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HomeMy WebLinkAboutWPO201900052 Review Comments WPO VSMP 2019-10-08Phone (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: Berkmar Drive Apartments Project file number: WP0201900052 Plan preparer: Timmons Group — Mitch Bowser [michell.bowser@timmons.com] Owner or rep.: Wendell Wood — Uptown Village LLC [ulcwww@embarqmail.com] Plan received date: Sept. 9, 2019 Date of comments: Reviewer: Oct. 8, 2019 David James - VSMP Geoff Elsie - VESCP [dj ames@albemarle.org] [gelsie@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. 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. Submit the SWPPP 2. Provide PPP site exhibit sheet. 3. SWPPP should note (TMDL) - Direct downstream of project `Powell Creek & its tributaries' is listed as an impaired stream with a TMDL according to 2016 DEQ impaired stream report. B. 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. Also, show locations where concentrated stormwater discharges. 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. Show SWM facility access path. The path should be 10' wide and surfaced with gravel or pavement if the access grade is over 20%. Show proposed SWM facility easement and access easement. Show 10' wide (min) vehicle maintenance access to the SWM facility's forebay & riser structure. [DSM, pg. 14 2. 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 23May2014.pdf 3. Provide the following: Stormwater Management Plan; SWM narrative (State how plan meets Water Quality/Quantity requirements); SWM facility's cross-section & details — show the design storm WSEs; General description of SWM facility operation and maintenance. 4. Show contributing drainage areas to the `Wet Pond' & `Hydrodynamic separator'. 5. Show specs and detail of hydrodynamic separator. 6. Show that the MTD is sized for the project (hitps://www.swbmp.vwrrc.vt.edu/bmps/hydrodynamic-devices/ - VADEQ Practice 16: Hydrodynamic Devices, Sizing information): a. Calculate the treatment volume to the device (TvBMP). The calculated TvBMPcan be obtained from the Virginia Runoff Reduction Method (VRRM) spreadsheets. b. Calculate the peak discharge of the obtained treatment volume (gpTv). DEQ's preferred method to calculate the peak discharge for a BMP drainage area is described here. c. Work with the MTD vendor to ensure that the obtained peak discharge to the device (gpTv) is less than or equal to the maximum treatment flow rate (MTFR) of the device (gpTv < MTFR). 7. Show land use map with percent surface areas & soils map. 8. Label ditches & channels. Provide design calcs. Show geometry and adequate lining information. 9. Provide the DA to each ditch; Catchment area to each inlet. Provide assumed values for inlet design (refer to LD-204). 10. Show pipe runs: Storm 5 to 3, 3 to 1, 61 to 3. 11. Show HGL (6-8' min head for Wet Pond), Label pipe crossing's separation distance, ensure 1' min. 12. Provide 2.0' or % D minimum cover (whichever is greater). Ensure cover is adequate for pipes 6 - 12. 13. Sheet 7 — You're DA B land cover values adds up to 7.64 ac and doesn't match the 7.80 ac shown (please correct any calcs). 14. Sheet 8 — You're DA B land cover values adds up to 5.76 and doesn't match the 7.80 ac shown (please correct any calcs). 15. Provide that channel protection is meet for the runoff to your limits of analysis (2-yr for any receiving channel/10-yr for pipe), or that Energy Balance was meet if entering a natural channel. 16. Provide stage -storage for the Wet Pond and stage -discharge curves for it's outlet structures. 17. Show that design criteria are met for the level 1 Wet Pond & forebay (VADEQ BMP Design Spec. 14). Show plan & profile views of design (Refer to Section 4: Typical Details). a. Show the elevations of permanent pool, treatment volume and maximum design water surface elevations for all appropriate design storms and safety storms b. Ensure minimum setbacks are met: 20 feet from property lines, 25 feet from building foundations, and 100 feet from septic system fields and private wells c. Show that CDA is at least 10 acres. d. Show planting plan, turf provided. e. Provide safety fence for vertical wall of pond & warning signs. f. Conduct soil tests to determine suitability for use as structural fill or spoil, compaction/composition needs for embankment, need for liner (A&B soils), or depth to ground water or bedrock (see section 6.3 of specs). g. Design the low -flow orifice to minimize clogging. h. Ensure adequate outfall protection (see section 6.5). i. Provide seepage control for barrel through embankment: Anti -seep collar, or filter and drainage diaphragm design. 18. Show embankment cross-section/profile — Show geometry (height, width, slope), cutoff trench, fill material, foundation material, internal drainage (as necessary), Riser & barrel (type, length, slope). 19. Investigate the impact of Wet Pond on downstream wetland (if the discharge will change the hydroperiod of the natural wetland). 20. Provide Mitigation Plan for the impacts to 100' buffer area around wetlands. 21. Provide VRRM file (email is fine). 22. Contact Ana Kilmer regarding nutrient credit purchase & agreement requirements. Currently 2.91 TP load credits required. Nutrient credit agreement required prior to plan approval. 23. A recorded SWM facility easement & deed required prior to permit issuance. 24. Record the SWM maintenance agreement. D. 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 location of all existing and proposed utilities and easements with deed book references. 2. Provide OP shape & stone size calcs (see VADEQ ESC HB Spec. 3.18). 3. Show low maintenance measures as finally stabilization measure of the E&SC plan. Low maintenance (not grass) ground cover shall be specified on the plans where grades are steeper than 3:1. {DSM, Sect 8A) 4. Provide CRS (VADEQ ESC HB Spec. 3.03) to graded width of access road from the entrance to the parking area. 5. Sheet 3.0 — Provide Temp. diversions (DD, Spec. 3.09) as perimeter control instead of SSF along proposed entrance road to parking area. Silt fence should not run across contours. DD should be used instead & lead to sediment trap or device near entrance. 6. Provide Temp. Sediment Basin (VADEQ ESC HB Spec. 3.14) design data sheet or similar as shown on pages III-12 to III-15. 7. Sheet 3.2 - Show spillway design detail or similar & values used. 1992 1.14 PRINCIPAL SPILLWAY DESICN RESICP, MCI, WATER EMERCFN_ SPuiwnv CREST R _____/_//_� --� � -WRIEX DEVICE 4 RISw fl QAN a CONCRETE BASE H = HEAD ON PIPE THROUGH EMBANKMFNT h - HEAD OVER RISER CREST L = LENGTH OF PIPE TRROUGH EMHAN%MENT OP= DIAMETER OF PIPE THROUGH EMBANKMENT Dr= DIAMETER OF RISER Source: Va. DSWC Plste 1. 14.7 8. Sheet 3.1— a. Tie in the grading alongside entrance road. b. There are a few spots where grading occurs outside the LOD (entrance road, cemetery, culvert, outside property) and the outfall pipe from SB. The LOD should include these areas. 9. A temporary grading/construction easement should be shown where grading/disturbance occurs on neighboring property. 10. Demarcate the Stream Buffer, Wetlands, and Tree Preservation areas. These will need to be part of the Initial Controls. 11. Provide copy of Wetland Disturbance permit issued from DEQ. 12. Show Stockpile area, Laydown-Staging area, Concrete -Chemical wash area, and Fueling location on the Erosion and Sediment Control sheets. 13. Show sediment trapping device at Construction Entrance, all waste water from vehicle tire washing must be directed into a trapping facility. 14. Change Construction Entrance legend to reflect a paved construction entrance on all plan sheets with legends. 15. Show Paved Construction Entrance Detail as per Albemarle County Design Standards Manual on Sheet C3.2 16. Add Rip/Rap to all Diversion Ditches at the outlet into the Basin and Trap. Make note on Legend and use symbols on plan sheets. 17. Show detail for Outlet protection on sheet C3.2 for Sediment Basin 1. 18. Show Blanket Matting on all slopes greater than 3:1. 19. Show Sediment Basin 1 conversion details. Detail the gabion baskets if that is what is being used, also the outlet detail at zero grade into the converted basin. 20. Add note that all slopes greater than 3:1 must have low maintenance vegetative ground cover. 21. Show Culvert and headwall details for culvert and headwalls as shown on sheet C3.1. 22. Need Curb Inlet Protection details. Must use an approved VESCH design, Gutter Waddles (Gutter Buddies) are not an approved method and will not be allowed. 23. Make note for Sediment Basin 1 indicating the need for an anti -vortex top, or if a trash rack is installed prior to conversion a temporary anti -vortex plate must be installed. Show details for both. -anti-vortex not required if weir control is maintained in the riser through all flow stages, including the maximum design storm or safety storm 24. Add note to Sheet C3.3 stating that any excess soils must be taken to an approved permitted waste site. 25. Add note to Sheet C3.3 stating that no erosion and sediment controls shall be removed without the Counties approval. 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/deptfonns.asp?department=cdenDUo File: WPO201900052 Berkmar Drive Apartments - 10-2019 Review.docx