HomeMy WebLinkAboutWPO202200036 Review Comments WPO VSMP 2022-12-19 (2)o rrht, �r County of Albemarle
+1+ COMMUNITY DEVELOPMENT DEPARTMENT
401 McIntire Road, North Wing Charlottesville, VA 22902-4579
IacrN�P Telephone: 434-296-5832
WWW.ALBEMARLE.ORG
VSMP Permit Plan Review
Project title:
Overlook Hotel
Project:
WPO2022-00036
Plan prepares
Shimp Engineering, 912 E. High St., Charlottesville, VA 22902
Chris Marshall, PE — chrisAshimp-engineering.com
Owner /Applicant:
WS Four LLC, 3600 Pacific Avenue, Virginia Beach, VA 23451
dou2 subcap.com
Plan received date:
12 Aug 2022
(Rev. 1)
4 Nov 2022
Date of comments:
8 Sep 2022
(Rev. 1)
19 Dec 2022
Reviewer:
John Anderson, PE, CFM
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 listed below. The
VSMP application content requirements can be found in County Code section 17-401.
A. Stormwater Pollution Prevention Plan (SWPPP)
The SWPPP content requirements can be found in County Code section 17-405. A SWPPP must contain
(1) a PPP, (2) an ESOP, (3) a SWMP, and (4) any TMDL measures necessary.
SWPPP
1. Please ensure SWPPP cover includes reference to WP02022-00036. (Rev. 1) Addressed.
2. Submit SWPPP' using county template located at
httys: //www. albemarte. org/home/showpublisheddocument/ 166/63720231032753
a. : Sec. 1, VAR10 permit registration, has been submitted. (Rev. 1) Partially addressed. As follow-up:
• Check New Permit Issuance, registration statement, p. l /top of form.
• Sec. II.C.: List off -site area estimated to be disturbed, TMP 78-13A. (Ac. to one -hundredth).
• Sec. IIC: Increase total area of disturbance by off -site area, bullet above.
• Sec. IIF: List Albemarle County (MS4).
• Sec. III, p. 2: Revise to include TMP 78-13A.
b. Sec. 6.A.: PPP Exhibit/s: Please show initial location of. (Rev. 1) Partially addressed.
i. Rain gauge. (Rev. 1) Addressed.
ii. Portable sanitary facilities (porta-john), as required. (Rev. 1) Addressed.
iii. Covered non -hazardous waste dumpster, if required. (Rev. 1) Addressed.
iv. Vehicle wash waters, draining to trapping measure (Not a sediment trap design, per se,
but shallow depression — 1-2 backhoe buckets. Avoid direct drainage to Ex. storm
system.) (Rev. 1) Partially addressed. As ollow-up: Vehicle wash waters are shown,
please show trapping measure.
v. Concrete wash -out. (Rev. 1) Persists. Concrete wash -out, required element. Legend includes,
please indicate initial location.
vi. On -site fuel, if required. (Rev. 1) Addressed.
vii. Paint, stucco, chemical storage, if required. (Rev. 1) Addressed.
c. Sec. 6E: List named individual responsible for PPP measures. (Rev. 1) Persists. SWPPP Sec. 6.E.
indicates qualified personnel is TBD.
Engineering Review Comments
Page 2 of 9
d. Sec. 8: Although Albemarle County will inspect, Applicant is required to retain qualified
(contractor/third-party) E&S inspection personnel to perform ESC inspections and evaluate
compliance relative to VESCH, Yd Edition, 1992. (Rev. 1) Persists. SWPPP Sec. 8
indicates qualified personnel is TBD.
e. Sec. 9: Ensure Signed Certification is signed and dated. (Rev. 1) Addressed.
f. New, Rev. 1: Sec 4,5 —Once review comments addressed, revise SWPPP to include ESC /SWM plan
sheets.
g. New, Rev. 1: Sec. I I Anclude 2019 VAR10 CGP, as with all other (Shimp Engineering) SWPPPs.
B. Pollution Prevention Plan (PPP) —see SWPPP item 2.b. above. (Rev. 1) Persists.
The PPP content requirements can be found in County Code section 17-404.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This
plan is disapproved for reasons listed below. The stormwater management plan content requirements can be
found in County Code section 17-403.
C2
1. General /Calculation packet:
a. Although proposed design need not reduce bypass flow (offsite-to-offsite), pipe capacity calcs
must include 24" HDPE bypass storm conveyance pipes in LD-229 table, calc. packet, p. 45.
(Rev. 1) Addressed.
b. Pe. 45:
i. From A9 to A8, 1.70 cfs peak flow exceeds pipe capacity, 1.3cfs. Please revise. (Rev. 1)
Addressed.
it. From A7 to A6, 3.07 cfs peak flow exceeds pipe capacity, 1.6cfs. Please revise. (Rev. 1)
Addressed.
iii. From A6 to A5, 4.60 cfs peak flow equals pipe capacity, 4.6cfs. Increase pipe DIA, or
pipe slope to ensure adequate capacity. (Rev. 1) Not addressed. Applicant response
(letter, 11/4/22): `The pipe capacity was entered incorrectly. This has now been
updated and the pipe capacity is sufficient for the peak flow.' As follow-up: Listed
capacity identical to initial value. Q10 = capacity. Please revise.
iv. From A413 to UGS, 3.47 cfs peak flow exceeds pipe capacity, 2.8cfs. Please revise. (Rev. 1)
Not addressed. Q10 exceeds pipe capacity. Please revise.
a Pg. 44: Revise LD-204 to include new storm inlet east of hotel entrance on U.S. Rt. 250 EBL. (Rev. 1)
Partially addressed. Applicant: `The existing DI west of the entrance will remain in use. A new inlet
east of the entrance would not meet the 90% efficiency typically required by VDOT.' As follow-up:
Include flowline and high -point spot elevations (C4) at intervals across development entrance to ensure
Rt. 250 runoff reaches DI west of development entrance and does not enter the development.
d. Include WP0202200036 on calculation packet cover. (Rev. 1) Addressed.
2. Include WP0202200036 in plan title, sheet Cl. (Rev. 1) Addressed.
3. Show Aabel managed steep slopes. Also applies to any grading, site, utility, or E&S Phl,2,3 plan sheet. It
is insufficient to show steep slopes only on ex. conditions sheet, since comparison with improvements or
grading is critical to review. (Rev. 1) Partially addressed. Applicant: `Managed steep slopes are now
shown on all relevant plan sheets.' As follow-up: Show managed slopes on C3. Label managed slopes on
C2, C3, C4.
4. Show /label existing tree line. (Rev. 1) Addressed.
5. Show /label existing sidewalk fronting SunTrust bank, U.S. Rt. 250. (Rev. 1) Addressed.
6. Show /label existing drainage feature on TMP 78-13A as perennial, intermittent, or defined channel (dry
watercourse). (Rev. 1) Addressed.
7. Show label surface features on TMP 78-13, including buildings or surface parking that overlay contour
areas depicted. (Rev. 1) Addressed.
8. Label apparent fence on TMP 78-13A that intersects Cl boundary of TMP 78-73A7. If this feature is relic
SF from prior development, provide label that ex. silt fence is to be removed. (Rev. 1) Note: Typos
corrected in initial comment /comment restated: Label apparent fence on TMP 78-73A7 that intersects C 1
C3
Engineering Review Comments
Page 3 of 9
boundary of parcel. Applicant: `This is proposed tree protection fencing for the existing treeline to
remain.' As follow-up: Remove linework for proposed tree protection fencing from C2, Existing
conditions, and show on ESC sheets.
9. Show Aabel existing easements on TMP 78-73A7 and 78-13A. (Rev. 1) Partially addressed. Applicant: `the
existing sanitary easement on 78-13A and the landscape easement on 78-73A7 are now shown.' As follow-up:
a. Please direct reviewer to landscape easement linework and label on sheet C2.
b. Please check variable width permanent grading easement, C4 if existing, please show /label on C2. If
proposed, linework appears to define extent insufficient to cover grading proposed with development.
Please clarify variable width permanent grading easement, whether existing, or, i[proposed, whether
sufficient.
10. Indicate existing retaining wall is to be removed, that is the case. 12,13049 photo of ex, Aa4 [ photo removed with
Rev. 1 comments]: (Rev. 1) Addressed.
11. Label existing storm pipe roughly parallel to parcel boundary at U.S. Rt. 250. (Rev. 1) Persists. Applicant: `This
will be provided once survey information is available.'
12. Label ex. inlet west of proposed entrance to Overlook Hotel `to be removed.' (Rev. 1) Addressed. Applicant:
`Ex. inlet west of entrance is meant to remain and is now shown accordingly.' Ref. 12,130,119 photo hell...:
[photo removed with Rev. 1 comments]
13. Label retaining wall at SWM facility. (Rev. 1) Addressed.
14. Shift /reorient (with leader line) `47 LF 12" HDPE' label since it obscures A2 structure label. (Rev. 1)
Addressed.
15. Revise 47 LF 12" HDPE to 15" HDPE, consistent with C5 profile. (Rev. 1) Addressed.
16. Show /label CG-12 either side of hotel entrance. (Rev. 1) Addressed.
17. Provide inlet on U.S. Rt. 250 immediately east of entrance to replace inlet removed immediately west of
entrance. U.S. Rt. 250 runoff should be captured prior to crossing hotel entrance. (Rev. 1) Addressed.
Applicant: `An inlet east of the entrance would not capture runoff at the 90% efficiency typically
required by VDOT. The inlet west of the entrance will remain which benefits from the jog in the curb
and gutter.'
18. Tie new storm pipe serving DI east of entrance to existing /proposed bypass storm conveyance west of
entrance, south of U.S. Rt. 250 EBL. Pipe should run beneath entrance. (Rev. 1) Addressed.
Applicant: `A new manhole, str. B2, will connect the existing 24" RCP from Rt 250 and existing 18"
HDPE under the proposed entrance.'
19. Provide, show, and label a public drainage easement over inlet /storm pipes that convey runoff from U.S.
Rt. 250 or north of U.S. Rt. 250 to daylight south of U.S. Rt. 250. A public drainage easement is required
over all elements of storm conveyance that carry runoff from U.S. Rt. 250, or areas north of U.S. Rt. 250.
(Rev. 1) Partially addressed. Note / ollow- :A recorded easement (plat) showing public drainage and
SWM facility easements is required prior to WPO plan approval. A separate easement plat application is
required. Plat requires deeds, formatted by Albemarle once SWM Maintenance Agreement is recorded.
20. Stepped retaining walls located on TMP 78-13A require permanent easement. Provide easement prior to
WPO plan approval, or prior to final site plan approval, latest. (Rev. 1) Persists. Applicant:
`Acknowledged, an easement plat will be provided for the stepped retaining walls prior to approval.
Proposed easement is now shown on the VSMP.' As follow-up: Show on C3. If shown /overlooked,
please notify reviewer since proposed stepped retaining wall easement cannot be located on C3.
21. Extend guardrail that ends 5 spaces south of parking lot island (near `118 LF 15" HDPE label) to last
parking space at south comer of parking lot, immediately adjacent to dumpster enclosure. (Rev. 1)
Addressed.
22. Existing sidewalk at U.S. Rt. 250, IMP 78-13A, may be mistaken as proposed, please label Ex. (Rev. 1)
Addressed.
23. (Entrance / ESP: 25' egress and 35' ingress radii are insufficient for land use. Ref. commercial /office
land use in Table 4-3, VDOT Road Design Manual, Appendix F. With ESP, provide Autoturn fig. using
SU-30 design vehicle to show outbound vehicles do not cross an outer travel lane, U.S. Rt. 250 EBL, and
that inbound vehicles do not mount curb /walk. 25'/35' do not meet VDOT Access Management
requirements.) (Rev. 1) Addressed. Applicant: `The Autotum figure for an SU-30 design vehicle is now
shown in the attached exhibit. Due to the entrance being located at the start of a third lane, a 25' entrance
radius allows the SU-30 to access the parking area without mounting the curb. The right turn out exist
radius is now 45' to give additional space. Per VDOT Figure 4-15, a 25' minimum is required for
moderate volume commercial entrances.' Engineering appreciates response /design revision.
C4
Engineering Review Comments
Page 4 of 9
24. Offsite surface detention basin requires maintenance agreement with owners of TMP 78-73A7 and 78-13A. (Rev.
1) Persists. Applicant: `An agreement will be provided and signed by owners of both parcels.'
25. Offsite retaining wall (TMP 78-13A) requires retaining wall maintenance easement (TMP 78-13A, Grantor, to
TMP 78-73A7 Grantee), independent of any other easement. Retaining wall maintenance easement and SWM
facility easements may overlap. (Rev. 1) Persists. Applicant: `Acknowledged, retaining wall maintenance and
swm easements will be provided and recorded. Proposed easements are now shown on the VSMP.' Also, please
see item 20, above.
26. Label typ. parking space L x W at 15 spaces south of /behind hotel. Provide clearance required to
avoid conflict with retaining wall. Ref. ACDSM 7 C 6 p. 17 of Manual. [ FSP-related.] (Rev. 1)
Addressed.
27. If proposed stepped retaining walls parallel with TMP 78-73B1+ or TMP 78-71A4 require (permanent)
geogrid placement or temporary construction access to construct improvements, provide required
easements as condition of WPO plan approval. (Rev. 1) Persists. Applicant: `Easements will be
provided for retaining walls and geogrid.'
28. Show off -site features downslope of detention pond emergency spillway to at least edge of existing
pavement (car dealership parking lot), and provide relief for emergency spillway flow that does not convey
emergency spillway flow across auto dealership parking lot. Label structures, pipes, conveyance required
to capture emergency spillway flow. Provide public drainage easement across off -site parcels for storm
conveyance below SWM facilities until SWM discharge reaches a natural receiving stream, likely
downstream of auto dealership parking lot. (Rev. 1) Addressed. Applicant: `Edge of pavement for car
dealership is now labeled. Runoff from the emergency spillway is captured by the existing 24" CMP at
inv. 454.8.' '
Satellite image, 24Q2 (blue bwi image outlines appFex. afea of emeFgeney spillway disehaFge) [ images removed
with Rev. 1 comments.]
Photos below FOPFOSORtative of auto dealeFship PaFlang Wt belaw Overlook 149tel
[image, removed with Rev. 1 comments]
29. Provide spot elevations at EP U.S. Rt. 250 EBL and in entrance throat to ensure Rt. 250 runoff does not
enter site, and to delineate flowline aligned with U.S. Rt. 250 CG sections E-W of entrance. (Rev. 1)
Persists. Applicant: `Spot elevations are now provided at the entrance.' As ollow-W: Provide
additional spot elevations, one (0010) is insufficient.
30.
31.
32.
RIJ
Remove sidewalk and CG linework across hotel entrance. (Rev. 1) Addressed.
Show CG12 and new sidewalk connecting to ex. sidewalk, either side of hotel entrance. (Rev. 1) Partially
addressed. As follow-un: Show CG-12 linework, as is typ. of SE plans. Also, shift B2, B4 or CG-12 labels
A building permit is required for wall ht. >3-ft. (Rev. 1) Persists. Applicant: `Acknowledged, retaining walls
require a building permit.'
(PE-) Sealed retaining wall design is required for wall ht. > 4-ft. Please submit to Engineering prior to
WPO plan approval, given integral relationship to storm pipe, grading, and SWM facility. (Rev. 1)
Persists. Applicant: `Acknowledged, signed and sealed retaining wall design will be submitted.'
C5
Engineering Review Comments
Page 5 of 9
34. Provide SL-1 labels, Str A2 and A3 (safety slab). (Rev. 1) Addressed.
35. Revise 47 LF 15"HDPE @ 12.8% to 47 LF RCP @ 12.8%.
(Note: 47' pipe penetrates stepped retaining wall: this pipe is partially in cut, over half its length in fill.
This pipe may not deform, crack, etc. RCP or DIP (not CMP) is required for this pipe section. HDPE may
NOT be substituted for RCP by contractor or design engineer during construction at this location.) (Rev.
1) Addressed.
36. Provide lintel detail where 47 LF RCP penetrates retaining wall, provide ref. to lintel detail on storm pipe
profile. (Rev. 1) Persists. Applicant: `A detail will be provided by the geotechnical engineer. This detail
will be included in the site plan once complete.'
37. Provide note concerning and requiring adequate compaction for storm structures or pipes in fill, which is
majority of storm conveyance upstream of 4640 SF R-Tank Underground Storage. Fill beneath storm
structures and pipes approaches or exceeds 20' in certain locations. (Rev. 1) May persist. Applicant:
`This note is now included with the storm profiles. Adequate compaction will be required for all storm
structures and pipes.' As follow-up: Please direct Engr to note on C5 profile since we cannot locate note.
38. Provide additional profile labels for 4640 SF R-Tank Underground Storage, including geogrid and at least
label ref. to 3" min. base material to help establish grade for R-Tank installation, convey design intent, aid
inspection, minimize error, and avoid misunderstanding during construction. (Rev. 1) Addressed.
Applicant: `Notes have been added to the profiles indicating min. 3" of compacted subgrade, geotextile
fabric, and geogrid installation per mnfr's installation instructions.'
39. Note: Critical installation steps of detention basin, R-Tank Underground Storage, and retaining walls,
particularly adjacent to SWM, require licensed engineer or qualified manufacturer's technical inspection to
affirm suitability of bearing strata, subgrade compaction, backfill, underdrain /weep placement, suitable fill,
adequate depth, etc, to confirm and ensure wall foundations subject to saturated conditions or supporting
hotel parking, aisles, or structures are not compromised by periodic inundation /submersion during rain
events (detention pond), or excessive vehicle surcharge /geotechnical forces. Provide notes on plan
requiring qualified geotechnical installation inspection, certification, and reporting /recordkeeping. (Rev. 1)
Addressed. Applicant: `A note is now provided that indicates appropriate design, inspection, and
certification is required by a geotechnical engineer.'
40. Emergency spillway may not be placed in fill without proper analytic design, and armoring. Ref. VA DEQ
Stormwater Design Specification, Appendix A Earthen Embankment. Provide design for detention pond
emergency spillway in fill. (Rev. 1) Addressed. Applicant: `The emergency spillway will use grouted rip -
rap as reinforcement in fill.' Shown on C12.
41. Label detention pond top of embankment elevation. Ensure top of embankment ht. >463.95'. C3 indicates
`top of dam' elev. =464'. (Rev. 1) Addressed.
42. Label detention pond floor elevation. (Rev. 1) Addressed.
43. Detail 2 (Storm profile AO -Ex. 24" RCP):
a. Label Str. AO, Al, 130, B1, B2. (Rev. 1) Addressed.
b. Provide INV/RIM data and inlet /MII type for each storm structure (descriptive labels). (Rev. 1)
Partially addressed. As follow-up: See detail 4, this sheet, and provide equivalent storm structure
labeling information; for example: MH-1, INV IN/OUT, Rim elev., etc.
c. Shift pipe captions L/DIA/slope so captions lie below pipe they describe. (Rev. 1) Addressed.
d. Profile indicates MH located in detention pond embankment, inconsistent with 0, Site and Utility
plan. Review profile and plan for accuracy /consistency. Revise profile as needed. (Rev. 1)
Addressed.
44. Label pipe slope between Str. A4 and R-Tank Underground Storage. (Rev. 1) Addressed.
45. Label pipe INV IN elevation at R-Tank, from Str. A4. (Rev. 1) Addressed.
46. Label R-Tank top elevation, appears to be 481'. (Rev. 1) Addressed. As ollow-up: In all profiles, remove
hatching that overlaps R-Tank text. Provide a clear `text window' for R-Tank top, INV, so text is more easily
readable.
47. Detail 1: Label INV OUT, Str. AI. (Rev. 1) Addressed.
C7
C10
Engineering Review Comments
Page 6 of 9
48. Provide label requiring %," steel plate in floor of MH Sir. Al. Ref. VDOT Drainage Design Manual, Ch. 9,
Storm Drains, 9.4.8.7, Max. Grade. (Rev. 1) Addressed.
49. Delete second sentence of text block in text box in upper right of plan sheet. "The sediment basin [shown
on TMP 78-13A] can remain after construction." This is incorrect. Once upslope areas are stabilized, the
sediment basin must be converted to SWM detention basin. ESC measures may not persist for future
development since ESC measures are temporary, future development is never certain, the feature will be
bonded as a SWM facility /bond could not be released, and plan indicates surface detention is required to
meet SWM quantity requirements. If this is not the case, that is, if pond is not needed to provide SWM
quantity control for Overlook Hotel, then notes and labels should indicate the sediment basin will be
removed and not converted to SWM control, once upslope areas are stabilized. Also, item 64.a., below.
50. At Str. 4, provide INV IN 47 LF 8" PVC from roof leader line. (Rev. 1) Addressed.
51. Provide /label storm profile: yd. drain roof leader line system behind (east of) hotel. (Rev. 1) Addressed.
52. The surface detention pond will detain surface runoff from grading and land use on TMP 78-13A. Ref. C4
and SWM Quantity note, C7. Clarify SWM Quantity note (slight text revision) to indicate surface
detention is required for Overlook Hotel development, and will be converted to a SWM facility once
upslope areas are stabilized, and it is no longer needed as a sediment basin for the Overlook Hotel
development. (Rev. 1) Addressed. Applicant: `The SWM note on sheet C7 has been updated accordingly.'
As follow-up: Please confirm SWM Quantity note still appears on C7, as location is difficult to fmd.
53. Revise pipe material for storm drain that passes beneath tiered retaining walls. Commend design that
selects least problematic location for crossing wall, but every attempt must be made with design and during
construction to ensure longevity and maintenance -free performance of this particular pipe: revise pipe
material type to RCP. Comment may repeat. (Rev. 1) Addressed.
54. Provide lintel design for retaining wall pipe crossing. Note: this pipe is within public drainage easement. (Rev. 1)
Persists. Applicant: `A detail for the pipe crossing will be provided. Acknowledged, this pipe is within a public
drainage easement.'
55. Note: VDOT Land Use Permit is required for work within public RW, U.S. Rt. 250, Richmond Road. (Rev. 1)
Persists. Applicant: `Acknowledged, all appropriate permits will be acquired.'
56. (FSP-related) Since road plan not required, provide evidence of coordination /approval of a Maintenance of
Traffic Plan with VDOT (MOT) with WPO Application (since ties to land disturbance), or not later than
final site plan (FSP) review /approval. A MOT with restriction on hours of operation will likely govern
work within VDOT RW, U.S. Rt. 250. An approved WPO plan and Grading Permit do not authorize
construction within U.S. Rt. 250 public RW. VDOT maintains jurisdiction over activity within, or
disturbance within public RW. (Rev. 1) Addressed. Applicant: `An MOT plan has been added as sheet
C 18. This will be distributed to VDOT for approval and all work will be coordinated with VDOT as part
of land use permit application.' As follow-up: Please confirm that Shimp Engineering will distribute,
independent of WPO202100036 review, or SDP202100039 (Approved ISP), or future FSP, the MOT to
VDOT, Charlottesville Residency, for VDOT review and approval.
57. It is unclear whether runoff from development reaches surface detention pond (no inlet pipe/s); please
confirm design intent and whether surface detention is to intercept surface sheet runoff only. (Rev. 1)
Addressed. Applicant: `The detention pond is intended mostly for the future development of parcel
78-13A and runoff from the adjacent retaining walls. All runoff captured from the hotel and parking
lot is routed to the underground storage system." As follow-up: Engineering rarely if ever encounters
off -site SWM that is not required by on -site development. If off -site detention pond serving future
development of parcel 78-13A persists and is shown, it means: 1) it must be bonded by owner of
TMP 78-13A, since bonds attach to parcels where SWM or ESC measures are located; 2) calculations
must indicate off -site detention pond capacity is not required for 78-73A7 compliance, but is, rather,
developed with Overlook Hotel with capacity held in reserve for future development of TMP 78-
13A. Please provide plan notes /calculation narrative that clarify design intent, notes /narrative that
in effect decouple detention pond from Overlook Hotel. Engineering anticipates a future WPO for
development of TMP 78-13A (Happy Boxes Pantops, LLC /Owner) will in some fashion reference
and rely upon WPO202200036, in whole or in part, for stormwater water guanfity compliance
purposes. We want this circumstance to be clear, to limit or hopefully avoid confusion.
Engineering Review Comments
Page 7 of 9
58. Review potential of undeveloped parcels with relatively low curve numbers north of U.S. Rt. 250 to
increase runoff since Overlook Hotel proposes to pipe /encase existing drainage feature. It is unclear if a
24" HDPE provides adequate capacity for either existing or future development in the upslope watershed.
Please consider undeveloped parcels that may contribute additional runoff to the existing storm system
beneath U.S. Rt. 250 that daylights south of U.S. Rt. 250 on TMP 78-13A. 12/30/19 photo, below. (Rev.
1) Withdrawn. Applicant: `The existing DI on Rt. 250 already releases runoff to the POA at the drainage
structure on 78-13A by the car dealership parking lot. We will not route any additional runoff north of
250 through our site.' This response highlights reason. Pipe downstream of drainage structure AO, TMP
78-13 (car dealership parking lot) is 24". Pipe beneath U.S. Rt. 250 is 24". Project 24" bypass will only
increase flow within bypass system from Str. Al to AO. Calculations indicate Q10 for this pipe section is
10.81cfs while capacity of this pipe section is 16.6cfs (p. 45, Cale. packet). Review comment withdrawn.
[image of Ex. 24" pipe beneath U.S. Rt. 250 removed with Rev. 1 comments.]
59. TWBW 92/85.5 at dumpster enclosure exceeds wall Max. In. for managed steep slopes, 18-30.7.5.A.1.
Revise to limit wall ht. to 6' Max. (Rev. 1) Addressed.
60. Provide stand-alone SWM plan: (Rev. 1) Addressed.
a. VSMP /WPO plan includes Mfr. details for R-Tank underground storage, installation, operation,
inspection, and maintenance, which is excellent (C13, C14). C15 includes Construction Record
Drawings (As -built) for VSMP. In addition, on a SWM plan sheet (C16 or C15), please provide:
i. Letter of nutrient credit availability (required for plan approval).
ii. VaRRM.xls site summary tab.
iii. SWM quality /quantity narrative (relocate from C7, E & S Narrative).
iv. Summary quantity /quality calculations —for example, include EB equation on the plans.
Table -chart, p. 40 of calculation packet, for example.
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 reasons listed, below. The erosion control plan content requirements can be found in
County Code section 17-402.
61. C4
a. Provide recorded permanent grading easement with adjacent parcel, TMP 78-13A, Happy Boxes Pantops, LLC.
(Rev. 1) Persists. Applicant: `A grading easement with parcel 78-13A will be provided.'
b. Related: provide copy of notarized agreement or recorded temporary construction access easement with owner of
TMP 78-13A. Ensure temporary construction access easement extends from areas to be graded to U.S. Rt. 250 at
such point that construction vehicles may exit Rt. 250 via asphalt ramp or commercial entrance and at a point
approved in advance by VDOT. (Rev. 1) Persists. Applicant: `A temporary construction access easement will be
provided.'
62. C8
a. Provide show label paved construction entrance at U.S. Rt. 250 EBL. (Rev. 1) Addressed.
b. Eradicate linework for ex. U.S. Rt. 250 C&G /sidewalk if removed in Phl. (Rev. 1) Addressed.
c. Remove proposed entrance radii linework and lines /curve delineating edge of parking lot at approx. contour
470' (that bisects trap 3). (Rev. 1) NA. Note: E&SC phasing revised.
d. Provide short length of on -contour SF a short way downslope of trap weirs, in E & S Plan PHI. (Rev. 1)
Addressed. Applicant: `SF is now shown downslope of sediment trap weirs.'
e. Shift STI, ST2 at least 2' downslope to ensure DD functions and there is sufficient fall from NW comer of site to
ST 1. This should not conflict with wall construction downslope. (Rev. 1) Addressed. Applicant: `The E&SC
plan has been revised to relocate the sediment traps. The new design does not conflict with retaining wall
location.'
f Provide TS, PS, MU for pipe installation AO to B2. (Rev. 1) Addressed.
g. Revise sequence to describe by-pass for runoff that daylights /exits 24" RCP beneath /south of U.S. Rt. 29 EBL.
It will take days for 385 LF 24 HDPE to be installed, and ESC measures for 24" bypass are critical to ensure no
offsite incident or impacts downslope to auto dealership parking. Existing drainage 10-yr event is likely
considerable; provide bypass during construction of 24" HDPE conveyance. (Rev. 1) Partially addressed.
Applicant: `The E&SC phasing for the construction of the new 24" HDPE pipe has been revised and is now
included in P112. This will be the only disturbance during Ph2. Spoils are to be placed upslope such that all
sediment remains in the trench per MS-16. Dewatering pumps with filter bags are to be used so that there is no
Engineering Review Comments
Page 8 of 9
surface runoff from disturbed areas into the existing inlet, which is also protected.'
As follow-up:
• C9: Provide note concerning dewatering pumps with filter bags.
• C9: Provide note concerning upslope side -cast of pipe trench excavate /spoils, per MS-16.
• C 13: Provide stream bypass /dewatering details, similar to VESCH Plate 3.25-1, 3.26-3, both of
which provide useful detail elements.
It. New (Rev. 1)
Previous submittal included ESC PH1,2,3, revised plan includes ESC PH1,2,3,4. As follow-up:
• CIO: Provide ESC measures to prevent runoff cresting tiered retaining walls at this phase, at a Min. SF at TW.
• Show and label wire -backed silt fence at base of tiered retaining walls, south and west of site (SF is shown in
some locations, not others), ensure all tiered walls south and west of site are shown/labeled wire -backed since,
as walls are constructed, significant volumes of upslope undisturbed material will be cut /excavated for geogrid,
soldier piles, etc.
• C11: Label floors of STI, ST2 (L x W).
63. C9
a. Offsite ESC controls (TMP 78-13A) require offsite owner be party to WPO plan bond and will require right of
entry Agreement to ensure Albemarle has right to enter and inspect ESC measures. (Rev. 1) Persists. Applicant:
`Adjacent parcel will provide access to E&SC measures and agreement will be in place for all work on this
parcel. Note that these parcels share the same owner under different LLCs.'
b. Show /label proposed contours (grading) at this phase, including at ends of retaining walls (tie grading to existing
grade). (Rev. 1) Addressed. Applicant: `Retaining wall grading and tie-in to intermediate grade is now shown in
Ph. 3.'
c. Show material or soil stockpile, this phase, as needed. (Rev. 1) Addressed.
d. Revise trap labels to: STI, ST2, ST3. (Rev. 1) Addressed.
e. Provide TS, PS, MU at this phase, where and as needed. (Rev. 1) Addressed.
f Clarify how runoff reaches traps STI, ST2, given proposed grade at this phase. (Rev. 1) Addressed. Applicant:
`Sediment trap plan has been revised, intermediate grading and diversion dike is now shown while parking area
is brought to grade to prevent water from flowing over the walls.' As ollow-up: See item 62.h. above.
g. Provide RWD as necessary if construction equipment must cross diversions. (Rev. 1) NA. Applicant: `Diversion
has been relocated to avoid construction traffic. In this case, a RWD would be difficult to maintain.'
h. Remove STI DA text box, not needed in PH2 since shown in PHI. (Rev. 1) Addressed.
i. Resolve ST3-retaining wall conflict, since shown to overlap. (Rev. 1) Addressed.
j. Show /label paved construction entrance on U.S. Rt. 250. (Rev. 1) Addressed.
k. Eradicate linework for ex. U.S. Rt. 250 C&G /sidewalk if removed by Ph2. (Rev. 1) Addressed.
I. DD shown in Ph are not shown in Ph2, clarify how Ph2 runoff reaches STs in Ph2, relative to proposed grading,
Ph2. Also, 09, item b., above. (Rev. 1) Addressed. Applicant: `Sediment traps and diversions have been
updated.'
in. Provide interim ESC measures needed to place backfill at stepped retaining walls that approach 20-ft. ht. in
location of ST3, which cannot occupy this space during wall construction. (Rev. 1) Addressed. Applicant: `A
more detailed E&SC plan is now provided to show controls during /after wall construction while areas are
brought to grade.' Also, please see item 62.h. above.
n. Recommend remove guardrail linework, unless installed in Ph2. (Rev. 1) Addressed. Applicant: `Guardrail is
now removed from Ph 2 as it will be installed after other work is complete.'
o. Recommend remove extraneous linework that encircles hotel. (Rev. 1) Addressed.
p. Provide access to sediment basin trap during this phase of construction. Show on plans. Ensure construction
access is traversable by AVID vehicles and construction equipment. (Rev. 1) Addressed.
q. Provide paved construction entrance to 78-13A for sediment basin trap construction, during this phase. (Rev. 1)
Addressed. Applicant: `A paved construction entrance is now provided on parcel 78-13A in order to access the
area around sediment trap 1 and the proposed storm structures.'
64.C12
a. Contributing DA to proposed sediment basin is too small to qualify for this ESC measure. VESCH states
(Conditions where practice applies) "Below disturbed areas where the total contributing drainage area is equal to
or greater than three (3) acres." DA =1.48 Ac., which yields impractical A, B, C values in basin design table: 0.5'
vertical difference between floor of basin and clean -out level, for example. An SB is not appropriate, and will not
be approved. Revise measure to sediment trap (ST4). (Rev. 1) NA. See item 64.c. below.
b. Provide ST4 design data. (Rev. 1) NA. See c., below.
c. Additional comments possible. (Rev. 1) Addressed. Applicant: `A sediment trap will now be used. The E&SC
Engineering Review Comments
Page 9 of 9
design has been updated to better stage retaining wall construction and only requires 2 traps.'
Process:
After approval, plans will have 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 have to be completed by the owner and submitted along with cash,
certificates or sureties for the amounts specified. The agreements will have to be approved and signed by the County
Attorney and County Engineer. This may take 24 weeks to obtain all the correct signatures and forms.
Stormwater Management Facilities Maintenance agreements will also have to be completed and are recorded. The
County's Management Analyst or other staff will prepare the forms and check for ownership and signature
information. The completed forms will have to be submitted along with court recording fees.
This project proposes nutrient credit purchase (2.26 lbsJ and requires SWM facility and SWM facility access
easements. This project may also require forest -open space easement (for SWM purposes).
After bonding and agreements are complete, county staff will 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 have to be paid directly to the state. For fastest processing,
this is done electronically with the emails provided on the application. 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, via the coverage letter, the County can hold a pre -construction conference.
Applicants must complete the request for 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 joint VSMP and
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 Applications:
httos: //www. albemarle. org/govemment/community-develol)ment/aooly-for/engineering-aoolications
Thank you.
Please call if any questions — tel. 434.296-5832-x3069, or email ianderson2&albemarle.org.
WP0202200036 Overlook Hotel 121922revI-c fix.docx