HomeMy WebLinkAboutSDP200800100 Review Comments Major Amendment, Final Site Plan 2008-07-14 (3)*-&A
County of Albemarle
Department of Community Development
Memorandum
To: Summer Frederick, Current Development Project Planner
From: Phil Custer, Current Development engineering review
Date: 14 July 2008
Subject: Moore's Creek Sanitary Sewer Treatment Facility Major Site Plan Amendment
(SDP- 2008 - 00100)
The site plan amendment for the Moore's Creek Sanitary Sewer Treatment Facility has been reviewed. At
this time, engineering review for current development cannot recommend approval to this site plan
amendment. The following comments are provided.
1. Before approval of this amendment is granted, a WPO (Water Protection Ordinance) plan
will need to be submitted and approved by engineering review. Currently, an application
has not been submitted.
It appears that there are some ESC measures shown on the site plan. Engineering review
will provide brief comments on the ESC scheme at the end of this memo. Also, it appears
water quality will need to be provided treating the new impervious area of tertiary filters
and UV disinfection facility on sheet C12 as well as chemical filling station area.
The SWM plan should analyze which areas of development will require stormwater
quality treatment by using the Modified Simple BMP spreadsheet. A detention waiver has
been granted by the county engineer.
2. The applicant should show the stream buffer lines on all sheets. The stream buffer is
100ft from the top of each of streambank of Moore's Creek. Disturbance of the stream
buffer will be allowed per 17- 321.1, but a mitigation plan must be submitted and approved
during the WPO plan review. Mitigation plan requirements can be found in the county
design manual available online.
3. The Bulk Chemical Storage facility in the floodplain will require a Special Use Permit for
fill in the floodplain. An application for this permit is available online. The storage of the
chemicals will be allowed in this building if they located at least Ift above the 100 -year
flood elevation. [18 -30.3]
4. Please provide the FEMA map number and date on the plan. The 20 scale sheets should
also show the FEMA floodplain. [DM]
5. Please provide existing topography on all 20 scale sheets. In areas being developed, there
is no existing topography.
6. Please show all critical slopes on the plan. A waiver of critical slope disturbance will be
required.
7. Please show safety railing for any wall over 4ft in height. [DM]
8. Provide a typical detail for all walls. Please include any safety railings on this detail as
well. [DM]
9. Curbing is required on both sides of the travelway on sheet C12. [18- 4.12.15]
10. A waiver of the travelway width will need to be given by the Zoning Administrator.
Engineering review supports the approval of this wavier. [18- 4.12.16]
Current Development
Engineering Review Comments
Page 2 of 2
11. Profiles are required in the sheet set for all new stormwater pipes. The profiles should
include all of the requirements listed in the checklist in the design manual. Please note
that the four foot drop specified in the IS -1 requirement includes drops from grates to
invert out elevation.
12. There seems to be a discrepancy between the sheet C12 and the calculation summary table
for pipe 5 -4. Also, please note that none of the structures in this set are labeled.
13. Inlet capacity calculations do not appear to provided.
14. Please provide drainage area maps for each drainage structure with acreages, hydrologic
coefficients, destination structures, and time of concentrations labeled.
The following comments regard the ESC measures shown on the site plan amendment. A full review will
be completed once an application and all other WPO plan requirements are received.
1. Please show limits of disturbance lines. [DM]
2. Please provide construction entrances to disturbed areas. [DM]
3. Silt fence cannot run across contour lines. On sheet C13, please provide a silt trap at the
low point with diversion dikes running east and west where the silt fence was called out.
[DM]
4. A narrative should be provided. [VESCH]
5. Please show soil stockpile areas where necessary. [DM]
File: E1_fmj_PBC_sdp200800100