feet vertically from the bottom of the practice?
New Impervious (acres)
Hillside @ OʹBrien Farm
4
AInfiltration (4.3.3)
Feasibility (4.3.3.1)
Has the infiltration rate (fc) of the underlying soil been confirmed to be at least
0.2 inches per hour by the soil testing requirements in Section 4.3.3.2?
Practice Type
* Questions preceded by an asterix (*) may change based on previously entered values
Has a groundwater mounding analysis been performed if the practice is
designed to infiltrate >1 year storm and the SHGWT <4 feet?
1
Have the proper setback requirements for groundwater source protection been
observed? (Section 4.3.3.1)
Has the practice been placed so that it will not cause intrusion problems for
down‐gradient structures? (Section 4.3.3.1)
Is the site free from subsurface contamination or prior approval obtained from
the Agency? (If approval is required based on prior contamination, include
Conveyance (4.3.3.2)
Is the basin designed with side slopes of 2:1 or flatter?
Yes No
NoYes
NoYes
Infiltration Basin
Infiltration Trench
Infiltration Chambers
Drywell(s)
Yes No
Yes No
Yes No
Yes No
Page 1 of 2
14 Existing Practice
15 Existing Practice
16 Existing Practice
Response Attachment location
17 Wet Pond A/Forebays
18
≤ 2 in/hr Existing Practice
> 2 in/hr Existing Practice
20*Existing Practice
21*Existing Practice
2 TRUE
Response Attachment location
22 Existing Practice
23*Existing Practice
24 (ac‐ft)Enter this on the eNOI
25 TV (ac‐ft)
0
Response Attachment location
26 Existing Practice
19*
Treatment Volume (TV) for infiltration practices may be calculated using the equations provided as design guidance
in Section 4.3.3.5 OR by demonstrating infiltration of the TV using TR‐20 or an approved equavalent.
What is the treatment volume provided by the STP?
What is the physical storage volume up to the overflow?
Pre‐Treatment (4.3.3.3)
Has pretreatment been provided for non‐rooftop runoff?
Attachment location: Indicate the specific location (i.e. appendix, page, plan sheet) where the requisite support documentation has
been provided within the application.
Does the site plan specify a landscaping plan that ensures dense and vigorous
vegetation over the contributing pervious drainage areas and the practice?
Landscaping (4.3.2.5)
Treatment (4.3.2.4)
↑ Enter this value on the Standards
Has direct access been provided to the practice for maintenance and
rehabilitation?
Is the forebay separated at least three (3) feet from the SHGWT or located over
impermeable soils?
What type of pretreatment is being
used?
Is the infiltration rate (fc) greater than or less than 2 inches per hour?
Is the forebay sized to hold at least 50% of the WQv?
If the practice is designed to infiltrate <1 year storm and runoff is delivered by
the main conveyance system, has it been designed as an off‐line practice?
Have the outfalls and the conveyance to the discharge point been
designed/protected to avoid erosive velocities?
Is the practice designed to completely dewater the treatment volume (TV)
within 48 hours after the storm event?
Swale
Filter Strip
Forebay
Deep Sump Catch Basins
Proprietary
Yes No
Yes No
NoYes
NoYes
Yes No
Yes No
NoYes
Yes No
Yes No
Page 2 of 2
Version: 11/30/2020 Project Name:
Discharge Point:
Wet Pond #
Practice Drainage Area
For Permit
Coverage
Not for Permit
Coverage
Total to
Practice
1 Total Area (acres)24.150 0.000
24.150
2 8.030 0.000
8.030
3 0.000 0.000
0.000
WQV for
credit
WQV not for
credit
Total
WQV
4 WQV to practice 0.7029 0.0000 0.7029 91
5 2
Response Attachment location
6 NA
0 1
Response Attachment location
7 Existing Pond
8 Existing Pond
9 Existing Pond
10 Existing Pond
11 Existing Pond
12 NA
13 Existing Pond
14*
Does the design specify an outlet that is stable for the Q10 storm event?
Is the outlet control structure located within the embankment for maintenance
access and safety?
New Impervious (acres)
Hillside @ OʹBrien Farm
4
AWet Pond (4.3.6)
Redeveloped Impervious
Discharges to Cold or
Warm Water Fishery?
Modified CN for WQ
(1.0ʺ) storm
Note: Designers may use the Practice Drainage Area Runoff Calculator (second tab) for calculation of practice‐
specific runoff volumes for other treatment standards.
Feasibility (4.3.6.1)
If receiving water from a stormwater hotspot, is the pond lined and prevented
from intercepting groundwater?
* Questions preceded by an asterix (*) may change based on previously entered values
Conveyance (4.3.6.2)
Has a emergency spillway been provided to safely convey the 100‐year storm
without overtopping the embankment?
↑Enter this value on the Standards
Compliance Workbook
Are end walls above pipe outfalls greater than 30 inches in diameter fenced
with pipe or rebar at 8 inch intervals?
Has a low flow orifice been provided to meet the WQV and CPV extended
detention requirements without clogging?
Have the outfalls and the conveyance to the discharge point been designed
and protected to avoid erosive velocities?
Are inlets stabilized to ensure that non‐erosive conditions exist during events
up to the 10‐year, 24 hour storm?
Yes No
Yes No
Yes No
No
No
Yes
Yes
Cold
Warm
NoYes
NoYes
NoYes
NoYes
Page 1 of 2
Response Attachment location
15
16
Response Attachment location
17 ft3 3420
18 ft3 23564
19 ft3 26984
20*
21 #########Yes
22
23 Basin
24
25
ac‐ft Enter this on the eNOI
Response Attachment location
26 Existing Pond
27 Existing Pond
28 Existing Pond
29 Existing Pond
Is the remaining WQV provided for by extended detention over 24 hours?
What type of pretreatment is being
used?
Has the permanent pool been excluded from calculations for storms greater
than the water quality event (1ʺ storm)?
Pre‐Treatment (4.3.6.3)
Has pretreatment been provided for non‐rooftop runoff?
Are all deep pool areas of ≥ 4 feet depth with side slopes steeper than 4:1 (H:V)
surrounded by a safety bench with ≤6% slope extending 10 feet outward from
the normal water edge to the toe of the side slope?
Landscaping (4.3.6.5)
Treatment (4.3.6.4)
Is at least 25% of the WQV stored in deep water zones with a depth between
four (4) and eight (8) feet?
What is the volume stored in the forebay or other volumetric pre‐
treatment if used? (minimum 10% WQV)
What is the volume stored in the permanent pool?
What is the total WQV stored at the normal water level (pre‐
treatment + permanent pool)?
Does the pre‐treatment volume plus the permanent pool equal at least 50% of
the WQV?
What is the Storage Volume of the practice. Include the permanent
pool and any volume used for providing extended detention.
Has a minimum flow path at normal water level of 3:1 been provided?
Has an aquatic been been provided that extends at least 5 feet inward from the
normal water edge and is no more than 18 inches deep?
Does the planting plan specify that no woody vegetation >2 inches in diameter
shall be planted or allowed to grow on or within 15 feet of the dam or the toe
of the embankment?
Attachment location: Indicate the specific location (i.e. appendix, page, plan sheet) where the requisite support documentation has
been provided within the application.
Has a planting plan been prepared showing how aquatic and terrestrial areas
will be stabilized, including plant species, plant locations, sources of plant
material and any required soil amendments?
Swale
Filter Strip
Forebay (10% WQv)
Deep Sump Catch Basins
Proprietary
NoYes
NoYes
NoYes
NoYes
NoYes
Yes No
No
No
Yes
Yes
NoYes
Page 2 of 2