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Home My WebLink AboutSUB201800039 Correspondence 2020-04-22 (2)® COLLINS ENGINEERING April 21, 2020 Matt Wentland, PE Department of Community Development 401 McIntire Road Charlottesville, VA 22902 RE: Briarwood Subdivision, Phase 6 Final Road Plan (SUB 201800039) `200 GARRETT ST, SUITE K CHARLOTTESVILLE VA 22902 j 434.293.3719 PH 434.293.2813 FX ( www.collins-engineering.com Thank you for your comments dated April 27th, 2018 on the above referenced project. Below are our responses to your comments. Should you have any questions during your review of this project, feel free to contact Graham Murray at graham@collins- engineering.com or Scott Collins at scott@collins-engineering.com. Engineering: 1. This comment is acknowledged. The project currently has an approved VSMP plan on file for SWM and ESC (WPO 201600054) and a new VSMP plan can be submitted as required. 2. This comment is acknowledged. Deed book and page numbers for all offsite easements will be provided prior to approval. 3. The plans have been provided and the pipe slopes are less than 16% per VDOT and Albemarle County DSM requirements. 4. Pipes located within VDOT right-of-way, which are to be maintained by VDOT, have velocities less than 10 ft/s. Pipes located outside of VDOT right-of-way, which are not maintained by VDOT, have pipe velocities between 3 and 20 ft/s in accordance with the Albemarle County Design Standards Manual, Section 6.A.1.d.4. 5. The 10-year HGL calculations are shown on sheet 9 and sheet 7 has been revised to show the HGL on the profiles. 6. Sheet 7 has been revised to specify %" thick steel plates at the bottoms of structures with 4'+ drops. 7. The plans have been revised to provide a proper riprap lined outfall where the storm sewer system discharges into the proposed SWM facility. The design can best be viewed on sheet 4. Please also see the attached calculations. 8. The plans have been revised to provide a maximum wall height of 6' where disturbances are proposed over managed slopes. Also, small swales at the top of the fill embankment are now proposed where disturbances to steep slopes are proposed. Additionally, yard drains are now specified at the rear of the lots. These yard drains will receive direct runoff from the homes' downspouts to prevent concentrated runoff, and to promote only sheet flow down the fill embankment. A note has been added to the top left portion of sheet 4 mandating these installations. 9. This comment is acknowledged. A note has been added to the top center portion of sheet 4 referencing this. VDOT 1. This comment is acknowledged and has been resolved. 2. This comment is acknowledged. 'Fill Notes' have been added in the upper left corner of sheet 4 mandating the contractor hire a 3rd party Geotechnical Engineer to analyze the embankment. 3. The requested note has been added to sheet 4's'Fill Note' number 2. 4. The plans have been revised and no longer propose storm sewer slopes in excess of 16%. 5. Pipes located within VDOT right-of-way, which are to be maintained by VDOT, have velocities less than 10 ft/s. Pipes located outside of VDOT right-of-way, which are not maintained by VDOT, have pipe velocities between 3 and 20 ft/s in accordance with the Albemarle County Design Standards Manual, Section 6.A.1.d.4. 6. The requested note has been added to sheet 5, below the 'Pavement Design' table. 7. The 10-year HGL calculations are shown on sheet 9 and sheet 7 has been revised to show the HGL on the profiles. Fire/Rescue 1. The plans have been revised to provide a cul-de-sac with a minimum diameter of 96'. Sheet 3 of the plans has been revised to include a label for the 48' radius. 2. Two 'No Parking' signs are now shown and labeled on sheet 3 to address this comment. 3. A fire hydrant flow test has been performed near this project recently. Sheet 1 has been updated under the 'General Notes' subsection entitled 'Fire Flow' in the bottom left corner of the page. ACSA 1. This comment is acknowledged and sheet 1's 'General Notes' subsection entitled 'Utilities' states this stie will be served by public water and sewer. 2. An 8" DIP water line is located within public right-of-way and is within 5' of the property. A note in the center of page 3 states this information. 3. A fire hydrant flow test was preformed approximately 0.20 miles from the intersection of Hummingbird Land and Sunset Drive. Sheet 1's 'General Notes' subsection 'Fire Flow' was added to the cover sheet to provide the results of this test. 4. An 8" sanitary sewer line and a sanitary sewer manhole are located onsite. Notes in the middle -right portion of sheet 3 state this information. 5. This comment and form are not applicable to this project. 6. This comment is acknowledged. No improvements or obstructions are shown within existing of future ACSA easements. All buildings and retaining walls are located outside the limits of the public right-of-way and ACSA easements. 7. This comment is acknowledged. 8. This comment is acknowledged. 9. This comment is acknowledged. 10. This comment is acknowledged. 11. This comment is acknowledged. 12. This comment is acknowledged. 13. This comment is acknowledged. Sincerely, Graham Murray, PE Graham Murray From: Stephen C. Rodgers <scr@wbswinchester.com> Sent: Friday, April 17, 2020 12:17 PM To: Graham Murray Subject: RE: Shallow Sanitary Sewer and MHs That's correct by using a 4" sanitary frame and cover. Thanks Steve Rodgers Cell 540 974-5207 From: Graham Murray [mailto:graham@collins-engineering.com] Sent: Friday, April 17, 2020 12:09 PM To: scr@wbswinchester.com Subject: Shallow Sanitary Sewer and MHs Good afternoon Mr. Rodgers, Thank you again for our informative conversation a few minutes ago concerning shallow sanitary sewer pipes and manholes. To recap the conversation, you informed me manholes can be constructed with a rim -to -crown of pipe depth as low as 26". Is this correct? Thank you again for your time. Graham Graham Murray, P.E. COLLINS ENGINEERING www.collins-enaineerina.com 200 Garrett Street, Suite K Charlottesville, VA 22902 Cell: (434) 566-3011 graham collins-engineering.com 'bVII1RNQ00 E�nsE b y PX W�- 9u*� r-dpk, rt neR VE��t l Val 3,!`i , r, � - �-n FcP "CAN G L M P'W\,J �• \5NtoSet-o ChAtiNct- S%,4C SLODCS = 3'A 1 'CIaC F-L,A.r, '*<. QPDMOV.0 E :s 5 CpMYlLrciC-, Fx4t fuA\JC4 Ftc'. {.PT PR L'upBL(tr QQ C}i�NA,(L SS TANG�+� fir. per: Z1,%6 cs (Taart cAa�4 p� err ' a3 ss (44\,rL`}ES % StAAu �ACPC4 of SAS ' �r c� ----- �' SA. ,n1 ,4' G�,� pp �ttt vauvw- Ffl�asc r sta�c- ��tm = 3 r Fx�.lA4 YJ�S1f�1 : �Jp[aT "V . ttT��Q V— �; �so '�aP�AC' chn��,t"C �ArtC�L�actir CAS-cu+-A�cv.�, . (An 1sAs- cw- TAOCOC ZOX- CRAIJWce~)� laW �)SM K are 7W r q, 69' < 0.5 (AMA.= aw' dv-cctk %A 3,va -3 ; dy, - 6 u VIA wa = D, -� 6-A CPEA J 1s�NH CNG Ca,) , fCA S'Srt¢LaG�c�l� c�1 \Wtj'S�-' TKt tAXt �Aa4CrlcN WILL %f -rj;t , SAME $Ict c STEC ; UOTR CMcRE �LO-a s) As THC T&A4eeorzoAl. eMAtm.<c, C=7ZNAL. %tZ6N : UJ W 5t fl , GL. '� RaF�AP �i Cs TASMC 5[ta` � Pt!✓1 ° 3° (-N = �v Ws 'T r �Ma�cKS �srv�PEos crauNc� Toe v.m �� w�, . lti' Pipe Outlet Riprap Channel Calculations Complex Channnel- Trapezoidal Channel Down Embankment at Pipe Out -Fall Input: Slope Flow (given) line x y n 0 0.000 1.000 0.050 (first n value not used) 1 3.000 0.000 0.050 2 4.000 0.000 0.050 3 7.000 1.000 0.050 Output: Depth 0.688 (Y) ( 0.688) Channel bed segment output: line Q V 1 6.40 9.02 2 10.20 14.83 3 6.40 9.02 Mon Apr 20 13:10:32 EDT 2020 A P 0.71 2.18 0.69 1.00 0.71 2.18 Page 1