HomeMy WebLinkAboutSDP200800144 Review Comments Final Site Plan and Comps. 2008-10-31ALg�,��
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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: SDP - 2008 - 00144, Crown Automotive Site Plan
WPO- 2008 - 00093, Crown Automotive SWM and ESC Plans
Plan preparer: Ankita Kot; Freeland and Kauffman, Inc.
Owner or rep.: Crown Motorcar Company, LLC c/o Asbury Automotive Group, Inc.
Date received: 24 September 2008 (plan signed date 10 September 2008)
Date of Comment: 31 October 2008
Engineer: Phil Custer
The Final Site, SWM, and ESC plans for Crown Automotive, received on 24 September 2008, have been
reviewed. The plans cannot be approved as submitted and will require the following changes /corrections
prior to final approval.
A. General review comments:
1. A boundary line adjustment appears to be necessary so that the building is only located on one
property. If the property boundary is not adjusted, the County Building Official may require a
firewall in the building between the two parcels.
2. An easement plat showing the required access, drainage, swm, private sanitary on the ACSA
property, and parking easements must be recorded prior to site plan approval.
3. Please note on all sheets and documents that the public road west of the site has been called
People's Place rather than Pantops Park Drive.
4. VDOT approval is required. At this time, VDOT comments have been forwarded to the
applicant. The applicant should work directly with VDOT regarding these comments.
B. Site Plan review comments:
1. Please make sure the date and source of the topography is listed on Sheet C2. [DM]
2. Please show all existing easements with deed book references, locations, and dimensions on
the properties involved.
3. Please shade all critical slopes on Sheet C2. [DM]
4. All slopes steeper than 3:1 will require a low maintenance, non - grassed groundcover. [DM]
5. The guardrails required at the top of the retaining walls must be a VDOT Standard. The site
plan must also specify the proper guardrail terminals as well.
6. A guardrail is needed in the southwest corner of TMP 78 -15. It appears that because of the
required distance the guardrail must be spaced from the face of the retaining wall, the wall will
need to be moved into the adjacent property and the easement will need to be larger.
Engineering review recommends working with TMP 78 -15C to eliminate the need for the 30ft
retaining walls by filling to meet grade.
7. A guardrail is also needed over the tiered retaining wall west of the building.
8. There cannot be a break at the guardrail at the filterra. The wall must be pushed into the
adjacent property. Engineering review recommends working with TMP 78 -15C to eliminate
the need for the retaining wall in this area.
9. Retaining walls B, C, E, and G should have both a guardrail and a taller safety /pedestrian
railing like the detail on Sheet RWS.
10. In many places, it does not appear there is enough room for a few of the walls and guardrails
considering the loss of 7.1 degree stacking angle of some of the walls. At 7.1 degrees, you
lose lft horizontal for every 8ft of wall height. For instance, at retaining wall C, the distance
between back of curb of the travelway and back of curb of the lot on sales office property is
4.5 ft. Considering the loss of lft because of the slope of the wall, the 3.3ft between the face
of wall and the back of the guardrail, and the 1.5ft width of the guardrail (total 5.8ft), there is
not enough room.
11. A private sanitary sewer easement is needed over the sewer lateral through TMP 78 -15B.
Also, a new drainage easement for pipe from the ACSA property to TMP 78 -15B will be
needed. A plat showing all of these easements (plus the existing and already proposed
easements in this set) must be recorded prior to site plan approval.
12. Please show drainage easements on the Landscape plan. No trees of significant size will be
allowed inside the drainage easements.
13. All entrances must have a VDOT designation. [DM]
14. All entrances must not exceed 4% for the first 40ft from the curbline of Route 250. [DM]
15. Please label all curbing with the proper VDOT designation. [DM]
16. There does not appear to be a loading space that meets 18- 4.12.18 provided on site. A waiver
from the Zoning Department will be required if one is not provided.
17. Please provide an island at the southwest corner of the new building that is at least 3ft wide.
18. An inlet should be provided east of the site entrance along Route 250. As currently designed,
close to 250 linear feet of 3.5 lanes will drain across the entrance and flow into inlet 4. Curb
inlet calculations should be provided for this new inlet and storm pipe. A drainage easement
will be required on this system of pipe.
19. All changes of direction in stormpipe systems must be at least 90 degrees.
20. Please provide traffic generation and distribution summarys.
21. Please use VDOT specifications in the parking lot pavement section.
22. Please correct the sidewalk detail. The sidewalk detail should not show a 6" curb unless it
meets a VDOT CG designation. The sidewalk detail must also show in section 4" of stone
base and 4" of concrete of 3000psi strength at 28 days or stronger that is reinforced with a
wire grid. Handicap ramps should be specified with a VDOT standard.
23. A dumpster pad detail meeting the requirements listed in the design manual is required.
24. The dumpster pad must be at least 18ft long.
25. Please provide more spot elevations in the area of the dumpster to assure that drainage does
drain across the footprint of the dumpster.
26. Please provide details for pipe systems running underneath a retaining wall. Pipes 11 -10, 15-
13, and 2 -1 will likely be close to the foundation slab of the proposed retaining walls.
27. The set appears to be missing several storm drain profiles. The following profiles should be
included in the set: RI -9, 15 -14, 18 -13, 12 -11, and 19 -9.
28. The following information needs to be shown in the drainage profiles:
a. A VDOT designation for each structure.
b. The throat length for each curb inlet.
c. The grate type for each grate inlet.
d. Structures will a vertical drop of 4ft or greater (including from the surface to the bottom of
the facility) must have VDOT Standard IS -1 specified.
e. All structures deeper than 12ft must have a VDOT Standard SL -1 (including existing
structure 7).
29. The drainage computations show that several of the proposed 36" pipes are undersized. Please
correct.
30. Drainage maps should be provided for the existing storm sewer main to estimate the flow
through the site. Currently, the drainage area map only shows the area draining to the new
proposed inlets. For instance, drainage area lines estimating the watershed for pipe system 19-
9 to determine the flow through pipe 9 -7.
31. In the drainage area maps, please include a hydrologic coefficient and a time of concentration
for each drainage area.
32. Will there be any grading from the base of the tiered walls to Peoples Place? Please provide
spot elevations at the base of the walls in this area. Has inlet 22 been placed at its current
location to catch runoff from the swale on the east side of Peoples Place?
33. Please specify a 2% cross slope on the travelway from the building down to Filterra 2.
C. SWM review 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. Please provide approval letters from the manufacturers of the prefabricated stormwater
systems ( Filterra and Contech) stating that as proposed, the facilities meet the minimum
standards and removal rates attributed to them by the Virginia DCR.
3. The output from the routing of the detention facility does not appear to meet the full
requirements of the design manual and state law in the cases when downstream channels are
inadequate. However, engineering review realizes that meeting those requirements with such
a small site is practically impossible and will grant a variation from the requirements.
Detention and satisfying the downstream channel limitations concerns will be approvable if
both the 2 and the 10 year storms are routed through only 3" orifice. The applicant may use
either the modified rational method (routing the critical storm) or the SCS method for the
facility. Please contact me to discuss this further.
4. In the post - development drainage area map for the detention facility, please provide the
acreage, hydrologic coefficient, and time of concentration. The acreage appears to be less than
the 2.8 acres that has been used in the routing calculations.
5. The post - development drainage area map is not correct. The drainage area line as drawn on
Sheet C20 appears to still be the limits of disturbance for the project rather than the drainage
area to the detention facility. For instance the drainage area to the facility should be extended
to the centerline of Route 250. Also, inlets 18 and 20 do not drain to the detention facility as
indicated in the map.
6. Engineering review has a few concerns regarding the Stormfilter systems:
a. As currently shown, both inlet pipes will be filled with water. Please place the inlet pipes
above the water elevation so that the upstream storm pipes are empty under normal
conditions.
b. The 4" orifices in the concrete boxes limit will cause storms of a high intensity to bypass
the treatment facility. The current setup does not appear to match the detail approved by
DCR in the VSMH. I am concerned a large percentage of the first flush will not be treated
with the two facilities as proposed. By my calculations, any storm that is more intense
than 0.33 in/hr will use the bypass.
Inlet 20 should drain to the detention facility and should be treated. A drainage easement will
be required on this pipe system.
The Stormfilter catch basins should be sized to treat the water quality volume for the drainage
area to them.
The SWM facility easement will need to be recorded on TMP 78 -15B before the site plan can
be approved.
8. Access should be provided in the detention facility to all inlet and outlet points.
9. A trashrack is required on all orifices.
10. Please provide a note on the plan that all manhole access to the detention facility must meet
all OSHA standards.
11. The equivalent of the VDOT Standard SL -1 should be provided for in the details for this
detention structure.
12. All pipes entering or leaving the facility must be a minimum 15" in diameter.
13. The topography in the parking lot uphill of Filterra 3 creates a channel that appears to bypass
the filterra. Please correct.
14. The SWM portion of the WPO bond will be computed once the plan has been approved.
15. Additional comments may be required based on the changes to the plan.
D. Site ESC review comments:
1. There appear to be conceptual problems with the erosion and sediment control plan and a full
review could not be completed. There are considerable issues when the site transitions from
Phase II to Phase III with the current plan. Engineering review recommends building a
sediment basin, using structure 7 as the riser, immediately after the stormsewer main (11 -10 -9-
7) is constructed and directing all water during construction to it. This way, the ESC measure
is in the corner of the site and can be removed and filled once the rest of the site is deemed
adequately stabilized by the site inspector.
2. A construction entrance is needed for each phase of the ESC plan.
3. The construction entrance must be placed in a location that does not require any initial
grading. The location proposed in phase I and I1 requires grading. Engineering review
recommends using the existing entrance (across from the entrance to Peoples Place) during the
initial phases of construction.
4. Pipe outlet sediment traps require a variance from the program authority. Please provide a
letter justifying the use of this facility if you continue to use it in place of a standard in the
VESCH and a fee for a variance request of $760.
5. Please label the critical slopes on the phase I plan.
6. Please provide dust control on site.
7. Please provide a parking and staging area for each phase of construction.
8. Please provide a location for a soil stockpile for each phase of construction.
9. This site will require significant amounts of soil in order to construct. Please specify the
borrow site so we can confirm the site has an adequate erosion control plan. Please include
this in the Offsite areas of the ESC Narrative.
10. The silt fence on the west end of the site will not filter water but will act more as a diversion
dike. Please replace this silt fence dike (or using the existing swale) to direct sediment -laden
water to the sediment basin facility until the site is to grade. (Please see comment D.1).
11. Please make the following changes in the ESC narrative:
a. A title is needed.
b. Please identify all steep slopes on the Crown parcel and the adjacent slopes on the ACSA
property as critical areas.
c. The please remove the reference to Flat Branch and Bull Run from the narrative. Those
water bodies do not exist in Albemarle County.
12. Inlet protection is needed on the existing inlets in the parking lot of the existing sales property.
13. Please remove the existing entrance from People Place in Phase III of the plan.
14. The ESC portion of the WPO bond will be calculated once the plans are ready to be approved.
15. Additional comments may be required based upon the required changes.
Once these comments have been addressed, please submit 2 copies of the revised plans,
calculations, and narratives to Current Development Engineering.
Please contact me at 434 - 296 -5832 ext. 3072 or email pcuster @albemarle.org if you have any questions.
File: El_fsp esc swm_PBC_Crown Automotive.doc