HomeMy WebLinkAboutWPO201900035 Review Comments WPO VSMP 2019-07-14COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
Phone (434) 296-5832 Fax (434) 972-4126
VSMP Permit Plan Review
Project title:
2265 Decca Lane — VSMP (Single -Family)
Project file number:
WP02019-00035
Plan preparer:
Kurt Gloeckner kurtgloeckner(&amail.com; Mike Myers: mike(a,30scale.com
1980 Fox Run Lane, Charlottesville, VA 22901
Owner or rep.:
Leigh and Craig Johnson
2265 Decca Lane, Charlottesville, VA 22901 craigjohnson3Aicloud.com
Plan received date:
3 Jun 2019
(Rev. 1)
14 Jul 2019 (digital)
Date of comments:
12 Jul 2019
(Rev. 1)
14 Jul 2019 (Also: SUB2019900097, email sent 7/14/2019 12:27 PM)
Reviewers:
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 reasons listed below. The
VSMP application content requirements can be found in County Code section 17-401.
( Please also see county email: initial VSMP /WPO plan review comments, 7/12/2019 6:37 AM.)
Note: Engineering welcomes (.PDF) preview prior to print re -submittal for final approval. Also, Applicant
(plan preparer /Gloeckner) and Engineering are scheduled to meet 16-Jul to review print plans (and plat
/SUB201900097) prior to final print plan /plat submittal.
A. Stormwater Pollution Prevention Plan (SWPPP) (Rev. 1) Comments persist.
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.
1. Sec. 1: provide 2019 Registration Statement. Information virtually identical to information furnished on
2014 Registration Statement. Link to form:
httD://www.albemarle.ore/uDload/imaees/forms center/deDarhnents/Community Develonment/forms/Enein
eering_and _WPO_Forms/CGP_Registration_ Statement _2019_FINAL _201904.pdf . Note:.PDF scan of
form is fine; email janderson2(iDalbemarle.ore, charris(&albemarle.org.
2. Sec. 6.: Provide with I I" x 17" Sec. 6 SWPPP Exhibit:
a. Rain gauge location
b. On -site fuel storage; lined containment with storage Vol. > Qio-24 hr event ( 5.57"), stored fuel Vol.
+ 10% (fuel + Q i o Vol.).
c. Non -hazardous solid waste dumpster /covered
d. Portable sanitary (porta John); downslope SF
e. Concrete wash -out /contained
f. Solvent /chemical storage /contained
3. Sec. E.: List named individual responsible for Pollution Prevention Practices; recommend RJ Cooper.
4. Revise title: Include ref. to WP02019-00035.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
Engineering Review Comments
Page 2 of 7
1. Anticipate addressed via SWPPP.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP.
This plan is disapproved for reasons listed in comments, below. The stormwater management plan content
requirements can be found in County Code section 17-403.
1. Revise Title Sheet (Plan) title to include: VSMP /WP02019-00035. (Rev. 1) Addressed.
2. Please delete Site Plan from VSMP /WPO Plan title. (Rev. 1) Addressed.
3. Sheet 2: Include note: `No grading or fill will occur in FEMA mapped floodplain.' (Rev. 1) Addressed.
4. Sheet 4
a. Although Wet Pond is designed for quantity control only, include note that VA DEQ Stormwater
Design Specification No. 14 construction and inspection standards apply.' (Rev. 1) Addressed.
b. Revise LS length to 40'. Also, item 6., below. (Rev. 1) Addressed.
c. Revise label ref. to 20' LS. Revise to 40' LS length. (Rev. 1) Addressed.
d. Recommend 1" =20' text, to accompany graphic scale. (Rev. 1) Addressed.
e. Provide additional inset cross-section profile for emergency spillway; include WSL for Q2,10,100
events (water depth) in spillway. Profile should indicate Q1oo does not overtop pond embankment.
Note: Q1oo depth is 473.77'; 100-yr event is contained within emergency spillway. (Rev. 1)
Addressed. As follow-u�: please revise highlight text to 477.0.
34, 0'
12.0' 10.0' 12.0'
TOP OF DAM=377.0
3.2' FREEBOARD 3', 100-YEAR WSE=473.77
10-YEAR WSE=473.19
SPILLWAY EL=473.0 2-YEAR WSE=473.01
POND SPILLWAY DETAIL SCALE: 1 "=10'
f. Provide spillway riprap dimensions (L X W X D). (Rev. 1) Not addressed, unless overlooked.
Sheet 5 makes apparent ref to sheet 3 detail. Sheet 3 does not include detail, or riprap dimensions.
NODE 07.0?%
J ` PROPOSED FOREST/OPEN SPA-
--� / A-0,9D AC (39,40C SF)
12 FOR
PS I _ PLAT ANDS MAINTENAN ER ACRE
AE
UNDER SEPARATE COVER)
t. PR ME MI
OEEP CL
FILTER FABI
PROTECTION
FOR N O 1
PS II i SHOEET00 F'
ET 4� <
4P� ���4�9�°0°`
��-
EROSION AND SEDIMENT CONTROL PLAN — PHASE 2
g. Provide wet pond floor dimensions (L X W X D). (Rev. 1) Addressed.
h. New, sheet 415:
i. Provide note /label that identify feature/s or delete extraneous leader line /lines.
Engineering Review Comments
Page 3 of 7
1 D,-M
SPILLS
�1
n. C
nl. C
5. Revise VaRRM (.xls) to include all disturbed area, that is, 3.20 Ac. 2-.0 1.5 Ac. forest /open space
(hydrologic soil group B) Eseils, 0.15 Ac. impervious, 3.05 Ac. turf, is an approach that meets water
quality requirement (9VAC25-870-65). (Rev. 1) Partially addressed. Asfollow-up: While revised plan
proposes 2.50 Ac. Forest /Open Space Easement, which appears sufficient to meet water quality
requirements, VSMP/WPO plan and revised Hydrology -Watershed Model (Report) must include VaRRM
.xls for this project. Plan may include summary site information (see screenshot below), but Report should
include more comprehensive .xls data. Initial plan /report do not appear to include VaRRM.xls data.
Note: Please do not include Wet Pond in forest /open space. Ref. 2016 DEQ guidance Memo, p. 12, table,
Forest & Open Space, bullet 5. Link: hqp://www.swbmp.vwrrc.vt.edu/wp-
contmt/uploads/2017/11NRRM New Cmpliance Spreadsheet_v3 082017.x1sm
Image, CDD estimate Forest/Open Space required to meet 3.20 Ac. LOD development; VaRRM.xls, v. 3.0
(ALSO: see Attached NRCS web -soil survey report; all soils within LOD are hydrologic c soil group: B)
1 DEQ Virginia RunoffRed-ri- Method New Detreiopmeat Comphonce Spreadsheet - Version 3.0
2 - 2011 B M P Standard s an d Spa c it cat ions 0203.3 Draft BMP Standards and Specifications
4 Project Name: 2265 Decca Lane, WP02019-"35, prelim data input cells
s Date: 7/12/19 ICDDI constant wlues
8Mp Design specrficotiona uar. 2013 Draft Stda & Specs calculation cells
7 Site Information
g Post -Development Project (Trea� ment Volume and Loajls)
10 Jj /
11 Land Cover (acres)
12 A %bil, I BSoils I 9S.11. I DSoils 1 -IN
Forest/0pen Span (-1--undisturbed, 1.50
13 paprotected foresVopen space or reforested land 1.50
paged Turt(x 1-dinurbed, graded for
14 yardsor otherturtto be mowed/managed 3.05 3.05
15 Imperviooccover (xres) 0.15 0.15
1.1 -For /Open 'Pare areas mustbeproetedin Anos with the Virginia- Reduction w- 1 4.70
19 w nual Rainfall pncM1esi 43 y
�n Tareet Rainfall Event linchesl 1.00
TP Load Reduction
6
ASoils
BSoils
CSoila
DSoils
Forest/f)pen space
0.02
0.03
0.04
0.05
anaged Turt
0.15
0.20
0.22
1025
Impervious Cover
0.95
1 0.95
0.95
10.95
-0.11
Engineering Review Comments
Page 4 of 7
6. Engineering recognizes level spreader (LS) disperses concentrated flow to sheet flow, but relies on design
std. provided with VA DEQ Stormwater Design Specification No. 2, Sheet Flow to Veg. Filter Strip, p. 3,
table 2.2, 13 LF /cfs to size LS.
a. Provide 40' length to accommodate Q10 flow =3.11 cfs. (Rev. 1) Addressed.
b. Provide (Typ.) LS detail: include Fig. 2.6 (Clearinghouse Spec. No. 2; pg. 8). This is a SWM plan
detail. (Rev. 1) Addressed.
c. Provide LS dimensions (L x W x H) and material type. (Rev. 1) Addressed. Note: recommend
revise LS detail label to include `treated' in LS material description (sheet 4).
7. Provide two (2) clean outs at first 2 bends in 8" PVC (nearest house), and provide four (4) std. VDOT MH-
1 (or Alt.) at the next four (4) downslope bends in 8" storm drain. Also, ESC Plan item Lb./c., below.
(Rev. 1) Addressed.
8. Provide 8" storm line profile. (Rev. 1) Partially addressed. As follow-up (sheet 6, 8" storm line profile):
a. Provide anchor blocks for any pipe grade > 16.0%; there appear to be 4 sections > 16%.
b. Provide pipe anchor detail. Ref. VDOT 2016 R&B Standards /VDOT Drainage Manual, p. 9-37.
VDOT Drainage Manual, 9.4.8.7 /pg. 9-37:
9.4.8.7 Maximum Grades
Slopes that incur uniform flow velocities in excess of 10 fps should be avoided because
of the potential for abrasion. Slopes in excess of 16% are not preferred because of the
need for anchor blocks. When anchor blocks are used, they should be installed at
every other pipe joint, as a minimum. (See Special Design Drawing No. A-73 and MA-
73 for Anchor Details for Concrete Pipe)
Corrugated pipe may be used on steep slopes in situations similar to those where
shoulder slot inlets are proposed. Corrugated pipe should not be used in areas where
the flow is expected to carry an abrasive bed load or that have PH and resistivity factors
beyond the ranges specified in the Allowable Pipe Type Table C in Standard PC-1 of
the VDOT Road and Bridge Standards. (See VDOT's Road and Bridge Standard PI-1,
for Anchor Details for Corrugated Pipe)
In steeper terrain, large elevation differences can be accommodated using drop
structures, otherwise known as "step down" manholes, to reduce the pipe gradient.
Y
Engineering Review Comments
Page 5 of 7
9. Include on the plans VA DEQ Stormwater Design Specification No. 14 (Wet Pond) construction sequence
and inspection steps listed at Sec. 8.1 and 8.2; Link: http://www.swbmp.vwrravt.edu/w -
content/uploads/2017/11/BMP-Spec-No-14 WET -PONDS v1-9 05112015.pdf Note: although wet pond is
being utilized for quantity control only, construction sequence and inspection are identical for quantity
control, except that with this design, Sec. 8.1 steps 7 and 13 are NA. Riser (principal spillway) inspection,
also NA. (Rev. 1) Not addressed. Please ref, link, above.
10. Include on plans periodic maintenance inspection for wet ponds. Ref. Attached. (Rev. 1) Not addressed,
unless overlooked. Ref. attachment to email sent 7/12/2019 2:29 PM.
11. Related to 5, above: SWM Forest /Open Space Easement plat with a Deed of Dedication is required prior to
VSMP Plan approval (under review /SUB2019-00097). Note: Engineering will format Deed of Dedication
template for Applicant once SWM Maintenance Agreement is recorded (please see Process section, below).
(Rev. 1) Comment persists; easement plat is under review: SUB201900097.
12. A SWM Facility Maintenance Agreement is required prior to final VMSP Plan approval. Please coordinate
Maintenance Agreement with Ana Kilmer, CDD Management Analyst (tel. 434.96-5832-x3246). (Rev. 1)
Comment persists. Also, email sent 7/14/2019 12:27 PM.
13. Include Note acknowledging SWM Facility As -built requirement/s apply to Wet Pond, pond spillway LS.
(Rev. 1) Addressed.
14. Include text of WPO /VSMP Construction Record Drawings Policy on Plans (Link (.PDF): (Rev. 1)
Addressed.http://www.albemarle.ore/upload/ima,ges/forms center/departments/Community_ Development/forms/Eng
ineering_and WPO Forms/WPO VSMP Construction_ Record Drawings Policy_ 23May2014.pdf).
15. SWM and ESC plan bonds must be posted prior to project receiving a grading permit (at pre -con meeting).
(Rev. 1) Comment persists. Also, email sent 7/14/2019 12:27 PM.
16. Submit VSMP bond estimate request form. A SWM Plan bond is required for wet pond: spillway, plunge
pools (stone), earthwork, LS, etc. (Rev. 1) Comment persists. Also, email sent 7/14/2019 12:27 PM.
Link:
hgps://www.google.com/url?q=https://www.albemarle.org upload/images/forms center/departments/Community Deve
lopment/forms/bonds/Bond—Reguest—to Establish a Bond.pdf&sa=U&ved=OahUKEwiX4d-
i25 zeAhV ikeAKHYDbAxkOFggGMAE&client=internal-uds-
cse&cx=013641561590022973988:g3cwjsrdbli&us¢=AOvVawO70B-uOuTu_Fa 5WrzNXdB).
New:
17. Sheet 2, slight clean-up (text over -write).
PROP. HOUSE
1 45 —8" HDPE 05.30%
$" "W(t7R7.REMOVED)
` LIMITS OF CLEARING AND
18. Sheet 9, slight clean-up:
4. ONCE POND HAS BEEN CONSTRUCTED AND STABILIZED. CONNECT 8"PVC STORM DRAIN PIPE TO
FRENCH DRAIN.
5. COMPLETE THE REMAINING SITE CONSTRUCTION AND STABILIZE AREAS NOT TO BE PAVED OR BUILT
UPON WITH PERMANENT SEEDING.
6. REMOVE THE TEMPORARY SEDIMENT CONTROL MEASURES ONLY AFTER ALL UPSTREAM AREAS HAVE
EEDSIWR,MANEWMMENFAEIOffWIANiiAtER,MM 5TQ0&WM FROM THE COUNTY E+S INSPECTOR.
(PER 9VAC25-840-40)
1. PERMANENT OR TEMPORARY SOIL STABILIZATION SHALL BE APPLIED TO DENUDED AREAS WITHIN
CFVFN nayA , AFTER VINIAI GRAnP7 IC RFA(' 4vn nNI ANY PnRTInK] nP' TIdF CITF T"APORARY Cnll
Engineering Review Comments
Page 6 of 7
CIMENT D IMAGE DUE TO II
TE OF STORMWATER RUNOFF FOR TH STATED FREQL
CORDANCE WITH THE FOLLOWING STA DARDS AND CR
OJJEECjTTSS THAT INCORPORATE NATUR CHA�NNN�EEL DDESK
'N�-MA`DE' S 9 W1lNlMSV
PROPOSED CONSTRUCTION OF A SINGLE—FAMILY DWI
A OF GREATER THAN 1 ACRE, WHICH REQUIRES THE
PROGRAM (VSMP) PERMIT.
THE PROPOSED CONSTRUCTION RESULTS IN A NET INCRE
IN ORDER TO MEET THE WATER QUANTITY AND QUALITY
D. Erosion and Sediment Control Plan (ESOP)
Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESOP. This plan
is disapproved for reasons listed in comments, below. The erosion control plan content requirements can be
found in County Code section 17-402.
1. Sheet 5
a. Revise labels:
i. Revise steep slopes to critical slopes. (Rev. 1) Addressed.
ii. Revise 20' LS length to 40'. (Rev. 1) Not addressed. Recommend incl label indicating
revised LS length, this sheet.
iii. Revise proposed 0.90 Ac. proposed forest /open space easement to 1.5 Ac., or value
sufficient to meet 9VAC25-870-65 requirement. (Rev. 1) Not addressed.
PROPOSED FOREST/OPEN SPA,
j A=0.90 AC. (39,400 SF)
(SEE SHEET 2 FOR ENTIRE VIE
PLAT AND MAINTENANCE AGRE
UNDER SEPARATE COVER)
oe
PROVIDE
DEEP CL I
rig Trn rAn�
b. Show /label 8" clean -outs at first 2 bends in 8" PVC storm drain pipe (nearest house). (Rev. 1)
Partially addressed. Asefollow-up: Recommend sheet 5 storm line bends include label reference
to sheet 6 profile; and that sheet 6 storm line profile ref sheet 7 Nyloplast ® structure (typ.) detail.
c. Provide, show, label four (4) VDOT MH-1 at next four (4) downslope bends in 8" PVC pipe. Or,
as discussed 7/12 (11 AM tel. call), provide Nyloplast V vertical access instead of VDOT MH-1.
(Rev. 1) Partially addressed —see l .b., above.
d. Provide Nyloplast detail/s. (Rev. 1) Addressed.
e. Provide trapping measure (reasonable volume) at downslope end of each clean -water diversion.
Alternatively, as discussed 7/12, provide LS parallel to contours as a temporary measure. If LS
provided, include VESCH, 3rd Edit., 1992, Plate 3.21-2 on plans (ESC plan detail). VESCH Std.
& Spec. 3.21 specifies Min. L =10'. (Rev. 1) Not addressed. Revised design pending. Ref. M.
Myers email, 7/14/2019 9:08 AM.
Engineering Review Comments
Page 7 of 7
2. Sheet 6
a. Provide paved construction entrance detail. See ACDSM, p. 8. (Rev. 1) Addressed. Link:
http://www.albemarle.org/upload/images/forms center/departments/community development/form
s/design_ standards _manual/Albemarle _ County Design Standards Manual 2015-04-25 draft.pdf
b. Include VESCH Table 3.32D on plans (permanent vegetation /Piedmont). (Rev. 1) Not
addressed. Revised design pending. Ref. M. Myers email, 7/14/2019 9:08 AM.
3. Sheet 7
a. Pre -Post runoff composite CN values may be revised to reflect only hydrologic soil group `13', but
this is not a requirement (Ref. Attached websoil survey report). (Rev. 1) Addressed.
b. For pre- or post areas and area listed in composite CN tables, please report a single acreage.
Acreage may vary from pre- to post, but within predevelopment or post -development condition,
please list a single pre- or post -development acreage, as discussed 7/12. (Rev. 1) Addressed.
c. Label Mechums River. (Rev. 1) Addressed.
The VSMP permit application and all plans may be resubmitted for approval when all comments have been
satisfactorily addressed. For re -submittals please provide 2 copies of the complete permit package with a completed
application form. (.PDF preview welcome).
Engineering plan review staff are available from 2-4 PM on Thursdays, should you require a meeting to discuss this
review.
Process
After approval, plans will need 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 need to be completed by the owner and submitted along with cash,
certificates or sureties for the amounts specified. The agreements will need to be approved and signed by the County
Attorney and County Engineer. This may take 2-4 weeks to obtain all the correct signatures and forms.
Stormwater Management Facilities Maintenance agreements will also need 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 need to be submitted along with court recording fees.
Stormwater Management Facility, SWM Facility Access, Forest /Open -Space Easements must be recorded prior to
final approval. This means a Grading Permit may be issued prior to recordation of VSMP-related easements.
After bonding and agreements are complete, and easement recorded, Albemarle County can hold a pre -construction
conference. Applicant will need to 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
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;
htt2://www.albemarle.org/deptforms.asp?departrnent--cdengMo
WP02019-000035 2265 Decca Lane 071419rev1