The URL can be used to link to this page

Home My WebLink AboutSUB201500123 Correspondence Road Plan and Comps. 2015-09-29 September 29, 2015 Mr. John Anderson County of Albemarle Department of Community Development 401 McIntire Road, Room 227 Charlottesville, VA 22902 RE: Old Trail Block 27—Road & Utility Plan (SUB201500123) Dear Mr. Anderson, I have reviewed and addressed your comments. The individual responses to the Block 27 comments are below. 1. Title sheet—Revise Erosion Control & SWM Note. Phase II Erosion control is not"provided by the existing SWM bio-retention pond (Upper Ballard Pond)." Upper Ballard Pond (UBP) must be protected against all erosion and sediment impacts since it is not an ESC basin or measure. Plan notes, profiles, sequence, etc. require careful revision. Also, item #4 below. The Erosion Control and SWM Note on the Title Sheet has been revised to say that Phase I & Phase II Erosion Control is provided by the existing sediment basin constructed with WP0201400004. 2. Sheet 13 —Remove pipe Str. #227 from this view, or indicate when it may be installed. Also, item #4, below. I added a note stating that Str. #229 (new design)will not be built until all upslope areas draining to Str. #228 are stabilized and the existing sediment basin is removed. 3. Recommend Str-148 (to be modified, sheet 2, Belgrove Street) be relocated to final Str. 148A location (sheet 3), and that Str. 148B (34.89 LF 15" DIA HDPE pipe, sheet 9) be placed prior to placing asphalt intermediate and surface asphalt courses on Belgrove Street. Str-148, approved under Block 28 & 29B, road plan is essentially a temporary feature that changes with this plan. This is a recommendation. Contractual obligations may prevent relocation of Str.148 prior to asphalt placement, but if this is the case, asphalt pavement and C&G must be demolished at owner's expense to affect Block 27 design. The final layer of asphalt will not be installed until the Block 27 road construction is completed. 4. Critical: Sheets 4, 6, 9 (Utility plan, Grading plan, Storm profile: Ex. #144-#230 (outfall)) reflect a post-construction stabilized condition by proposing removal of Ex. Sediment Basin (see WPO 201500042). This is problematic. There is possibility that future development of blocks 7, 6, 26, or 35 will require trap/basin in similar location (ref. WPO201400004, sheets 3, 9, 10). Construction of structures between inlet #223 and UBP (outfall) is contingent upon complete upslope stabilization of all areas/blocks draining to Str. #223 to ensure negligible sediment-laden runoff reaches Str. #223. Str. #223 makes direct connection with UBP, an aesthetic amenity that provides habitat and quality/quantity Mgmt. (4 x WQV) for 43± on-site/110± off-site Ac. (sheets 9, 10; WPO201400004). Revise site, road, and VSMP plans using notes, labels, details, and sequence to state that until all upslope areas requiring ESC control are stabilized (via Ex. Sediment basin approved under WPO201400004/proposed to be modified under WP0201500042), only pipe #223A may be shown as an outfall from Str. #223 (WP0201500042, sheet 3). Str. #223 is proposed to replace Ex. Str. 156A. Note: This topic was discussed in detail in email (J. Anderson, 5/21/2015 6:46 AM) and Initial Site Plan comments, SDP201500015, 20-May 2015, items 8, 9, 12, 13, 15, 17, 21. There is no discernible response to ISP comments. I have redesigned the storm structures so that all of the contributing runoff from Block 27 and future Blocks 7, 6, 26, and 35 will be directed into the regraded sediment basin. I have shown the eventual outfall storm pipe (Str. #229-#230), but have included notes stating that this pipe will not be built until all upslope areas draining to Str. #228 have been stabilized and the existing sediment basin has been removed. 5. Sheet 3 —Max spread at Str. 213,= 6' (sheet 14, spread= 8.9'). Revise. I have revised the storm structure so that the maximum spread at Str. #213 is less than 6'. 6. Sheet 5 —Remove structures #227, 228, 229 from this plan view, or indicate when they may be installed. Also, items #2, 4, above. I have indicated that structures #229 -#230 will not be installed until all upslope areas draining to Str. #228 have been stabilized and the existing sediment basin has been removed. 7. Review ISP comment#11 —revise accordingly. Note: RP sheet 14 does not account for future development of Block 7. Revise runoff coefficient "C" for inlet Str. #201, 203, 209, 211, 215. Revise storm sewer design table/calculations. Design must avoid situation seen between inlet Ex. Str. #132 and Ex. #154 where runoff CFS appears to exceed pipe capacity. I have revised the runoff coefficients for the inlets along the Eastern side of Orion Lane. Note that there will be storm sewer structures installed in the future development of Block 7 so that the drainage areas going to the inlets located along the Eastern side of Orion Lane will be less than shown in these plans. Ultimately, I feel that the storm sewer structures proposed in Block 27 have sufficient pipe capacity to carry runoff from the future development of Block 7. 8. Revise inlet computation tables to reflect increased runoff from future impervious areas in Block 7 that may reach inlets on Orion Lane. Also, #7 above. The inlet computation tables have been revised accordingly. 9. Golf View Dr./Orion Lane—Provide VC at PVI Sta. 21+18.45 and at PVI Sta. 10+18.00, respectively. Ref ACDSM 7.A., which ref review checklist/Also, road plan application checklist: "Vertical curves at all grade transitions." Required for public/private streets—please note this item is checked on Application checklist. Vertical curves are now provided at the PVI's on Golf View Drive and Orion Lane. 10. Min. K, sag = 15. Revise Orion Lane VC, PVC Sta. 13+87.50, K=9.82. This VC is 72.24' from Int. Golf View Drive. Additional curves with K<15 are not as distant to intersecting streets. Apply min K values (ACDSM)to crest/sag curves except as needed to transition 2.08% cross-grade to intersecting street grade. The K value for the VC on Orion Lane at PVI Sta. 14+00.00 has been revised to 17.74. 11. Recommend show delayed construction of planting strip and sidewalk between Str. #223 and UBP to limit demolition required when storm runoff structures between#223 and UBP are installed, which may be much later than other improvements. Ex. Sediment basin to be modified under WP0201500042 (Amendment to WPO201400004) and shown on SUB201500123/SDP201500035 (sheet 6) will remain as both ESC and intermediate SWM control until all upslope areas are stabilized, which may be an extended period of time. I have revised the design of the storm sewer so that the installation of future Str. #229-#230 will not require any demolition to the planting strip or sidewalk. 12. Replace label references to Alpha Street with Orion Lane. (Sheets 2, 3, 4, 6, ....) All label references should now call out Orion Lane, not Alpha Street. 13. Revise road grade elevation/contours at east end of Golf View Drive consistent with WPO201500042, sheet 4. Note: contours (WPO sheet 4) at end of Golf View Drive may require revision since WPO sheet 4 must show Ex. Sediment Basin(to be modified) continuing. Also see #4. The road grade elevations/contours at the east end of Golf View Drive are consistent with the basin re-grade. 14. Reconcile storm sewer profile Ex. #144 - #230 (outfall) with plan view. In profile view, please revise to show riprap outfall protection above rather than below UBP Normal WSE= 672.60'. The profile view of Str. #230 now shows the riprap outfall protection above the UBP Normal WSE. 15. Recommend consider inlet shaping detail relative to inlet Str. #223, which for the intermediate future, directs runoff via structure 223A to Ex. Sediment basin (ref. WP0201500042/ WPO201400004). Later, Str. #223 will direct runoff to UBP. Inlet shaping cannot do both at the same time. As a result of the revised design of the storm sewer system, I do not feel that this comment applies to the plan anymore. The future pipe will be core-drilled into the existing inlet. Inlet shaping will be installed at this time, as required. John Anderson From: John Anderson Sent: Tuesday, November 17, 2015 5:32 PM To: Ammy George; 'Bill Ledbetter' Cc: Dave Brockman;Glenn Brooks Subject: WP0201500042 -Old Trail Village, block 27 Attachments: SKM_364e-En15111717300.pdf; SKM_364e-En15111717310.pdf;WPO201500042_Old Trail-block 27_110215revl.pdf Bill, Ammy, Several 2-Nov. comments not addressed—I think I realize what happened. At times, review comments may be addressed, but in responding to comments there may be follow-up request. I highlight request for follow-up with colored text. I use this format for all reviews—generally without issue—but understand that if scanning for Not Addressed, it may be easy to pass over Addressed. As follow-up... This appears to have happened. Example: :t,:oordili '-ly i';fee° cad 41 (4+1t e',Je'-'7 11", (Rev. 1)Addressed via redesign. As follow-up. please include language from RGA comment response letter in Note. sheets 4. 8. Please revise Notes to read [sheet 4/8): "Str. #229 will not be built until all upslope areas draining to Str. #228 are stabilized. and the Ex. Sediment Basin is removed. per County Inspector approval. These upslope areas include all of the contributing runoff from block 27 and finure blocks 7. 6. 26 and 35." Also: SHEET 3: Please remove/delete note that reads: "Upon site stabilization. install permanent outfall into Upper Ballard Pond(Str.L229 - #230) & remove temp.kip,s,Str#231 and Str#232." This note may be misconstrued, Also: -Ref. Attached. Compare SB clean-out Elev. with VESCH detail/plan vertical scale. Check `wet storage' against `sediment cleanout point'—VESCH Plate 3.14-2: V MJN. 1.0" -°O.5' MIN. 1.0' ,... � �� rye RISER CREST 67 C-Y.j AC. OEYVATER?INC DRY ' STORAGE r! wait ocvi C vditii 67 C.Y./ AC. - " WET " STORAGE `'1 firT1.!$'411?3MPOW-nfigl SEDIMENT CLEANOUT POINT (" WET STORAGE REDUCED ro 34 C.Y./ ACPC) Compare with design: 1 K. J l 111'CNI GL.L V.f LL1—Uv I .v ' °ft./ RISER REST ELEV=679. 75 -: -- E ISTIN ISER .._ STRUCT RE C ANOUT $EL.EV.=6 ' 6.75 Revise sediment basin Elev./design if necessary—please call to discuss if any questions. Please review 2-Nov. comments with follow-up requests listed at: SWM Plan,#3; ESC Plan, #5.b.ii- These are minor yet important edits—they relate to when runoff may outfall to Upper Ballard Pond. What I offer- If questions,please call —I am generally available/responsive Revise/send .PDFs (SWM#3,ESC#5.b.ii;NEW—Sediment basin profile) Will be glad to withhold comment on 11-13-15 plans—goal is to Approve With .PDF revisions, will be positioned to Approve Then,need 2 print copies of each revised sheet, County will replace 11-13 sheets Also,need 2 additional complete sets of plans—will then have 4 for Approval This can occur as quickly as you send .PDF revisions. I apologize for any misunderstanding tied to embedded follow-up. Ammy, Bill, I enjoy working with you. A personal Note: It will be difficult to accept complaint in this circumstance. In my view relationship with March Mountain is damaged. In time, it may improve. I depend on each of you. We support OTV projects any way that we can. Thanks for your patience. John E.Anderson, PE I Civil Engineer II Department of Community Development I County of Albemarle,Virginia 401 McIntire Road I Charlottesville,VA 22902 434.296.5832 ext.3069 2 .11 *sr- "'e PHONE(434)977-0205 FAX(434)296-5220 lomi ROUDABUSH, GALE &ASSOCIATES, INC. INFO @ROUDABUSH.COM LAND SURVEYING A PROFESSIONAL CORPORATION ENGINEERING Serving Virginia Since 1956 LAND PLANNING 914 MONTICELLO ROAD CHARLOTTESVILLE,VIRGINIA 22902 WILLIAM J.LEDBETTER,L.S. J.CLINT HARMON,L.S. CHRISTOPHER C.MULLIGAN,P.E. DAVID A.JORDAN,L.S. AMMY M.GEORGE,LA BRIAN D.JAMISON,L.S. November 13, 2015 Mr. John Anderson, Civil Engineer II Albemarle County Department of Community Development 401 McIntire Road Charlottesville,Virginia 22902 Regarding: SUB201500123 Old Trail Village Block 27 - Road Plans Dear Mr.Anderson, I have reviewed your comments from November 2, 2015. The individual responses to those comments are below. 5. Max spread at Str. 213 =6' (sheet 14, spread =8.9'). The size of the inlet has been revised to reduce the spread to be less than 6' with a depth of less than 2". If you have any questions or comments, please feel free to contact me. Sinc rely, I __ Animy e s 'ge SUB201500123 Old Trail Village Block 27 11/13/2015