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HomeMy WebLinkAboutWPO201400096 Review Comments 2015-06-23 WENGINEERS SURVEYORS PLANNERS ASSOCIATES June 23,2015 Michelle Roberge, P.E. County of Albemarle Department of Community Development 401 McIntire Road, Room 227 Charlottesville, VA 22902-4596 Re: Stonefield Block D2 VSMP—WPO 2014-000096 WWA Project No. 214075.02 Dear Ms. Roberge: Enclosed please find two (2) copies of the revised Stonefield Block D2 Final Site Plan for the above-referenced project. We offer the following responses to your comments dated June 22, 2015: A. VSMP(WPO2014000096) 9) Comment: Please follow VDOT road standards with a crown. This will change the location of inlets. Please note road plans will require approval prior to subdivision of lots. [Revision 1] Comment partially addressed. Per our meeting, VDOT roll top curb and ribbon curb are approvable. Provide plan view, front view and cross section of curb transitions: roll top to CG-2, ribbon curb to CG-2. [Revision 2] Applicant should detail the transition from the 3' roll top curb with the 2' gutter in front of the inlet. Applicant and I discussed adding a note to clarify the transition. Response: A note has been added. 27) Comment: Revise 108.1 to a curb inlet. y [Revision 2] Provide curbing at end of driveway for better capture to sump inlet. Response: Curbing has been provided. 36) Comment: Verify adequate radius is provided for emergency access. Also, what is the maximum difference between the pavement cross slope and the approach road grade? [Revision 2] Change grade slightly for road to be flush with grass paving system. The grading shows 6" curb. 3040 Avemore Square Place • Charlottesville,VA 22911 Telephone(434) 984-2700 •Fax(434) 978-1444 Charlottesville •Lynchburg Nose Response: The grades have been adjusted. We trust that the above responses and revised plans properly address the outstanding items. If you have any questions, please contact me. Sincerely, WW Associates, Inc. ,/ Robert C. Umberger Project Manager 3040 Avemore Square Place • Charlottesville,VA 22911 Telephone(434) 984-2700 • Fax(434)978-1444 ................................................................................................................................................ Charlottesville •Lynchburg Page 2 of 2 i , ...we W A iim ENGINEERS SURVEYORS PLANNERS ASSOCIATES June 10,2015 Michelle Roberge, P.E. County of Albemarle Department of Community Development 401 McIntire Road, Room 227 Charlottesville, VA 22902-4596 Re: Stonefield Block D2 VSMP—WPO 2014-000096 WWA Project No. 214075.02 Dear Ms. Roberge: Enclosed please find two (2) copies of the revised Stonefield Block D2 Final Site Plan for the above-referenced project. We offer the following responses to your comments dated May 29, 2015: A. VSMP (WPO2014000096) 1) Comment: On page 24 the safety fence and silt fence have switched. It appears to be an error on linetypes. See near primary construction entrance. °-' [Revision 1]Comment addressed. 2) Comment: Scale is wrong for sheet 24. [Revision 1]Comment addressed. 3) Comment: Please clarify phasing either by stating in sequence of construction or on plan. It is not clear when SB-1 will be removed. Place a note that states lots 46-57 can be built after the basin is removed. 1.= [Revision 11Comment addressed. 4) Comment: The diversion dikes are also located where townhomes will be constructed. This will not work if lots will be graded to subgrade elevations. Show a sediment trap near the primary construction entrance. Provide a note stating lots 62- 65 can be built after ST has been removed. [Revision 1]Comment addressed. 5) Comment: I recommend making the secondary entrance the only construction entrance to make the previous comment work. --- [Revision 1]Comment addressed. 3040 Avemore Square Place •Charlottesville,VA 22911 Telephone(434)984-2700 •Fax(434) 978-1444 Charlottesville •Lynchburg 6) Comment: The RWD should be perpendicular to the road and not as an angle as shown. .' [Revision 11Comment addressed. 7) Comment: Revise the PPP with the most updated and approved E&S. You can submit when plans are ready to be approved. ]Revision 1]Comment addressed. This will need to be added to SWPP onsite. v 8) Comment: The placement of geogrid for the retaining wall will encroach on the neighboring property.Please address easements. [Revision 1]Comment not addressed. Show encroachment lines on grading plan. V Response: The extent of geogrid that is available is shown on Drawing Numbers C-10 and C-11 as well as notes not allowing encroachment. Comment: Please follow VDOT road standards with a crown. This will change the location of inlets. Please note road plans will require approval prior to subdivision of lots. [Revision 1]Comment partially addressed. Per our meeting, VDOT roll top curb and ribbon curb are approvable. Provide plan view, front view and cross section of curb transitions: roll top to CG-2, ribbon curb to CG-2. Se. ket p(ttn CcrntflUd �, icC S )if( feVW ?t`�1l 1'1� !- Response: Plan, front an�cross sections of transition have been added to Plan. 111 G 1 10) Comment: Runoff from townhomes should be captured, as much as possible, with I'/f inlets within the roadway rather than with roof drains. Please revise in conjunction YCi;i11 with comment 9. [Revision 11Comment partially addressed. Show roof drains are sized for 10 year storm. See in front of lots 81-89. iy Response: The maximum drainage area to the roof drain leaders is 0.06 acres. Therefore, the maximum 10 year flow is 0.31 cfs. The full flow capacity of a 12" HDPE pipe at 0.5% is 3.28 cfs. The minimum slope on the roof drains is 3%. Therefore, the roof drains are adequate as designed. 11) Comment: The retaining walls should be designed to meet 30.7.5 if the walls were not approved on the ZMA plans. a) Retaining walls over 6' should be broken into stepped walls. The separation between walls is 3'and shall be landscaped with screening shrubs planted on ten (10)foot centers. b) Address 30.7.5 9(b)(3)(ii). As noted in comment 8, it appears the abutting parcels will be impacted when constructing the retaining wall. Please note there 3040 Avemore Square Place •Charlottesville,VA 22911 Telephone(434) 984-2700 •Fax(434) 978-1444 Charlottesville•Lynchburg Page 2 of 6 appears to be a staircase to lot 2L. Also, there are accessory structures near the boundary line of lot 6R or 6L. c) Address 30.7.5 9(c)(2), Width and location of benches. The reverse slope shall be approximately 17% or flatter. The bench gradient to the outlet shall be between two(2) percent)and three(3)percent. [Revision 1] Comment addressed. The retaining walls are shown on an approved ZMA. 12) Comment: Show drainage easements for pipes connecting yard inlets to stormsewer system. {Revision 1] Comment partially addressed. Show drainage easements for lots V 81-89. Response: The drainage lines collecting the roof runoff have been moved off of the property and onto common area. 13) Comment: For the lots near the retaining wall, the 10'-15' backyards show swales that divert runoff to yard inlets. These swales need to function as swales long after construction. Issues arise when homeowners decide to fence off property or build patios. With these assumptions, please incorporate a stormsewer design that anticipates the assumption noted. Typically, inlets are shown for every 3 lots. Also, show drainage easements through the yards. U [Revision 1] Comment addressed. 14) Comment: It will also be difficult to ensure positive drainage be to inlets in the backyards near the retaining wall. Please field verify topo in this area and change /grading if necessary.I recommend placing spot elevations. •--' [Revision 1] Comment not addressed. Place spot elevations behind lots 3-4, behind lots 26- 30,behind 38-40. Response: Spot shots have been added. Comment: Lots 22-29 have runoff from the adjacent property. Yard inlets are shown to capture runoff, but inlets are prone to clogging. It appears overland relief is attempted between lots 26-27, which is a benefit. Please show more of a depression to YD-20 by creating a berm between lots 26 and 27. You may need to increase inlet size to ensure maximum capture and avoid a micropool in a backyard. Show ponding depth. Show another inlet at the bottom of hill to connect YD-20 to inlet at road. [Revision 1] Comment partially addressed. The spread for inlet 19 is 10'. Revise grading for inlets 21 and 19. Show inlets are in a swale to inlet 20, then provide relief to drain between lots 26-27. Response: The grading has been revised around inlet 19 to reduce the spread. 3040 Avemore Square Place •Charlottesville,VA 22911 Telephone(434) 984-2700 •Fax(434) 978-1444 Charlottesville •Lynchburg Page 3 of 6 6) Comment: YD-21 has a 520 contour that creates a depression for the inlet;however, it does not appear that YD-21 will capture much. It will most likely be picked up by YD-20. Please change contour 520 to show positive drainage to YD-20. Show only one depression towards YD-20. I recommend moving these inlets closer to YD-20 depression. [Revision 1] Comment partially addressed. The spread for inlet 19 is 10'. Revise grading for inlets 21 and 19. Show inlets are in a swale to inlet 20, then provide relief to drain between lots 26-27. Response: The grading has been revised around inlet 19 to reduce the spread. 17) Comment: It appears there is a general permit coverage letter for 26.3 acres. This covers blocks F,G&D. Please note,the SWPP package was submitted under blocks G and will be stored with application WPO201400102. [Revision 1] Comment acknowledged. 18) Comment: Please note the SWPP on site should have all the approved PPPs for Blocks F, G&D. [Revision 1] Comment acknowledged. 19) Comment: Pitch sidewalk slope away from wall in front of lots 83 and 84. Response: The sidewalk slopes away from the wall. ) Comment: Fix 512 contour near lot 21. Response: The contour has been smoothed out. —21) Comment: Place detail of DI's. Response: VDOT details of DI's have been added to Drawing Number C-33. 22) Comment: Move manholes away from roll top curb. See near lot 74 and 63. Iktrc rl VD" 4-v19 egA.R4 Response: The manholes have been placed so that the lid can be rotated out of the curb. jk,d- sy(A y A note has been added instructing the contractor to do so. \7224 Comment: Provide enough transition between roll top curb and CG-2. See near lot 62. Response: The DI-3 has been replaced with a DI-1. 3040 Avemore Square Place •Charlottesville,VA 22911 Telephone(434) 984-2700 •Fax(434) 978-1444 Charlottesville •Lynchburg Page 4 of 6 Noe %woe v2() Comment: Pitch sidewalk grade away from wall near lot 83-85. Response: The grade is sloped away from the wall. ,/25) Comment: For yard drain details on sheet 32, specify material type. Also, provide 24" and 30"grate detail. Response: The yard drains are PVC with ductile iron graves. Additional details have been added. 26) Comment: Label YD-15 on sheet 11. 'Response: YD-15 is labeled. lipComment: Revise 108.1 to a curb inlet. Response: 108.1 will remain a DI-1 with the location adjusted as discussed. i28) Comment: Verify capacity is ok with existing pipes. For example after ex 108, ex 2,after str 243,ex 23 etc. Response: The existing downstream pipes have been checked and the capacity is 'sufficient. -"29) Comment: Show a manhole for proposed ex 25.2 on plan to match profile. Response: Ex. 25.2 is showing a manhole on plan. Comment: Verify connection of pipe from yd-13 to existing manhole is possible. There is an existing pipe from the west. Response: The new pipe is significantly higher than the existing pipe. 31) Comment: Include YD 26 in table for inlet design. '.--- Response: YD 26 is shown on inlet design table on Drawing Number C-19. ,x 32) Comment: Provide a profile for 23.4-23.1. 23 3 _ � I Response: The profile has been added on Drawing Number C-15. 0 Comment: Capacity of pipe from 25.2 is exceeded. 2IS., _ Response: The slope has been adjusted so that pipe from 245.2 is within capacity. P v '( \0040 Avemore Square Place •Charlottesville,VA 22911 C^' !b' •• D` .v e(�jL Telephone(434) 984-2700 •Fax(434) 978-1444 AD S 4I9. Charlottesville •Lynchburg (Q°' IA Page5of6 e. C eokil • 34) Comment: Show str 23.2-ex23 capacity calcs on VSMP plan. It appears to be shown on site plan only. y,/Response: The calls are on both plans. 35) Comment: Please note a road plan and road bond is required prior to the approval of the final plat. Response: Noted. 36) Comment: Verify adequate radius is provided for emergency access. Also,what _` is the maximum difference between the pavement cross slope and the approach road grade? 'Response: The radius for emergency access is a minimum of 25' as requested. The cross slope of Inglewood is 2%producing a maximum slope difference of 7%. We trust that the above responses and revised plans properly address the outstanding items. If you have any questions, please contact me. Sincerely, WW Associates, Inc. Robert C. Umberger Project Manager 3040 Avemore Square Place • Charlottesville,VA 22911 Telephone(434) 984-2700 •Fax(434) 978-1444 Charlottesville •Lynchburg Page 6 of 6 ...., (W A ,z, /i(k'_ 1 - ENGINEERS idSURVEYORS it 9-t'- i. �:',r t) . `,�' PLANNERS ASSOCIATES April 17,2015 Michelle Roberge, P.E. County of Albemarle Department of Community Development 401 McIntire Road, Room 227 Charlottesville, VA 22902-4596 Re: Stonefield Block D2—VSMP Application WWA Project No. 214075.02 Dear Ms. Roberge: Enclosed please find two (2) copies of the revised Final Site Plan for the above- referenced project. We offer the following responses to your comments dated December 5, 2014 with regard to the Minor Amendment application: A. WPO (WPO2014000096) 1) Comment: On page 24 the safety fence and silt fence have switched. It appears to be an error on linetypes. See near primary construction entrance. . tesponse: The symbols have been adjusted. 2) Comment: Scale is wrong for sheet 24. t Response: The scale has been changed. ,3) Comment: Please clarify phasing either by stating in sequence of construction or on plan. It is not clear when SB-1 will be removed. Place a note that states lots 46- 57 can be built after the basin is removed. / Response: The Phase 1 infrastructure will be built prior to removal of SB-1. SB-1 will be removed when the site is substantially stabilized and when approved by the Albemarle County E&SC Inspector. 4) Comment: The diversion dikes are also located where townhomes will be constructed. This will not work if lots will be graded to subgrade elevations. Show a sediment trap near the primary construction entrance. Provide a note stating lots 62-65 can be built after ST has been removed. 3040 Avemore Square Place •Charlottesville,VA 22911 Telephone(434) 984-2700 •Fax(434) 978-1444 Charlottesville•Lynchburg Response: The diversion dikes have been adjusted. A Comment: I recommend making the secondary entrance the only construction entrance to make the previous comment work. Response: We request that both entrances be made available. There is a water connection at the primary location. A water truck will be utilized at the secondary location. Comment: The RWD should be perpendicular to the road and not as an angle as shown. Atesponse: The RWD has been adjusted. 7) Comment: Revise the PPP with the most updated and approved E&S. You can submit when plans are ready to be approved. Response: The PPP has been updated and included with this submission. 8) Comment: The placement of geogrid for the retaining wall will encroach on the neighboring property.Please address easements. Response: The wall will be installed without encroachment. ( v 9) Comment: Please follow VDOT road standards with a crown. This will change the location of inlets. Please note road plans will require approval prior to subdivision of lots. Response: VDOT road standard details have been used. The road will not be crowned to facilitate proper drainage. 110) Comment: Runoff from townhomes should be captured, as much as possible, with inlets within the roadway rather than with roof drains. Please revise in conjunction with comment 9. Response: The townhome roofs are captured with inlets except for 3 blocks that have half of the roofs going into roof drain collector pipes. -11) Comment: The retaining walls should be designed to meet 30.7.5 if the walls were not approved on the ZMA plans. a) Retaining walls over 6' should be broken into stepped walls. The separation between walls is 3'and shall be landscaped with screening shrubs planted on ten(10)foot centers. 3040 Avemore Square Place •Charlottesville,VA 22911 Telephone(434) 984-2700 •Fax(434) 978-1444 Charlottesville •Lynchburg Page 2 t}•{'✓/ f 4 ����:G wry. "^,� 3-` P Vii. K, !�,• . w r !r, :� L.i < • .// - �,•����`„ /. - (L?Gr - 4 Response: The walls are shown on the ZIVTA plans. b) Address 30.7.5 9(b)(3)(ii). As noted in comment 8, it appears the abutting parcels will be impacted when constructing the retaining wall. Please note there appears to be a staircase to lot 2L. Also, there are accessory structures near the boundary line of lot 6R or 6L. Response: The walls will be built within the property limits including all necessary shoring. c) Address 30.7.5 9(c)(2), Width and location of benches. The reverse slope shall be approximately 17% or flatter. The bench gradient to the outlet shall be between two(2) percent)and three(3)percent. Response: There are no benches in the walls. Of.( 12) Comment: Show drainage easements for pipes connecting yard inlets to r,pi"_✓ stormsewer system. Response: Easements are shown. 13) Comment: For the lots near the retaining wall, the 10'-15' backyards show swales that divert runoff to yard inlets. These swales need to function as swales long after construction. Issues arise when homeowners decide to fence off property or build patios. With these assumptions, please incorporate a stormsewer design that anticipates the assumption noted. Typically, inlets are shown for every 3 lots. Also, show drainage easements through the yards. Response: Additional inlets have been shown. 14) Comment: It will also be difficult to ensure positive drainage be to inlets in the backyards near the retaining wall. Please field verify topo in this area and change grading if necessary. I recommend placing spot elevations. Response: Grading has been adjusted. 15) Comment: Lots 22-29 have runoff from the adjacent property. Yard inlets are shown to capture runoff,but inlets are prone to clogging. It appears overland relief is attempted between lots 26-27, which is a benefit. Please show more of a depression to YD-20 by creating a berm between lots 26 and 27. You may need to increase inlet size to ensure maximum capture and avoid a micropool in a backyard. Show ponding depth. Show another inlet at the bottom of hill to connect YD-20 to inlet at road. 3040 Avemore Square Place •Charlottesville,VA 22911 Telephone(434)984-2700 •Fax(434)978-1444 Charlottesville•Lynchburg Page 3 of 4 Response: Additional yard drains have been added as needed. 16) Comment: YD-21 has a 520 contour that creates a depression for the inlet; however, it does not appear that YD-21 will capture much. It will most likely be picked up by YD-20. Please change contour 520 to show positive drainage to YD- 20. Show only one depression towards YD-20. I recommend moving these inlets closer to YD-20 depression. Response: There is a depression at YD-20. ,-4-7) Comment: It appears there is a general permit coverage letter for 26.3 acres. This covers blocks F, G & D. Please note, the SWPP package was submitted under blocks G and will be stored with application vitesponse: Noted. 18) Comment: Please note the SWPP on site should have all the approved PPPs for Blocks F, G&D. Response: Noted. We trust that the above responses and revised plans properly address the outstanding items. If you have any questions,please contact me. Sincerely, WW Associates, Inc. Robert C. Umberger Project Manager 3040 Avemore Square Place • Charlottesville,VA 22911 Telephone(434) 984-2700 •Fax(434) 978-1444 Charlottesville •Lynchburg Page 4 of 4 w ,....., r iim ENGINEERS SURVEYORS PLANNERS ASSOCIATES May 5,2015 Michelle Roberge, P.E. County of Albemarle Department of Community Development 401 McIntire Road, Room 227 Charlottesville, VA 22902-4596 Re: Stonefield Block D2—VSMP Plan WWA Project No. 214075.02 Dear Ms. Roberge: Enclosed please find four (4) copies of the revised Stonefield Block D2 VSMP Plan for the above-referenced project. We offer the following responses to your comments dated May 4, 2015 with regard to the Minor Amendment application: A. Stormwater Pollution Prevent Plan (SWPPP) The SWPPP content requirements can be found in County Code section 17-405. A SWPPP must contain(1) a PPP, (2) an ESCP, (3) a SWMP, and (4) any TMDL measures necessary. 1) Comment: The DEQ permit for this area is VAR100061. Please include all approved E&S and PPP plans with SWPP on site. Response: The approved E&S and PPP plans will be added to the SWPP on site upon approval. B. Pollution Prevent Plan (PPP) The PPP content requirements can be found in County Code section 17-404. 1) Comment: Provide an 11"x 17" PPP for this area. Response: A copy of the PPP plan is attached. 3040 Avemore Square Place •Charlottesville,VA 22911 Telephone(434) 984-2700 •Fax(434) 978-1444 Charlottesville•Lynchburg C. Stormwater Management Plan (SWMP) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This plan is disapproved. The stormwater management plan content requirements can be found in County Code section 17-403. 1) Comment: This is an interim plan only and a stockpile onsite is being proposed. There is a pending review for the full buildout plan. Please note the full-buildout proposal will amend this plan and should be titled "VSMP amendment." The WPO application will be relabeled as WPO 2014-96. Response: The label has been added to the cover sheet. D. Erosion and Sediment Control Plan (ESCP) Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESCP. This plan is disapproved. ✓1) Comment: Provide anti-seep collar or alternative to anti-seep collar. Response: An anti-seep collar has been added. t!2) Comment: Add a note for connection of barrel to riser. "Connections between barrel and riser shall be watertight." Response: A note has been added to drawing number C-2. 3) Comment: Add a note if anti-seep collars are used. "Connections between anti- seep and barrel shall be watertight." Response: A note has been added to drawing number C-2. We trust that the above responses and revised plans properly address the outstanding items. If you have any questions,please contact me. Sincerely, WW Associates, Inc. / 1 i r!/f d dff,,jn� ! L ✓ Robert C. Umberger Project Manager 3040 Avemore Square Place • Charlottesville,VA 22911 Telephone (434) 984-2700 •Fax(434) 978-1444 Charlottesville•Lynchburg Page 2 of 2