HomeMy WebLinkAboutWPO202000017 Review Comments WPO VSMP 2020-08-24Phone (434) 296-5832
COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia22902-4596
VSMP Permit plan review
Project title: Proffit Road Townhomes South
Project file number: WP0202000017
Plan preparer:
Owner or rep.:
Plan received date:
Date of comments:
Reviewer:
Justin Shimp
Albemarle Land Development
March 23, 2020
July 20, 2020
May 7, 2020
Aug. 24, 2020 (Rev. 1)
David James
Fax (434) 972-4126
(j ustin@shimp-engineering. com]
[brent@greenstonematerial.com]
[djames2@albemarle.org]
County Code section 17-410 and Virginia Code §62.1-44.15:34 requires the VSMP authority to act on any
VSW permit by issuing a project approval or denial. This project is denied. The rationale is given in the
comments below. The application may be resubmitted for approval if all of the items below are satisfactorily
addressed. The VSMP application content requirements can be found in County Code section 17-401.
A. General
1. Cover — Add WP0202000017 under title. (Rev.1) Addressed.
2. (Rev.1) Complete VSMP application form with each resubmittal.
B. 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.
1. Registration Statement:
a. Update the Start & End dates under Section IV. (Rev.1) Addressed.
b. Add `County of Albemarle' for Section IV.E. (Rev.1) Addressed.
2. Complete Sect. 9 — Signed Certification (Rev.1) Comment still valid.
C. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
1. Submit a PPP exhibit sheet. (Rev.1) Please include offsite area on the PPP. Also, add a
Staging area & symbol.
D. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWW.
This plan is disapproved, and the reasons are provided in the comments below. The stormwater
management plan content requirements can be found in County Code section 17-403.
1. Provide LD-347 or equivalent calcs & show HGL in the storm sewer profiles.
(Rev.l) Addressed.
2. Show drainage area fOF the eHtFHnee and show that the eHtFflnee will be fFee of
flooding a.._:.... the 25 - - St,.--H. (Rev.l) Acknowledged; Comment withdrawn.
3. Provide curb to keep stormwater on -site:
(Rev.l) Acknowledged.
4. Provide ditch or berm:
(Rev.l) Acknowledged.
5. Provide proposed inlet drainage area map. (Rev.l) Acknowledged. Provide on map
for each inlet: drainage area size, time of concentration, flow path, C value.
6. You will need to confirm that the off -site `Biofilter' facility's will handle this site's
drainage area since you are diverting stormwater directly to it. (Rev.l) Not currently
addressed. Need to investigate the original design plans. Please show current DA to
biofilter. Any increase volume, or flow may need to be diverted around facility to a
receiving channel or alternative.
7. Show WSE on the weir plate in str. A4. (Rev.l) Partially addressed. Indicate the
design storm elevation for the 1-,2-,10-yr storm.
8. Sheet 9 — Provide A2 to At info. (Rev.l) Addressed.
9. I was unable to find this Stormtech MC-4500 system listed on DEQs approved list
posted on the BMP Clearinghouse website. (Rev.l) Addressed. Thanks for the
clarification.
10. VRRM — Please verify (with DEQ) the pollutant removal eff% of this Stormtech
system. (Rev.l) Addressed. Thanks for the clarification.
11. Show that the MID is sized for the project
(httas://www.swbmp.vwrre.vt.edu/bmps/hydrodynamic-devices/ - VADEQ Practice 16:
Hydrodynamic Devices, Sizing information):
a. Calculate the treatment volume to the device (TvBMP). The calculated TvBMP can
be obtained from the Virginia Runoff Reduction Method (VRRM) spreadsheets.
b. Calculate the peak discharge of the obtained treatment volume (gpTv). DEQ's
preferred method to calculate the peak discharge for a BMP drainage area is
described here.
c. Work with the MTD vendor to ensure that the obtained peak discharge to the
device (gpTv) is less than or equal to the maximum treatment flow rate (MTFR) of
the device (gpTv < MTFR).
(Rev.l) Addressed.
12. Show TvBMP area of the Stormtech. (Rev.l) Addressed.
13. Sheet 12 - Show these post-dev areas of runoff on the map. (Rev.l) Addressed.
14. Show/label `SWM facility' casements for the underground detention and
Stormtech system. (Rev.l) Addressed.
15. Provide minimum easement width for the SWM pipes to follow sizing,
EASENIENT WIDTH = DIAMETER . J' - 2 (HE') . 10' i.0' ?II]o
[ACDSM, p.15[.
(Rev.l) H is measured from grade to the top of foundation. It looks like you might
have measured from grade to the top ofpipe.
16. Record the SWM maintenance agreement prior to approval. [Sec. 17-4151
(Rev.1) Comment still applies.
17. A recorded SWM facility easement plat & deed prior to permit issuance.
(Rev.l) Comment still applies.
18. Provide letter of availability from the off -site nutrient bank provider. Currently 1.16 TP
load credits required [Sec. 17-403 A.91 (Rev.l) Acknowledged. Currently L37
credits needed
19. Provide list of materials and price for the Stormtech MC-4500 system for the bond
20.
21.
est. (Rev.l) Addressed.
(Rev.1) Sheet 9 (Weir plate detail) — Orifices under 3" are susceptible to clogging &
increase maintenance. Increase diameter, provide anti -clogging device/feature.
(Rev.l) Show/Provide how this circled area will drain to Str. A8.
E. 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, and the reasons are provided in the comments below. The erosion control
plan content requirements can be found in County Code section 17-402.
1. Cover — Visually field verify topography & existing site show on sheet 3 and provide date of
field verification. (Rev.l) Addressed.
2. Show location of all existing utilities and easements with deed book references.
(Rev.1) Addressed.
3. Provide offsite easement for proposed drainage connection to offsite SWM facility. A letter from
off -site property owner is enough for this plan review, but any legal easements will need to be
signed by the property owners. [ACDSM, p.221 (Rev.l) Partially addressed. You can also
record an easement plat.
4. Sheet 4 — Please show all grading elevation labels (a few missing). (Rev.l) Addressed.
5. Sheet 6 —
a. Provide CRS (3.03) for the road. (Rev.l) Acknowledged.
b. Provide SCC (3.17) instead of DV & CIP. That way you have both outlet & inlet
protection. DV not meant to receive concentrated flow. (Rev.1) Partially
addressed. Provide channel design and determine appropriate liner needed.
Velocity below Ups will require EC-2 or equivalent, 4-10fps will need EC-3.
The silt fence shown is enough, so CIP not needed.
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.
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.
After bonding and agreements are complete, county staff will need to 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 need to be paid
directly to the state. For fastest processing, this is done electronically with the entails 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 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 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;
btip://www.albemarle.ory/deptfortns.asp?department==cdengWo