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HomeMy WebLinkAboutWPO201800059 Review Comments WPO VSMP 2018-08-31Phone (434) 296-5832 OF Alga. VIRGSry�P COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902-4596 VSMP Permit plan review Fax (434) 972-4126 Project title: UNIVERSITY OF VIRGINIA FOUNDATION TENNIS FACILITIES Project file number: WP0201800059 Plan preparer: Dewberry Engineers, Inc. [dkeeler@dewberry.com] Owner or rep.: Nat Perkins, UVAF [nperkins@uvafoundation.com] Plan received date: July 23, 2018 Date of comments: Aug 31, 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. The WPO plan contains only the E&SC and SWM portion. Please submit only those sheets for approval for future submittals. 2. Cover sheet — Rename title to VSMP Plan for "Project Title" and include WPO#. 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 ESOP, (3) a SWMP, and (4) any TMDL measures necessary. 1. Registration Statement: a. Change HUC to JR15 b. 9.58ac is the limits of disturbance according to the plan. 2. Include state waters with TMDL directly downstream, Morey Creek. 3. Include PPP exhibit sheet. 4. Insert copy of General Permit coverage when obtained. 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. A 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. Show proposed SWM facility and access easement. 2. Please provide electronic version of VRRM spreadsheet. 3. Show MH access at weir location. Show another MH access midway and at the opposite end to underground vault. 4. Sheet 5.02 - Show on the details the storm structure ID and rim elevation. Show invert of cleanout at connection. 5. Sheet 5.03 - Confirm if `top of weir' is not the `top of weir wall' and weir length is 6'. 6. Sheet 6.02 - You're travel time for sheet flow is quite low. Please review and provide analysis/computation of Tc and Q, peak runoff (pre -/post-). 7. Sheet 6.03 - a. You're numbers are entered wrong for the storage depth calculation for both biofilters. b. You show 6209cf for the Lvl 1 and should be 4674cf, 6217.5cf for LA 2. c. The pre -treat cell vol. should be at least 15% of the total Tv. d. Unable to find ref. sheet under `Note:'. 8. Reduce pipe velocity for Stm 25 (18fps). The minimum pipe velocity = 15fps. 9. Show callouts for each slot drain and provide depth and sizing details. 10. Sheet 6.07 - You're showing permeable pavement (PP) of 0.13ac treating 0.3lac, and PP of 0.17ac treating 1.+ac. The CDA should not be more that 2:1 for a Lvl.l and 1:1 for a Lvl.2 facility and 100% impervious. {VADEQ SW Design Spec. 71 11. Sheet 6.07 - a. Show DA total that's captured by the inlets/structures, and show undetained DA. b. Show value for total impervious treated - it's cutoff. c. Correct callout to W. 12. Show 10-yr WSE for bioretentions in the details. 13. Show cleanout locations and detail for biorentions. 14. Because ponding depths are 1-ft (max) ensure chosen plants will survive, or substitute alternates. 15. Add Figure 9-B.2. Typical Biofilter Planting Specifications to the notes. {VADEQ SW Design Spec. 7} 16. Permeable Pavement - a. May not be allowable due to compacted subgrade soils. Provide infiltration tests at depth. b. Show paver thickness, compressive strength, bedding layer, reservoir layer, filter layer depths. c. Show pavement design can handle all traffic loads. d. Show underdrain and observation well locations. e. Ensure that landscaping & maintenance operations minimizes the risk of sediment, mulch, grass clippings, leaves, etc. inadvertently clog the paving surface. 17. Sheet 6.04 - a. Add to notes under 8.2, Step 9 - Installation of Interlocking Pavers. The basic installation process is described in greater detail by Smith (2006). o Place edge restraints for open -jointed pavement blocks before the bedding layer and pavement blocks are installed. Permeable interlocking concrete pavement (IP) systems require edge restraints to prevent vehicle loads from moving the paver blocks. Edge restraints may be standard VDOT curbs or gutter pans, or precast or cast -in -place reinforced concrete borders a minimum of 6 inches wide and 18 inches deep, constructed with Class A3 concrete. Edge restraints along the traffic side of a permeable pavement block system are recommended. o Place the No. 57 stone in a single lift. Level the filter course and compact it into the reservoir course beneath with at least four (4) passes of a 10-ton steel drum static roller until there is no visible movement. The first two (2) passes are in vibratory mode, with the final two (2) passes in static mode. The filter aggregate should be moist to facilitate movement into the reservoir course. o Place and screed the bedding course material (typically No. 8 stone). o Fill gaps at the edge of the paved areas with cut pavers or edge units. When cut pavers are needed, cut the pavers with a paver splitter or masonry saw. Cut pavers no smaller than one-third (1/3) of the full unit size. o Pavers may be placed by hand or with mechanical installers. Fill the joints and openings with stone. Joint openings must be filled with VDOT No. 8 stone, although VDOT No. 8P or No. 9 stone may be used where needed to fill narrower joints. Remove excess stones from the paver surface. o Compact and seat the pavers into the bedding course with a minimum low - amplitude 5,000-lbf, 75- to 95-Hz plate compactor. o Do not compact within 6 feet of the unrestrained edges of the pavers. 18. Account for the drainage runoff from Stm 32. Show existing downstream facility, structure, etc. 19. Sheet 6.06 — Show BMPs CDA boundaries and acreage. 20. Provide infiltration tests for area of permeable pavement. 21. Show underdrains slope at least 5% to outlet. 22. Confirm bottom of facilities are at least 2 feet from seasonal high groundwater table. 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. Property line doesn't match linetype symbol. Show any disturbance outside of property line in an easement. 2. Show the limits of disturbance line on the existing and demo sheets. It appears that some areas to be disturbed aren't shown. 3. Show existing drainage divides. 4. Show all existing sanitary sewer & water easements, deed book/page ref. There appears to be ACSA Water Lines - [Restricted] RWSA Water Lines - [Restricted] AC SA Seaver Lines - [Restricted] RWSA Sewer Lines - [Restricted] FiParcels Dam Break Inundation Zones State -Water Protection Ordinance Buffers ❑rivew ays Roads Railroads Lakes and Reservoirs Ponds Major Streams Other Streams 100 Year Floodplain Steep Slopes Overlay TYPE critic al S lopes ArcR a arder[In ternal] N 5. Show drainage areas going to the sediment traps. 6. Provide an overview sheet showing existing and proposed drainage patterns. Show existing drainage divides and 7. Tie in grades for ST #2 to existing. 8. Show weir outlet for traps. Piped, allowed? L =6xDA 9. Show OP for Stm 32. 10. Provide calcs/stone sizing for each OP. 11. Show design of OP from Stm 26.OP should be installed at nearly flat grade; otherwise design for a channel w/ liner type. 12. Show ditch calcs & lining type for any constructed ditches. 13. Sheet 3.11, A-1— Tie proposed to existing contours. 14. Sheet 3.11/3.12 — a. The grades tying in to stairwell appear to be grader than 2:1. b. Show the transitioning grades of the sediment traps from phase I. 15. Show existing right-of-way with street name, route number & width labeled. 16. Show proposed street name and right-of-way. 17. Provide OP shape & stone size calcs (see VADEQ ESC HB Spec. 3.18). 18. Provide low maintenance ground cover hardier than grass, which will not require mowing for slopes steeper than 3:1 as a final stabilization measure. 19. There appears to be a lot of cut work. Provide estimate of cut & fill balances. Ensure waste area(s) will handle the volume. 20. Show silt fence around stockpile area. 21. Fix matchline references on phase I sheets. 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; http://www.albemarle.org/deptfon-ns.asp?departrnent=cdengLypo