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Home My WebLink AboutWPO201800073 Review Comments WPO VSMP 2018-11-091. Avoid wetlands to extent practicable; provide exhibit/s showing roadway CL shift to the west to avoid wetlands to extent practicable. 2. Stormwater Management Note, C0.0 references "Stomrwater Mangement /BMP Analysis and Floodplain Study for the UVA Research Park at Northfork" by Dewberry & Davis, October 1997." The note continues: `The Research Park has been master planned for Stormwater Management for the future build - out of the research park. The Majority of this road project drains to the large wet pond to the east that was designed and constructed to handle quantity and quality for the future build -out of the research park including this road connection.' End note. (Ref. document /link [CV : httn://www.albemarle.org/weblink/search.aspx?dbid=3&searchcommand=%7b%5bCDD- Planning%5 d:%5bApplicationNumber%5d=%22 WPO200600087%22%7d Also/same link: "UVA Research Park, Town Centers III and IV, Engineering Calculations," prepared for UVA Real Estate Foundation by Frank D. Cox, Jr., PE /Cox Company, 220 E. High St., Charlottesville —Nov. 30, 2006, Rev. March 8, 2007. This document appears highly -relevant and useful to VMSP /WPO Plan submittal. Review and include salient information from this document. See Exhibit 1, beginning p. 18 of .PDF. Also: pre -development drainage map, p. 7; a road design not identical with design proposed with WPO201800073, p. 8-9; etc.) a. Title sheet notation does not of itself sufficiently address plan requirements if compared with VA Administrative Code stormwater quality or quantity regulations. It is unclear if Applicant is requesting Engineering accept existence of a study as sufficient basis for issuing a VSMP VPDES permit under 9VAC25-870-48, without additional detail or context, including: narrative, data, routings, pond plan /profile, As -built for Ex. large wet pond, drainage maps, calculations, etc. Engineering recommends Timmons take a conventional approach and piece together information; that is, provide rationale that guides plan review, including whether 9VAC25-870-48 is basis of VSMP /WPO Plan Application (Grandfathering). Please provide reference to a ZMA, SP, SDP, or WPO approved prior to July 1, 2012 that explicitly includes BMPs designed to meet then -current stormwater management requirements and included with the Dewberry 1997 study. The reference study is twenty-one years old. There are few immediately recognizable approved ZMAs, SDPs, SPs, or WPOs in Albemarle County's online document system (CV) that align with the 1997 study (WP02006-00087 does). Timmons must provide information sufficient for Engineering to approve WP0201800073 without pulling past plans, many of which are listed in CV as not approved. 9VAC25-870-48, -93 /94 (Definitions /Applicability), -95 (General), -96 (Water ualit ), -97 (Stream Channel Erosion), and -98 (Flooding) likely govern proposed roadway construction. Engineering recommends query CV (or visit CDD to request /consider and review) the following possibly relevant Applications (listed by type, then chronologically): i. ZMA2005-00002 ii. SP2008-00062 iii. SDP1997-00046 iv. SDP1998-00043 v. SDP2000-00025 vi. SDP2000-00077 vii. SDP2000-00098 viii. SDP2001-00005 ix. SDP2001-00011 x. SDP2001-00047 xi. SDP2002-00064 xii. SDP2002-00072 xiii. SDP2002-00110 xiv. WP0200600087 (Approved plan not shown in CV; documents only.) 3. Remove road plan sheets from VSMP /WPO Plan, including: C1.1 - C1.3, C4.4 - C4.9; C6.0, C6.1, C7.0, C8.0 - C8.3: these sheets present road plan details. 4. SWPPP a. Sign Sec. 1, VPDES Certification (Print, sign, title, date) b. Lat./Lon. provided appear to be a location in Louisa County. Please revise Lat./Lon. c. Sec. 5: Provide SWM Plan d. Sec. 9, Signed Certification: please sign e. Revise inspection log to provide space for description of inspection observations —see image, below EROSION AND SEDIMENT CONTROL FACILITIES INSPECTED: (Inspections shall be conducted according to Part IIF2 of the Permit. However, if the discharges of stormwater from construction activities are to surface waters identified as imparied, inspections shall be conducted according to Part IB4d.) Facility Identification Date and Time of Inspection Operating Properly (Y/N) Description of inspection observations 5. Copy Construction Record Drawing (As -built) Policy to plans: htW://www.albemarle.oreLupload/images/forms_center/departments/Communi!y Development/forms/Engi neering_and WPO Forms/WPO VSMP Construction Record Drawings Policy 23Mgy2014.pdf C3.0 6. Stormwater Runoff Considerations: Expand to provide descriptive narrative connection to a prior -approved site plan, special use permit, or water protection ordinance permit that positively confirms proposed development meets state stormwater quality and quantity requirements. 7. Include note that requires Owner to obtain all required state or federal permits, including VDEQ Individual Permit, VMRC General Permit, or US ACE Nationwide permit (wetland impacts), etc. 8. List special conditions of US ACE permit on the plans. Identify, number, and quantify area impact to wetlands (SF). Identify wetland type/s using text, labels/notes, graphic symbols. 9. Include ACDSM Paved (construction entrance) Wash Rack detail. Measure required. See ACDSM, p. 8. 10. Define /specify slope stabilization seed mix (Ref. legend, C3.2). 11. C3.0 : It appears 2" d C3.0 (details) should be labeled sheet C3.1. 12. C3.1 (relabeled): Include stream diversion detail; for example, VESCH plate 3.25-1, or variation showing sandbag dam /pump -around diversion C2.0 13. Provide at least one hundred (100) Ex. contour labels. No legible contour labels appear to be shown. (It is difficult verging on impossible to interpret existing conditions.) 14. Label development parcel TMP. Label each adjoining parcel with TMP#. 15. Provide Mitigation Plan for stream crossings (2:1 mitigation required). Label WPO buffer areas, if multiple areas. Provide landscape schedule for each WPO buffer area. 16. Revise critical slopes labels; replace with managed or preserved steep slopes labels. 17. C3.2 — C3.5: Increase Ex. contour labels so legible. C3.2 18. Label ST1 floor dimensions in plan view. 19. ST 1 design treats Max. limit, 3.0 Ac. Show 3.0 Ac. drainage area boundaries for this sediment trap. 20. ST1: Avoid wetlands. Relocate ST1 since this sediment trap discharges to downslope wetlands, by design. This means, any event that exceeds capacity of ST1 will discharge sediment to wetlands, by design, which may cause permanent or irrevocable and not incidental impact. Do not propose sediment trapping measures upslope of or immediately adjacent to wetlands. 21. Relocate roadway if necessary to avoid and minimize wetland impacts. Alternatively, provide copy of USACE Permit authorizing proposed wetland impacts. 22. Label dimensions 39 cy Culv-3 inlet protection to aid review, construction, and inspection. 23. Label Area (acreage) of Limits of Clearing and Grading, x.xx Ac. 24. Calculate velocity (Q2) for channel at bottom of future fill slope, upslope of Culv-3. Provide soil stabilization, permanent riprap, or concrete conveyance channel as required for this channel. 25. Show, estimate, label area of wetland impacts (SF). Identify wetland type: emergent, riverine, palustrine. 26. List U.S. Army Corps of Engineers Nationwide permit (USAGE NWP-27 /other) issued for this project. List date of permit issuance. VSMP /WPO cannot be approved without copy of current USACE permit authorizing specific impacts to specific areas identified, shown and labelled on the VSMP /WPO plan. 27. Show wetland protective measures; for example, timber matting and fencing equivalent to tree protection, for wetlands to be preserved and not authorized by USACE permit to be disturbed or impacted, either temporarily or permanently, by project activity. Plans identify no wetlands to be preserved, except by virtue of location outside LOD. Recommend wetland preservation as cornerstone of design. See other comments on topic of impact avoidance and minimization, especially concerning Applicant need to acquire and provide copy of relevant federal or state wetland, stream, or aquatic resource permits. Design Calculations & Narrative, 9/24/18: 28. Culvert 1 Table breaks across 2 pages; reformat so visible as single sheet. 29. Culverts 1, 2, 3 design outfall velocity exceeds 10.0 fps. Include VESCH Yd Edit., plates 3.36-4 and 3.36-5 on plan sheet C3.0 or C3.1. Ensure labels, notes etc. identify locations requiring VESCH Std. & Spec. 3.36, and identify which We stabilization matting is required. 30. (RP comment) Max. outfall velocity is 15fps. Ref Drainage Plan checklist (drainage computations, p. 2). Revise design such that outfall velocity for all culverts is < 15fps (Q2). 31. Provide outfall protection calculations. Ref. VESCH Std. & Spec. 3.18 plates 3.18-3 and /or 3.18-4. 32. Culvert 3 OP width 2 is insufficient. Width 1 =6.0' is likely adequate (ref. comment #31). Ref. VESCH. J. Anderson, PE, Albemarle County Engineering Division Nov. 9, 2018