HomeMy WebLinkAboutWPO201800012 Review Comments WPO VSMP 2018-02-20COUNTY 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:
VSMP Plan for Greenmont Hopworks
Project file number:
WP0201800012
Plan preparer:
Shimp Engineering, PC [Justin@shimp-engineering.com]
Owner or rep.:
Keene Land Trust bmurray@courtsquareventures.com]
Plan received date:
31 January 2018
Date of comments:
20 February 2018
Reviewer:
WW Associates, Inc.
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 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 Section 2 — Provide a copy of the DEQ coverage letter when obtained.
2. SWPPP Section 7 Item 3II — change second to last word in sentence from "exceptional" to
"impaired."
3. SWPPP Section 9 — Complete and sign the certification.
4. SWPPP Section 10 — Per VAC25-880-70 Part K, provide the persons with the authority to sign
inspection reports or to modify the stormwater pollution prevention plan.
5. SWPPP Section 11 — Per VAC25-880, provide a copy of the construction general permit.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
1. SWPPP Section 6 — Per Albemarle County Code Section 17-404, the location of the PPP
activity/protection is to be graphically/clearly marked on the plan.
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. The cover sheet of the SWM calculation booklet is to contain the design professional's seal with
signature and date.
2. The pipe slopes, pipe lengths, and outlet slopes for the 1-year, 2-year, and 100-year routing of the
detention and bioretention pond do not match information shown on details 1, 3, 5, and 6 on sheet
C6. Correct plan and calculation booklet and reroute as necessary.
Engineering Review Comments
Page 2 of 3
3. Per the Albemarle County Engineering Design Standards Manual Section 5, provide adequate
vehicle access: 10-foot width graded at less than 20%, if over 20% a gravel or paved surface must
be provided. Access must be provided to all structures and forebay cleanout areas. Stormwater
management (SEM) easements must be provided over all access and facilities and are to be
shown on the plan. Provide plat and deed for recordation. WPO plan cannot be approved until
SWM agreement, plat and easements are recorded.
4. A minimum top of berm/embankment width of 8 feet is to be provided for the detention facility
and the bioretention facility. Adjust plan accordingly.
5. Bioretention level 2 has been specified by the design professional and as such the design must be
modified to provide the following:
a. Depth of media to be a minimum of 36 inches.
b. Provide surface area calculation for bioretention facility.
c. Provide BMP geometry calculation i.e. ratio length of shortest flow path and length from
the most distant inlet to outlet to ensure 0.8 ratio.
d. Provide pretreatment cell volume calculation to demonstrate a storage volume equal to
15% of the total Treatment Volume (inclusive) and a calculation demonstrating a 2:1
pretreatment cell length to width ratio.
e. The underdrain is to be equipped with a cleanout at the upstream end as the drainage area
exceeds 1 acre and provide a detail of the cleanout.
f. The 1.4-foot thick underground storage layer is to be below the invert of the underdrain
pipe.
g. An observation well along with a detail is to be provided to facilitate inspections?.
6. The detention pond embankment must have a 2-foot freeboard above the routed 100-year water
surface elevation.
7. Landscaping details, notes, and schedule for the bioretention facility plantings are to be placed on
this WPO plan.
8. Change the title of the `Conserved Open Space' to `SWM Forest and Open Space Easement'.
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.
1. The Albemarle County Critical Resources Map denotes a Water Protection Buffer traversing the
southern border of the property. Please show the 100-foot wide stream buffer and label as such
on the plan.
2. The plan shows proposed slopes steeper than 3:1. These slopes shall have a low maintenance (no
grass) ground cover specified on the plan per the Albemarle County Engineering Design Manual
Section 8 and shall be labeled as such on the plan.
3. Please provide Albemarle County Engineering General Construction Notes for Erosion and
Sediment Control Plans Notes 10 through 20 on the plan.
4. Provide dust control symbol to legend and show location of dust control on the Phase I and Phase
II plan sheets.
5. The Phase I plan denotes silt fence running across contour lines on the south side of the sediment
trap. Place silt fence tangents parallel to the contours.
6. Provide a temporary slope drain (TSD) into the sediment trap to prevent discharge over the fill
slope to the north of the sediment trap.
7. Provide sizing computations for outlet protection at storm drain structure ST1 and new 15-inch
CMP driveway culvert at new entrance from S.R. 712 Plank Road.
Engineering Review Comments
Page 3 of 3
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 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;
httD://www.albemarle.or2/deDtforyns.aSD?deDartment--cden2wi)o
File: WP0201800012 Greenmont Hopworks 2-15-18-ENG