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HomeMy WebLinkAboutWPO201400096 Review Comments WPO VSMP 2019-04-18COUNTY 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: Stonefield Block D2, Phase 2 — VSMP Amendment Project file number WPO2014-00096 Plan preparer: Mike Myers, PE / 30 Scale LLC, 871 Justin Drive, Palmyra, VA 22963 [ mike(&30scale.com ] Owner or rep.: Christopher at Stonefield LLC, 10461 White Granite Drive, Suite 103 Oakton, VA 22124 Plan received date: 4 Mar 2019 Date of comments: 18 Apr 2019 Reviewer: John Anderson WPO2014-00096, Amendment 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 for reasons outlined, below. The application may be resubmitted for approval if all comment items are satisfactorily addressed. 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. Link to County template: httt)://www.albemarle.org/ul)load/imaaes/forms center/departments/Community Development/forms/Encin eering_and WPO Forms/Stormwater_Pollution Prevention Plan SWPPP template.pdf 1. Provide SWPPP. Use county template (link, above). The PPP content requirements can be found in County Code section 17-404. SWPPP —Provide 11" x 17" Exhibit. Recommend ESC Plan as template. Show solid/non-hazardous waste dumpster; sanitary facilities (port -a John); solvent -paint storage; concrete wash -out; on -site fuel storage. DEQ, during periodic inspections of active projects, instructs on importance of an Exhibit that shows location of these features. All should drain to containment. For example, silt fence downstream of port-a- john. Concrete wash -out, dumpster draining to trapping device (lined, in case of concrete wash -out). On - site fuel storage berm with 1 Oml liner, sized to hold fuel volume + 2 yr. storm event. .PDF samples available. Exhibit is not intended as a detailed design, but to show containment and locations which may change over time. Exhibit is a construction aid and resource protection/inspection management tool. C. Stormwater Management Plan (SWMP) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This plan is disapproved for reasons listed, below. The stormwater management plan content requirements can be found in County Code section 17-403. Sheet 1: SWM Amendment Narrative (Note: plan revises VAR 10I551): `The Amendment reduces the impervious area that was originally proposed with WPO201400096, and therefore stormwater management — water quantity control requirements are satisfied.' Engineering accepts this statement. Engineering Review Comments Page 2 of 4 Water Quality: `As shown on the approved WPO plans (WPO201400096), water quality control for block D2 is met by a combination of existing downstream BMP facilities (a Vortechnics structure and a Stormfilter facility), and supplemented by onsite Filterra box planter structures to meet the remaining phosphorus removal requirements. The appropriate BMP worksheets have been updated and included with this VSMP Amendment.' Engineering accepts this statement, with additional review comments: 1. Attach (attached 3-sheet partial plan set, WPO201400096); revise sheet 1 Index. 2. Include Site Plan Amendment sheets 7 (Ex. Conditions /Demo Plan), and 8 (Layout); revise index. [SDP201900012] 3. Include sheet 13 (source -?), since referenced in descriptive labels for ditches #1 and #2, Phase 2, ESC plan (VSMP plan sheet 8). 4. Please contact Carla Harris, Albemarle County /CCD-Engineering to ensure no lapse in VAR10 permit coverage ( charris(a-)albemarle.org ). 5. Ensure structure labels are not obscured by drainage area divide heavy linework (are clearly readable). 6. Filterra Str. 6A does not appear to be shown to scale. Check scale of this 12' x 6' structure. [Related: ensure FSP, SDP201900012 sidewalk at Filterra Str. 6A is 4' wide, Min., per Code of Development.] 7. Check scale of Filterra Str. IA and 4A. Revise as needed to show true scaled dimensions for these structures. [8' x 4', 6' x 6', respectively.] Sheet 5 8. Using design ratio Area Filterra (ftz): Area (ftz) drainage area=0.33%, Filterra Str. 4A Min. required area is 38.8 ftz. 36 ftz is provided. Revise to provide Min. Filterra area for proposed DA. 9. Revise table to include original size (dimensions) of approved plan Filterra Str. #244.1, 25.5, and 23.4. Sheet 6 10. Revise sheet block, lower right (sheet # misprint). 11. Engineering recommends against 0.50% pipe slope. If As -built condition <0.50%, Applicant must propose remedy, which may include pipe replacement. [Str. 6 - 244] 12. Q(ACC /cfs), 2A — 2 exceeds Q(cap). Revise such that flow in storm pipe, 2A — 2, is open flow regime, else design entire system to be watertight [i.e., specify materials, provide specifications.] D. Erosion and Sediment Control Plan (ESOP) Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESOP. This plan is disapproved for reasons listed, below. The erosion control plan content requirements can be found in County Code section 17-402. Sheet 1 1. List LOD with this plan, block D2, Phase 2, to assist with DEQ permitting, and ESC Plan bond estimate. VAR10I551 will be revised with this plan. LOD =5.65 Ac. includes Phase 1. The majority of Phase 1 is either hardscaped, or stabilized. 2. List source of topography. Ensure topography is recent. Note: Ref. ESC Plan checklist for plan reviewers: `Date and source of the topographic information: All topography should be at least visually field verified by the designer within the last year.' Sheet 7 3. Provide SAY along NW property boundary, to protect site from trespass, and residents from harm. 4. Provide wire -backed SF along SE property boundary to protect Stonefleld hotel -restaurant -shopping patrons that may park within feet of this active construction site. 5. Revise existing contours to reflect existing contours. It appears years -old plans may be source of existing topography. See related comment requesting topo be field verified (checklist requirement: field -verify within the last year). Also, see note directing contractor to remove excess sediment from Ex. sediment basin to a bottom of basin elevation of 494'. Ex. sediment basin floor elevation is shown as 492'. 6. Label Ex. sediment basin floor dimensions (L x W). Engineering Review Comments Page 3 of 4 7. Copy sediment basin design information from WPO201400096 to this plan, if source of basin design, if sediment basin is relied upon for ESC under this plan, as it appears to be. 8. (Note: Owner of 061 WO-03-00-019E2 will likely be required to be listed on the ESC Plan bond for this VMSP /WPO plan Amendment.) 9. Given 1-way directional travel on Strong Blvd., contractor may maintain traffic control with a flagger, but may not barricade or close in -bound 1-way traffic on Cash Alley. Delete physical barricade label /symbols. 10. Revise CE to PCE (paved washed rack). 11. DD#2: Provide linework and note/s that indicate a sediment trap (or trap -like) feature to redirect DD#2 flow, where DD#2 turns N to E. Although contours favor a turn, without a settling /trapping measure, in less frequent events, runoff may leave the site or impact adjacent property. If sediment trap is used, provide design. If less formal measure is used, provide sufficient graphic /text information to indicate design intent. 12. Show Str. 23.2. 13. Revise Water and San. Line labels to include both `Existing' and `To be abandoned' or `To be Removed.' 14. Show LOD. Include LOD linetype in ESC legend. Estimate Area of LOD (ft2) with this plan. 15. Provide RW diversion at NW corner of Phase 2 site, at Int. Cash Alley and Kober Way. 16. Provide note or contours to direct DD#1 storm runoff into Str. 7. Sheet 8 17. Eliminate Note that reads: `Contractor to use a physical barricade to re -direct traffic while alley is under construction.' Cash Alley 1-way traffic circulation must remain unimpeded during construction. (Note: Several residents of Block D2, Phase 1 have separately shared site access concerns, which are reflected in review comments.) k D2, Phase 2.] 18. There is a label ref. to sheet 13. This does not appear to be a ref. to Site Plan, but since note ref. calculations, provide design calculations for ditches # 1 and 2, and support selection of protective lining type. 19. Sheet makes ref. to geotechnical engineer recommendations. As construction proceeds, furnish copies of all geotechnical reports, measurements, observations, recommendations, and test values to Engineering Division, Albemarle County. .PDF to janderson201albemarle.org is sufficient. Sheet 9 20. Copy Phase 2 Work Notes to sheet 8. 21. Provide Narrative sequence that relates building construction sequence and Filterra installation. Filterras must remain off-line until all upslope areas are stabilized. Engineering Review Comments Page 4 of 4 The VSMP permit application and all plans may be resubmitted for approval when all comments have been addressed. For re -submittal, please provide 2 copies of the permit package with a completed application form. Engineering plan review staff is available from 2-4 PM on Thursdays if you wish to meet 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, or deed bk.-pg. reference to existing Agreement provided. 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 (if an existing Agreement is not recorded). After bonding and agreements are complete, county staff will need to enter project information in a DEQ database for state application processing (this VSMP Plan appears to modify VAR10I551). 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 (SWPPP Registration Statement). 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. Easements must be recorded prior to VSMP approval (statement does not apply in this instance; VSMP plan relies on Ex. BMPs). Proof of purchase of nutrient credits (if any) is required to receive a Grading Permit. After DEQ coverage is issued, the County can hold a pre -construction conference. Applicants will need to complete the request using 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 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; htW://www.albemarle.ora/deptforms.asp?departrnent--cdengmMo Ifyou have questions /concerns, please contact me at janderson2aalbemarle.org or at 434.296-5832-x3069. Thank you J. Anderson, Engineering WP0201400096 Amendment Stonefield Block D2, Phase 2 041819