HomeMy WebLinkAboutWPO201800068 Review Comments 2018-12-21 tkapra.
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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
VSMP Permit plan review
Project title: ACSA Operations Center Expansion Parking Lot Expansion
Project file number: WP0201800068
Plan preparer: Derek Marshall [darshall@dewberry.com]
Owner or rep.: Alex J.Morrison [amorrison@serviceauthority.org]
Plan received date: Sept 5,2018
Nov 21,2018
Date of comments: Oct 4,2018
Dec 21,2018
Reviewer: David James [djames@albemarle.org]
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.General
1. Please submit only the VSMP plans (SWPPP,PPP,SWM,E&SC plans) for approval.
(Rev.1)Addressed.
2. Remove sheets C3.0,C3.2,L1.0,L1.1,E1.0,E1.1 & E1.2.
(Rev.1)Addressed.
3. Cover sheet—Remove '100% Submission' from title. Include the WPO# `WP0201800068'
under title.Remove the approvals block.
(Rev.1)Addressed.
B. 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. Registration Statement—Section 7,Add the County of Albemarle as the MS4 operator.
Section 8,The disturbed area reported (0.42ac)doesn't match the disturbed area of 0.56ac
according to the plan/calcs.
(Rev.1)Addressed.
2. Section 6(B)—The print out copy did not show all the contents typed into the boxes, please
show all.
(Rev.1)Addressed.
3. Insert copy of General Permit coverage when obtained.
(Rev.1)Acknowledged.
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C.Pollution Prevention Plan(PPP)
The PPP content requirements can be found in County Code section 17-404.
1. Show any proposed clearing/grading activities,paving operations, landscaping operations,E&S
controls, staging, stockpile,borrow, fueling,waste disposal,vehicle/equipment washing,concrete
washout locations on the PPP.
(Rev.!)Partially addressed. Show all E&SC and clearing/grading operations.Turn off
existing contours& use thicker linetype for LOD(for clarity).
D. 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. Provide supporting calcs verifying discharge of orifice/weir design.
Response: Stage-discharge and stage-storage tables and graphs are included on sheet C6.3.The
orifice and weir design is included the hyrodocad printout for the"Summary for Pond 1 P:
Storage" for each storm. ... 1-,10-,100-yr ... sheets C6.3-C6.4.
(Rev.1)Addressed.
2. Provide HGL calcs for 10-yr design. Show HGL in profiles.
Response: ...HGL is shown on the profiles on sheets C4.0 and C4.1.
(Rev.!)Addressed.
3. Show proposed easement over underground storage pipes. The easement width is calculated
according to equation in the Design Standards Manual, Section 6C. Label the easement as a
`SWM facility, easement'.The easement should encompass the detention pipes and
structures to the outfall connection.
(Rev.!)Addressed. See comment 10.
4. Submit the VRRM spreadsheet,pdf is fine.
a. (Rev.!)You're showing use of a MTD-Filtering that treats 0.22 Ac. The only
proposed SWM facility shown in the plans is the underground detention system and
is not a filtering device.Please revise VRRM.
b. (Rev.!)In the `Runoff Volume and CN Calculations' summary table incorrect
precipitation values are given for the location per NOAA Atlas 14. Please revise
VRRM.
124w II (2 24-2.90) II (2.69-3.50) II (3.34 4.35) II (3.95 5.15)
24-hr 3.03 3.66 4.68 5.54
{2.72 3 40) (3 29.4 12) (4.19 516) (4.94 6.20)2-day (3.037.99) II (3.894 3
3.84) II (4. .6.15) II (5.8-7.22 r((((
5. Sheet C6.0-Provide analysis/computations to verify the discharge values shown at the
outfall points.
Response: Computations and routing for outfall 1 and 2 have been provided on sheets C6.3-C6.4.
Water quantity narrative and summaries have been added to sheet C6.2.
(Rev.1)Partially addressed. Should the D.A. Onsite be 0.23ac,not 0.32ac(Please verify)?
6. Sheet C6.0/C6.1 -Show the land cover areas of site. (%)Impervious cover. Show/indicate
structure#6 mentioned. is this STRM 6 shown on sheet C1.0?
(Rev.1)Addressed.
7. Additional impervious area is being proposed with sidewalk/stairway. This area must be
accounted for water quantity/quality analysis. Show that it meets reg. requirements under
Part H B.
Response: The land disturbance...has been accounted for in the water quantity and quality calc...
This is met through the purchase of nutrient credits, proof of which is provided on sheet C6.3.
(Rev.1)Addressed.
8. Sheet C6.3—Energy Balance worksheet shown is confusing!
(Rev.!)Sheet C6.2: `Energy Balance-Outfall 1'-Provide analysis/verification of each
outfall,where do you get your Runoff Volume(RV)values of 0.020 ac-ft(pre-dev)& 0.058
ac-ft(post-dev).Doesn't appear to correlate with VRRM(0.11ws-in)or Routing(0.052af).
`Energy Balance-Outfall 2'—Should the value be 0.08cfs(Pre-development discharge),not
0.18cfs (Please verify)? Same thing as above,where did you get your RV values?
You're showing `Channel type' as Natural—wrong! You can't use Energy Balance because
the runoff from site does not discharge into a natural conveyance system.You must
demonstrate that water quantity{9VAC25-870-66) requirements are satisfied by showing
the 2-/10-yr design post-dev discharge is confined within the SWM system onsite and
satisfies limits of analysis.
Response: The energy balance spreadsheet calculates the allowable 1-year discharge from the site
area and takes into account the"offsite"area from the existing parking lot that flows into the
detention pipes and is contained in the system. ... This calculates the maximum allowable peak
discharge of 0.77 cfs.
Manmade outfalls are allowed to use E.B. to meet channel protection criteria. 9VAC25-870-
66.B.1.b. ...
(Rev.1)Addressed;Thanks for clarifying.
9. ACSA to contact Ana Kilmer(Management Analyst)regarding nutrient credit agreement and
necessary documentation.Provide verification of nutrient credit purchase.—0.35 lb/yr cr. needed
per VRRM
(Rev.!)Acknowledged;ACSA is working with Ana on what she needs to complete the
nutrient credit agreement.
10. [New] (Rev.1) SWM easement plat & deed of dedication must be reviewed/approved/
recorded prior to VSMP plan approval.
11. [New] (Rev.1)Include this checklist in the plan set.
http://www.albemarle.org/upload/images/forms center/departments/Community Develop
ment/forms/Engineering and WPO Forms/WPO VSMP Construction Record Drawings
Policy 23Mav2014.pdf
E. 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. Show date and source of topography information: All topography should be at least visually
field verified by the designer within the last year.Provide date when site was last inspected.
{9VAC2 5-870-66/
(Rev.!)Addressed.
2. Show areas of managed slopes on sheet C1.0 & C3.1. This may impact the currently proposed
wall and grading in or adjacent to those areas. {18-30.7.5}
Response: These areas have now been added to requested sheets. Per note 7 from Site Plan
Review comments, the retaining wall design with 1' bench at base is permissible.
(Rev.1)Addressed.
3. Adjust your limits of disturbance(LOD) to include the grading behind proposed wall.
(Rev.1)Addressed.
4. Show area of the new sidewalk/stairway improvements on the E&SC phase sheet(s)with
control practices in place.
(Rev.!)Addressed.
5. Show any offsite improvements including grading operations in a permanent easement. Provide
evidence that neighboring property owner is in agreement with this offsite work in the easement.
This can be a letter of agreement signed by neighboring property owner. (DSM, Sect. 8C, 3F)
Response: An easement has been added to sheet C3.1 and labeled "Proposed temporary
construction and permanent maintenance easement". ...
(Rev.!)Partially addressed.Rename/show label as mentioned above on sheet C3.1.
6. Sheet C2.0—Show paved construction entrance at 70'. Extend to proposed access gate.
(Rev.!)Addressed.
7. Sheet C5.0—The County, requires paved construction entrances. The current CE detail with
the one in the County's Design Standards Manual. (DSM,Sect. 3F)
(Rev.1)Addressed.
8. Please show the steep slopes or managed/preserved slopes.
(Rev.1)Addressed.
9. Show location of all existing and proposed utilities and easements with deed book
references.
(Rev.1)Addressed.
10. Provide low maintenance(not grass) ground cover specified on the plans where
grades are steeper than 3:1. IDSM,Sect 8A)
(Rev.1)Addressed.
11. Indicate slopes 3:1 and over.
(Rev.1)Addressed.
12. Provide some permanent stabilization measure for the ditches in front of wall to
prevent erosive action.
(Rev.!)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.
d" ' 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;
http://www.albemarle.org/deptforms.asp?department=cdengwpo
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