HomeMy WebLinkAboutWPO201800059 Review Comments 2019-06-24 June 24, 2019
David James '
County of Albemarle
Department of Community Development
401 McIntire Road, Room 227
Charlottesville,VA 22902
RE: UVA Foundation Tennis Facilities (WPO201800059)
Dear Mr.James,
In response to your VSMP comments (Rev. 3)via email dated June 14, 2019,we offer the following
responses:
A. General
1. The WPO plan contains only the E&SC and SWM portion. Please submit only those sheets
for approval for future submittals.
(Rev.1) Addressed.
2. Cover sheet—Rename title to VSMP Plan for"Project Title" and include WPO#.
(Rev.1)Addressed.
3. (Rev.1)Add the storm sewer profile sheets.
(Rev.2)Addressed.
4. (Rev.2) Cover sheet—Change the WPO#to WPO201800059.
(Rev.3)Addressed.
B. Stormwater Pollution Prevention Plan (SWPPP)
1. Registration Statement:
a. Change HUC to JR15
b. 9.58ac is the limits of disturbance according to the plan.
(Rev.1)Addressed; 10.75ac LOD.
2. Include state waters with TMDL directly downstream, Morey Creek.
(Rev.1)Addressed.
3. Include PPP exhibit sheet.
(Rev.1)Addressed.
4. Insert copy of General Permit coverage when obtained.
(Rev.1) Acknowledged.
V 5. (Rev.1) Section 6(B)—The print out copy did not show all the contents typed into the boxes,
please show all.
(Rev.2/3) Not addressed.
Dewberry Response: New print copies provided with complete contents shown in Section
6B.
C. Pollution Prevention Plan (PPP)
1. Show any proposed clearing/grading activities, paving operations, landscaping operations,
E&S controls, staging, stockpile, borrow,fueling,waste disposal,vehicle/equipment
washing, concrete washout locations on the PPP.
Mr.David James •
•
UVA Foundation Tennis
WPo2oi800059
June 24,2019
Page 2 of 7
(Rev.1) Clearing and grading activities, paving operations, landscape operations, E&S
controls, staging, stockpile, borrow areas not shown/identified.
(Rev.2) Not addressed.
(Rev.3)Addressed.
D. Stormwater Management Plan (SWMP)
1. Show proposed SWM facility and access easement.
(Rev.1)The easement width for the outfall pipes is not shown correct&should follow this
equation:
EASEMENT WIDTH = DIAMETER+2'+2(H-5')+ 10' (20' MIN.) {DSM, pg.15}
(Rev.2) Addressed.
2. Please provide electronic version of VRRM spreadsheet.
(Rev.1)Addressed.
3. Show MH access at weir location.Show another MH access midway and at the opposite end
to underground vault.
(Rev.1)Acknowledged; N/A.
4. Sheet 5.02-Show on the details the storm structure ID and rim elevation.Show invert of
cleanout at connection.
(Rev.1)Acknowledged; N/A.
5. Sheet 5.03-Confirm if'top of weir' is not the 'top of weir wall' and weir length is 6'.
(Rev.1)Acknowledged; N/A.
6. Sheet 6.02-You're travel time for sheet flow is quite low. Please review and provide
analysis/computation of Tc and Q, peak runoff(pre-/post-).
(Rev.1)Addressed.
7. Sheet 6.03-
a. Your numbers are entered wrong for the storage depth calculation for both
biofilters.
b. You show 6209cf for the Lvl 1 and should be 4674cf; 6217.5cf for Lvl 2.
c. The pre-treat cell vol. should be at least 15%of the total Tv.
d. Unable to find ref. sheet under'Note:'. -
(Rev.1)Acknowledged; N/A.
8. Reduce pipe velocity for Stm 25 (18fps).The minimum pipe velocity= 15fps.
(Rev.1)Addressed.
9. Show callouts for each slot drain and provide depth and sizing details.
(Rev.1)Addressed.
10. Sheet 6.07-You're showing permeable pavement(PP) of 0.13ac treating 0.31ac,and PP of
0.17ac treating 1.+ac.The CDA should not be more that 2:1 for a LvI.1 and 1:1 for a Lvl.2
facility and 100% impervious. {VADEQ SW Design Spec. 7}
(Rev.1)Acknowledged; N/A.
11. Sheet 6.07-
a. Show DA total that's captured by the inlets/structures, and show undetained DA.
(Rev.1) Provide inlet design computations (LD-204). Fix the linetype/scale elements so
features of map are legible.Show the post-dev. contours.
(Rev.2)Addressed.
b. Show value for total impervious treated - it's cutoff.
n Dewberry°
Mr.David James
UVA Foundation Tennis.
WPo2oi800059
June 24,2019
Page 3 of 7
(Rev.1) Addressed.
c. Correct callout to 'A'.
(Rev.1)Addressed; N/A.
12. Show 10-yr WSE for bioretentions in the details.
(Rev.1)Acknowledged; N/A.
13. Show cleanout locations and detail for bioretentions.
(Rev.1) Acknowledged; N/A.
14. Because ponding depths are 1-ft(max) ensure chosen plants will survive, or substitute
alternates.
(Rev.1) Acknowledged; N/A.
15. Add Figure 9-B.2.Typical Biofilter Planting Specifications to the notes. {VADEQ SW Design
Spec. 7}
(Rev.1)Acknowledged; N/A.
16. Permeable Pavement—
a. May not be allowable due to compacted subgrade soils. Provide infiltration tests at
depth.
b. Show paver thickness, compressive strength, bedding layer, reservoir layer,filter
layer depths.
c. Show pavement design can handle all traffic loads.
d. Show underdrain and observation well locations.
e. Ensure that landscaping&maintenance operations minimizes the risk of sediment,
mulch,grass clippings, leaves, etc. inadvertently clog the paving surface.
(Rev.1)Acknowledged; N/A.
17. Sheet 6.04—
a. Add to notes under 8.2, Step 9- Installation of Interlocking Pavers.The basic
installation process is described in greater detail by Smith (2006).
i. Place edge restraints for open-jointed pavement blocks before the bedding
layer and pavement blocks are installed. Permeable interlocking concrete
pavement(IP) systems require edge restraints to prevent vehicle loads from
moving the paver blocks. Edge restraints may be standard VDOT curbs or
gutter pans, or precast or cast-in-place reinforced concrete borders a
minimum of 6 inches wide and 18 inches deep, constructed with Class A3
concrete. Edge restraints along the traffic side of a permeable pavement
block system are recommended.
ii. Place the No. 57 stone in a single lift. Level the filter course and compact it
into the reservoir course beneath with at least four(4) passes of a 10-ton
steel drum static roller until there is no visible movement.The first two (2)
passes are in vibratory mode, with the final two (2) passes in static mode.
The filter aggregate should be moist to facilitate movement into the
reservoir course.
iii. Place and screed the bedding course material (typically No. 8 stone).
iv. Fill gaps at the edge of the paved areas with cut pavers or edge units.When
cut pavers are needed, cut the pavers with a paver splitter or masonry saw.
Cut pavers no smaller than one-third (1/3) of the full unit size.
Dewberry°
• Mr.David James
WA Foundation Tennis
WPo2o1800059
June 24,2019
Page 4 of 7
v. Pavers may be placed by hand or with mechanical installers. Fill the joints
and openings with stone.Joint openings must be filled with VDOT No.8
stone, although VDOT No.8P or No. 9 stone may be used where needed to
fill narrower joints. Remove excess stones from the paver surface.
vi. Compact and seat the pavers into the bedding course with a minimum low-
amplitude 5,000-lbf, 75-to 95-Hz plate compactor.
vii. Do not compact within 6 feet of the unrestrained edges of the pavers.
(Rev.1) Acknowledged; N/A.
18. Account for drainage runoff from Stm 32. Show existing downstream facility, structure, etc.
(Rev.1)Acknowledged; N/A.
19. Sheet 6.06-Show BMPs CDA boundaries and acreage.
(Rev.1) Acknowledged; N/A.
20. Provide infiltration tests for area of permeable pavement.
(Rev.1)Acknowledged; N/A.
21. Show underdrains slope at least 5%to outlet.
(Rev.1) Acknowledged; N/A.
22. Confirm bottom of facilities are at least 2 feet from seasonal high groundwater table.
(Rev.1)Acknowledged; N/A.
23. (Rev.1) Include this checklist on the plan set.
http://www.albemarle.org/upload/images/forms_center/departments/Community_Develo
pment/forms/Engineering_and_WPO_Forms/WPO_VSMP_Construction_Record_Drawings_
Policy_23May2014.pdf
(Rev.2)Addressed.
24. (Rev.1) Show maintenance access easement to the SWM pond.The forebay& riser structure
should be accessible for inspection/maintenance. {DSM, pg.12}
(Rev.2)Addressed.
25. (Rev.1)The forebay should be 4 to 6 feet deep.Show riprap outlet protection. It's
recommended to add a vertical sediment depth marker to measure sediment deposition,
but not required. {VADEQ SW Design Spec.,App'x D}
(Rev.2) Addressed.
26. (Rev.1)Sheet 6.01-Show Hydrocad output for 4S area(s).
(Rev.2)Addressed.
27. (Rev.1) Sheet 6.02-Show proposed contours on the post-dev. map where you're showing
existing.
(Rev.2)Addressed.
28. (Rev.1)Sheet 6.04-Correct SWM narrative, change from 10.57 to 10.75 &6.86 to 6.87.
(Rev.2) Please correct the values presented under the 'Summary:'.
(Rev.3)Addressed.
29. (Rev.1)Submit a WPO amendment to Golf Course Project (WP02018-16) showing reduction
in nutrient credit availability of 1.1 lb/yr. State that credits from Golf project are being
applied to this project(WP02018-59).
(Rev.2)Addressed.
30. (Rev.1) Sheet 6.06-I think the CN should be lower.There appears to be existing trees in the
parking lot and around building (Pre-dev.).The pond area is considered impervious area
(Post-dev.).
Dewberry°
• Mr.David James
UVA Foundation Tennis
WPo2oi800059
June 24,2019
Page 5 of 7 •
(Rev.2)Addressed.
31. (Rev.2)Submit SWM deed of easement& plat-to be recorded prior to plan approval.
(Rev.3)Comment still valid. Submit hardcopies of plat along with form&fee payment.
Dewberry Response: UVAF to provide upon recording.
32. (Rev.2) Contact Ana Kilmer about nutrient credit agreement-to be recorded prior to
grading permit being issued.
(Rev.3)Comment still valid.
Dewberry Response: UVAF to provide upon purchase of credits.
33. (Rev.3)Correct the profile sheets(C4.08-4.11)&C6.07. Refer to engineering's latest site
plan comments(SDP201900002).
Dewberry Response: Profile sheets and storm schedules have been corrected.
E. Erosion and Sediment Control Plan (ESCP)
1. Property line doesn't match linetype symbol.Show any disturbance outside of property line
in an easement.
(Rev.1)Verify with planner.
(Rev.2)Acknowledged.
2. Show the limits of disturbance line on the existing and demo sheets. It appears that some
areas to be disturbed aren't shown.
(Rev.1)Addressed.
3. Show existing drainage divides.
(Rev.1)Addressed.
4. Show all existing sanitary sewer&water easements, deed book/page ref.There appears to
be some ACSA pipes as shown (see map), please verify.
(Rev.1)Addressed.
5. Show drainage areas going to the sediment traps.
(Rev.1)Acknowledged; N/A.
6. Provide an overview sheet showing existing and proposed drainage patterns.Show existing
drainage divides and
(Rev.1)Addressed.
7. Tie in grades for ST#2 to existing.
(Rev.1)Addressed; N/A.
8. Show weir outlet for traps. Piped, allowed? L=6xDA
(Rev.1)Addressed; N/A.
9. Show OP for Stm 32.
(Rev.1)Acknowledged; N/A.
10. Provide calcs/stone sizing for each OP.
(Rev.1) Not shown on C3.14, unable to locate.Show riprap class/stone size used.
(Rev.2)Addressed.
11. Show design of OP from Stm 26. OP should be installed at nearly flat grade; otherwise
design for a channel w/.liner type.
(Rev.1) Show apron at 0%.bottom grade to receiving channel.
(Rev.2) Addressed.
Dewberry®
Mr.David James
UVA Foundation Tennis
WPo2oi800059
June 24,2019
Page 6 of 7
12. Show ditch calcs& lining type for any constructed ditches.
(Rev.1)TBD.
(Rev.2)Addressed.
13. Sheet 3.11, A-1-Tie proposed to existing contours.
(Rev.1)Tie-in the proposed grades near STM 30.
(Rev.2)Addressed.
14. Sheet 3.11/3.12-
a. The grades tying in to stairwell appear to be greater than 2:1.
(Rev.1) Not addressed, grading not shown. I see>2:1 on sheet 3.11 next to cart path
and sheet C3.14 near the outfall.
. (Rev.2) Addressed.
b. Show the transitioning grades of the sediment traps from phase
(Rev.1) Acknowledged; N/A.
15. Show existing right-of-way with street name, route number&width labeled.
(Rev.1)Addressed.
16. Show proposed street name and right-of-way.
(Rev.1)Addressed.
17. Provide OP shape &stone size calcs (see VADEQ ESC HB Spec. 3.18).
(Rev.1)Show riprap class/stone size used.
(Rev.2)Addressed.
18. Provide low maintenance ground cover hardier than grass,which will not require mowing
for slopes steeper than 3:1 as a final stabilization measure.
(Rev.1) I see >3:1 on sheet 3.12 next to the travelway and cartpath &on sheet 3.13 next to
the future clay court.
(Rev.2)Addressed.
19. There appears to be a lot of cut work. Provide estimate of cut&fill balances. Ensure waste
area(s) will handle the volume.
(Rev.1)Addressed.
20. Show silt fence around stockpile area.
(Rev.1)Addressed.
21. Fix matchline references on phase I sheets.
(Rev.1) Addressed.
22. (Rev.1) Sheet 3.11-Show grading next to stairway and tennis facility.
(Rev.2)Addressed.
23. (Rev.1)Sheet 5.01-Correct drainage area to sediment basin; should be 8.52ac, 8.14ac
entered.
(Rev.2) Addressed.
24. (Rev.1) Phase II ESC sheets(mostly around perimeter)-Add TS,PS, MU symbols for 3:1 and
greater slopes.Add B/M symbols to 3:1 slope area leading to SW basin. B/M recommended
on slope areas where mulch won't hold.{VADEQ ESC HB,Spec. 3.35,3.36}
(Rev.2)Addressed.
25. (Rev.2)Sheet 2.12-Add IP to existing inlet with invert 538.01'
(Rev.3)Addressed.
el Dewberry®
Mr.David James
UVA Foundation Tennis
WPo2o1.800059
June 24,2019
Page 7 of 7
Thank you for your attention in this matter. Please contact me with any questions or concerns at (804)
205-3356 or email cpalmore@dewberry.com
Sincerely,
Cameron Palmore, P.E., L.S
Dewberry
Dewberry®