HomeMy WebLinkAboutWPO201400097 Review Comments WPO VSMP 2015-03-27
COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
Phone (434) 296-5832 Fax (434) 972-4126
Project: University of Virginia Physicians Group – Northridge - VSMP
Plan preparer: Timmons Group
Owner or rep.: University of Virginia Physicians Group
Plan received date: 25 Feb 2015
Date of comments: 26 Mar 2015
Reviewer: Michelle Roberge
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. No additional fee is required for resubmittal. 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) The area to be disturbed on the registration statement should match the plans. I believe it is .46
acres.
[Revision 1]Comment partially addressed. The applicant is now showing .74 acres LOD.
Please list on the title sheet under site data.
2) Provide a tab for the general permit coverage. This can be inserted when you receive the letter
from DEQ.
[Revision 1]Comment aknowledged
3) In tab 8, include a Pollution Prevention Awareness section. Describe training and procedures to
provide awareness and compliance for all measures in this document; waste management, wash
waters, prevention measures, etc.
[Revision 1]Comment addressed.
4) Since no operator is assigned, the owner can sign the second page of SWPP. I recommend
removing the certification verbiage after tab 4, tab 8, and tab 10. The second page will suffice if it
is signed by the owner. Then in tab 5, please include our Delegation of Authority form. This form
can be found in the following link:
http://www.albemarle.org/deptforms.asp?department=cdengwpo
Use this template to develop the Albemarle County SWPP in the future.
[Revision 1]Comment not addressed. The applicant acknoweledged my comment, but we
should have a copy with signatures. Please have the owner sign the registration statement,
Engineering Review Comments
Page 2 of 5
and the Delegation of Authority form prior to the approval of the VSMP.
5) Please note impaired waters. It appears Ivy Creek is on the 2012 Impaired Waters - 303(d) List.
[Revision 1]Comment addressed.
6) Please note any changes to the SWM and E&S plans need to be updated in the SWPP .
[Revision 1]Comment acknowledged.
B. Pollution Prevention Plan (PPP)
1) Include an 11”x17” plan showing the fueling stations, porta-johns, solid waste disposal, and
concrete wash areas. This can be marked up by the operator as construction progresses.
[Revision 1]Comment not addressed.
C. Stormwater Management Plan (SWMP)
1) Revise the “Total Disturbed Acreage”(Site Data tab) from .29 to .46 on the VRRM spreadsheet
and title sheet of plan.
[Revision 1]Comment partially addressed. LOD is now .74 acres. Please list on the title sheet
under site data.
2) Please note the title sheet should not include “Major Site Plan Amendment.” Revise to “VSMP
Plan.”
[Revision 1]Comment addressed.
3) In the Channel and Flood Protection tab, please change the 24 hr rainfall events to the following:
This will change the CN value to 87.
[Revision 1]Comment addressed. CN is 86.
4) Revise the CN value to 87 for post development conditions in HydroCAD calculations.
[Revision 1]Comment addressed.
5) For calculation in HydroCAD, change 1 yr, 2 yr, 10 yr, and 100 yr- 24 hour rainfall to match chart
in comment 3.
[Revision 1]Comment addressed. CN is 86.
6) On sheet C6.0 the plan shows .46 acres to be disturbed, but does not match total area in the water
quality calculations section. Please revise to match the total .46 acres.
[Revision 1]Comment not addressed. The total disturbed acreage is .74 acres. However, 0.26
acres does not need to be included when determining phosphorus removal. This is a
temporary laydown area only and it does not appear to add new impervious or revise turf
area. You will meet quality requirement with level 1, but please revise the Site Data tab to
reflect correct info. Feel free to contact me if you have any questions.
Engineering Review Comments
Page 3 of 5
a)Revise the total disturbed acreage to .48 acres. Also, revise impervious and turf areas.
Phosporus removal is .05 lbs/yr.
b) Revise the managed turf area stated in the narrative. It does not match the plans.
c) Revise the acreage in the water quality section of sheet C6.0 to match above comment (a).
d) On sheet C6.0, revise 10 year peak flow for pre and post to match report.
e) (NEW COMMENT) Has the capacity of pipe downstream of biofilter been checked ?
Please provide analysis for 10 year storm.
7) Show a forebay. Line the forebay to avoid short cut around treatment. See VA DCR Stormwater
Design Specification No. 9 for sizing. Please note the total surface area required for the biofilter is
approximately 160 sf.
[Revision 1]Comment addressed. Applicant is correct that level one provides options for
pre-treatment: a pretreatment cell, grass filter strip, gravel diaphragm, gravel flow
spreader, or another approved (manufactured) pre-treatment structure. It’s a good practice
to have a forebay, but it is not a requirement with this proposal.
8) Revise the biofilter layout to avoid the narrowed section. Please note long rectangular shaped
basins do not work well.
[Revision 1]Comment addressed. Shape is rectangular now.
9) Remove the filter fabric below the #57 stone.
[Revision 1]Comment addressed.
10) Place a 2” choker stone (#8 or #89 washed gravel) between the filter fabric and the #57 stone.
[Revision 1]Comment partially addressed. Please remove the filter fabric underneath the
pea gravel. The new standards prefer this. Also, geotextile fabric should wrap sides of
biofilter only. The idea is to allow for more infiltration.
11) Place a note for soils under the #57 stone, “Rake 8” of soil beneath #57 stone.”
[Revision 1]Comment addressed.
12) The gravel flow spreader to the far west of the biofilter does not align well with the biofilter and
forces concentrated flow to make a sharp bend towards the biofilter. Please revise.
[Revision 1]Comment addressed.
13) Show the gravel flow spreader detail with the biofilter detail on C6.0. This can be found in the VA
DCR Stormwater Design Specification No. 9. Please show the 2” gravel diaphragm lip and label
the type of stone. Revise the plan view. Also, there should be a 2-4”elevation drop from the curb
cut into the gravel or stone diaphragm.
[Revision 1]Comment partially addressed. The applicant provided the detail. There was a
typo in my previous comment where I stated 2” for the gravel diaphrahm width. I meant to
say the no 57 stone area should be 2’ wide and not 1’.
14) Show compacted soil around the 24” Nyoplast riser. Place note, “Ramp compacted soil layer up to
lip of structure.”
[Revision 1]Comment addressed.
15) The plants proposed within the biofilter are a type of switchgrass. Please see the planting specs in
Engineering Review Comments
Page 4 of 5
VA DCR Stormwater Design Specification No. 9. It appears you will meet the perennial garden
with shrubs, but show perennial plantings as well as the burgundy switchgrass. Please note that
switchgrass can mature to 2-3 feet wide. It appears about 29 plants would be needed for the 179 sf
area. Please note this amount may change when you resize the biofilter per comment 7.
[Revision 1]Comment not addressed. The planting plan for a level 1 is shown below. See
planting requirement from section 6.8. Showing switchgrass only, which is considered
turf/groundcover, is inadequate. I recommend adding winterberry holly since switchgrass is
a warm season grass only.
16) Please include the SWM notes from our Design Standards manual.
[Revision 1]Comment addressed.
New comment:
17) Please include the symbol for permanent seeding (PS) on sheet C3.1. Show for both areas of
disturbance.
18) Show area of stockpile and how much in cubic yard. Show contours. Also, show perimeter
control measure. Show stabilization of stockpile per comment 17.
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
Engineering Review Comments
Page 5 of 5
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;
http://www.albemarle.org/deptforms.asp?department=cdengwpo
Sincerely,
Michelle Roberge