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HomeMy WebLinkAboutWPO201800088 Review Comments 2019-04-12PROJECT MANAGEMENT SHIMCIVIL ENGINEERING LAND PLANNING ENGI N EERI NGa April 12, 2019 Mr. John Anderson Department of Community Development 401 McIntire Road Charlottesville, VA 22902 RE: WPO 201800088 Pantops Corner VSMP Dear John, Thank you for your review of the revision of the VSMP Plan for Pantops Corner We have revised the plan per the your most recent comments dated February 20, 2019. See below for detailed responses to each of your comments. A. SWPPP 1. Individual responsible for practices (Sec. 6E) added. Individual named as qualified personnel (Sec. 8) added. Loose sheets have been included, they can be added into the SWPPP. SWM Plan C3 11. The easements are shown on C4 not C3, this is intentional. To keep the plan has to be readable, C3 shows the surface layout and does not show easements. Easements are shown on C4 will all other utility features. SWM Facility easement expanded per diagram noted. For an 8' CMP, the easement width on the uphill side is 32' offset from the edge of pipe (corresponding to a max cover of 15', for the lower edge it is a variable width offset roughly following the 370' contour (width corresponding to a max cover of 13' and for excavation depth tying in to the retreating slope). 16. See above, these easements are shown on C4, the utility layout plan. C5 24. Comment noted, see notes added to C11. Inspection frequency is listed on C6. a. See below c. Corrugation can be selected from a variety of options, and has specified at 1" height. d. #57 stone is eligible material per our numerous previous conversations with the manufacturers of these systems and is preferred by contractors as it is easy to obtain and install. C11 CMP Detention note #7 revised to specify #57 stone. Page 1 of 3 L Noted. 4' Space provided, welded access ladder added to weir plate for further ease of access. Hydraulic modelling is accurate because 2' has been added after the weir plate, providing a full 24' of cylindrical space in this barrel for a total of 470 If of pipe storage, as entered into the model. k. Detail provided, see updated C11. m. After conversations with the manufacturers, the note has been revised to be soiltight. This is due to the fact that the system is perforated. Hugger band and slip joint details have been added. Please note that this plan has detailed the essential installation requirements, however engineer cannot guarantee quality of installation by plans alone. We are confident that the current details will provide sufficient guidance to contractor if the notes and details are followed. n. Riser detail added. o. These are included and have been expanded, see comment responses elsewhere. p. Noted. Easement plat has been submitted. q. C11, Notes 8 & 10 updated and resolved. Table is not provided, rather qualifications of soil backfill are provided. To address note 7, the riser detail includes riser concrete support detail addition for risers with traffic loads. C11 33. A typical profile has been added. We will not have profiles for each barrel, as this will be redundant information and will not contribute to better installation. This is not stated arbitrarily, but because of our experience having designed over a dozen of these systems. As was discussed on the phone, the ultimate installation plans will come from the detention manufacturer, still we are confident that this current plan provides sufficient detail for both the manufacturer to generate appropriate system plans and for the contractor to properly install the system. a. Addressed. b. Inverts are all the same, provided on profile. c. Inverts are all the same, provided on profile. d. The SL-1 detail is for MH-1 manholes. These risers are not MH-1's, and have 30" diameters, which is the same diameter as the SL-1 openings, thus SL-1's are not appropriate. Typically, these detention systems require confined space certified personnel who would enter the detention with a tether system. B. PPP 1. Named individual added. C. ESCP C7 40. Rip -rap outfall depth added. Page 2 of 3 A Von CM Included with this letter you will find a VSMP application, 2 copies of the VSMP plan, 2 copies of the added SWPPP slipsheets, and 2 copies of the calculation packet. If you have any questions or concerns about these revisions please feel free to call me at (434) 299-9843 or email Justin Shimp at Justin@shimp-enRineerinR.com and we can discuss any questions that you may have in further detail. Best Regards, Keane Rucker, E.I.T. Shimp Engineering, P.C. Page 3 of 3 RECEIVED APR 15 2019 Cc MMINiTY DE vt=L6l-- lvl.:NT