HomeMy WebLinkAboutWPO201100055 Review Comments Erosion Control Plan 2011-09-23ALg�,��
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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:
The Shops at Stonefield -Regal Cinema Final Site, ESC, and SWM Plans;
SDP - 2011 -00047 and WPO- 2011 -00055
Plan preparer:
Mr. Herb White, PE; W & W Associates
Owner or rep.:
Albemarle Place EAAP LLC
Date received:
(Rev. 1) 31 August 2011
22 June 2011
Date of Comment:
(Rev. 1) 23 September 2011
3 August 2011
Engineer:
Phil Custer
The final site, ESC, and SWM plans for The Shops at Stonefield -Regal Cinema (SDP- 2011 -00047 and
WPO- 2011 - 00055) received on 31 August 2011, have been reviewed. The plans can be approved after the
following comments have been addressed:
A. Final Site Plan, Private Road Plan, and Drainage Plan Review (SDP- 2011 - 00047)
1. Engineering revic�, — , oncerned wi— — ane parking spaces close to the entrances that have
limited sight lines because of the building walls. Some of the spaces near the entrances may need
to be eliminated. Please provide an analysis of parking spaces around the entrances in relation to
the sight lines. (18- 7.2.7)
(Rev. 1) Comment has been withdrawn. The applicant has stated that there are no walls at the
entrances to the garage so sight distance is not limited.
2. Please provide typical details for the walls used on site. The details should show a handrail at the
top of the wall.
(Rev. 1) Comment has been addressed.
3. For all walls taller than 4ft on Sheet C -7, please callout a handrail.
(Rev. 1) Comment has been addressed.
4. Please provide the deedbook and page number for the ACSA easement on the Sperry property for
the new line to EX MH S -17. Please note that this site plan cannot be approved until this
easement is recorded.
(Rev. 1) Typically, offsite service authority easements require recordation of a plat before site
plan approval can take place. I have forwarded the documents provided tome to others within
the Community Development Department to get their opinion on whether the signed
agreements between Albemarle Place and Northrup Grumman are adequate for the county to
issue site plan approval. Have any of the documents provided tome been recorded at the
county courthouse?
Please add a ditch north of Main Street (on the hotel block) from Inglewood to a new drop inlet
that goes into Inlet 43.6.
(Rev. 1) Comment has not been addressed. Since Inlet 43.6 is sized for the watershed, a
continuous concrete or asphalt curb can be shown on the plan to address this comment. If the
plans are built concurrently, this curb will not need to be constructed. If there is a delay
between hotel construction and the construction of this road, we will have an acceptable plan.
6. For storm drain and road profiles, please also show the existing grade line of the site before the
mass grading plan was executed.
(Rev. 1) County Engineering has provided relief on this requirement to allow a cut fill exhibit
to address this comment.
B. Erosion and Sediment Control Plan Review (WPO- 2011 - 00055)
1. Che se to the :s ESC JM sheets, but no WPO application was
submitted. A review of both plans was performed anyway. Please provide a WPO application and
$600 fee as soon as possible so that this comment letter can be tied to this application.
(Rev. 1) Comment has been addressed.
2. Because of strict requirements of Water Protection Ordinance Section 17- 207.B.2, erosion and
sediment control plans for projects of such a large size must be designed to be closed out as soon
as possible. For this reason, subsequent plans cannot assume that the sediment basins constructed
with the mass grading application will remain online. Therefore, each ESC plan must be a
standalone application.
This ESC plan assumes that the mass grading plan has been completed and is stabilized, but still
relies on the sediment basin for ultimate sediment treatment. This ESC plan must be a standalone
plan.
(Rev. 1) Except for the modification mentioned in comment B3 below, the current plan is
acceptable. However, it's critical to make clear that this plan is not a standalone plan, but
relies on a sediment basin and temporary pipe system that was approved and constructed under
WPO- 2009 - 00074, Albemarle Place Mass Grading. Without this plan, the plan currently under
review (WPO- 2011 - 00055) would not meet state standards. The nine month disturbance limit
for this mass grading plan will be reached on 112612011. Before that date, an extension must
be approved by the Board of Supervisors since the reason for the extension is a construction
sequencing decision made by the applicant, and not something out of the applicant's control
such as poor weather. To receive this extension, the applicant must provide a request for
extension by 1112312011 to the clerk of the Board of Supervisors. If the Board of Supervisors
does not allow a portion of the mass grading plan that is relied upon by a subsequent plan to
remain active, that plan approval would be invalidated and a stop work order for all related
construction will be issued until an amendment is approved that meets state regulations without
the basin.
Sediment -laden water must not enter the stormsewer system and detention facilities. Inlet
protection is more often than not an inadequate measure because the inlets are constructed well
after initial land disturbance. Even after installation, storm inlets are often bypassed because their
rim elevation is higher than the subbase and gravel around them until the final stage of
construction. Until both portions of the site are nearly complete, much of the water will be
draining to the northeast. It looks as though diversions on the north and east at the limits of
construction for both areas (cinema and the parking lot) can be installed to direct runoff to
sediment basins retrofitted onto structures 43.6 and 48 or 49.
(Rev. 1) There is an issue with the construction sequence in the parking lot west of Stonefteld
Blvd. An extension of the temporary system to the south (to approximately Inlet 61 or 62) will
be necessary. As the parking lot is graded and the inlets installed, water will bypass these
facilities and run into the street unless there was an extension of the temporary system to this
area to accept this water in a sump condition with the other inlets in the area sealed. Also, this
parking lot drainage system goes to the permanent storm water facility without a settling facility
which is not allowable per the meeting between the applicant and the county regarding this
issue.
Sediment -laden water will be allowed to travel through temporary pipe systems that are filled in
after stabilization has occurred. The county will consider these systems as temporary slope
drains since they are not permanent and carry sediment -laden water to settling facilities.
However, temporary slope drains have maximum drainage areas of 5 acres. The county will
grant a variation from this standard to allow the 6.3acre watershed proposed in this plan if the
temporary storm line diameter is increased to 30': I also recommend increasing the slope of
the pipe to further safeguard against clogging (though, this is not a requirement). Please also
see the previous comment.
4. Please provide clearer language on the plan that the mass grading plan and the Stonefield Blvd.
Plan is to be completed and stabilized prior to the start of this application. It is important to the
implementation of this plan that these areas are stabilized.
(Rev. 1) Please refer to comments B2 and B3.
5. For simplification of the design of the ESC plan, I recommend that the ESC plan for the cinema,
parking lot for the cinema, and Stonefield Blvd. are combined into one plan, assuming all projects
can be completed in 9 months.
(Rev. 1) This comment was only a recommendation.
6. Please do not show the filterras on the erosion and sediment control sheets.
(Rev. 1) Comment has been withdrawn.
7. Silt fence is needed on the west side of the sanitary sewer line from Sta. 10 +50 to 13 +50 in case
the sediment basin has been removed.
(Rev. 1) Comment has been addressed.
8. Please call out the depth of an adequate sump on inlet 66 on sheet C -19.
(Rev. 1) Comment has been addressed.
9. Construction entrances are likely needed on the west and east sides of Stonefield Blvd. Otherwise,
construction traffic must enter onto the Hydraulic Road to access the two construction areas on this
plan, which is undesirable.
(Rev. 1) Comment has been addressed.
10. Please provide a completed Bond Estimate Request Form to the county engineer to receive an ESC
bond.
(Rev. 1) A completed Bond Estimate Request Form has been received and an estimate will be
provided shortly.
C. Stormwater Management Plan Review (WPO- 2011 - 00055)
1. The set submitted to the county includes ESC and SWM sheets, but no WPO application was
submitted. A review of both plans was performed anyway. Please provide a WPO application and
$600 fee as soon as possible so that this comment letter can be tracked.
(Rev. 1) Comment has been addressed.
2. Please provide an approval letter from Filterra that the current layout is acceptable to them.
(Rev. 1) Comment has been addressed.
3. Every parcel that requires a stormwater management facility must sign a Stormwater Mana.eg ment
Facility Maintenance Agreement with the County. Please complete this form and submit it to Ana
Kilmer with a $17 recordation fee after reading the instructions online. Another agreement may be
required for the master stormwater management plan approved under WPO- 2010 - 00023.
(Rev. 1) Ana Kilmer has determined that the previously recorded Stormwater Facility
Maintenance Agreement for the project covers all new facilities.
4. Please provide a completed Bond Estimate Request Form to the county to receive an additional
SWM bond.
(Rev. 1) A completed Bond Estimate Request Form has been received and estimates will be
provided shortly.
File: E2_ecp swm fsp_PBC _ sdp- 2011 -00047 The Shops at Stonefield -Regal Cinema.doc