HomeMy WebLinkAboutWPO200800083 Review Comments Erosion Control Plan 2008-09-11ALg�,��
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COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road
Charlottesville, Virginia 22902 -4596
Phone (434) 296 -5832 Fax (434) 972 -4126
Project: WPO- 2008 - 00083; SDP - 2008 - 00130; UVA Long Term Acute Care Hospital
Plan preparer: Mrs. Ammy George; Timmons Group
Owner or rep.: Kirtley Family Holdings and University of Virginia Health Services Foundation
Date received: 11 August 2008
Date of Comment: 11 September 2008
Engineer: Phil Custer
The final site, ESC, and SWM plan for the UVA Long Term Acute Care Hospital has been reviewed. The
following comments are provided.
A. SDP - 2008 -00130 General Review Comments
1. These plans cannot be approved until the site and WPO plans for the Sieg maintenance parcel are
approved. At this time, approval has not been received for the Sieg maintenance site.
2. VDOT approval is required. At this time, VDOT approval has not yet been received.
3. It appears the sanitary sewer lateral for the hospital was drawn through a proposed inlet.
4. The parking calculations submitted in this site plan need to be approved by the Zoning
Administrator. After taking part in a meeting with Charlie Hurt, I understand that a separate study
will be submitted to the County.
Please provide a 30ft access easement north of the loading dock for a possible future connection
from the Kirtley warehouse area. Please provide a construction easement on either side of the
access easement.
B. SDP - 2008 -00130 Final Site Plan Comments
1. Please clearly reference each wall to a detail. In this set, there does not appear to be a detail for the
retaining /screening wall around the loading dock. (This wall and site plan doesn't appear to match
the ARB submittal.)
2. Safety railings are required on all retaining walls greater than 4ft in height.
3. Please show a private sanitary sewer easement through the Northridge and Sieg properties for the
lateral from the Kirtley warehouse.
4. A drainage easement is needed along the pipe system on the Korean Church property carrying
LTACH drainage. The width of the drainage easement must be computed using the equation
listed in the design manual. This drainage easement must be recorded with a deed of easement
before the site plan can be approved.
5. Please show an access and parking easement over all spaces on the Northridge property and extend
this easement to the Sieg property line and the entrance onto Route 250.
6. The existing entrances from Northridge and the private access easement must be called out as a
VDOT Standard entrance. If these entrances do not meet the VDOT standards, they must be
upgraded. It appears that the entrance of the private access easement (to the Korean Church,
Kirtley Warehouse, and ambulance drop off) does not meet the standard.
7. Please show adequate sight distance on the site plan set from the two entrances.
8. Please show the existing striped areas between the handicap spaces in the Northridge lot east of the
entrance to the proposed hospital.
9. Curbing is required around the ambulance drop off area except at the entrance to the building.
10. The maximum grade for parking/loading areas is 5 %.
11. The curvilinear spaces on the southeast corner of the hospital appear to be narrower than 9ft.
12. Sidewalks abutting curbs must be 6ft in width, exclusive of curb, or a bumper block must be
provided.
13. Engineering review maintains a policy of overland flow relief in case of inlet/drainage system
failure. It appears that spot elevation 20ft south of inlet 116 should be Ift lower and overland flow
relief will be achieved for all inlets.
14. The applicant must provide a traffic generation and distribution summary for the site development.
The traffic impact analysis was not submitted with this application and must be submitted prior to
final approval. (PC condition #2)
15. The drainage profiles must include: a VDOT designation for each structure, throat length for each
curb inlet, and the grate type for each drop inlet (if applicable).
16. VDOT standard inlet shaping (IS -1) is required on all structures where the flow drop is 4ft or
greater (this includes drop from the surface to the bottom of the structure).
17. VDOT standard safety slabs (SL -1) are required on all structures taller than 12ft. This requirement
also applies to the structures within the BMP system.
18. Please provide an accurate profile of the downstream system from structure 100. This profile must
match all MS -19 calculations (see comment 132).
19. Please accurately show what structure 200 will look like in the plan view. The detail does not
match what is shown in the plan view sheets. (Also, on sheet C5, the note for the detail of
structure 200 refers to the wrong sheet.)
20. Please provide a detail regarding how the stormfilter structure will be set on the existing inlet base.
Please clearly show how access will be maintained to the bottom of the structure.
21. Please provide drainage area maps for each structure including: drainage area lines, acreages,
hydrologic coefficient, time of concentration, and the structure labels.
22. Does the hospital have any other roof drain pipes exiting the building on the eastern half of the
building?
C. WPO- 2008 -00083 Stormwater Management Plan Comments
1. SWM facility maintenance agreements will need to be recorded for both properties before the site
plan can be approved. Please submit these documents with fees directly to Pam Shifflett after
consulting the guidelines available on the county website.
2. A letter from the manufacturer stating approval of the stormwater systems needs to be sent to the
county.
3. Please extend the SWM easement over all BMP structures.
4. The pre - development drainage area map is not accurate. The drainage area lines should not run on
the property line.
5. Please adjust the grading to capture all of the parking lot and travelway around the two -story
building.
6. Please provide the standard county notes for SWM plans.
7. In the removal rate calculations, the applicant indicates that the project is located in the
development area when actually the entire site, except for the southern portion draining to the
roadside Swale, drains to a water supply reservoir.
8. The county maintains the current policy of the state by giving proposed stormfilters a removal rate
of 50 %. The application of the stormfilters in drainage area 2 is satisfactory due to the low
removal rate. However, it seems in drainage area 1 more quality treatment will be required. In
addition to the larger stormfilters (sized for 1 ") shown in the plan, the applicant should provide
more water quality treatment in drainage area 1. Possible solutions include: providing a biofilter
above the detention system used to treat the roof runoff, providing an appropriately sized
cistern /rainwater harvesting system, or pervious paving in the travelway and parking areas around
the 2 -story building. The county will not accept the BMP as designed especially when such a high
removal rate is required.
9. A trash screening system should be provided in structure 106 before entering the detention system.
10. Three inches is the smallest orifice allowed in the county. Please adjust the detail and routing.
11. Please supply a detail showing the profile of the detention system specifically showing how access
from the surface is provided into the 1Oft pipe. The calculations indicate that the system will be
placed at an odd slope and this should be shown in this detail.
12. The pipe from the 96" volume manhole is called out as 15" in the site specific detail but is 3" in
the Contech detail.
13. In the calculations, there is a 1.5 inch orifice assumed at the bottom of plate in the facility, but the
detail does not show this. In order to provide the water quality treatment, it appears this orifice
should be removed.
14. Were the routings performed assuming an empty structure? If so, what is the estimate drawdown
time for the stormfilter system? If the drawdown time is too long, the system should be routed
with some of the water quality volume still present in the system.
15. Please provide calculations showing that the volume below the orifices in the structure is greater
than or equal to the water quality volume.
16. Please provide spot elevations on the plan showing that the access path is flat. (It appears that
there will be a 649 plateau between the building and the edge of the detention facility.)
17. A SWM bond has not been computed at this time. The bond will be computed once the plans are
approved.
D. WPO- 2008 -00083 Erosion and Sediment Control Plan Comments
1. If the applicant intends to use "super silt fence ", a variance is needed from the program authority
because the method is not listed in the VESCH. Please submit a letter requesting this variance
including reasons why the measure is proposed and a fee of $760.
2. In initial phase of site disturbance, the ESC measures proposed in the southwest corner of the site
are not adequate. Silt fence cannot treat concentrated discharge. Please provide a sediment trap
with diversion dikes in this area. It seems that locating a trap close to the existing parking lot
(where the handicap spaces and concrete plaza will be) would work for ESC control until the
storm drain is installed.
3. The adequate channel analysis of downstream system is not as detailed as the county requires.
Please provide an analysis as described in the latest edition (8/18/08) of the design manual (page 7
of 42). Each segment of the downstream network should be checked. The analysis should stop
once the development is 1% of the watershed as stated in Virginia ESC law.
4. Will this plan require fill from off -site or need to dispose of excess soil? If so, please include a
statement in the narrative under "Off -site areas" referencing that.
5. All construction and site improvement need to be shown within the limits of disturbance.
6. Please provide on the plan symbols for dust control, temporary seeding, and permanent seeding.
7. The construction entrance must drain to a sediment trap or basin. The construction entrance
should also not be placed in a location that requires significant grading and tree removal.
Engineering review recommends using the existing pavement already on site. I do not understand
the construction entrance note on sheet C14 because existing pavement is not proposed to be used
as the CE.
8. Please provide a soil stockpile location on the plan. [DM]
9. Please provide a staging and parking area. Please also describe how the parking demand for the
Northridge site will be managed with the construction traffic and construction workers parking
demand and the loss of parking spaces in the Northridge lot. It appears that the lot on the Sieg
property may need to be constructed first.
10. Inlet protection is missing from a few inlets in the area of the construction activities.
11. Phase H of the ESC plan appears to be missing many ESC measures that should remain in place
from the Phase I plan.
12. Please specify in the construction sequence when and how the detention system will be installed
while the site is disturbed. Is there any way to take the system offline until the site is deemed
stabilized? Otherwise, the surface inlets may have to be sealed until site stabilization.
13. An ESC bond has not been computed at this time. The bond will be computed once the plans are
approved.
File: El_fsp swm esc_PBC_wpo0800083- sdp0800130 UVA LTACH