HomeMy WebLinkAboutWPO201800039 Review Comments WPO VSMP 2018-06-29Short Review Comments Report for:
WPO201800039
SubApplication Type:
HOLLYMEAD DAM SPILLWAY IMPROVEMENTS - VSMP
Stormwater Management/BMP Plan
Erosion and Sediment Control Plan
Date Completed:06/04/2018
Reviewer:John Anderson CDD Engineering
Review Status:Requested Changes
Reviews Comments:
Division:
Date Completed:06/29/2018
Reviewer:John Anderson CDD Engineering
Review Status:Approved
Reviews Comments:Ref. RMS Doc. -Nutrient Credit Purchase Agreement (061018)
Division:
Page:1 of 1 County of Albemarle Printed On:November 19, 2018
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: Hollymead Dam Spillway Improvement - VSMP
Project file number: WPO201800039
Plan preparer: Jeremy Young, Schnabel Engineering [jyoung@schanbel-eng.com ]
Maria Mutuc, JMT [mmutuc@jmt.com ]
Owner or rep.: Albemarle County, FES, Environmental Services Division, Water Resources
Program / Stavros Calos [scalos@albemarle.org ; gharper@albemarle.org ]
PMD contact: Walter Harris IV, wharris@albemarle.org
Plan received date: 5/21/18
Date of comments: 6/4/18
Reviewers: John Anderson
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. Please see 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. 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.
Engineering Division requests permission to include revised ES sheets in SWPPP booklet –please grant
Engineering permission to do this, once sheets revised.
SWM Plan
1. A/E contract excludes stormwater management plan required by Albemarle County, but Engineering
requests VaRRM .xls summary data (that county provides) be copied from runoff reduction spreadsheet
summary prepared by Albemarle County, as well as disclaimer identifying County as source of data. Also,
if Schnabel /JMT are able to do this, there will be no need for a pre-application meeting with the county
(Department of Community Development). CDD proposes a trade-off: placing SWM-related information
on sheet ES-2 in lieu of a pre-application meeting. Please let us know if this works for JMT /Schnabel.
2. If so, please:
a. Copy /paste summary information from Attached summary .PDF to sheet ES-2 –entire summary.
b. Retitle index, ES-2, to “Erosion and Sediment Control, and SWM General Notes”.
c. Include SWM design disclaimer: “SWM-related data, including site impervious area assumptions
and summary information from the Virginia Runoff Reduction Method Spreadsheet, version 3.0
(VRRM_ReDev_Compliance_Spreadsheet_v3_082017) is included by JMT as a strict courtesy.
JMT did not prepare and does not warranty or support analysis, assumptions, or compliance
evaluation relating to SWM requirements or design elements of this project, which will be
reviewed by local VSMP Authority (Albemarle County), the same entity that prepared and
developed SWM-related information, including VRRM .xls. Albemarle County specifically
requests a SWM-related design disclaimer appear on project plans.”
d. Provide SWM Narrative (cut-paste Verbatim):
i. This (project) land disturbing activity is subject to the VSMP (Sec. 17-302), and is not
exempt from the VSMP (Sec. 17-302). Water quality compliance is subject to total
Engineering Review Comments
Page 2 of 4
phosphorus load reduction requirements.
ii. Albemarle contends water quantity requirements (9VAC25-870-66) do not apply to or
affect portions of project that improve primary spillway riser or repair primary and
emergency spillway conduits, including a new outfall structure. These activities ‘maintain
the original line and grade, hydraulic capacity, and original construction of the project’
(Sec. 17-303/G.). Remaining portion of this project armors the downslope face of
Hollymead Dam with articulating concrete block (ACB), and constructs crest walls to
ensure stability and integrity during the PMP event, per state dam safety regulations.
iii. Albemarle County chose to use the Re-development spreadsheet. Initial dam construction
is considered initial (new) development.
iv. Albemarle County accepts 0.0 Ac. pre-redevelopment and 0.0 Ac. post-development
impervious values, since new impervious is a new outfall structure designed in-line with
outfall at an elevation less than (<) receiving stream normal water elevation. Albemarle
views this area as partially submerged, comparable to existing water surface (pervious).
Articulating concrete block (ACB) is a pervious embankment armoring system.
v. 1.0 Ac. of pre-Redevelopment forest is a conservative estimate.
vi. Conversion of forest to turf is required; dam embankment must be clear of vegetation.
vii. The VaRRM .xls calculates 0.20 TP Load Reduction (lb./yr.) required.
viii. Albemarle intends to purchase 0.20 Nutrient Credits (lb.) from an eligible nutrient bank.
ix. Albemarle cannot construct on-site SWM. The site is a dam. The downslope face is a
structural surface. Albemarle has acquired offsite temporary construction /permanent
drainage easements to construct spillway improvements and perform periodic spillway
maintenance, only.
x. Albemarle County is source of stormwater management-related assumptions and
compliance evaluation with respect to ordinance. See SWM design disclaimer.
e. Provide Floodplain Development Narrative (cut-paste Verbatim)
i. Albemarle County will prepare a Floodplain Permit Application, and requests Schnabel
Engineering sign the Application and provide PE-certification LETTER to County Engineer
(Floodplain Administrator) that spillway design causes no increase in the base flood
elevation of Powell Creek and Hollymead Lake, to either Zone AE floodway, or floodway
fringe. Schnabel statement that the ‘hydrologic routings and hydraulic design of spillway
improvements to this high-hazard classification dam contained in a Final Design Report
(March 9, 2018) are sufficient evidence to support PE-seal ‘No rise’ in BFE Certification.
ii. No Rise PE-certification is prerequisite to VSMP approval. (Code Sec. 30.3.12).
iii. Include image, below /black & white (VFRIS: http://cmap2.vims.edu/VaFloodRisk/vfris2.html)
Engineering Review Comments
Page 3 of 4
B. Pollution Prevention Plan (PPP) – Addressed, included with SWPPP.
The PPP content requirements can be found in County Code section 17 -404.
C. 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.
Also, please see thirty-six (36) VSMP review comments sent as email attachment on 3/28/2018 4:08 AM.
1. Revise text on title sheet to read VSMP/WPO2018-00039.
ES-3
2. Provide LOD label that defines Area of LOD (4.291 Ac.)
3. Copy silt trap dimensions (ST-1, ST-2) to ES-3; show bottom of trap dimensions on plan view, each trap.
4. Provide diversion dike upslope of silt fence that runs downslope at LOD, east to west, both north and south
of the stream. Diversion dikes are required to divert runoff to silt traps. Silt fence does not divert runoff.
5. Revise Phase I LOD to stop at shoreline (See 3/28 comment #33.a.)
6. SWPPP Exhibit: Provide on-site fuel station note requiring double-wall and 10-ml plastic-lined
containment; berm sufficient to hold 1.1 × 10-yr. rainfall event Vol. (See 3/28 comment #33.b.)
7. SWPPP Exhibit: Provide note that contractor may change initial locations of storage areas, concrete
washout, vehicle fueling, portable sanitary facilities, and solid waste dumpster.
8. ES-4: (Work with Schnabel) to show bypass extension of Ex. 54” diameter outfall known to be required
that is sufficient to allow construction of the new mass concrete outfall structure.
9. ES-3, ES-4: Label proposed riprap lined channel ‘permanent.’ Provide dimensions (ES-4) to supplement
Plate 3.17-1. Provide ditch design computations for proposed riprap lined channel (2-yr velocity; 10-yr.
capacity).
10. Note: Comments relating to temp haul road (comment #26) no longer applicable with haul road re-design.
Process
Note: Comments are relatively minor. Engineering welcomes .PDF submittal of revised sheets for preview prior
to print submittal. County anticipates VSMP plan approval within 7 calendar days of .PDF (preview), provided
all comments are addressed, including ‘No-rise’ PE-Certification (Floodplain /Schnabel Engineering), and
Nutrient Credit purchase (by County) approved by County Attorney’s Office.
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 (by Albemarle County) directly to the state. For fastest processing, this is
done electronically with the emails provided on the application. DEQ should notify applicants (Walter Harris, IV,
Albemarle County /PMD) with instructions on how to pay fees. When DEQ approves the application, they will
issue a permit coverage letter to the county.
After DEQ coverage is issued, via the coverage letter, the County can hold a pre -construction conference.
Applicants (FES /PMD) will need to complete the request for a pre-construction conference form. The form
identifies the contractor and responsible land disturbed, 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. ore/deptforms. asp?department=cdenywpo
If you have any questions or concerns, please contact me either by email (janderson2@albemarle.org) or by
Engineering Review Comments
Page 4 of 4
phone at 434.296-5832 ext. 3069. Thank you.
J. Anderson, Engineering Division
VSMP_Hollymead Dam Spillway Improve_WPO201800039_060418.doc