HomeMy WebLinkAboutWPO201400096 Review Comments WPO VSMP 2019-08-26COUNTY 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:
Stonefield Block D2, Phase 2 — VSMP Amendment
Project file number
WP02014-00096
Plan preparer:
Mike Myers, PE / 30 Scale LLC, 871 Justin Drive, Palmyra, VA 22963
[ mike(&30scale.com ]
Owner or rep.:
Christopher at Stonefield LLC, 10461 White Granite Drive, Suite 103
Oakton, VA 22124
Plan received date:
4 Mar 2019
(Rev. 1)
9 Jul 2019
(Rev. 2)
15 Aug 2019
Date of comments:
18 Apr 2019
(Rev. 1)
5 Aug 2019
(Rev. 2)
26 Aug 2019 —Approved, ep nding SWPPP update /2019 Registration Statement
Reviewer:
John Anderson
Majority of comments addressed with Revision 1. If gray -scale, Addressed. If black print or follow-up, revision
requested, or recommended
WP02014-00096, Amendment
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 approved pending SWPPP update to
SWPPP booklet (onsite /SWPPP mailbox). Also, provide complete /signed .PDF of 2019 VPDES permit
registration statement; link:
http://www.albemarle.orL,/unload/imaees/forms center/departments/Community Development/forms/Eneineerin
g_and _WPO_Forms/CGP_ Registration _Statement _2019_FINAL _201904.pdf
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. Link to County template:
http://www.albemarle.org/upload/images/forms_center/departments/Community Development/forms/Engin
eering and _WPO_Forms/Stormwater_Pollution _Prevention _ Plan_ SWPPP_template.pdf
Provide SWPPP. Use county template (link, above). (Rev. 1, 2) Ref. PPP, item 1., below. On -site SWPPP.
Update booklet /PPP Exhibit in Mailbox. Also, please send 2019 VPDES Permit Registration Statement;
link, above.
The PPP content requirements can be found in County Code section 17-404.
SWPPP —Provide I I" X 17" Exhibit. Recommend ESC Plan as template. Show solid/non-hazardous waste
dumpster; sanitary facilities (port -a John); solvent -paint storage; concrete wash -out; on -site fuel storage.
DEQ, during periodic inspections of active projects, instructs on importance of an Exhibit that shows
location of these features. All should drain to containment. For example, silt fence downstream of port-a-
john. Concrete wash -out, dumpster draining to trapping device (lined, in case of concrete wash -out). On -
site fuel storage berm with 10ml liner, sized to hold fuel volume + 2 yr. storm event. .PDF samples
Engineering Review Comments
Page 2 of 5
available. Exhibit is not intended as a detailed design, but to show containment and locations which may
change over time. Exhibit is a construction aid and resource protection/inspection management tool. (Rev.
1/2) Addressed. Applicant response (7/8/19): `Please note that there is a current SWPPP in the site
mailbox. Once approved, the amended WPO201400096 signed plan set will be added to the mailbox.'
Engineering accepts this response provided updated SWPPP Exhibit is included in the site SWPPP
mailbox, as well as approved plan set (I I" X 17"). Comment persists.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP.
This plan is approved.
Sheet 1: SWM Amendment Narrative (Note: plan revises VAR10I551): `The Amendment reduces the
impervious area that was originally proposed with WPO201400096, and therefore stormwater management —
water quantity control requirements are satisfied.' Engineering accepts this statement.
Water Quality: `As shown on the approved WPO plans (WPO201400096), water quality control for block D2 is
met by a combination of existing downstream BMP facilities (a Vortechnics structure and a Stormfilter facility),
and supplemented by onsite Filterra box planter structures to meet the remaining phosphorus removal
requirements. The appropriate BMP worksheets have been updated and included with this VSMP Amendment.'
Engineering accepts this statement, with additional review comments:
1. Attach (attached 3-sheet partial plan set, WPO201400096); revise sheet 1 Index.
2. Include Site Plan Amendment sheets 7 (Ex. Conditions /Demo Plan), and 8 (Layout); revise index.
[SDP201900012]
3. Include sheet 13 (source -?), since referenced in descriptive labels for ditches #1 and #2, Phase 2, ESC plan
(VSMP plan sheet 8).
4. Please contact Carla Harris, Albemarle County /CCD-Engineering to ensure no lapse in VAR10 permit
coverage ( charriskalbemarle.org ). (Rev. 1) Addressed. [VAR10I551; Reissuance submitted —confirmed
815.]
5. Ensure structure labels are not obscured by drainage area divide heavy linework (are clearly readable).
6. Filterra Str. 6A does not appear to be shown to scale. Check scale of this 12' X 6' structure. [Related:
ensure FSP, SDP201900012 sidewalk at Filterra Str. 6A is 4' wide, Min., per Code of Development.]
7. Check scale of Filterra Str. I and 4A. Revise as needed to show true scaled dimensions for these
structures. [8' X 4', 6' X 6', respectively.]
Sheet 5
8. Using design ratio Area Filterra (ft2): Area (ft2) drainage area=0.33%, Filterra Str. 4A Min. required area is
38.8 ft2. 36 ft2 is provided. Revise to provide Min. Filterra area for proposed DA. (Rev. 1) Not
addressed. Applicant response: `As discussed, the Filterra design is based on the grandfathered
requirements.' As follow-up: Please see email sent 8/5/2019 10:02 AM: `Technical Bulletin 6, Minimum
Standard 3.11 C, Filterra ® Bioretention Filter System (rev. 11/01/02) appears to apply to Stonefield block
D2, though this is a grandfathered project. Please call to discuss if questions (Meeting scheduled, 3pm,
8/5/19). Link: https://www.deq.virizinia.lzov/Portals/0/DEQ/Water/Publications/TechBulletin6.pdf ' (Rev.
2) Addressed.
9. Revise table to include original size (dimensions) of approved plan Filterra Str. #244.1, 25.5, and 23.4.
Sheet 6
10. Revise sheet block, lower right (sheet # misprint).
11. Engineering recommends against 0.50% pipe slope. If As -built condition <0.50%, Applicant must propose
remedy, which may include pipe replacement. [Str. 6 - 244]
12. Q(ACC /cfs), 2A — 2 exceeds Q(cap). Revise such that flow in storm pipe, 2A — 2, is open flow regime,
else design entire system to be watertight [i.e., specify materials, provide specifications.]
Engineering Review Comments
Page 3 of 5
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.
Sheet 1
1. List LOD with this plan, block D2, Phase 2, to assist with DEQ permitting, and ESC Plan bond estimate.
VAR10I551 will be revised with this plan. LOD =5.65 Ac. includes Phase 1. The majority of Phase 1 is
either hardscaped, or stabilized.
2. List source of topography. Ensure topography is recent. Note: Ref. ESC Plan checklist for plan reviewers:
`Date and source of the topographic information: All topography should be at least visually field verified by
the designer within the last year.'
ChPPi 7
3. Provide SAF along NW property boundary, to protect site from trespass, and residents from harm.
4. Provide wire -backed SF along SE property boundary to protect Stonefield hotel -restaurant -shopping
patrons that may park within feet of this active construction site. (Rev. 1) Withdrawn. Review error.
5. Revise existing contours to reflect existing contours. It appears years -old plans may be source of existing
topography. See related comment requesting topo be field verified (checklist requirement: field -verify
within the last year). Also, see note directing contractor to remove excess sediment from Ex. sediment
basin to a bottom of basin elevation of 494'. Ex. sediment basin floor elevation is shown as 492'. (Rev. 1)
Addressed. Applicant response: `As discussed, the existing topography was based on a recent field survey.
The existing sediment basin was not topo'ed for safety reasons. The plan contours for the sediment basin
have been added to the plans. It will be incumbent on the contractor to excavate to the required wet volume
when sediment has reached the cleanout elevation.' Engineering accepts this response.
6. Label Ex. sediment basin floor dimensions (L X W). (Rev. 1) (Partially) Addressed. As follow-up: Ref.
VESCH, 3rd Edit., 1992, Std. & Spec. 3.14, Temporary Sediment Basin, p. 111-79/80: `Basin shape: To
improve sediment trapping efficiency of the basin, the effective flow length must be twice the effective flow
width. This basin shape may be attained by properly selecting the site of the basin, by excavation, or by the
use of baffles.' Provide baffles to increase flow path to ensure proper performance. (Rev. 2) Addressed.
7. Copy sediment basin design information from WPO201400096 to this plan, if source of basin design, if
sediment basin is relied upon for ESC under this plan, as it appears to be.
8. (Note: Owner of 061 WO-03-00-019E2 will likely be required to be listed on the ESC Plan bond for this
VMSP /WPO plan Amendment.) (Rev. 1) Withdrawn.
9. Given 1-way directional travel on Strong Blvd., contractor may maintain traffic control with a flagger, but
may not barricade or close in -bound 1-way traffic on Cash Alley. Delete physical barricade label /symbols.
10. Revise CE to PCE (paved washed rack).
11. DD#2: Provide linework and note/s that indicate a sediment trap (or trap -like) feature to redirect DD#2
flow, where DD#2 turns N to E. Although contours favor a turn, without a settling /trapping measure, in
less frequent events, runoff may leave the site or impact adjacent property. If sediment trap is used, provide
design. If less formal measure is used, provide sufficient graphic /text information to indicate design intent.
(Rev. 1) Addressed. DD #2A added.
12. Show Str. 23.2.
13. Revise Water and San. Line labels to include both `Existing' and `To be abandoned' or `To be Removed.'
14. Show LOD. Include LOD linetype in ESC legend. Estimate Area of LOD (ft') with this plan.
15. Provide RW diversion at NW corner of Phase 2 site, at Int. Cash Alley and Kober Way.
16. Provide note or contours to direct DD#1 storm runoff into Str. 7.
Sheet 8
17. Eliminate Note that reads: `Contractor to use a physical barricade to re -direct traffic while alley is under
construction.' Cash Alley 1-way traffic circulation must remain unimpeded during construction. (Note:
Several residents of Block D2, Phase 1 have separately shared site access concerns, which are reflected in
review comments.) (Rev. 1) Addressed. Applicant response: `The note has been eliminated in favor of
using a flagger to maintain traffic control.'
Engineering Review Comments
Page 4of5
k D2, Phase 2.]
18. There is a label ref. to sheet 13. This does not appear to be a ref. to Site Plan, but since note ref.
calculations, provide design calculations for ditches # 1 and 2, and support selection of protective lining
type.
19. Sheet makes re£ to geotechnical engineer recommendations. As construction proceeds, furnish copies of all
geotechnical reports, measurements, observations, recommendations, and test values to Engineering
Division, Albemarle County. .PDF to janderson2galbemarle.org is sufficient.
Sheet 9
20. Copy Phase 2 Work Notes to sheet 8.
21. Provide Narrative sequence that relates building construction sequence and Filterra installation. Filterras
must remain off-line until all upslope areas are stabilized.
22. New: Revise wash water note, sheet 10 since vehicle wash water may not drain directly to a storm inlet,
without separate measure (sediment trap, for example). Vehicle wash waters are not land disturbance -
related. Inlet protection is at times the only measure available for land disturbance; short of this, petroleum -
related contaminants /fine clay rinsed from vehicle wheels /carriage may not be introduced directly to
Stonefield /Albemarle Place detention system/s, or receiving streams. Inlet protection (gravel /filter fabric)
offers inadequate protection against petroleum distillates, or fine particles. Fine clay requires a settling
measure, while care must be taken not to rinse oil from construction vehicles. Revise note: eliminate
reference to storm sewer inlet #1. (Rev. 2) Addressed.
Please submit two (2) print copies of updates to SWPPP (inspector /file). Update SWPPP in field (SWPPP
mailbox /incl 2019 Registration Statement /Revised ESC-SWM Plan sheets; any item revised with Amendment).
Please submit four (4) full-size print copies of revised VSMP /WPO plan that includes all revisions shown on
.PDFs sent via zip download, 8/15/19, with transmittal to reviewer's attention that states `Not for review, for
stamped approval,' at earliest convenience.
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,
Engineering Review Comments
Page 5 of 5
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.
A Stormwater Management Facilities Maintenance Agreement will also need to be completed and recorded, or deed
U.-pig. reference to existing Agreement provided. (Note: While recorded SWM Agreements cover various WPOs
for Albemarle Place /Stonefield, none appears to cover Block D2 Filterra units, or WP02014-00096, specifically.)
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 (if an existing
Agreement is not recorded).
Final VSMP Plan approval is contingent upon SUB201900120 (Easement Plat) approval. SWM Facility /Access
Easement must be recorded prior to Final VSMP Plan approval, and is prerequisite to receiving a Grading Permit.
Note: Revised VSMP plan sheets include bk.-pg. labels for recorded revised /new drainage, access, ACSA, and
SWM Facility /Access easements.
After bonding and agreements are complete, the County can hold a pre -construction conference. Applicants will need
to complete the request using 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;
htW://www.albemarle.orp-/deptfonns.asp?department=cdenaMMo
Ifyou have questions /concerns, please contact me at janderson2&albemarle.org or at 434.296-5832-x3069.
Thank you
J. Anderson, Engineering
WP0201400096 Amend Stonefield Block D2, Phase 2 082619rev2