HomeMy WebLinkAboutWPO202100043 Review Comments WPO VSMP 2022-01-13t� OF ALB
County of Albemarle
COMMUNITY DEVELOPMENT DEPARTMENT
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VSMP Permit Plan Review
Project title: Crozet Animal Wellness Center— VSMP
Project file number:
Plan preparer:
Owner or rep.:
Applicant:
Plan received date:
(Rev. 1)
(Rev. 2)
Date of comments:
(Rev. 1)
(Rev. 2)
Reviewer:
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Shimp Engineering, 912 E. High St., Charlottesville, VA 22902
Chris Marshall, EIT, chrisAshimp-engineering.com
AnnMae Holdings LLC
1100 Crozet Ave., Crozet, VA 22932
Hillary Cook, DVM
1100 Crozet Ave., Crozet,
2 Aug 2021
22 Oct 2021
13 Jan 2022
2 Sep 2021
16 Nov 2021
VA 22932 — dnccooke(a),,wriail.com
401 McIntire Road, North Wing
Charlottesville, VA 22902-4579
Telephone: 434-296-5832
WWW.ALBEMARLE.ORG
13 Jan 2022 [ Plan may be approved once easement plat is recorded.]
John Anderson
County Code section 17-410 and Virginia Code §62.1-44.15:34 requires the VSMP authority to act on any
VSMP permit by issuing a project approval or denial. This project is denied for two reasons listed below.
The VSMP application content requirements can be found in County Code section 17-401.
Rev. 1 Note: 0 49 11 0.19 lb. nutrient credit purchase proposed, required to meet 9VAC25-870-65
requirements.
A. Stormwater Pollution Prevention Plan (SWPPP)
The SWPPP content requirements can be found in County Code section 17-405. A SWPPP must contain
(1) a PPP, (2) an ESCP, (3) a SWMP, and (4) any TMDL measures necessary.
(Items 1, 2, 3 relate to Sec. 1 of SWPPP DEQ CGP Registration Statement)
1. Sec. II, G. —Complete Estimated Project dates. (Rev. 1) Addressed.
2. Review /revise Sec. II, C. if estimated area to be disturbed changes in response to comments, elsewhere.
(Rev. 1) Addressed.
3. Sec. III, Offsite Support Activity — Site is unbalanced. Cut north of existing east parking lot, demolition, a
stream relocation, and excavation (BMPs 1 and 2) will generate excess material. Prior to receiving a
Grading Permit, Construction Activity Operator must identify off -site waste /spoil location, secure an off -
site permit, if needed, and estimate volume and type of material to be exported from this site. Proposed
grading /demolition indicate export is unavoidable. Revise Sec. III of Registration Statement as needed.
(Rev. 1) Partially addressed. Applicant (letter 10/22/2021): "Registration statement has been updated to
include offsite disposal of excavated material. The permit will be updated once the disposal location is
determined." As ollow-up: A grading permit cannot be issued until an off -site disposal site is identified.
(Rev. 2) NA. Applicant (letter d. 1/12/22): `Registration statement has been updated. Since the second
BMW was removed, offsite soil disposal is not anticipated. Site remains balanced. A dumpster has been
indicated on the PPP Exhibit.'
Engineering Review Comments
Page 2 of 6
4. Provide a complete SWPPP for project, use 12-section county template. Only Sec 1 of the SWPPP
(Registration Statement) appears to have been submitted. Link to template:
htti)s://www.albemarle.org/home/showl)ublisheddocument/166/637202310327530000 (Rev. 1)
Addressed.
5. Include 2019 Notice of Termination form. Link:
http://www.albemarle.org/upload/images/forms center/departments/Comm mityDevelopment/forms/EngineerinP and
_WPO Forms/CGP Notice of Termination 2019 FINAL 201904.pdf (Rev. 1) Addressed,
6. Revise SWPPP title to include ref. to VSMP /WP02021-00043 (Rev. 1) Addressed,
7. New (Rev. 1):
a. Remove Calculation packet from SWPPP; begins at p. 33. (Rev. 2) Addressed.
b. Include copy of 26-p. 2019 VAR10 in SWPPP, Sec. 11. [ link
https:/Aaw.lis.virginia.¢ov/admincode/title9/a¢encv25/chapter880/section70/ ] (Rev. 2) Not addressed. As
follow- u :Please revise SWPPP by inserting 26-p. 2019 VAR10 after p. 35 of 44 pg..PDF. See link above.
c. Include inspection logs, Sec. 12 (Rev. 2) Addressed.
d. Sec. 6.A. — Include I I" x 17" PPP Exhibit. (Rev. 2) Addressed.
e. Sec. 6E. — Complete this section since contractor is selected (R. E. Lee and Sons)_ List a named individual
responsible for PPP practices. (Rev. 2) Addressed.
f Sec. 8 —List named individual responsible for compliance inspections. (Rev. 2) Addressed.
B. Pollution Prevention Plan (PPP) — See above. (Rev. 2) Addressed.
The PPP content requirements can be found in County Code section 17-404.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This
plan may be approved once SWM facility and public drainage easement plat is recorded. Easement plat
requires separate application, review, and approval process. Link to easement plat application:
https: //www.albemarle. org/home/Showpublisheddocument/ 1052/637624089314100000 .
1. Calculation Packet
a. P. 24: [Image removed with Rev. 1 comments.]
b. p. 25: [Image removed with Rev. 1 comments.]
c. Please confirm routing output, p. 25, is consistent with p. 24 graphic which appears to group and
show sub -catchments 1 S, 3S routing to detention 1 (4P), sub -catchment 2S routing to detention 2
(1P), and then 4S, 1P, and 4P evaluated as POAI. Pg. 25 output appears to group modeled output
differently. We can't follow it, but this may be due to general lack of familiarity with how
HydroCAD organizes data output. Please clarify, for our understanding. (Rev. 1) Addressed.
Applicant: "The routing output as shown on page 24 is correct. The information on page 25
provides basic information for each item and does not display them in the order that they are
routed. The model has been updated to remove BMP 2 and the developed area previously shown
for additional parking behind the building."
d. Pg. 11, PDF report:
i. Provide RV p,e & , RP post-dev calculations. Clarify source of these energy balance
equation values, which do not appear to derive from VRRM.xls provided in calculation
report. (Rev. 1) Partially addressed. Applicant: "RV predev and postdev calculations
are included in the respective hydrocad reports. The energy balance equation is used for
determining water quantity compliance and is not necessarily the same area as the VRRM
uses for water quality compliance. The energy balance equation values are based on the
drainage area of the site where as the VRRM is based on the limits of disturbance," As
follow-up: Comment is restated. Please use VRRM re -development spreadsheet, not
VRRM.xls for new development. From the Runoff Volume and CN tab of the re-
development compliance spreadsheet, take/use RV pre- RV post- in calculations. That is,
VRRM.xls re -development spreadsheet is source of RV values. Regret initial comment
Engineering Review Comments
Page 3 of 6
did not flag proper spreadsheet, and hope to clarify that RVpr -developed and RVaevelopea
values in table titled Crocet Animal Wellness, p. 12 of Calc. packet, should derive from
the Runoff Volume and CN tab of the VRRM.xls re -development spreadsheet. (Rev. 2)
Addressed. Note: On -site treatment of Stormtech UG SWM facility to treat 0.14 lb./yr.
of phosphorus, with 0.19 lb./yr. phosphorus credits.
2. CL Please revise to include ref. to WP02021-00043 (Applies to Calc. packet, SWPPP cover, as well).
(Rev. 1) Addressed.
3. C3 C4C4
a. Show /label SWM Facility /Access easement. n_c eesefneH4 diagf... " 'DST", _ 15, ifflage
be4ew [Image removed with Rev. 1 comments.], ensure easement is adequate. [
https:H/ .albemarle.org/Home/ShowDocument?id=270 ] (Rev. 1) Addressed. Also, see Applicant
response, item 3.b. below.
b. Provide public drainage easement downstream of BMPs 1 and 2 to point of confluence with
relocated stream. (Rev. 1) Addressed. Applicant: "A 20' easement has been added for the SWM
facility and storm pipe downstream of BMP 41, BMP #2 is no longer needed and has been
removed."
c. Respond to (any) County Water Resources review comments on design, generally, or effect of
design on downstream county BMP (constructed wetland), specifically. (Rev. 1) May persist.
Engineering defers to Water Resources. (Rev. 2) Addressed. Applicant inquired [December 17,
2021 3:08 PM], Engineering checked [November 16, 2021 1:50 PM, January 7, 2022 11:23 AM
email to Water Resources] —no response received. Withdrawn. Applicant: `Per conversation with
John Anderson on 1/7/22, Water Resources comments are considered closed.' An accurate
statement.
4. Submit separate plat application for SWM Facility /access and public drainage easements. A deed is
required to be recorded with this easement plat. Link to easement plat application:
https://www.albemarle.org/home/Showpublisheddocument/1052/637624089314100000 (Rev. 1) Persists.
Applicant: "A plat application will be submitted. Drainage easements are shown for the SWM facility and
storm pipe." (Rev. 2) Persists. Applicant: `A plat application will be submitted. Drainage easements are
shown for the SWM facility and storm pipe.'
5. C4 proposes BMP 42, Str. B 1, nearly coincident with the relocated stream. Provide additional plan detail
to show how design will effect intersection between B 1 riprap outfall and the relocated stream, resistant to
erosion. Provide labels, notes, elevations, etc., to ensure outfall riprap is resistant to 2-yr event velocity of
the relocated stream, not just BMP #2 discharge velocity. This outfall will experience erosive forces of the
relocated stream. (Rev. 1) NA -Withdrawn. Applicant: "Structure B 1 and BMP #2 have been removed as
the additional parking area behind the property is no longer being constructed. Additionally, the stream
relocation is no longer required."
6. C4: Label L x W x D riprap dimensions, at Str. B1. (Rev. 1) NA -Withdrawn. Applicant: "Structure B1 is
no longer needed and has been removed."
7. C5: Provide a storm profile for the entire length of BMP #2. Provide prominent existing grade linework,
since this BMP occupies a former streambed. On this profile, please include notes, labels, etc. that specify
suitable fill in area (former streambed) undercut to provide adequate material and compaction for BMP #2.
(Rev. 1) NA -Withdrawn. Applicant: "BMP #2 has been removed as the additional parking area behind the
property is no longer being constructed. Additionally, the stream relocation is no longer required."
8. C5: Provide adequate cover above crown of pipe at ES-1, Str. A5. Crown of pipe may not be exposed.
Engineering recommends MH with grate inlet at this location for performance, safety, and maintenance
reasons. Proposed grade Str. A5 may concentrate debris, occlude inlet, or partially block 15" HDPE pipe,
if no grate, or if poorly maintained. Proposed design may inadvertently admit substantial debris directly
into BMP #1. (Rev. 1) Addressed. Applicant: "Acknowledged, the ES-1 has been replaced with a DI-7
grate inlet and manhole to reduce change of blockages."
9. C9
a. Revise so that —70-deg proposed bend in stream is less severe. Revise to maximum extent, using
as much space as is available on site to create a less severe bend around the new parking area.
Engineering Review Comments
Page 4 of 6
e_o 1, image bel@,A. [ Image removed with Rev. 1 comments.] (Rev. 1) NA. Applicant:
"Modifying the stream is no longer required as the additional parking area has been removed."
b. Design and label structural bank stabilization (riprap /grouted rip rap) for streambank, Area 2,
image below.
c. Provide details for natural design concept (channel re-routing), including: in -stream structures,
bank stabilization, riffle -run, etc. Reference Albemarle County Chapel Hill Stream Restoration
project plans for example of detail provided with a natural design concept. [WPO201800038]
10. C10: Provide (small diameter orifice) debris cage detail. (Rev. 1) Addressed.
11. Cll
a. Please confirm that BMP #2 4" SCH. 40 perf PVC underdrain INV=653.00 beneath the BMP, is
intended to transition to INV IN=653.83 at Manhole B3.
b. It appears from C 11 (and C 13 Stormtech details) that both BMPs 1 and 2 are effectively
submerged during the 10-yr event to a stone -void saturated depth higher than the top of each
system. Please:
i. Confirm whether this is the case. (Rev 1) Addressed. Applicant: "The ]0-yr WSE is
above the top of the Stormtech system but below the top of stone."
ii. Calculate buoyant force on Std. MH and provide buoyancy calculations for Stormtech
system, and MH. Albemarle Engineering cannot assume or interpret Mfr. literature for
ADS SC -740 Stormtech chambers with isolator row, in this regard. Provide
conventional buoyancy calculations, assuming 0.4 stone void ratio. (Rev. 1) Partially
Addressed. Applicant: "The manholes are concrete and have a weight greater than
potential buoyant force of water. A buoyancy calculation as performed on the Stormtech
system itself. The weight of the stone and asphalt above the system far exceeds the
buoyant force of water assuming a completely full chamber. The calculation has been
provided with this submittal," As follow-up: Please direct Engineering to plan sheet or
calc. packet pg. for buoyancy calculation. (Rev. 2) Addressed. Buoyancy Calculation,
undated, submitted with email (January 13, 2022 9:29 AM) indicates stone/asphalt
weight (above Stormtech) > 1.25*buoyant force: Yes. (11,750.80 lb. > 3,580.20 lb.)
iii. List C13 Table l Acceptable Fill Material A, B, C, D specs on C11. i.e., label foundation
stone, embedment stone, initial fill, final fill (unless NA) on CI 1 profiles for BMP 1, 2.
c. Stability of MHs is a particular concern with this design given WSL, 10-yr. Provide narrative,
notes, labels, specifications as needed to ensure MH-to-Stormtech connection is rigid and
inflexible, if consistent with manufacturer's recommendations and design/performance intent.
Long-term performance and system integrity pose concern, given 10-yr WSL.(Rev. 1) Addressed.
Applicant: "Acceptable fill material from C 13 Table 1 is now indicated on the BMP profile on
sheet C 11. All connections are rigid and in accordance with manufacturer's recommendations.
The manholes are precast concrete and are resistant to the buoyant force of water in the system."
d. List SC-740 top of pipe elevation on C 11 profile, BMP 1 and 2. (Rev. 1) Addressed.
12. Show /label debris cage for 3" orifices, weir A2, weir B2 details, C 11. (Rev. 1) Addressed.
D. Erosion and Sediment Control Plan (ESCP)
Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESCP. This plan
is approved.
1. C6
a. Management Strategy and Sequence of Construction (Rev. 1) NA. Applicant: "The channel
diversion is no longer required as the parking area behind the building and BMP 42 have been
removed. VESCH 3.25 and 3.26 are no longer needed."
i. Phase 1 lists clean water diversion of existing engineered channel, but provides no
narrative detail relative to this aspect of construction. C7 shows a line with arrows which
corresponds to Phase 1 clean water diversion of existing engineered channel, but no other
details. C9 includes label that reads: `re-route channel using natural design concepts.'
Engineering Review Comments
Page 5 of 6
Please provide general detail, a detailed sequence, labels, natural design concept details,
VESCH diversion channel (crossing) plates (may modify), VESCH dewatering details,
channel lining, etc.
ii. Specifically, include VESCH Std. & Spec. plates, details, notes, guidance, installation
sequence for:
1. 3.25
a. Include plate 3.25-1 (may modify, as appropriate)
b. Include plate 3.25-2
c. Notes concerning undercutting material unsuitable to serve as subgrade
to BMP #2
2. 3.26
2. C7
a. Revise stone CE to paved CE. (Rev. 1) Addressed.
b. Where CWD crosses paved CE, label diversion paved RWD. In effect, construct paved berm
across paved construction entrance, or provide suitable alternative diversion across site entrance.
(Rev. 1) Addressed.
c. N-S CWD traps water just south of existing entrance to site against N face of E-W CWD. Revise
to avoid ponding, or diversion break-thru at this location. (Rev. 1) Addressed.
d. C7 or C8: Indicate pavement TBR. Revise SWPPP, Sec. 1 (Registration Sec. III) to indicate off -
site demolition debris export. (Rev. 1) Addressed.
3. C8
a. Label ST floor dimensions (L x W) to aid review, bond estimate, inspection. (Rev. 1) Addressed.
b. Label Area of Limits of Disturbance (x.xx Ac.). (Rev. 1) Addressed.
c. Provide ST design table, and data. If overlooked, please notify reviewer. (Rev. 1) Addressed.
d. Note: Limits of Disturbance are anticipated to increase and appear somewhat arbitrary to limit
LOD <1.0 Ac. Revising grade to introduce a gradual stream bend N of new parking west of
building will increase LOD. (Rev. 1) Partially addressed. As follow-up: Please revise SWM
Quantity narrative, 06, to reference 0.66 Ac. LOD, consistent with plan labels and SWPPP. (Rev.
2) Addressed.
e. Label proposed grade N of building (3:1, 2:1, etc.). (Rev. 1) Not addressed. (Rev. 2)
Withdrawn. Although 2:1 proposed grade not labeled, if scaled, does not exceed 2:1 Max. grade.
f. Any grade steeper than 3:1 requires permanent vegetative stabilization hardier than grass. Specify
permanent stabilization for grade steeper than 3:1. (Rev. 1) Addressed.
Process:
After approval, plans will have to be bonded. The bonding process is begun by submitting a bond estimate request
form and fee to the Department of Community Development. One of the plan reviewers will prepare estimates and
check parcel and easement information based on the approved plans. The County's Management Analyst will
prepare bond agreement forms, which will have to be completed by the owner and submitted along with cash,
certificates or sureties for the amounts specified. The agreements will have to be approved and signed by the County
Attorney and County Engineer. This may take 24 weeks to obtain all the correct signatures and forms.
Stormwater Management Facilities Maintenance agreements will also have to be completed and recorded. The
County's Management Analyst or other staff will prepare the forms and check for ownership and signature
information. The completed forms will have to be submitted along with court recording fees.
This project requires separate easement plat application, review, and approval. Once plat is reviewed and comments
are addressed, Engineering will format template deeds (SWM / public drainage) to be recorded with the plat. Please
submit easement plat application at earliest convenience. Note: easement plat with deeds must be recorded prior to
receiving a Grading Permit.
Engineering Review Comments
Page 6 of 6
Also, please note: 94S W 0.19 lb. nutrient credit purchase is proposed to meet 9VAC25-870-65
requirements.
After bonding and agreements are complete, county staff will (if LOD > 1 Ac.) enter project information in a DEQ
database for state application processing. DEQ will review the application information based on local VSMP
authority approval. At this time, the DEQ portion of the application fees will have to be paid directly to the state. For
fastest processing, this is done electronically with the emails provided on the application. DEQ should notify
applicants with instructions on how to pay fees. When DEQ approves the application, they will issue a permit
coverage letter. This should be copied to the county.
After DEQ coverage is issued, via the coverage letter, the County can hold a pre -construction conference.
Applicants must complete the request for a pre -construction conference form, and pay the remainder of the
application fee. The form identifies the contractor and responsible land disturber, and the fee remaining to be paid.
This will be checked by county staff, and upon approval, a pre -construction conference will be scheduled with the
County inspector. At the pre -construction conference, should everything proceed satisfactorily, a joint VSMP and
grading permit will be issued by the County so that work may begin.
County forms can be found on the county website forms center under engineering,
hftl)://WWW.albemarle.org/del)tforms.asv?department--cdengwpo
Thank you.
Please call if any questions — tel. 434.296-5832-x3069, or email 4anderosn2&albemarle.org.
WP0202100043 Crozet Animal Wellness Center 011322 rev2