HomeMy WebLinkAboutWPO202000037 Correspondence 2020-10-19 (3)SHIMP ENGINEERING, P.C.
Design Focused Engineering
October 13, 2020
John Anderson, PE
County of Albemarle
Department of Community Development
401 McIntire Road, North Wing
Charlottesville, Virginia 22902
RE: Response Letter #1 for WP0202000037 Galaxie Farm VSMP
Dear John,
Thank you for your review of the Road Plans for Galaxie Farm Subdivision. This letter contains
responses to County comments dated August 18, 2020. Our responses are as follows:
A. Stormwater Pollution Prevention Plan (SWPPP)
SWPPP: Provide. Please use SWPPP template, link:
https://www.albemarle.org/home/showdocument?id=166. (Rev. 1) Partially addressed. As follow-up:
1. Sec. 1, Registration Statement:
a. Cover:
i. Parcels under development appear to be 9, 15; please check /revise as needed.
Parcels revised to list 9 & 15.
ii. Please include reference to WP0202000037 in SWPPP title.
WPO2020-37 reference added.
iii. Revise SWPPP title project name to match WPO Plan title.
Title now matches project name.
b. Sec. IV.E: List Albemarle County since parcels under development are within Albemarle
County MS4.
Albemarle County Listed
c. Sec. IVY: Check `yes' since Galaxie Farm is (itself) a common plan of development (vs. single
parcel without subdivision).
Noted, you are correct - `yes' checked.
2. Sec. 4, ESC Plan: Include plan sheets, once review comments addressed.
FSC Plan sheets now included.
3. Sec. 5, SWM Plan: Include plan sheets, once review comments addressed.
SWM Plan sheets now included.
4. Sec. 6.A., PPP Exhibit -include in 11" x 17" Exhibit in SWPPP.
PPP Plan sheet now included.
5. Sec. 6.E.. Pcrson: Name individual responsible for PPP prior to permit registration with DEQ.
Person Responsible now named.
912 E. High Sr. Charlottesville, VA 22902 1434.227.5140 1 shimp-engineering.com
B. Pollution Prevention Plan (PPP)
1. Provide PPP Exhibit (SWPPP Sec. 6A) that identifies preliminary location of:
a. Rain gauge
b. Portable sanitary facilities
c. Covered non -hazardous solid waste dumpster
d. Concrete wash -out draining to trapping device
e. Paved construction entrance w/ spray wash
f. Paint /Stucco /Solvent storage
g. Lined (10ml) on -site fuel storage containment sized for fuel volume + 10-yr storm event x
1.1
We left out the PPP from the SWPPP, it is included in this submittal. These items are
included in the PPP.
C. Stormwater Management Plan (SWMP)
1. Addressed.
1. Addressed.
2. Addressed.
3. Addressed.
4. Addressed.
5. Addressed.
6. C19
a. Addressed.
b. Addressed.
c. Addressed.
Revise Runoff Quality Narrative (p. 2 calc. packet) to reflect post -developed 2.80 Ac. Forest
/Open space land cover condition (p. 84). Also:
a. Final plat must include metes and bounds that establish 2.80 Ac. forest /open space
easement (Rev. 1) Persists. Applicant: `Noted. We have already hired Roger W. Ray &
Associates to complete the final subdivision plat, they will prepare this using our
AutoCAD linework as well as Road & V SMP plans.'
Noted.
b. Addressed.
8. VSMP Plan SWM Calculation Packet
a. Addressed.
b. Addressed.
c. Addressed
d. Pg. 13 v. Pg. 85: It is difficult to reconcile table values (p. 13) listing on- /offsite turf
/impervious areas that rout to BMP 1 (via Str. F2) with VRMM.xIs 4.60 Ac. /1.60 Ac.
turf /impervious area values (pg. 85, DA A) that route to Mfr. Treatment. Please clarify.
Video -call may be helpful. (Rev. 1) Partially addressed. Applicant: `Noted..." As follow-
up: From WPO201200087 (MFA @Mill Creek) Calculations /undated -untitled (CV), p.
1: (IMAGE OMITTED) WPO201200087 Calculations (Skimp Engineering), 8/12/13, 64-
pg. doc (CV), p. 4: (IMAGE OMITTED) WPO201200087, Final Site Development Plan
for Albemarle Health & Rehabilitation Center, C9, Landscape Plan (Shimp Engineering)
references an existing SWM easement at deed bk.-pg. 4425-165. Instrument at 4425-165
is power of attorney. This power of attorney references a plat dated August, 2013, revised
October 9, 2013, but the plat is not attached, and if recorded, it is unclear where. As
follow-up:
912 E. High St.. Charlottesville, VA 22902 1434.227.51401 shlmp-engineenrig.rom
i. Since an upstream/offsite BMP is relied upon in calculations for Galaxie Farm,
provide accurate bk.-pg. reference to SWM easement for the biofilter at
Albemarle Health & Rehabilitation Center
This is actually DB 4425-325 and reference has been provided in plans
(Sheet C9, `BMP OFFISTE DRAINAGE NOTE") and in packet (Page 8,
"Galaxie Farm Postdev Small POA Drainage Map"). Copy of this
Easement/BLA plat is included with this submittal.
ii. Images above from MFA project require some clarification; for example:
1. There appear to be three paths for MFA downslope runoff, but this may
be in the pre -developed and not post -developed condition. Engineering
requests post -developed runoff drainage map downslope of MFA
dcvelopment.
This map is the pre -developed map, post -developed map is now
included. This post-dev map shows the following areas drain to the
MFA Biofilter: 257,689 sf total (5.91 ac), with 135,573 sf imp (3.11
ac). This leaves 5.91- 3.11=2.80 ac turf in the pond drainage area. So
the calculated area is 2.80 ac turf, and 3.11 ac imp for the biofilter
matches the drainage in the WPO 2012-87 calculations.
2. HydroCAD schematic above shows Galaxie residue apparently not
receiving MFA biofilter discharge; request clarification.
Please refer to updated "Galaxie Farm Postdev Small POA Drainage
Map" (page 8 of SWM Calc Packet). In the HydroCAD schematic
from WP02012-87, the "Galaxie Residue" is a drainage area/
subcatchment, not a destination. This Galaxie Residue language
stems from a BLA where part of TMP 91-12C — owned by Galaxie
LLC, was dedicated to the MFA property. That Residue is now
included in Subcatchment 2S. The destination is "Frazier" and
refers to TMP 91-12B — owned by the Fraziers. This "Frazier"
destination is now shown as Reach 6R, t
iii. With WP0202000037, provide MFA post -developed turf and impervious area
values that drain to the biofilter and then to Galaxie Faun so we may compare
with VRRM.xls for Galaxie Farm. It is unclear without post -developed drainage
map for MFA and tabular (sf) data for turf /impervious areas that drain to the
biofilter how to allocate additional treatment (phosphorus reduction) to already -
treated runoff that reaches Galaxie Farm StormTech Mfr. system. Provide maps,
tables, etc. that align with MFA post -developed conditions (p. 17, Calc. packet)
for comparison between MFA post -developed condition, including MFA BMP,
and Galaxie Farm VRRM.xls.
After reviewing the packet, I realized I omitted a very important map: the
"Postdev BMP Treatment Map" which explained the areas used in the
VRRM spreadsheet. This is now included in the SWM Quality Section. The
map should be fairly self-explanatory. The MFA areas are listed in the Post -
Development Drainage Map in "Independent Reports" Section — MFA
Biofilter Offsite Drainage Area. Additional notation was also added to the
"PostDev Small POA Drainage Map".
iv. Revise EBE (p. 68 /Calc. booklet) reference to pg. 31 to pg. 32 (RVpre).
Reference revised.
e. Addressed:
i. Addressed.
ii. Addressed.
iii. Addressed.
912 E. High St.. Charlottesville, VA 22902 1434.227.51401 shlmp-engineenrig.rom
iv. Addressed.
9.
Addressed.
10.
Addressed.
11.
Addressed.
12.
Addressed.
a. Addressed.
b. Addressed.
c. Addressed.
d. Addressed.
i. Addressed.
ii. Addressed.
iii. Addressed.
iv. Addressed.
13. Addressed.
D. Erosion and Sediment Control Plan (ESCP)
1. Addressed.
2. Addressed.
3. Addressed.
4. Addressed.
5. Addressed.
a. Addressed.
b. Addressed.
c. Addressed.
C10
6. Addressed.
7. Addressed.
8. Coordinate with USACE for permit coverage (work in a live stream, cofferdam, structure
installation, stream impact /loss of stream reach). Provide evidence of USACE NW permit
issuance. (Rev. 1) May persist. Applicant: `Per attached email with Vinny Pero at USACE, this
project falls under nonreporting Nationwide Permit 18.' As follow-up: Please send email with
Vinny Pero to reviewer (was not attached).
Email with stream disturbance plans and USACE acknowledgement of Nationwide
Nonreporting Permit 18 was sent on 10/7/2020. PDF copy of email chain from USACE
included in this submittal.
9. Estimate /report live stream reach loss (LF). Rev. 1) Partially addressed. Similar to item 8, not
attached, please send plans sent to Vinny Pero to reviewer. Anticipate loss of live stream reach:
1451f.
Email with stream disturbance plans and USACE acknowledgement of Nationwide
Nonreporting Permit 18 was sent on 10/7/2020. PDF copy of email chain from USACE
included in this submittal.
C10
14. Addressed.
10. Addressed.
912 E. High St.. Charlottesville, VA 22902 1434.227.51401 shlmp-engineenrig.rom
It. Addressed.
12. Addressed.
13. Addressed.
14. Addressed
15. Addressed.
16. Addressed.
17. Addressed.
C11
18. Addressed.
19. Addressed.
20. Addressed.
21. Addressed.
22. Addressed.
23. Addressed.
24. Addressed.
25. Addressed.
26. Addressed.
C13
27. Addressed.
28. Addressed.
29. Addressed.
30. Addressed.
31. Addressed.
E. Mitigation Plan
32. C17, Mitigation Plan:
a. Addressed.
b....requires applicant to enter into a 5-year maintenance and performance guarantee, which will
also stipulate minimal survival required after two growing seasons of 600 plants per Ac. Provide
5-year maintenance and performance guarantee as condition of VSMP /WPO plan approval.
(Rev. 1) Partially persists. Applicant: `Math updated to reflect strategy revision. DCR source
listed. 5-yr maintenance and performance guarantee noted (guarantee documents will be handled
by Nicole Scro). Additional notes added.'
Guarantee documents are being handled by Nicole Scro. We expect she will deliver within a
weeks time.
c. Addressed.
Cl. Addressed.
e. Addressed.
If you have any questions or concerns about these revisions, please feel free to contact me at
keane@shimp-en 'ngr eering com or by phone at 434-227-5140.
Regards,
912 E. High St.. Charlottesville, VA 22902 1434.227.51401 shlmp-engineenrig.rom
Keane Rucker, Err
Shimp Engineering, P.C.
912 E. High St.. Charlottesville, VA 22902 1434.227.51401 shlmp-engineenrig.rom