HomeMy WebLinkAboutWPO201900060 Review Comments WPO VSMP 2020-01-29Phone (434) 296-5832
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WP02019-00060
COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
Fax (434) 972-4126
VSMP Permit Plan review
UVA Foundation — 1725 discovery Drive
Jonathan Showalter /Timmons Group[ionathan.showalter(atimmons.com]
608 Preston Ave., Suite 200 / Charlottesville, VA 22903
University of Virginia Foundation / P.O. Box 400218
Charlottesville, VA 22904-4218 [ cschooley(a)uvafoundation.com ]
21 Oct 2019
13 Jan 2020 (digital-1/13/2020 3:55 PM)
20 Nov 2019
29 Jan 2020
John Anderson
County Code section 17-410 and Virginia Code §62.1-44.15:34 requires the VSMP authority to act on any
VSMP permit by issuing a project approval or denial. This project is denied for reasons outlined, below.
The application may be resubmitted for approval if all comment items are satisfactorily addressed.
A. Stormwater Pollution Prevention Plan (SWPPP) (Rev. 1) Comments persist. Applicant response:
`Much of this information is not yet available. An updated SWPPP will be provided with the next
submittal.' Engineering accepts this response and anticipates update with next submittal.
(Ref. Applicant email: 1/13/2020 3:55 PM)
The SWPPP content requirements can be found in County Code section 17-405. A SWPPP must contain
(1) a PPP, (2) an ESCP, (3) a SWMP, and (4) any TMDL measures necessary.
a. Sec. 1 (Registration Statement) Complete 2019 VPDES (VAR10) Registration
b. Sec. 4./5. —Update once ESC-SWM plan sheet revisions complete
c. Sec. 6.E. Name individual responsible for PPP practices
d. Sec. 8 List named individual responsible for inspections
e. Sec. 9 (Signed Certification) Please sign
f. Sec. 11 (General Permit Copy) Please include 2019 VAR10
g. Include 2019 Notice of VPDES Termination
h. List WP02019-00060 on cover of SWPPP
The PPP content requirements can be found in County Code section 17-404. (Rev. 1) Comments persist;
see above.
1. If Sec. 6 PPP Exhibit is revised, please provide an updated Exhibit.
2. Sec. 6.A Revise PPP Exhibits, p. 28-29 SWPPP, to show rain gauge location/s.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP.
This plan is approved ep nding review and approval of Pond 1 As -built drawing. Initial review comments
L-12. addressed; grayscale:
1. Revise plan title to include ref. to VSMP /WP02019-00060.
Engineering Review Comments
Page 2 of 7
2. Revise vicinity map to more clearly identify site location.
3. C2.0 — Provide existing contour labels; none are provided.
4. Include image, below (or similar), from Timmons Group UVA Foundation —1725 Discovery Drive Design
Calculations & Narrative, October 21, 2019, on C6.0 with caption /label that identifies 1725 Discovery
Drive (blue circle, image blow) to cross-reference and clearly identify project site, relative to Pond 1.
5. Include image, below /similar: USGS 7.5' quadrangle, Earlysville VA, 2016, to show approximate (county -
estimate) watershed Pond 1 comprising —465 Ac., on sheet C6.0. Revise drainage area reference on C6.0
which may underreport actual s of Pond 1 watershed (revise 83.90 Ac. reference to avoid confusion).
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6. C6.0 — Provide note that identifies project location in sub -basin shown on Design Calculations & Narrative,
P. 9.
7. C6.0 — Provide additional qualifying descriptions to support how this 0.73 Ac. impervious gain fits within
p. 9 projections for sub -basin ultimate development impervious land cover without change to Exhibit CN
Engineering Review Comments
Page 3 of 7
value. Identify p. 9 sub -basin (Exhibit) CN value that applies to project, a value that WPO plan and Design
Narrative maintain is unchanged with proposed development at 1725 Discovery Drive.
8. C6.1: Pre/post CN value =67 (reported with cross section 1 — 4 profiles) appears unrelated to Exhibit p. 9
CN values. Please clarify. Ref. image, below.
DRAINAGE AREA: 26.5 AC
PRE/POST CN: 67
PRE/POST TC: 26 MIN
2-YEAR Q: 19.92 US
2-YEAR V: 3.44 FPS
10-YEAR Q: 51.37 US
10-YEAR ELEV: 524.81'
540 540
535
535
'
/
530
/ 530
/
525
10-YR WSE = 524.81' 525
520
520
9+50 10+00 11+00 12+00
CROSS SECTION 1 PROFILE
HORIZ SCALE: 1"=50'
VERT SCALE: 1'=5
9. Note: This and other development projects that rely on Pond 1 for quality and quantity compliance are not
strictly grandfathered unless requirement at 9VAC25-870-48. L(iv.) is satisfied between individual project
sites and Pond 1, yet, if (iv.) is true at Pond 1 outfall, and if Pond 1 was built per design, and if Applicant
confirms that, to -date, watershed development impervious area does not increase the CN value in any sub -
basin of Pond 1 (Ref. p. 9 /Design Report), then review position is that Pond 1 provides SWM for projects
within Pond 1 watershed, per 9VAC5-870-48. Please confirm that this is the case: that CN value in project
sub -basin is unchanged with new building /additional parking. Albemarle still considers channel and flood
protection between proposed development and Pond 1. While Pond 1 may provide SWM quality -quantity
control at limits of analysis, channel and flood protection between development sites and pond is a review
and regulatory concern, unless proven otherwise.
9VAC25-870-48.1.(iv.): ` and iv has not been subsequently modified or amended in a manner resulting
in an increase in the amount of phosphorus leaving each point of discharge, and such that there is no
increase in the volume or rate of runoff'] While there may be increase in the amount of phosphorus
leaving a specific site compared with the pre -development condition, provided proposed design of 1725
Discovery Drive is consistent with Dewberry & Davis, October 1997 document CN value for its sub -basin,
then review position is that there is no increase in permitted volume or rate of runoff from Pond 1 outfall.
10. C6.1: Channel Adequacy /capacity -velocity between 1725 Discovery Drive development, and Pond 1:
a. Ref. 9VAC25-870-97: Stream channel erosion, para. B., references 9VAC25-840-40, Minimum
Standards.
Engineering Review Comments
Page 4 of 7
b. Min Std. 19 (9VAC25-840-40.19.b.(2.)(a.) requires `Natural channels shall be analyzed by the use
of a two-year storm to verify that stormwater will not overtop channel banks nor cause erosion of
channel bed or banks.'
c. Ref. VESCH, Yd Edit., 1992, Table 5-22. Provide additional data on receiving stream substrate.
Compare with table values to ensure velocities at x-sections 1- 4 are non -erosive. Table 5-22
indicates velocities above 2.5 s may be erosive in certain unlined earthen (natural) channels.
Report /list observed substrate between development and Pond 1 at each x-section, on sheet C6.1.
d. Ref. DEQ guidance /DCR Technical bulletin #1 (link:
https://www.deq.vir ig nia.gov/Portals/0/DEQ/Water/Publications/TechBulletinl.pdf ) Stream Channel
Erosion Policy Guidance. Review especially guidance, DCR TB 1, p. 11, Ultimate Development
Conditions, and confirm analysis performed for (WPO2019-00060) submittal includes Engineer's
best estimate of ultimate development along the receiving stream between 1725 Discovery Drive
and Pond 1, which may in future contribute additional runoff, and increase volume or velocity in
e.
f.
13
Once ultimate development conditions are analyzed, `If existing natural receiving channels or
previously constructed man-made channels or pipes are not adequate, the applicant shall `consider
measures listed at DCR TB 1, p. 7. Also, please review DCR TB 1, pp. 8-11. Revise design, as
needed.
Revise Water Quantity Analysis Channel Adequacy text block, C6.1, as needed. Velocity < 5fps
is not always nonerosive. Also, base design on ultimate development conditions. Please note
multiple road stub -outs for future development along Discovery Drive (GIS image, above).
Channel cross sections panel:
Label Lewis and Clark Drive.
ii. Label Ex. structure beneath L&C Drive.
iii. Evaluate Ex. structure beneath L&C Drive based on ultimate development conditions. If
inadequate to convey runoff from ultimate development, propose remedy.
iv. If design remedy requires modification to Ex. structure beneath L&C Drive, provide
comprehensive profile and plan design information, including LD-229.
11. Label drainage structures across plan sheets to correspond with Design Calculations & Narrative, Pipe and
Inlet Computations tables.
Engineering Review Comments
Page 5 of 7
12. Design Calculations & Narrative: Revise Project Narrative - Stormwater Management Summary consistent
with review comments above, and any plan or channel or pipe revisions required by ultimate development
conditions.
13. Note: Since Pond 1 Drainage Area > 460 Ac., analysis downstream of Pond 1 is unnecessary. Project LOD
< 1% Pond 1 DA. Project total LOD z1.29 Ac. Ref. DCR TB one -percent rule, p. TB1-7. (Rev. 1) As
follow-up: Please see Sec. D., ESCP, below, minor item 1.
14. Furnish relevant Pond 1 As -built data that corresponds with approved Pond 1 dam /spillway elevation data.
Although this data was requested in connection with SUB201800171, unless mistaken, it was not
furnished. As -built data for pond 1 dam /spillway is requisite to approval of WPO201900060. Please see
request sent December 03, 2018 4:57 PM (J. Anderson to J. Showalter) in connection with SUB20180017 -
Lewis and Clark Drive Extension, including text, reading (in part): (Rev. 1) Comment persists.
`Engineering needs to correlate Lewis & Clark Road Ext. to a prior -approved plan for TMP #32-6R, under
whatever guise (Approved Master Plan, Approved Cox Engineering plans, Approved Dewberry Davis
Study, etc.). Important documents are contemporaneous with suspended site plans, but we cannot locate a
clearly -approved SWM plan for UVA Foundation Research Park, especially for ponds 1 and 2. Important
documents and applications are twenty years old. This is the task: identify a prior -approved SWM plan
(with SWM facilities) meeting Part IIC design criteria for improvements proposed under WPO201800073.
We need Timmons to make the connection -please consider:
1. Identification of prior -approved stormwater management plans for ponds 1 and 2.
I have researched this without luck. I cannot make clear connection between a prior -approval and this
Application.
It is not enough that recently approved WPO plans may have referenced Dewberry Davis Study, or
Cox Engineering plans.
2. Design of ponds 1 and 2 relative to VSMH, 1999, Vol. II, Appendix 5D worksheets (ponds 1 and
2).
3. As -built condition of ponds 1 and 2 relative to approved plans. We cannot locate As -built
drawings.
4. Location of ponds 1 and 2 relative to drainage divides, relative to improvements
(WPO201800073).
5. USACE approval of wetland impacts associated with WPO201800073 /SUB201800171.
6. Cumulative development ( % impervious) relative to prior -approved SWM plan/s.
That is, with WPO201800073, % impervious cover from a cumulative standpoint.'
[Also, county email, James Howard -Smith to Jonathan Showalter, Timmons, 12/19/2018 7:07 AM. Re.
SDP199800043 Approved Final Site Plan and Comps, Pond 1; sheet 32: Spillway / Dam Profiles. Note:
plan is metric.]
Link to SDP199800043: https:Hlfweb.albemarle.or,g/weblink/search.aspx?dbid=3&searchcommand=%7b%SbCDD-
Planning%5d:%5bApplicationNumber%5d=%22SDP 199800043%22%7d.]
D. Erosion and Sediment Control Plan (ESCP)
Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESCP. This plan
is disapproved for limited reasons listed, below (two minor items). The erosion control plan content
requirements can be found in County Code section 17-402.
After reviewing revised ESC Plan, two minor items /edits (Note: Initial review comments addressed; grayscale):
1. C3.0 total LOD Area (appears) =1.31 Ac. Please revise. ( Check my math. )
2. C3.1 Check for CE-SF conflict; it appears SF may partially obstruct CE. Limit SF to avoid conflict
1. C3.0 - Since LOD areas of this two-phase project (building; parking) do not overlap, revise project
description to clarify that total limits of disturbance z1.29 Ac.
2. C3.1 - Provide RWD at end paved construction entrance.
3. C3.3 - Label existing contours.
Engineering Review Comments
Page 6 of 7
4. C3.4 (Also, site plan -related)
a. Eliminate nuisance ponding in right-angle corners of lower elevations of proposed upper parking
lot.
b. Label CG-2 / CG-6.
c. Label drive aisle width.
d. Provide typ. dimensions, parking spaces.
e. Label concrete ribbon curb at each entrance to upper parking lot. Provide detail.
f. Recommend profile for north and south side entrances to proposed upper parking lot that show
smooth transitions, and spot elevations.
g. Recommend receiving walks on east side of existing lower parking lot that align with proposed
sidewalks (2 locations) on west side of lower parking lot.
h. Label retaining wall.
i. Please ref. 18-30.7.5.a. L/2. construction standards, re. wall ht.; stepped walls required if wall ht.
W (proposed design wall ht. =10.3' on managed steep slopes cannot be approved.)
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j. Apply for building permit for retaining wall.
k. WPO plan approval does not approve retaining walls.
1. Provide CG-12 wherever walks encounter curbing (label ramps).
5. Provide safety fence to protect building occupants and visitors during all phases of project.
The VSMP permit application and all plans may be resubmitted for approval when all comments have been
addressed. For re -submittal, please provide .PDF preview prior to print submittal.
Engineering plan review staff is available from 2-4 PM on Thursdays if you wish to meet to discuss this review.
Engineering Review Comments
Page 7 of 7
Process
After approval, plans will need to be bonded. The bonding process is begun by submitting a bond estimate request
form and fee to the Department of Community Development. One of the plan reviewers will prepare estimates and
check parcel and easement information based on the approved plans. The County's Management Analyst will
prepare bond agreement forms, which will need to be completed by the owner and submitted along with cash,
certificates or sureties for the amounts specified. The agreements will need to be approved and signed by the
County Attorney and County Engineer. This may take 2-4 weeks to obtain all the correct signatures and forms.
Stormwater Management Facilities Maintenance agreements may also need to be completed and recorded. The
County's Management Analyst or other staff will prepare the forms and check for ownership and signature
information. The completed forms will need to be submitted along with court recording fees.
After bonding and agreements are complete, county staff will need to enter project information in a DEQ database
for state application processing. DEQ will review the application information based on local VSMP authority
approval. At this time, the DEQ portion of the application fees will need to be paid directly to the state. For fastest
processing, this is done electronically with the emails provided on the application (SWPPP Registration Statement).
DEQ should notify applicants with instructions on how to pay fees. When DEQ approves the application, they will
issue a permit coverage letter. This should be copied to the county.
After DEQ coverage is issued, the County can hold a pre -construction conference. Applicants will need to complete
the request using a pre -construction conference form, and pay the remainder of the application fee. The form
identifies the contractor and responsible land disturber, and the fee remaining to be paid. This will be checked by
county staff, and upon approval, a pre -construction conference will be scheduled with the County inspector. At the
pre -construction conference, should everything proceed satisfactorily, a grading permit will be issued by the County
so that work may begin.
County forms can be found on the county website forms center under engineering;
hLtp://www.albemarle.ora/deptfonns.asp?department--cdenMUo
Ifyou have questions /concerns, please contact me atjanderson2galbemarle.org or at 434.296-5832 -0069.
Thank you
I Anderson, Engineering Div.
WP0201900060 UVA Foundation — 1725 Discovery Drive 012920rev1