HomeMy WebLinkAboutSDP200800080 Review Comments 2008-06-27t]
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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- 00053, Vault ESC Plan
SDP -2008- 00080, Minor Amendment
Plan preparer:Delta Airport Consultants, Inc. fax 804 275.8371
Owner or rep.:Barbara Hutchinson, Executive Director fax 434.974.7476
Date received:16 May 2008
Date of Comment:27 June 2008
Engineer:Phil Custer
The ESC plan and the minor amendment to the site plan for the electrical upgrade work at the
Charlottesville Airport, received on 16 May 2008, have been reviewed. The plan cannot be approved as
submitted and will require the following changes /corrections prior to final approval.
A. General Review Comments
1. Please accurately show all stream buffers.
2. A SWM plan will be required for the electrical vault area.
3. Please show the treeline on the plan. [DM]
4. It is unclear what the gravel drive to the vault is coming off from. Nothing is labeled on the
plan.
B. WPO -2008 -00053 ESC Plan Review Comments:
1. Please show on an overview plan of the airport where all earth disturbing activity, including
utility line replacement, will be taking place with appropriate limits of disturbance. Please
specify which work will be done in pavement and in soil. ESC measures may be required for
some of the other work on this plan than just the electrical vault. [VESCH]
2. The limits of disturbance line for the electrical vault construction does not appear to close.
Does work continue towards the runway area? If' so, please make sure the limits of
disturbance reflect this.
3. Considering ESC comments 1 and 2, it appears an addition to the WPO fee will be necessary.
4. It is understood from previous conversations with the applicant that wet storage in the
sediment trap violates airport regulations. Please provide a letter requesting a variance from
this state standard and how erosion control standards are met or exceeded with a proposed
alternative.
5. Please state on the plan all applicable VESCH minimum standards.
6. It appears that the plan needs the standard symbols for permanent seeding, temporary seeding,
construction entrance, and a diversion dike.
7. Please provide dust control on the plan.
8. Please show the grading for the sediment trap on sheet 22.
9. The diversion dike appears to travel uphill on the plan.
10. Engineering review is concerned with a lack of an adequate channel. Please address.
11. Please provide on the plan the standard county notes for General Construction and General
Notes for Erosion and Sediment Control found in the latest version of the county design
manual availabk;- online.
12. Please show outlet protection on both culverts.
13. A bond will be computed once all comments are addressed.
C. SDP - 2008 -00080 Minor Amendment Plan Review Comments:
1. The minor amendment should not be approved until the SWM plan is.
Please contact me at (434)296 -5832 ext. 3072 should you have any questions.
File: E1_esc _ mia_PBC_08- 00053__08 -00080 Airport Electrical vault
IL 1!-
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- 00053, Vault ESC Plan
SDP -2008- 00080, Minor Amendment
Plan preparer:Delta Airport Consultants, Inc. fax 804 275.8371
Owner or rep.:Barbara Hutchinson, Executive Director fax 434.974.7476
Date received:16 May 2008
Rev. 2) 3 September 2008
Date of Comment:27 June 2008
Rev. 2) 10 October 2008
Engineer:Phil Custer
Rev. 1) Andv Lowe
Rev. 2) Phil Custer
The ESC, SWM, and the minor amendment for the electrical upgrade work at the Charlottesville Airport,
received on 3 September 2008, have been reviewed. This letter comments on the third submittal made to
the County. The second submittal was reviewed under an alternative review procedure with just a
checklist. All comments that were addressed with the second submittal are stated as so. To maintain the
same layout in the applicant's response letter, many of the comments appear twice in the list below. The
plans can be approved after the remaining comments have been addressed.
When the plan is resubmitted, please include a new, complete calculations packet.
A. General Review Comments
2. A SWM plan will be required for the electrical vault area.
Rev. 2) A plan has been submitted. Please see the comments below.
B. WPO- 2008 -00053 ESC Plan Review Comments:
d. It is understood from previous conversations with the applicant that wet storage in the
sediment trap violates airport regulations. Please provide a letter requesting a variance from
this state standard and how erosion control standards are met or exceeded with a proposedalternative.
Rev. 2) Please clearly show the depth of the stone in the sediment trap. It appears theunderdrainpipeisplacedinthein -situ soil.
5. Please state on the plan all applicable VESCH minimum standards.
Rev. 2) Comment not addressed The applicable minimum standards from Chapter 8 of theVESCHneedtobelistedonthesheetset.
8. Please show the grading for the sediment trap on sheet 22.
Rev. 2) Grading was shown but the review of the sediment trap was difficult because the
contour lines are unclear. III plan view, it is hard to determine what the bottom, wet, weir,
and embankment elevations are supposed to be and how it matches the calculations. Please
clarify. It does not appear that the embankment grading is shown correctly.
10. Engineering review is concerned with a lack of an adequate channel. Please address.
Rev. 2) Comment not addressed The calculations appear to analyze the newly constructed
channel at the outlet of the 8" culvert The adequate channel that must be proven is at the
outfall of the biofilter.
12. Please show outlet protection on both culverts.
Rev. 2) Comment has not been addressed Outlet protection is required fir all culverts.
13. A bond will be computed once all comments are addressed.
Rev. 2) The ESC portion of the WPO bond will be computed once the plan is approved
C. SDP- 2008 -00080 Minor Amendment Plan Review Comments:
1. The minor amendment should not be approved until the SWM plan is.
Rev. 2) Comment remains unchanged
D. WPO- 2008 -00053 Plan Review Comments from the checklist review:
3. Provide Plan view and details for all stormwater facilities and site layout as shown on the site
plan sheets, preferably at a scale of 1 " =30' or 1 " =20'.
Rev. 2) The contours of the biofilter are difficult to make out It is unclear what the
elevations of the top of embankment, weir, and biofilter bed are in this drawing. It appearsthatthegradingneededtoconstructthefillfortheembankmentisalsonotshown.
4. Provide cross- section details for each facility embankment.
Rev. 2) Please see comment 11 and 20.
Provide cross- section details for each biofrlter with minimum floor dimensions lableled.
Rev. 2) The cross- section has been provided Please see comments 11 and 20.
9. Provide water quality removal rate computation summary for each facility in the countyworksheetformat.
Rev. 2) The computation summary table appears to be incorrect. Engineering review
agrees that the biofrlter facility should be sized to achieve a 50% removal rate. However,
the water quality volumes (both required and provided) appear to be incorrect. Given the
impervious area you provided (%S of 2.67 acres), the required WQv is 242cf (9ey). The
biofrlter as designed will likely have a provided WQv of 42cy (not 134) if the maximum
ponding depth of Ift was used Please correct the computation table.
10. Provide detention computation summary for each facility in the county worksheet format.
Rev. 2) Detention will not be required in the biofrlter if an adequate channel is proved bythecalculations.
11. A SWM plan is required in addition to the Stormwater Management Plan submitted.
Rev. 2) It is d/fJicult to review the geometry of the bio titer because none of the contours
are labeled The plan also appears to have intermediate contours leftover from the erosion
and sediment control plan. Additionally, it appears the "temporary slope drain" is designed
to be a permanent feature with this pltrur. The use of the temporary slope drain as the
permanent outfaH the biofrlter is not acceptable. Please provide a ricer or a spillway
and channel down the slope.
12. Please state on the plan all applicable VESCH minimum standards.
Rev. 2) Comment not addressed. The applicable minimum standards from Chapter 8 of the
VESCH need to be listed on the sheet set.
16. Engineering review is concerned with a lack of adequate channel. Please address and include
cross - sections.
Rev. 2) Comment not addressed The calculations appear to analyze just the newly
constructed channel at the outlet of the 8" culvert. The adequate channel that mist be
proven is at the outfall of the biofilter.
17. Please show outlet protection on both culverts.
Rev. 2) Comment has not been addressed. Outlet protection will be required because the
channels will not be established with grass at the time of construction. The permissible
velocity for exposed earth is much lower than that of Bermuda grass.
18. (Sheet 6 of 30) Provide all applicable VESCH minimum standards.
Rev. 2) Comment not addressed. The applicable minimum standards from Chapter 8 of theVESCHneedtobelistedonthesheetset.
20. (Sheet 7 of 30) provide a detail of the proposed biofilter.
Rev. 2) The details on sheet 7A are not yet approvable. Please correct the following:
a. The soil mix must beat least 2.Sft. [DMJ
b. The elevations of the bed mix, bottom of weir, and embankment must be clear. It
appears the outlet of the sediment trap would need to be retrofitted The use of
sediment trap weirs in the permanent condition does not work because the water
escapes through the stone before it gets the opportunity to drain through the soil
Inix.
c. The weir should be at an elevation of 6" or I ' above the bed elevation.
d. From reading the contours in plan view, it appears the top of the embankment is
615 rather than 617.
23. (Sheet 22 of 30) Provide a sormwater management plan similar to Vault Site Grading Plan.
Rev. 2) See comment 11.
25. (Sheet 22 of 30) Provide a construction entrance at the existing perimeter access road.
Rev. 2) Comment not addressed The applicant has implied that a construction entrance is
not required for the site because vehicles leaving the site must travel on the existing internal
roads before entering onto a public street. Tlris would be allowable if these roads drained
to an existing sediment basin or trap. However, all sediment deposited oil these internal
roads will drain to SWM facilities and county waterways without ESC measures.
27. (Rev. 2) The applicant has removed the county's standard SWM and ESC notes from the
set. These need to be included before the plan can be approved
28. (Rev. 2) The applicant must submit a Stormwater Management Facility Agreement and fee.
Please submit this document with fee directly to Pam Shifflett after consulting the
guidelines available on the county website.
29. (Rev. 2) The SWM portion of the WPO bond will be computed once the plan is approved
Please contact me at (434)296 -5832 ext. 3072 should you have any questions.
Application #: i SD Short Review Comr
Project Name:harlAlbemarle Air ort Authori Mi Amendment Minor Amendme
Date Completed: 08/01/2008
Reviewer: Andrew Lowe Engineer Z &CD
Review Status: Requested Changes
Reviews Comments: This project has been reviewed by the engineering group in current development at Albemarle
County. A copy of the plan has been red -lined with comments and is available at the Community
Development Office for pick -up.
See WP0200800053 —- - - -_ J
Date Completed: 07/09/2008
Reviewer: Bill Fritz Planner Z &CD
Review Status: Administrative Approval
Reviews Comments: Approved subject to addressing engineers comments
Page: 1.00 County of Albemarle Printed On: Wednesday, November 19, 2008
Page 1 of 1
Philip Custer
From: Philip Custer
Sent: Friday, November 14, 2008 11:27 AM
To: 'JNixon @deltaairport.com'; 'William M. Eschenfelder'; 'bhutchinson @gocho.com'
Cc: Bill Fritz; Amy Pflaum; Ray Lilly
Subject: Engineering Review of Airport Electrical Vault (WPO- 2008 - 00053; SDP - 2008 - 00080)
Goodmorning,
The Erosion & Sediment Control and Stormwater Management Plans (WPO -2008- 00053) submitted 12
November 2008 have been received by Engineering Review. Approval of the plans has been granted with the
condition that the standard County notes for ESC and SWM plans be added to sheet 7A (Sheet 13 did not
include the lists) and the biofilter mix be specified as "State approved mix" rather than "Luckstone Biofilter
mix ". Once these revisions have been made, please submit 7 sets (sheets 1, 3, 4, 6, 7, 7A, 22, and 22A) of the
WPO plan to Current Development Engineering.
The E &SC bond amount is S21,000. The SWM bond amount is S7,000. The forms and
instructions to post the Water Protection Ordinance Bond can be found on the Community Development
Department Web site on www.albemarle. or& , .
A completed copy of the Standard Stormwater Maintenance Agreement and fee for recordation for the stormwater
facilities is required prior to final approval J 17 -30413] The forms and instructions can be found on the Community
Development Department Web site on w
You may contact Pam Shifflett (Albemarle County Department of Community Development) at ext. 3246
for further information on bonding procedures and Maintenance Agreements.
Once the E &SC bond and the SWM bond have been posted, the SWM maintenance agreement recorded, and the
site plan approved, you may contact the Department of Community Development to arrange a pre - construction
meeting with a County Erosion & Sediment Control Inspector.
In addition, engineering review recommends approval to the minor site plan amendment (SDP -2008- 00080).
Please contact Bill Fritz of Current Development at ext. 3242 regarding approval of the Site Plan. The sheets
needed for the site plan approval will likely differ from the sheets needed for the WPO set.
Please let me know if you have any questions
Thanks,
Phil
1 1/14/2008