HomeMy WebLinkAboutWPO202000051 Review Comments WPO VSMP 2020-12-21Phone (4341296-5832
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COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
VSMP Permit Plan Review
Boys and Girls Club, Driver's Ed — VSMP
WP0202000051
Bryan Cichocki, PE [ bryan.cichockiAtimmons.com ]
Craig Kotarski, PE, Timmons Group — 608 Preston Ave, Suite 200,
Charlottesville, VA 22903 lcraia.kotarski(i�timmons.com ]
Boys and Girls Club, 1000 Cherry Ave., Charlottesville, VA 22903
[ioierceAbeclubcva.org ]
6 Nov 2020
21 Dec 2020
John Anderson
Fax (434) 972-4126
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.
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.
Submit SWPPP; use county template: httos://www.albemarle.org/home/showoublisheddocument?id=166
Please ensure that SWPPP. once submitted:
1. Sec. 1, Registration Statement is complete. Complete Sec. 1 as condition of VSMP /WPO plan approval.
a. Sec. IV, E., (MS4); Please leave blank.
b. Sec. VI, Certification: Please complete (print mane, sign, date).
2. Sec. 4, 5: Include revised ESC and SWM plan sheets, once comments addressed.
3. Sec. 6.A. / Exhibit: Indicate location rain gauge /other required PPP measures.
4. Sec. 6.E. —List named individual responsible for pollution prevention practices rip or to project pre -
construction meeting.
5. Sec. 8. — List named individual qualified to perform compliance inspections prior to pre -construction
meeting (prerequisite to receive Grading Permit).
6. Sec. 9., Signed Certification: Individual who prepared SWPPP document must sign as condition of VSMP
/WPO plan approval. Also, Albemarle cannot register project with DEQ until SWPPP Sec. 9 is complete.
7. Include 2019 Notice of Termination form. (Attached /.PDF).
8. SWPPP title includes ref. to VSMP /WPO2020-00051.
B. Pollution Prevention Plan (PPP) — See above.
The PPP content requirements can be found in County Code section 17-404.
C. Stormwater Management Plan (SWMP)
Engineering Review Comments
Page 2 of 5
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This
plan is disapproved for reasons listed below. The stormwater management plan content requirements can be
found in County Code section 17-403.
1. Revise WPO plan per Engineering Initial Site Plan review comments (10-Dec 2020) items 2-4, 9-11, 12 (b,
c, g, h). Ensure ISP review revisions carry over to WPO plan resubmittal.
2. C1.3: Provide VDOT ST-1, IS-1, PB-1 details on the plans (steps, inlet shaping, pipe bedding).
3. C5.0
a. Clarify whether pipe 301 discharge is to surface or manmade subgrade structure. If discharge is to
surface, ensure discharge is to a stormwater conveyance channel, as existing topography at pipe
301 discharge are evenly spaced contours without a defined channel. This slope will erode if
concentrated flow is released with no proposed change in grade, to define a channel.
b. Align pipe 301 outfall with pipe. An outfall structure should not deflect direction of discharge.
Provide MH structure at pipe 301 discharge to deflect discharge, unless design relies on ex. MH.
4. C3.4: Label Ex. SWM facility (Mfr. wetland).
5. C5.1
a. Recommend a vault -style cover with locking feature for underground detention access located in
paved surface between loop and west wing of building. This point of access should be limited to
authorized personnel only with no possibility of trespass by youth patrons of the facility.
b. With next submittal, provide tiered retaining wall TW BW elevations.
6. C5.0, C5.1
a. Show and label SWM facility easements for underground detention systems. Label SWMI,
SWM2. Ensure easement widths meet ACSM easement diagram guidance, p. 15
(httos://www.albemarle.org/Home/ShowDocument?id=270 ).
b. Clarify via inset details the precise location /structure type/s that house SWMI, SWM2 weir
plates. Precise detail is needed.
7. C6.3
a. Revise SWMI weir plate detail top of pipe elevation to 548'.
b. Provide small-scale plan views for SWMI, SWM2 weir plate structures that show access ladders,
pipe penetrations, weir plates and manway clearances ( access to each side of each weir plate) to
check for potential conflicts. Also, 8.d., immediately below.
c. Provide debris cage details for SWMI, SWM2 weir plate orifice openings, unless overlooked.
d. Provide additional weir plate details: steel gauge, manner of connection to housing (pre -fabricated,
welded, etc.).
e. Provide UG detention system profile details (bedding, inv elevations, system slope, if any, min.
depth of cover, etc.).
8. C6.2
a. Consider and offset any effect of diminished treatment of existing stormwater facility. C3.4
depicts post -developed condition with no Drainage Area 1 concentrated runoff reaching Ex.
SWM. C2.4 shows 24" RCP outfall removed with project. Please update design, VRRM.xIs re-
development worksheet, and /or calcs if current/existing condition DAl runoff reaches wetlands,
which perform water quantity /quality functions, which may diminish in the post-dev condition.
b. Pre -developed drainage area map may be inaccurate in that it may underestimate volume of runoff
or areas currently draining to ex. stormwater facility. Instead, the pre-dev DA map implies DAI
does not route to Ex. SWM facility /wetlands, when linework shows concrete flume which appears
to route a portion of runoff to this facility via 24" RCP outfall (removed with project). Ex.
contours /riprap appear to indicate a portion at least of pre-dev DA 1 runoff reaches Ex. SWM
(blue circle, image, below). If existing Mfr. wetland is overgrown or poorly maintained, pre-dev
runoff analysis must assume a pre -developed condition with functional existing SWM facility.
C. Label analysis point 2 on post-dev DA map. Additional comments possible.
RA
Engineering Review Comments
Page 3 of 5
� F/
Include construction installation (Mfr.) notes and periodic maintenance requirements for proposed
underground detention, on the plans.
10. Calculation booklet
a. Revise cover to include WPO202000051.
b. Provide LD-204, I =6 in. for inlet capacity analysis.
c. Revise inlet length, Str. 202, to limit excessive spread (=12.093').
d. Recommend increase inlet lengths, Str. 206 and 208, from 6' and 4', respectively, to allow drivers
to exit vehicles to dry pavement ( recommend avoid 9.599' and 9.164' spread, respectively).
e. Revise 6' inlet length, Str. 402, to ensure spread (9.012') is < %: travel lane width + 2' gutter pan,
or, <8'. Drive aisle =24', two-way travel, this means %: travel lane width W.
f. Revise narrative, p. 3, to include discussion of Ex. county SWM facility (mfr. wetland). Provide
comprehensive description of quality /quantity benefits provided by existing on -site SWM, and in
the proposed post-dev condition. Project narrative /SWM does not mention ex. SWM facility.
g. Narrative, p. 3, explains that `Two underground detention systems will be installed to meet
stormwater quantity requirements. SWMI is 50 linear feet of 84" CMP while SWM2 is 220 linear
feet of 96" CMP. Together, these pipes reduce the 1-year, 24-hour storm to meet the requirements
of the energy balance equation.' Energy balance applies at each discharge point. Revise narrative
or design to ensure energy balance is achieved at each post -developed discharge to natural
conveyance.
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 disapproved for reasons listed, below. The erosion control plan content requirements can be found in
County Code section 17-402.
C3.0
1. Develop a more detailed, additional -phase ESC plan that:
a. Shows proposed mass grading required to construct improvements (pavement, building, walls,
etc.)
b. See detailed ESC Plan developed for WPO202000005, Boys and Girls Club Northside, for
examples of interim mass -grading, ESC measures, etc.
a C3.3
Engineering Review Comments
Page 4 of 5
i. Phase 1 shows no proposed grading, other than grading for STI, ST2, ST3.
ii. Label sediment trap floor dimensions.
iii. Shift ST2 slightly downhill so DD inflow to ST2 travels a farther distance, with increased
residence time. DD runoff is introduced too close to ST weir outfall.
iv. Label ST2, ST3 weir riprap dimensions ( L x W x D).
v. Revise diversions to ST2 to avoid 90-deg turns. Concentrated runoff will likely break
through bends. Recommend replace ST2 with separate STs, one at each 90-deg bend,
with area in between these two smaller STs directed to drain to one, or the other.
vi. Coordinate location, size of all traps with mass grade plan, sequence of construction, and
final improvements. STs must function for a period of time, must accommodate
construction of walls, building, paved surfaces, etc.
vii. The proposed 2-phase ESC plan gives no clear understanding of how the site, or ESC
measures, will progress from existing condition thru final stabilization /site buildout.
d. C3.0: Revise sequence of construction to provide additional specific ESC detail from existing
condition thru final improvements (building, walls, athletic field, pavement /sidewalks).
e. C3.4
i. Consider additional ESC measures for 10' (vertical interval) steeply -graded slopes south
of building.
ii. Label steepest portion of graded slope west of stairs from elevation 561 to 544 (2.5:1,
3:1, etc.).
iii. Provide /specify permanent groundcover (vegetative cover) hardier than grass for any
proposed graded slope steeper than 3:1.
iv. Label proposed slopes steeper than 3:1, provide /reference plant schedule (specify species
other than grass).
2. C5.1: Provide ditch detail /calc. velocity in ditch created by new/proposed contours south of building, west
of tiered retaining walls downslope of building (blue arrow, image, below).
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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. During the pandemic to avoid document quarantine requirements, Albemarle encourages digital
submittals.
Engineering plan review staff are available via teleconference, 2-4 PM on Thursdays, should you require a meeting
to discuss this review.
Engineering Review Comments
Page 5 of 5
Process:
After approval, plans will have to be bonded. The bonding process is begun by submitting a bond estimate request
foam 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 foams, 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.
After bonding and agreements are complete, county staff will 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,
http://www.albemarle.org/del)tforms.asv?department=cdengwpo
WP020200005I Bovs and Girls Club_ Drivers Ed 122120