HomeMy WebLinkAboutWPO201400068 Review Comments WPO VSMP 2014-12-15�pF A
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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: Farmington Country Club Southside Improvements -WPO
Plan preparer: WW Associates
Owner or rep.: Farmington Country Club
Plan received date: 9 Dec 2014
Date of comments: 15 Dec 2014
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 approved. You may
contact Ana Kilmer (Albemarle County Department of Community Development) at ext. 3246 for further
information on bonding procedures and maintenance agreements.
A. WPO (WP02014000068)
1) [Comment] Show soil map of site.
[Revision 1] Comment addressed. The soils are shown on sheet C -12.
2) [Comment] The drainage area A table on sheet C -13 shows a BMP practice to a rain garden #2.
The plan does not show a rain garden. Please clarify if you are proposing a rain garden.
[Revision 1] Comment addressed. There is no rain garden proposed. This has been removed
from the table.
3) [Comment] The sloped area south of the proposed parking lot all drain to the biofilter, but only .5
acres is shown going to the bioretention practice. It appears more than .5 acres will drain to
biofilter. Please revise.
[Revision 11 Comment addressed. Applicant confirmed the areas going to the biofilter. The
existing improvements north of parking lot will drain into an existing stormsewer system
that will eventually bypass the biofilter.
4) [Comment] Add this note on C -12 for biofilter mix. "Tested for acceptable phosphorus index
between 10 and 30 or between 7 and 23 mg/kg of P in soil media."
[Revision 1] Comment addressed.
5) [Comment] Submit perc rate for biofilter area. (One per 1,000 sq ft of filter surface). Also, verify
that the bottom of #57 aggregate is 2' above seasonably high water table.
[Revision 1] Comment not addressed. The bottom of the biofilter is 601.16 and the geotech
report states that groundwater is present at test site HA -3. The geotech submitted an email
Engineering Review Comments
Page 2 of 5
stating that the water is perched at HA -3. The response doesn't clear up my concern about
groundwater due to the following reasons:
i) The tests were not advanced below 601 (the bottom of the biofilter). If it is perched
how far below is the groundwater table? We need to clarify that there is no
groundwater at 2' below the biofilter.
ii) The response from the geotech states the 6 nearby IT locations were dry as well.
Which 6 tests is he referencing? This is useful if tests are within the biofilter
area.
Here are my recommendations.
A) You can resubmit the report addressing the above concerns. We just need the
geotech to sign and seal the doc. The email below will not suffice.
B) Or revising layout to raise bottom of basin elevation to 603. For example, you can
move the biofilter just south of the parking lot to a higher elevation. If A doesn't
work, then unfortunately, we will have to explore option B.
Revision 2] Comment addressed. ECS Mid - Atlantic, LLC advanced three additional boring
samples below the bottom of proposed biofilter. See certified letter from ECS.
6) [Comment] Label underdrain with Schedule 40 PVC with cleanouts. Show 12" depth for #57
aggregate.
[Revision 1] Comment addressed.
7) [Comment] The geometry of basin does not meet spec of bioretention design criteria. Short
circuiting should be prevented. Please revise.
[Revision 1] Comment addressed.
8) [Comment] Show the 2' gravel diaphragm level spreader at pretreatment area. On profile view,
show the lip on level spreader.
[Revision 11 Comment addressed.
9) [Comment] I recommend moving the curb cut location away from the corner of parking lot and
shifting layout of gravel spreader to enter far east side of biofilter.
[Revision 1] Comment addressed.
10) [Comment] Two rip rap strips are shown on plan, but only one profile view is shown. Please show
both since one is from sidewalk and the other from the culvert under the golf cart path. My
concern is that #57 stones will wash away at steeper slopes. The detail shown is for sheet flows off
pavement, then into a pretreatment area that is flat. Please clarify design since the detail has been
modified.
[Revision 1] Comment partially addressed. The weir is 5' wide on plan view. Please revise to
provide room for weir as it appears to conflict with the gravel level spreader location.
[Revision 2] Comment addressed.
Engineering Review Comments
Page 3 of 5
11) [Comment] The water quantity analysis for channel protection should show the actual drainage
area to the point of analysis, such as drainage area A, B, C and existing areas. The CN should be
different to drainage area D. The spreadsheet shows how much phosphorus to remove, but channel
analysis cannot be determined by the separate disturbed drainage areas alone since the CN is not
correct.
[Revision 1] Channel protection is addressed. At our engineering meeting, we directed
applicant to show adequate channels further downstream since the energy balance equation
at point of discharge was not met. The entire site is owned by Farmington Country Club
and applicant was able to look 450' downstream to show adequate channel within their site.
12) [Comment] Please clarify the total drainage area to pond. It appears to be larger than what is
shown.
[Revision 11 Comment addressed.
13) [Comment] Clarify the surface elevation of the bioretention area. The profile shows 607, but the
plan view shows 606.
[Revision 11 Comment addressed. The surface elevation is 606.
14) [Comment] Relabel bioretention facility #2 under the Bioretention Facility sizing calculations. It
should be bioretention facility #1.
[Revision 1] Comment addressed.
15) [Comment] Submit a Pollution Prevention Plan and a Stormwater Pollution Prevention Plan.
[Revision 1] Comment addressed.
New Comment
16) [Comment] The disturbed acreage on sheet C10 should match the registration statement in
the SWPP.
[Revision 21 Comment partially addressed. It should also match the SWPP. The SWPP does
not need to be resubmitted, but the actual SWPP on construction site should match
registration statement.
17) [Comment] The forebay area is in addition to the bioretention area required. It is sized to at least
15% of the total Treatment Volume. Please revise.
[Revision 2] Comment addressed. The forebay was resized.
18) [Comment] For future reference, please use the Albemarle County SWPP template. For
example, you can use /create the tables from section 6 B), C), D) E) F) and G).
[Revision 21 Comment acknowledged.
Erosion and Sediment Control Plan (ESOP)
1. [Comment] Sediment trap outlet needs to be extended to the bottom of the slope /disturbed soil
area to prevent additional sediment loss during trap overflows.
[Revision 11 Comment addressed.
2. [Comment] Paved construction entrance detail needs to be on the plan. The Albemarle County
Engineering Review Comments
Page 4 of 5
Temporary Paved Construction Entrance detail can be found in the County Design Standards
Manual.
[Revision 11 Comment addressed.
3. [Comment] Please remove the bio- filter components from the E &SC plan sheets. Bio- filter
components should be shown on the SWM pages.
[Revision 11 Comment addressed.
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;
hlt2://www.albemarle.org/del2tforms.asp?department--cdenaMMo
Engineering Review Comments
Page 5 of 5
Sincerely,
Michelle Roberge