HomeMy WebLinkAboutWPO201600070 Review Comments Plans Reviewed By 2017-08-29COUNTY 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: Belvedere Phase IV A
Project file number: WP0201600070
Plan preparer:
Collins Engineering [scott@collins-engineering.com]
Owner or rep.:
Belvedere Station Land Trust [rhauser@stonehaus.net]
Plan received date:
14 Nov 2016
7 March 2017
Date of comments:
19 Dec 2016 (Rev. 1)
6 April 2017 (Rev.2)
29 August 2017 (Rev.3)
Reviewers:
David James — VSMP
Geoff Elsie -- VESCP
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. 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. Section 1— A signed DEQ Registration Statement needed as part of SWPPP
(Rev.2) Partially addressed. #9 areas given appear different from what is shown on the plans.
(Rev.3) Not addressed.
2. Section 2 - Provide a copy of DEQ coverage letter when obtained
(Rev.2) Acknowledged.
(Rev.3) Not addressed.
3. Section 10 — Complete/sign Delegation of Authority
(Rev.2) Acknowledged.
4. (Rev.2) Section 4 — Provide reduced size copy of ESC plan.
(Rev.3) Not addressed.
5. (Rev.2) Section 5 — Provide reduced size copy of SWM plan.
(Rev.3) Not addressed.
6. (Rev.2) Provide an additional copy of your SWPPP. Two (2) are needed.
(Rev.3) Not addressed.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
1. Show and label potential pollutant sources on the "exhibit sheet" that are on the list marked in
Section 6 of SWPPP; Update your PPP "exhibit sheet" showing these sources.
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(Rev.2) Addressed; add to SWPPP.
(Rev.3) Acknowledged.
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. Cover sheet: Sign and date engineering seal (Ref. 18-32.6.1).
(Rev.2) Not addressed.
(Rev.3) Addressed.
2. Show callouts for any permanent ditches/channels. These should have typical sections, and design
calcs on plans (designed to meet part II(B) requirements).
(Rev.2) Addressed with an approved Road Plan.
(Rev.3) Acknowledged.
3. Proposed slopes greater than 3:1 to have low maintenance (not grass) ground cover specified on
plan (Design Manual, sect. 8A).
(Rev.2) Sheet 2 -- Include note that an approved groundcover type/species will be installed
on disturbed areas of slopes greater than 3:1 as a final stabilization measure as shown on
the ESC plan.
(Rev.3) Addressed.
4. Confirm depth to seasonal high groundwater table and bedrock (minimum 2 ft. below the design
bottom of the facility).
(Rev.2) Geotechnical tests are required per VADEQ SW Design Spec. 15, Sect. 5 (Soils) and
Sect. 6.3 (Required Geotechnical Testing). Geotechnical report should address all requirements.
(Rev.3) Purchase nutrient credits now and modify later.
5. Show area of Forest/Open Space to be protected for phase IVA.
(Rev.2) Acknowledged. Areas of Forest/Open space to be Areas of undisturbed Forest/Open
space shall be protected as such in agreements, deed of dedication of easement, and platted within
an easement.
(Rev.3) Recorded SWM deed/plat & maintenance agreement required prior to approval.
6. Ext. Detention: Show dimension and sizing of ED components in the details (i.e. orifice). A 24-
hr target drawdown time recommended; provide design storm stage storage elevations for ED,
and drawdown times calcs. [Note: A minimum 10 acres DA is recommended for ED to function
properly. There are higher maintenance requirements for ED with DA < 10 acres.] Provide landscaping
plan (VADEQ SW Design Spec. 15).
(Rev.2) The reverse slope pipe is shown extending to the floor of micropool, and should extend to
mid -depth of micropool as noted on Design Spec. 15, Sect. 6.5. Include note / provide for the
aquatic bench and metered rod for forebay (Sect. 6.4). Provide documentation of `previously
reviewed and approved routing calculations' (not found). Per the design for a level 1 ED, if a 12-
24 hr drawdown time cannot be met than your design fails criteria. Provide/Show design storm
elevations in profile views.
(Rev.3) Partially addressed. I'm not sure what previously reviewed/approved routing
calculations you are referring to. Provide drawdown calcs to size the orifice for the 24-hr
storm. The 15-hr is used? (Sect. 6.2).
Include the following notes on ED barrel installation:
1. RCP should have bell and singular spigot joints with rubber gaskets and should
equal or exceed ASTM Designation C-361.
2. The bell and spigot pipe should be placed with the bell end upstream.
3. Joints should be made consistent with manufacturer recommendations.
4. After the joints are sealed for the entire run ofpipe, the bedding should be placed so
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that all spaces under the pipe are filled.
5. All reinforced concrete pipe conduits should be laid in a concrete bedding for their
entire length.
6. This bedding should consist of high slump concrete placed under the pipe and up the
sides of the pipe at least 25% of its outside diameter, and preferably to the spring line,
with a minimum thickness of 3 inches, or otherwise as shown on the drawings.
Side slopes should be 4:1 (Sect. 6.6).
Show low -flow orifice details/dims.
Specify type of turf cover to be used. Refer to this link
http://www.albemarle.org/nativeplants/.
Woody vegetation may not be allowed to grow within 15 feet of the toe of the embankment.
Existing trees within the buffer area should be preserved during construction (Sect. 6.7).
Add to facility maintenance requirements:
a. Inspect the low -flow orfice every 6 months.
b. Sediment removal every 5-7 years, or when forebay 50% full.
7. There appears to be pollutant load remaining (VRRM worksheet), before considering purchasing
credits, consider implementing further upstream PR practices. Describe how the chosen practice
fits into the overall SWM strategy. Were other practices considered and found insufficient?
(Rev.2) Acknowledged.
8. Please contact Ana Kilmer for information about nutrient credit purchasing documentation and
requirements.
(Rev.2) Acknowledged; Purchase of credits is required before plan approval.
(Rev.3) Purchase of credits is required before plan approval.
9. (Rev.2) Cover sheet: Include the WPO number; Change project info in side title block from
FINAL ROAD & UTILITY PLAN to VSMP PLAN.
(Rev.3) Addressed.
10. (Rev.2) Sheet 6 - Correct `Proposed Subarea A Impervious' area tables.
(Rev.3) Addressed.
11. (Rev.2) VRRM spreadsheet submitted needs to be reviewed and corrected. Values are
inconsistent with what's shown in the plans (e.g. PR is 1.34 in plans & 1.83 in spreadsheet).
(Rev.3) According to VRRM spreadsheet 2.05 lb/yr phosphorus remain. According to Sheet
6 -1.54 lb/yr credit will be purchased. Account for the difference remaining.
12. (Rev.2) There are inconsistent amounts in the plan for drainage area to basin (4.25 vs. 3.25).
Show overall drainage area map, drainage divides, and subareas (Pre- & Post-).
(Rev.3) Correct for the actual drainage area for SB#1. Two are shown 3.79ac & 4.25ac.
13. (Rev.3) Sheet 3 - The project area is stated to be 5.75ac -Is this correct?
14. (Rev.3) Show 5.05 ac area to be treated with breakdown of land cover areas on SWM plans.
15. (Rev.3) How is the runoff from the future development lots being treated post -development
once ST#1 is removed?
16. Calculations -
a. Show where you determined runoff depth Q values, they do not match NOAA Atlas 14
values for the design storms.
b. Show the values used in calcs/worksheets.
17. Sheet 6 -
a. Show Tc path post -development for verification of lengths.
b. Quantity: Subarea A needs to account for entire disturbed area.
c. Quality: Show calcs for required credits needed.
18. Sheet 7 - It is recommended to use callouts to details sheet for readability.
19. Provide OP sizing calcs for SB#1.
20. A SWF maintenance agreement, an easement plat/deed for the facility & 10' wide access are
required before plan approval.
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21. Outfall shall extend to a natural conveyance channel.
D. Erosion and Sediment Control Plan (ESOP)
Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESCP.
This plan is approved. The erosion control plan content requirements can be found in County
Code section 17-402.
1. Bondstone Owner signature needed on VSMP application.
(Rev.2) Addressed.
2. Need Signature on plans from PE.
(Rev.2) Not addressed.
(Rev.3) Addressed.
3. Correct Baffle call out on Basin 1 Detail.
(Rev.2) Addressed.
4. Add Inlet Protection for Phase II wash rack. Need Inlet Protection for Basin IA.
(Rev.2) Addressed.
5. Remove 12' length of 6" pipe shown on basin detail leading to micropool. Show stub and cap at
the low flow orifice.
(Rev.2) Addressed.
6. (Rev.2) Show IP/OP details.
(Rev.3) Addressed.
7. (Rev.2) Use diversion instead of SF alongside Fowler Street.
(Rev.3) 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.
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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;
hILtp://www.albemarle.org/deptforms.asp?department=cdengwpo
File: WPO201600070_Belvedere Phase IVA - VSMP - 4-17 Review(3).docx