HomeMy WebLinkAboutWPO202000058 Correspondence 2021-02-03SHIMP ENGINEERING, P.C.
Design Focused Engineering
February 2, 2021
John Anderson, PE
County of Albemarle
Department of Community Development
401 McIntire Road, North Wing
Charlottesville, Virginia 22902
RE: Response Letter #1 for WPO2020-58 Albemarle Business Campus — VSMP Plan
Dear John,
Thank you for your review of the VSMP Plan for Albemarle Business Campus. This letter contains
responses to County comments dated January 8, 2021. Although we typically list county comments in
grey, in an effort to expedite this document, and because your comments were very straightforward and
simple to address, we will just list our responses below. NOTE: this plan now includes mass grading for
ABC Block 1. As is noted in the plans, the Block 1 area is not intended to be developed during Block 2
development and will simply serve as a borrow site for soil. As such, only ESC measures are shown on
Block 1.
A. Stormwater Pollution Prevention Plan (SWPPP)
1. SWPPP now included
2. New signed Registration Statement included.
3. Noted, the export data not included. It is unlikely that there will be export, but yes, if this data
could be completed by the General Contractor (EDC) at the precon. meeting that would be
helpful.
B. Pollution Prevention Plan (PPP)
1. PPP for blocks 1 & 2 included. PPP's include all items identified in comment letter.
C. Stormwater Management Plan (SWMP)
1. SWM design for ABC Phase 2 (Block 1) — since this is mass grading only, and will be allowed to
return to natural open space condition, and since grading will not alter the runoff characteristics,
no additional SWM design is required at this time. If/when this plan is revised in the future, it will
be included in either a VSMP plan Amendment or occur under a separate permit with a different
WPO application, depending on the developer's scheduling, which is not set at this point.
2. Noted, this will take place in the future if/when that site is developed.
Review Comments
Cl
1. Plan subtitle includes WPO2020-00058
2. Note added to reference WPO2018-00044, as well as clarify the SWM breakdown.
3. SDP2020-00066 referenced.
4. Noted, revised per SDP comments
5. Note added RE visual verification
6. Floodzone note date revised.
912 E. High Sr. Charlottesville, VA 22902 1434.227.5140 1 shimp-engineering.com
C7
7. VSMP plan now incorporates phased construction.
8. C3: Phasing lines added to C4. Clarifying notes added to C2.
9. C5: Note added to C2 about the development of Block 1. Mass grading is shown on ESCP sheets.
10. Compaction requirement notes for these pipes/storm structures placed in fill added.
11. Structure C2 revised to avoid the requirement for steel plate at invert.
12. Safety slab specified where needed. Some structures revised to avoid need for slabs.
D. Erosion and Sediment Control Plan (ESCP)
1. C9: SL-1 Detail (and others) added to C9.
C12
2. Basin floor labelled.
3. Rip -rap labelled, may be a bit difficult to view.
4. Basin contours revised, and tie into existing. Note: basin will be larger than required for Phase
lA&lB.
5. Staging area revised to better fit new ESCP phasing. New area grading shown.
6. Wash rack symbol shown, rack will drain to basin.
7. Sequencing notes revised to address culvert demo & tie-in.
8. B, B3, B4 labelled in ESCP.
9. Noted, the profile B2-B4 inverts were incorrect and has been fixed to match existing
grades/inverts.
10. Revised grading & mass grading now shown.
11. Note added to retain this relic facility. The facility does drain into proposed SWM system, but
this does not alter the destination, treatment, or flow characteristics of the pond.
12. Noted.
a. The VDOT inlet headwater nomograph is added to the SWM packet to show this. No
flooding above downstream ridge or basin embankment occurs from the inlet control
conditions from the 36" pipe. (Nomograph included in this submittal as a single loose-
leaf sheet).
b. Notes added to ESCP on removal of basin and utilizing dewatering techniques for final
(phase 5) backfill of this area.
13. Noted, plan revised and made more detailed to address this. in the initial phase, that area will
remain undisturbed with no sediment laden runoff.
14. Revised with phasing plan, notation, and contouring linework.
15. Conflict revised.
16. Main street labelled.
17. Mass grading for phase 1B & 2 shown.
18. Noted, basin should be sufficient to construct all but Building Phase 5 (the hotel), during which
point dewatering techniques will be used to control sediment.
19. Additional contour & ESC item labels added.
20. Noted, phasing added.
21. Diversions more clearly labelled.
22. Ex. asphalt path labelled.
23. Noted, SF removed from initial phases.
24. SAF moved to optimal locations (as dictated by each phase)
25. Noted, this has been cleaned up in the plan sheets.
26. Noted.
27. Basin design table revised:
a. DA included.
912 E. High St.. Charlottesville, VA 22902 1434.227.51401 shlmp-engineenrig.rom
b. Basin side slopes added
c. Baffle note added
d. Post size revised to 6" square
e. Anti -flotation calcs included with this submittal as loose-leaf sheet, will be included with
the basin calcs in final S WM packet.
f. With the use of corrugated pipes, anti -seep collars are not required as the exterior
corrugation serves the same purpose as the collars.
E. Mitigation Plan
n/a
If you have any questions or concerns about these revisions, please feel free to contact me at
keane@skimp-engineering.com or by phone at 434-299-9843.
Regards,
Keane Rucker, EIT
Shimp Engineering, P.C.
912 E. High St.. Charlottesville, VA 22902 1434.227.51401 shlmp-engineenrig.rom