HomeMy WebLinkAboutWPO201800086 Review Comments WPO VSMP 2019-11-12�OF Aign.
COUNTY OF ALBEMARLE
ah 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: Brookhill Blocks 9-11
Project file number: WP0201800086
Plan preparer: Collins Engineering — Scott Collins [scott@collins-engineering.com]
Owner or rep.: Riverbend Development — Alan Taylor [alan@riverbenddev.com]
Plan received date: 26 Nov 2018
Date of comments: 08 Jan 2019
Reviewers: Emily Cox
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. 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. 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. SWPPP was not provided with this submission. Provide two copies of a SWPPP. If overall
Brookhill SWPPP is to be used, provide updated registration statement and an overall sheet
showing disturbed area covered by the registration statement.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
1. PPP was not provided with this submission. Provide two copies of a PPP and ensure it contains
everything as outlined in County Code section 17-404. If E&S plan is intended to be used for PPP,
ensure it shows all requirements and provide a note stating it is also PPP.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a
SWMP. 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. Professional seal must be signed and dated on the calculations package.
2. The Overall Brookhill Stormwater Quality Compliance Table must be updated and provided with
this application.
3. [Sheet 2] Label the buffer as proposed greenway per the approved ZMA. There is no existing
buffer. Also, update note 2. Ensure greenway is labeled consistently throughout plans.
4. Please provide the following document on the plans:
httD://www.albemarle.oriz/ul)load/imaees/forms center/departments/Community Development/for
ms/En in�g_and_WPO_Forms/WPO_VSMP_ Construction_ Record _Drawingsy 23May
Engineering Review Comments
Page 2 of 5
2014.pdf
5. Please note that since this plan does not include the proposed road connection to Ashwood
Boulevard, an additional WPO Plan will be necessary for that road design before the associated
road plan can be approved.
6. Ensure this TMP is covered by the existing SWM maintenance agreement. Otherwise, a SWM
maintenance agreement will be necessary before plan approval.
7. Is the proposed SWM preservation easement area the forest and open space easement? Or is it the
greenway that is to be dedicated to the county? If it is forest and open space, it should be labeled as
SWM forest & open space and the following note should be on the plan and plat: "The SWM
Forest and Open Space Easement is subject to the guidance set forth by DEQ in the Virginia
Stormwater Management Program. The areas will remain undisturbed in a natural, vegetated state,
except for activities as approved by the local program authority, such as forest management,
control of invasive species, replanting and revegetating, passive recreation (e.g., trails), and limited
bush hogging to maintain desired vegetative community (but no more than four times a year)."
8. Please show SWM facility easement around stormwater facility and access road.
9. [Sheet 15] Show plan #, not just note stating, different set of plans.
10. [Sheet 16] Is outfall pipe from the pond 12" or 15"? It is shown as 15" in E&S, but 12" in SWM.
11. [Sheet 15] Show design and drainage area for "proposed diversion associated with this set of
plans..."
12. [Sheet 15] Clarify the note stating that "two proposed adequate pipe outfalls ... sub area less than
1 %..."... Show drainage areas for each and compare to the overall area. Also label/distinguish each
concentrated outfall. This is slightly shown/labeled in the calculations packet for the outlet
protection, however, it is very unclear on the plans.
13. [Sheet 15] Please distinguish drainage areas and outfalls with labels, such as 1, 2 3 or A, B, C. It I
very confusing to read and follow.
14. [calculations packet] There is only one drainage area shown (DA A), when this area is actually
made up of several drainage areas?
15. [calculations packet] What is the Qdev for the SWM outfall? Calculations show it must be less
than 0.14, but do not say what it is. Also, the flood protection states the same thing (post less than
pre, but does not give any numbers)
16. [calculations packet] Please label remaining outlets (1-5) on the plans. Also, if these are just sheet
flow, they are not "concentrated flow" and do not have to be analyzed. How is flood protection
being addressed with these outlets, 1-5? The package only outlines channel protection.
17. [runoff reduction] Please clearly show the 35.34 acres and associated areas that are being used in
the calculations.
18. [Sheet 16] Retaining wall design must be provided since it is part of the SWM facility grading.
19. [Sheet 16] Provide safety bench and aeration for the level II wet pond per:
hgps://www.swbmp.vwrrc.vt.edq wp-content/uploads/2017/11/BMP-Spec-No-14_WET-
PONDS_vl-9_05112015.pdf
20. [Sheet 16] Provide contour labels.
21. [Sheet 16] Provide outlet protection for the inflow to the pond.
22. Since there are no pipe/storm drain calculations, provide pipe design information for SWM facility
outfall (size, capacity, flow, velocity).
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, and the reasons are provided in the comments below. The erosion control
plan content requirements can be found in County Code section 17-402.
Engineering Review Comments
Page 3 of 5
1. [Sheet 3]: Ensure detail and notes for construction entrance match the design standards manual,
page 8.
http://www.albemarle.org/upload/ima,ges/forms_center/departments/community development/for
ms/design standards _manual/Albemarle _ County Design_ Standards_ Manual_2015-04-
25 draft.pdf
2. Please clearly show limits of disturbance vs property line vs buffer lines vs drainage divide lines vs
silt fence and tree protection lines. It is unclear in some locations. There is a note stating they are
offset for graphic reasons, however, silt fence should be INSIDE the limits of clearing and grading
because it requires disturbance for installation.
3. Per section 2.4.1 Greenway and 2.4.2 Buffers of the code of development, both the greenway and
buffers shall not be located in any lots. Lots 1-12. 32-46 and 76-95 appear to have lot lines within
buffers. Please revise.
4. [Sheet 2] Please update Block 4B and road plan notes. Do not list under review, simply list the file
#. Also note, the road plan is an SUB, not SDP.
5. [Sheet 2] Show DB & PG for all existing, recorded easements. This includes easements associated
with Block 4B, etc.
6. [Sheet 3] Dimensions for diversion channel crossing are not legible. Please increase the font size.
Also, please distinguish between type A, B or V crossing.
7. [Sheet 3] The project description in the narrative states that 19.77 acres will be disturbed, while
Sheet 5 states that 24.4 acres will be disturbed. Please clarify.
8. [Sheet 4] Provide a north arrow.
9. [Sheet 4] Please label limits of construction. It appears that there is disturbance to preserved slopes
and greenway, which is not allowed per the approved ZMA. Also, please show the buffer along
29 since this is an overall sheet.
10. Provide drainage area to all silt fence showing that it meets the requirements of 0.25 ac per 100 ft
of silt fence.
11. [Sheet 5] The diversion dike to sediment trap #1 will not function. There is a low point in the
southwestern corner of the drainage area (as drawn). Water will not flow to sediment trap #1 as
drawn. Please add additional control at the low point and revise drainage area and diversion dike
to sediment trap #1.
12. Grading is shown in the buffer (greenway) and preserved slopes. This is only allowed as shown in
the approved ZMA.
13. Are the project limits the same as the limits of constriction? Please clarify.
14. Please clarify all hatches on the plan. A legend would be very helpful. Also a legend with drainage
divide line, soil type line, etc would be helpful.
15. [Sheet 5] Note regarding 70' buffer at the top of the sheet is not sufficient. A sheet must show that
there is no disturbance to the buffer.
16. [Sheet 7] There is work shown outside of the project limits line?
17. [Sheet 7] Is the sediment trapping device for the construction entrance an existing trap? If not,
show the proposed grading. Also, SF is currently shown going through this trap?
18. [Sheet 7] Provide design information for proposed culvert (drainage area, flow, velocity, size, etc).
Also, show design information for proposed rip -rap outfall. Currently silt fence is also shown
going through the rip -rap.
19. [Sheet 7] 1:1 slopes are not allowed, even if temporary.
20. [Sheet 7] The outfall to sediment basin #1 is not completely shown. Provide matchline or adjust
viewport.
21. [Sheet 7] Provide permit or note that permit is not required for work in the stream with the
proposed culvert.
22. [Sheet 10] Please clarify or revise ST #4 vs ST #3.
23. [Sheet I I] Proposed concrete washout is in the middle of a proposed road?
Engineering Review Comments
Page 4 of 5
24. [Sheet 13] Show tops and bottoms of proposed retaining wall.
25. [Sheet 14] Drainage areas for traps and basins do not appear to match what is shown on the plan
view sheets. Please clarify.
26. [Sheet 14] Weir length for ST #1 is calculated as 17 ft., but is shown as 6 ft. on the plans. Also,
the storage area does not have a 2:1 length to width area. Please revise.
27. [Sheet 14] Outlet protection design table should show the flow and/or velocities that design of
outlet protection is based on. Or add a note stating calculations are in the attached supplemental
calculation booklet.
28. [Sheet 14] ST #2: The maximum embankment height should be 5' from the toe of the stone outlet.
This appears to be 6ft. Please revise.
29. [Sheet 16] Ensure trash rack includes anti -vortex device.
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.
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 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 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;
hlt2://www.albemarle.org/deptforms.asp?department=cdengno
Engineering Review Comments
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