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HomeMy WebLinkAboutWPO201200039 Review Comments Erosion Control Plan 2012-08-06Philip Custer From: Philip Custer Sent: Monday, August 06, 2012 6:18 PM To: 'Tom Gallagher'; jbeirne @wwassociates.net; 'rumberger @wwassociates.net' Cc: Esther Grace; Ana Kilmer; Mark Hopkins; Christopher Perez Subject: Engineering Approval of District Avenue Extended Good afternoon, I have reviewed the latest submittal of the District Avenue Extended ESC and Road plans (WPO- 2012 -00039 and SUB - 2012- 00043), received 27 July 2012. All previous comments have been addressed and the ESC and Road plans are hereby approved on the condition that all other agencies approve the plan. Please submit one additional copy of the plan to me so that the files can be passed off to the county inspectors. The applicant should not submit this extra set until approval from all other agencies is in hand. The applicant has provided a signed bond estimate request form. The form requested a road bond, but no fee of $250 was submitted. A road bond will not be computed until this fee is provided. The ESC bond has been computed to be $55,900. To post the ESC bond, please contact Ana Kilmer (x3246) or Esther Grace (x3823) after all agencies have approved the plan. Please forward consent from the offsite owner to Ana or Esther at the time of the posting of the ESC bond. Please let me know if you have any questions. Thanks, Phil 296 -5832 x3072 BOND ESTIMATE - EROSION CONTROL Spreadsheet last revised:12 -5 -01 PROJECT NAME: District Avenue Road Plan Extension PROJECT NUMBER: WPO- 2012 -00039 DATE OF ESTIMATE: 08/06/12 ESTIMATE BY: PBC BASED ON: Plan signed 7 -26 -2012 WATER ITEM DESCRIPTION UNIT QUANTITY UNIT COST ITEM TOTAL SEED, FERTILIZE, MULCH ACRE 4.99 1500 7485 SILT FENCE LF 1500 5 7500 SAFETY FENCE LF 0 3 0 TEMPORARY FILL DIVERSION LF 0 3 0 DIVERSION DIKE LF 0 3 0 TEMPORARY SLOPE DRAIN LF 0 20 0 SEDIMENT TRAP 1 ACRES 0 1000 0 SEDIMENT BASIN 1 ACRES 0 1000 0 CULVERT INLET PROTECTION EA 0 500 0 INLET PROTECTION EA 7 200 1400 OUTLET PROTECTION EA 4 200 800 EC -2 & 3 DITCH PROTECTION LF 2500 10 25000 RIP -RAP LF 0 55 0 CHECK DAMS SQ.YD. 0 30 0 PAVED CONSTRUCTION ENTRANCE EA 1 2000 2000 subtotal 44185.00 project management 6627.75 subtotal 50812.75 CONTINGENCY LS 10% 5081.28 TOTAL 55894.03 BOND AMOUNT REQUIRED 55900.00 s in" ENGINEERS SURVEYORS PLANNERS ASSOCIATES July 26,2012 Phil Custer County of Albemarle Department of Community Development 401 McIntire Road Charlottesville, Virginia 22902 Re: District Avenue Road Extension Plan (Albemarle Place EAAP LLC) SUB-2012-00043 and WPO-2012-00039 WWA Project No. 208026.60 Dear Mr. Custer: This letter is to document and respond to your review comments dated July 10, 2012. Our responses are as follows: A. Road Plan Review Comments (SUB-2012-00043) 1. Comment: Revised Proffer 1.B (3/23/2012) refers to this temporary street stating that the design standards for it must be approved by the Director of Community Development. The use of the rural cross-section for the majority of this street is acceptable. The superelevation of the street is permissible but not recommended by county staff because the slope of the southbound lane would direct drifting vehicles into the northbound lane rather than onto the shoulder as a normal crowned road would. The pedestrian path along the road must be upgraded to at least prime and double seal. Shade trees must also be provided on the south side of the walking path at an interval of no greater than 50ft. Please provide an unstopped through movement for District Avenue and one stop sign on Blackbird or provide traffic data showing that a three way stop is warranted. (Rev. 1) Comment has been addressed. 2. Comment: There is a safety issue at the Route 29 intersection due to the proximity of the retaining wall to the turning movement onto District Avenue from 29 Northbound. Please address this concern. If the beginning of the retaining wall can be shifted west, there will still be a safety concern associated with the start of the wall since it is inside the clearzone. To start, obtaining an offsite easement appears critical. (Rev. 1) The adjustment made by the applicant is acceptable. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville 3. Comment: Please provide traffic data supporting that the stacking distances at the intersection with Route 29 will be acceptable for this phase of construction. (Rev. 1) The stacking distances are currently acceptable, but after further review of the intersection, a change to the eastbound approach is required. The single eastbound lane must become the southern-most left turn lane, not the northern. The lane shift of 12ft must occur over 125ft. Please send a sketch of this change to myself and Joel when the adjustments have been made. Response: The lane configuration has been revised as requested. Please refer to Dwg. C-9 for details. 4. Comment: Please provide a gradual transition from the rural section to the urban section by tapering the edge of the shoulder. Please also gradually increase the height of the curb from 0" to 6" over at least 20ft. (Rev. 1) The 5ft curb transition is acceptable but the note on sheet C-9 isn't clear. Response: The note on Dwg. C-9 has been revised in order to clarify the intent of the transition. 5. Comment: Please provide a speed limit sign for the northbound traffic at approximately Sta. 28+00. The speed limit sign for southbound traffic appears too close to the intersection. (Rev. 1) Comment has been addressed. 6. Comment: Please clearly show in the grading plan and profile an adequate sump at Structures 139 and 140. (Rev. 1) Comment has been addressed. 7. Comment: Please show the existing and proposed grade lines for the centerline of each roadside ditch. (Rev. 1) The applicant has provided road cross sections along the wall, which is acceptable. 8. Comment: In addition to the existing road grade shown,please provide the existing grade before mass grading so the areas of actual fill can be more clearly determined. This new existing grade line will influence where the correct locations for the CD-1's are. (Rev. 1) Comment has been addressed. 9. Comment: Please provide Inlet Shaping(IS-1) on all structures. (Rev. 1) Comment has been addressed. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville Page 2 of 5 Now- 10. Comment: Please show in the plan all easements necessary for the road, sidewalks, and drainage channels and pipes. (Rev. 1) Access and sidewalk easements were not shown within the plan. These easements must be located at least Ift outside of the channel and sidewalk. Response: An access and sidewalk maintenance easement has been added to the plans as requested. Please refer to Dwg. C-14 for details. 11. Comment: This comment is only advisory. The final plan for the first several hundred feet of Fourth Street from Route 29 will be expected to provide shade trees between the back of curb and retaining wall as shown in the approved preliminary plan. It is recommended that the design of this plan account for the expectations of the final construction plan. 12. Comment: VDOT approval must be provided. County Engineering supports VDOT's comment requiring a continuation of the Route 29 cross slope into District Avenue Extended and providing a low point west of the Route 29 gutterline. (Rev. 1) VDOT approval has not yet been received. Response: Noted. B. Erosion and Sediment Control Plan Review Comments (WPO-2012-00039) 1. Comment: This plan relies on the downstream sediment basin for the majority of its effectiveness. However, the extension to the 9-month stabilization deadline granted by the County Engineer expires on July 26th. If this plan continues to rely on the sediment basin, it will be invalidated if construction is not completed by July 26th and the Board of Supervisors does not grant an extension to the plan. In order for the Board to consider granting an extension of the stabilization requirement, the request must be received by the Clerk of the Board of Supervisors by May 26th. My recommendation is to make this request to the Board AND design this plan so that it can be considered independent of the mass grading plan/sediment basin. This can be done by providing a sediment trap below structure 135 and replacing the silt fence west of this outlet with a diversion to Sta. 33+75. (Rev. 1) The applicant has indicated in this plan that it relies on the sediment basin approved with the mass grading plan. Reliance on this sediment basin for most of the sediment control is acceptable until the previous plan expires, in which case the plan currently under review becomes void. 2. Comment: Between steps 2 and 3 in the construction sequence,please add a step to construct all perimeter measures. (Rev. 1) Comment has been addressed. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville Page 3 of 5 *awl 'Nano 3. Comment: It is critical to this plan to get the clean water to bypass the construction area so that the silt fence is not blown out. Please state in the construction sequence (see above comment) that structures 141, 142, 143, 144, and 145 as well as SCC-1 and SCC-3 must be completed and stabilized before road construction can begin. (Rev. 1) Comment has been addressed 4. Comment: The construction entrance must drain to a sediment trapping measure. (Rev. 1) The applicant has indicated in this plan that it relies on the sediment basin approved with the mass grading plan. Reliance on this sediment basin for most of the sediment control is acceptable until the previous plan expires, in which case the plan currently under review becomes void. 5. Comment: Please provide riprap or sod stabilization on all channels upstream of the stormwater pond and downstream of the ESC measures in this plan. (Rev. 1) The applicant has indicated in this plan that it relies on the sediment basin approved with the mass grading plan. Reliance on this sediment basin for most of the sediment control is acceptable until the previous plan expires, in which case the plan currently under review becomes void. 6. Comment: Please provide a RWD across the entrance at 29 to direct runoff towards the sediment basin/trap downstream of structure 135. (The VDOT comment regarding the vertical profile at this entrance seems to make this change unnecessary, however.) (Rev. 1) Comment has been addressed. 7. Comment: Please provide a completed Bond Estimate Request Form to the county engineer to receive an ESC bond A grading permit cannot be issued until a bond is posted (Rev. 1)A Bond Estimate Request From has not yet been received The owner of TMP 61 W-3-18 will need to sign this form and be party to the ESC bond unless all necessary easements have been recorded. Response: Noted. A Bond Estimate Request Form with the appropriate signatures will be provided under separate cover. 8. Comment: (Rev. 1) The ESC plan must be modified to show the increase to the land disturbance resulting from the addition of the waterline work. Response: The area of land disturbance has been modified accordingly. Please refer to Dwg. C-10. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville Page 4 of 5 C. Stormwater Management Plan Review Comments (WPO-2012-00039) 1. Comment: The update to stormwater calculations for the intermittent pond BMP is acceptable. No modification to the existing SWM plan (WPO-2010- 00023) is warranted with this application. At the time of this plan's approval, two additional copies of Sheet C-18 will be necessary for me to include in the file. I trust that the above responses and plan changes properly address the outstanding issues. If you have any questions, please contact me. Sincerely, WW Associates, Inc. /4, - -- John Beirne, Jr. Senior Project Enginee cc: Thomas R. Gallagher, Edens, Inc. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville Page 5 of 5 ,....., ......, inWENGINEERS SURVEYORS PLANNERS ASSOCIATES June 13,2012 Phil Custer County of Albemarle Department of Community Development 401 McIntire Road Charlottesville,Virginia 22902 Re: District Avenue Road Extension Plan SUB201200043 WWA Project No. 208026.60 Dear Mr. Custer: This letter is to document and respond to your review comments dated May 9, 2011. Our responses are as follows: A. Road Plan Review Comments (SUB-2012-00043) 1. Comment: Revised Proffer 1.B (3/23/2012) refers to this temporary street stating that the design standards for it must be approved by the Director of Community Development. The use of the rural cross-section for the majority of this street is acceptable. The superelevation of the street is permissible but not recommended by county staff because the slope of the southbound lane would direct drifting vehicles into the northbound lane rather than onto the shoulder as a normal crowned road would. The pedestrian path along the road must be upgraded to at least prime and double seal. Shade trees must also be provided on the south side of the walking path at an interval of no greater than 50ft. Please provide an unstopped through movement for District Avenue and one stop sign on Blackbird or provide traffic data showing that a three way stop is warranted. Response: The detail for the pedestrian path has been revised to show prime and double seal, shade trees are now provided on the south side of the walking path, and the pavement markings have been revised to allow for a through movement on District Avenue at its intersection with Blackbird Lane as requested. 2. Comment: There is a safety issue at the Route 29 intersection due to the proximity of the retaining wall to the turning movement onto District Avenue from 29 Northbound. Please address this concern. If the beginning of the 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville retaining wall can be shifted west, there will still be a safety concern associated with the start of the wall since it is inside the clearzone. To start, obtaining an offsite easement appears critical. Response: The terminus of the retaining wall has been modified by providing a radius return. Please refer to Dwg. C-9 for details. Please note the grading between the retaining wall and the adjacent property has been revised in an effort to lower the height of the wall. The grading shown will require permission from the adjacent property owner to grade offsite. The developers are currently in negotiations to obtain the necessary documentation and have received a verbal agreement allowing the grading to be performed. Confirmation of this permission will be provided when it is received. 3. Comment: Please provide traffic data supporting that the stacking distances at the intersection with Route 29 will be acceptable for this phase of construction. Response: Traffic information from Bowman for the stacking distances has been provided with this submittal as requested. 4. Comment: Please provide a gradual transition from the rural section to the urban section by tapering the edge of the shoulder. Please also gradually increase the height of the curb from 0" to 6" over at least 20ft. Response: The change from the rural section to the urban section has been modified to provide a more gradual transition. The height of the curb will be transitioned over a distance a 5' as discussed. Notes are provided on the plans to the affect. Please refer to Dwg. C-9 for details. 5. Comment: Please provide a speed limit sign for the northbound traffic at approximately Sta. 28+00. The speed limit sign for southbound traffic appears too close to the intersection. Response: The speed limit sign for the southbound traffic has been relocated to approximately Sta. 38+30 to provide more distance from the intersection. A speed limit sign has been provided at approximately Sta. 28+00 for the northbound traffic as requested. Please refer to Dwg. C-13 for details. 6. Comment: Please clearly show in the grading plan and profile an adequate sump at Structures 139 and 140. Response: The grading plan and tops for the structures in question have been modified to allow for a more pronounced sump. Please refer to Dwgs. C-9 and C-17 for details. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville Page 2 of 6 7. Comment: Please show the existing and proposed grade lines for the centerline of each roadside ditch. Response: As discussed the existing grade lines have been added to the road sections in lieu of adding the grade lines for the ditches to the road profiles. Please refer to Dwg. C-14 for details. 8. Comment: In addition to the existing road grade shown,please provide the existing grade before mass grading so the areas of actual fill can be more clearly determined. This new existing grade line will influence where the correct locations for the CD-1 's are. Response: The profile of the existing grade prior to rough grade operations has been added to the road profile and the locations of the CD- ls have been adjusted accordingly. Please refer to Dwgs. C-8 and C-9 for details. 9. Comment: Please provide Inlet Shaping (IS-1) on all structures. Response: As discussed inlet shaping has been added to Str. 136 and Str. 136.1. Please refer to Dwg. C-17 for details. 10. Comment: Please show in the plan all easements necessary for the road, sidewalks, and drainage channels and pipes. Response: Drainage easements for the conveyance of the offsite water from the Comdial property are shown on Dwgs. C-8 & C-9. Access easements for the new roadway provided are shown as part of the typical sections on Dwg. C-14. 11. Comment: This comment is only advisory. The final plan for the first several hundred feet of Fourth Street from Route 29 will be expected to provide shade trees between the back of curb and retaining wall as shown in the approved preliminary plan. It is recommended that the design of this plan account for the expectations of the final construction plan. Response: Adequate planting area has been provided between to the back of curb and the retaining wall to accommodate future plantings. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville Page 3 of 6 12. Comment: VDOT approval must be provided. County Engineering supports VDOT's comment requiring a continuation of the Route 29 cross slope into District Avenue Extended and providing a low point west of the Route 29 gutterline. Response: Noted. Please note the approved profile from the VIKA road plans has been revised due to conflicts with the existing grades on Rt. 29. The profile for the extension of District Avenue has been revised to reflect the changes to the VIKA profile. B. Erosion and Sediment Control Plan Review Comments (WPO-2012-00039) 1. Comment: This plan relies on the downstream sediment basin for the majority of its effectiveness. However, the extension to the 9-month stabilization deadline granted by the County Engineer expires on July 26`h. If this plan continues to rely on the sediment basin, it will be invalidated if construction is not completed by July 26th and the Board of Supervisors does not grant an extension to the plan. In order for the Board to consider granting an extension of the stabilization requirement, the request must be received by the Clerk of the Board of Supervisors by May 26`h. My recommendation is to make this request to the Board AND design this plan so that it can be considered independent of the mass grading plan/sediment basin. This can be done by providing a sediment trap below structure 135 and replacing the silt fence west of this outlet with a diversion to Sta. 33+75. Response: A request has been submitted to the Board of Supervisors requesting an extension of the stabilization requirement. The erosion plan has not been modified and continues to rely on the downstream sediment basin with this submittal. 2. Comment: Between steps 2 and 3 in the construction sequence, please add a step to construct all perimeter measures. Response: The construction sequence has been modified accordingly. Please refer to Dwg. C-10 for details. 3. Comment: It is critical to this plan to get the clean water to bypass the construction area so that the silt fence is not blown out. Please state in the construction sequence (see above comment) that structures 141, 142, 143, 144, and 145 as well as SCC-1 and SCC-3 must be completed and stabilized before road construction can begin. Response: The construction sequence has been modified accordingly. Please refer to Dwg. C-10 for details. Please note that these areas drain to the existing north sediment basin and any sediment laden runoff will be treated in that facility. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville Page 4 of 6 4. Comment: The construction entrance must drain to a sediment trapping measure. Response: The runoff from the construction entrance will be treated in the existing north sediment basin. Additional sediment trapping measures are not necessary. 5. Comment: Please provide riprap or sod stabilization on all channels upstream of the stormwater pond and downstream of the ESC measures in this plan. Response: The runoff from the channels will be treated in the existing north sediment basin. Additional stabilization measures in the channels will not be necessary. 6. Comment: Please provide a RWD across the entrance at 29 to direct runoff towards the sediment basin/trap downstream of structure 135. (The VDOT comment regarding the vertical profile at this entrance seems to make this change unnecessary, however.) Response: A RWD has been provided across the entrance at Rt. 29 as requested. Please refer to Dwg. C-11 for details. 7. Comment: Please provide a completed Bond Estimate Request Form to the county engineer to receive an ESC bond. A grading permit cannot be issued until a bond is posted. Response: A completed Bond Estimate Request Form will be submitted under separate cover. C. Stormwater Management Plan Review Comments (WPO-2012-00039) 1. Comment: The update to stormwater calculations for the intermittent pond BMP is acceptable. No modification to the existing SWM plan (WPO-2010- 00023) is warranted with this application. At the time of this plan's approval, two additional copies of Sheet C-18 will be necessary for me to include in the file. Response: Two additional copies of Dwg. C-18 will be provided once the plan is approved. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700 •Fax(434)978-1444 Lynchburg•Charlottesville Page 5 of 6 I trust that the above responses and plan changes properly address the outstanding issues. If you have any questions,please contact me. Sincerely, WW Associates, Inc. tZ/V 1//1 �� - _ John Beime, Jr. Senior Project Engineer cc: Thomas R. Gallagher, Edens, Inc. 3040 Avemore Square Place•Charlottesville,Virginia 22911 Telephone(434)984-2700•Fax(434)978-1444 Lynchburg•Charlottesville Page 6 of 6 Philip Custer From: Philip Custer Sent: Tuesday, July 10, 2012 5:30 PM To: 'Tom Gallagher; 'rumberger@wwassociates.net; 'hwhite@wwassociates.net' Cc: Glenn Brooks; Christopher Perez Subject: Engineering Review of District Avenue ESC and Road Plan Attachments: E2_rp ecp swm_PBC_wpo-2012-00039 sub-2012-00043 District Ave Extended.doc Good evening, Attached is the engineering memo from the review of the first revision of District Avenue Extended (WPO-2012-00039 and SUB-2012-00043), received 14 June 2012. The remaining comments are minor and will not require additional road and ESC plan review fees, unless significant changes are proposed. It is my understanding that a refund of the original fee of$1070 for SUB-2012-00043 was initiated at the time that the site plan application was requested. Since two private street plan reviews were performed,a total fee of$800 is required for this application. Please provide this fee as soon as possible for the road plan,SUB-2012-00043. Please let me know if you have any questions. Thanks, Phil 296-5832 x3072 1 ALg�,�� �'IRGINZ� COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road Charlottesville, Virginia 22902 -4596 Phone (434) 296 -5832 Fax (434) 972 -4126 Project: District Avenue Extended; SUB - 2012 -00043 and WPO- 2012 -00039 Plan preparer: Mr. Herb White, PE; W & W Associates Owner or rep.: Albemarle Place EAAP LLC Date received: 5 April 2012 (Rev. 1) 14 June 2012 Date of Comment: 14 May 2012 (Rev. 1) 10 July 2012 Engineer: Phil Custer The first revision of the ESC and road plans for District Avenue Extended (WPO- 2012 -00039 and SUB - 2012- 00043), received on 14 June 2012, have been reviewed. The plans can be approved after the following comments have been addressed: A. Road Plan Review Comments (SUB- 2012 - 00043) 1. Revised Proffer LB (3/23/2012) rek.J Lv L...s temporary street stating that the design standards for it must be approved by the Director of Community Development. The use of the rural cross - section for the majority of this street is acceptable. The superelevation of the street is permissible but not recommended by county staff because the slope of the southbound lane would direct drifting vehicles into the northbound lane rather than onto the shoulder as a normal crowned road would. The pedestrian path along the road must be upgraded to at least prime and double seal. Shade trees must also be provided on the south side of the walking path at an interval of no greater than 50ft. Please provide an unstopped through movement for District Avenue and one stop sign on Blackbird or provide traffic data showing that a three way stop is warranted. (Rev. 1) Comment has been addressed. 2. There is a safety issue at the Route 29 intersection due to the proximity of the retaining wall to the turning movement onto District Avenue from 29 Northbound. Please address this concern. If the beginning of the retaining wall can be shifted west, there will still be a safety concern associated with the start of the wall since it is inside the clearzone. To start, obtaining an offsite easement appears critical. (Rev. 1) The adjustment made by the applicant is acceptable. 3. Please provide traffic data supporting that the stacking distances at the intersection with Route 29 will be acceptable for this phase of construction. (Rev. 1) The stacking distances are currently acceptable, but after further review of the intersection, a change to the eastbound approach is required. The single eastbound lane must become the southern -most left turn lane, not the northern. The lane shift of 12ft must occur over 125ft. Please send a sketch of this change to myself and Joel when the adjustments have been made. 4. Please provide a gradual transition from the rural section to the urban section by tapering the edge of the shoulder. Please also gradually increase the height of the curb from 0" to 6" over at least 20ft. (Rev. 1) The 5ft curb transition is acceptable but the note on sheet C -9 isn't clear. 5. Please provide a speed limit sign for the northbound traffic at approximately Sta. 28 +00. The speed limit sign for southbound traffic appears too close to the intersection. (Rev. 1) Comment has been addressed. 6. Please clearly show in the grading plan and profile an adequate sump at Structures 139 and 140. (Rev. 1) Comment has been addressed. 7. Please show the existing and proposed grade lines for the centerline of each roadside ditch. (Rev. 1) The applicant has provided road cross sections along the wall, which is acceptable. 8. In addition to the existing road grade shown, please provide the existing grade before mass grading so the areas of actual fill can be more clearly determined. This new existing grade line will influence where the correct locations for the CD -1's are. (Rev. 1) Comment has been addressed. 9. Please provide Inlet Shaping (IS -1) on all structures. (Rev. I) Comment has been addressed. 10. Please show in the plan all easements necessary for the road, sidewalks, and drainage channels and pipes. (Rev. 1) Access and sidewalk easements were not shown within the plan. These easements must be located at least Ift outside of the channel and sidewalk. 11. This comment is only advisory. The final plan for the first several hundred feet of Fourth Street from Route 29 will be expected to provide shade trees between the back of curb and retaining wall as shown in the approved preliminary plan. It is recommended that the design of this plan account for the expectations of the final construction plan. 12. VDOT approval must be provided. County Engineering supports VDOT's comment requiring a continuation of the Route 29 cross slope into District Avenue Extended and providing a low point west of the Route 29 gutterline. (Rev. 1) VDOT approval has not yet been received. B. Erosion and Sediment Control Plan Review Comments (WPO- 2012 - 00039) 1. This plan relies on the downstream sediment basin for the majority of its effectiveness. However, the extension to the 9 -month stabilization deadline granted by the County Engineer expires on July 26r''. If this plan continues to rely on the sediment basin, it will be invalidated if construction is not completed by July 26`" and the Board of Supervisors does not grant an extension to the plan. In order for the Board to consider granting an extension of the stabilization requirement, the request must be received by the Clerk of the Board of Supervisors by May 26`h. My recommendation is to make this request to the Board AND design this plan so that it can be considered independent of the mass grading plan /sediment basin. This can be done by providing a sediment trap below structure 135 and replacing the silt fence west of this outlet with a diversion to Sta. 33 +75. (Rev. 1) The applicant has indicated in this plan that it relies on the sediment basin approved with the mass grading plan. Reliance on this sediment basin for most of the sediment control is acceptable until the previous plan expires, in which case the plan currently under review becomes void. 2. Between steps 2 and 3 in the construction sequence, please add a step to construct all perimeter measures. (Rev. 1) Comment has been addressed. 3. It is critical to this plan to get the clean water to bypass the construction area so that the silt fence is not blown out. Please state in the construction sequence (see above comment) that structures 141, 142, 143, 144, and 145 as well as SCC -1 and SCC -3 must be completed and stabilized before road construction can begin. (Rev. 1) Comment has been addressed. 4. The construction entrance must drain to a sediment trapping measure. (Rev. 1) The applicant has indicated in this plan that it relies on the sediment basin approved with the mass grading plan. Reliance on this sediment basin for most of the sediment control is acceptable until the previous plan expires, in which case the plan currently under review becomes void. 5. Please provide riprap or sod stabilization on all channels upstream of the stormwater pond and downstream of the ESC measures in this plan. (Rev. 1) The applicant has indicated in this plan that it relies on the sediment basin approved with the mass grading plan. Reliance on this sediment basin for most of the sediment control is acceptable until the previous plan expires, in which case the plan currently under review becomes void. 6. Please provide a RWD across the entrance at 29 to direct runoff towards the sediment basin /trap downstream of structure 135. (The VDOT comment regarding the vertical profile at this entrance seems to make this change unnecessary, however.) (Rev. 1) Comment has been addressed. 7. Please provide a completed Bond Estimate Request Form to the county engineer to receive an ESC bond. A grading permit cannot be issued until a bond is posted. (Rev. 1) A Bond Estimate Request Form has not yet been received. The owner of TMP 61 W -3 -- I8 will need to sign this form and be party to the ESC bond unless all necessary easements have been recorded. 8. (Rev.]) The ESC plan must be modified to show the increase to the land disturbance resulting from the addition of the waterline work. C. Stormwater Management Plan Review Comments (WPO- 2012 - 00039) The update to stormwater calculations for the intermittent pond BMP is acceptable. No modification to the existing SWM plan (WPO -2010- 00023) is warranted with this application. At the time of this plan's approval, two additional copies of Sheet C -18 will be necessary for me to include in the file. File: E2_rp ecp swm_PBC _ wpo- 2012 -00039 sub - 2012 -00043 District Ave Extended.doc Philip Custer Noe From: Philip Custer Sent: Monday, May 14, 2012 10:45 AM To: 'Tom Gallagher; 'Tom Gallagher; 'hwhite@wwassociates.net; rumberger@wwassociates.net Cc: Christopher Perez Subject: District Avenue Extension Attachments: El_rp ecp swm_PBC_wpo-2012-00039 sub-2012-00043 District Ave Extended.doc Good morning, Attached is the engineering comment letter from the first review of the ESC and road plans for District Avenue Extended (WPO-2012-00039 and SUB-2012-00043), received 5 April 2012. Please let me know if you have any questions. Thanks, Phil (434)296-5832 x3072 1 ALg�,�� �'IRGINZ� COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road Charlottesville, Virginia 22902 -4596 Phone (434) 296 -5832 Fax (434) 972 -4126 Project: District Avenue Extended; SUB - 2012 -00043 and WPO- 2012 -00039 Plan preparer: Mr. Herb White, PE; W & W Associates Owner or rep.: Albemarle Place EAAP LLC Date received: 5 April 2012 Date of Comment: 14 May 2012 Engineer: Phil Custer The ESC and road plans for District Avenue Extended (WPO- 2012 -00039 and SUB - 2012 - 00043), received on 5 April 2012, have been reviewed. The plans can be approved after the following comments have been addressed: A. Road Plan Review Comments (SUB- 2012 - 00043) 1. Revised Proffer 1.13 (3/23/2012) refers to this temporary street stating that the design standards for it must be approved by the Director of Community Development. The use of the rural cross - section for the majority of this street is acceptable. The superelevation of the street is permissible but not recommended by county staff because the slope of the southbound lane would direct drifting vehicles into the northbound lane rather than onto the shoulder as a normal crowned road would. The pedestrian path along the road must be upgraded to at least prime and double seal. Shade trees must also be provided on the south side of the walking path at an interval of no greater than 50ft. Please provide an unstopped through movement for District Avenue and one stop sign on Blackbird or provide traffic data showing that a three way stop is warranted. 2. There is a safety issue at the Route 29 intersection due to the proximity of the retaining wall to the turning movement onto District Avenue from 29 Northbound. Please address this concern. If the beginning of the retaining wall can be shifted west, there will still be a safety concern associated with the start of the wall since it is inside the clearzone. To start, obtaining an offsite easement appears critical. 3. Please provide traffic data supporting that the stacking distances at the intersection with Route 29 will be acceptable for this phase of construction. 4. Please provide a gradual transition from the rural section to the urban section by tapering the edge of the shoulder. Please also gradually increase the height of the curb from 0" to 6" over at least 20ft. 5. Please provide a speed limit sign for the northbound traffic at approximately Sta. 28 +00. The speed limit sign for southbound traffic appears too close to the intersection. 6. Please clearly show in the grading plan and profile an adequate sump at Structures 139 and 140. 7. Please show the existing and proposed grade lines for the centerline of each roadside ditch. 8. In addition to the existing road grade shown, please provide the existing grade before mass grading so the areas of actual fill can be more clearly determined. This new existing grade line will influence where the correct locations for the CD -1's are. 9. Please provide Inlet Shaping (IS -1) on all structures. 10. Please show in the plan all easements necessary for the road, sidewalks, and drainage channels and pipes. 11. This comment is only advisory. The final plan for the first several hundred feet of Fourth Street from Route 29 will be expected to provide shade trees between the back of curb and retaining wall as shown in the approved preliminary plan. It is recommended that the design of this plan account for the expectations of the final construction plan. 12. VDOT approval must be provided. County Engineering supports VDOT's comment requiring a continuation of the Route 29 cross slope into District Avenue Extended and providing a low point west of the Route 29 gutterline. B. Erosion and Sediment Control Plan Review Comments (WPO- 2012 - 00039) 1. This plan relies on the downstream sediment basin for the majority of its effectiveness. However, the extension to the 9 -month stabilization deadline granted by the County Engineer expires on July 26th. If this plan continues to rely on the sediment basin, it will be invalidated if construction is not completed by July 26`h and the Board of Supervisors does not grant an extension to the plan. In order for the Board to consider granting an extension of the stabilization requirement, the request must be received by the Clerk of the Board of Supervisors by May 26th. My recommendation is to make this request to the Board AND design this plan so that it can be considered independent of the mass grading plan /sediment basin. This can be done by providing a sediment trap below structure 135 and replacing the silt fence west of this outlet with a diversion to Sta. 33 +75. 2. Between steps 2 and 3 in the construction sequence, please add a step to construct all perimeter measures. 3. It is critical to this plan to get the clean water to bypass the construction area so that the silt fence is not blown out. Please state in the construction sequence (see above comment) that structures 141, 142, 143, 144, and 145 as well as SCC -1 and SCC -3 must be completed and stabilized before road construction can begin. 4. The construction entrance must drain to a sediment trapping measure. 5. Please provide riprap or sod stabilization on all channels upstream of the stormwater pond and downstream of the ESC measures in this plan. 6. Please provide a RWD across the entrance at 29 to direct runoff towards the sediment basin /trap downstream of structure 135. (The VDOT comment regarding the vertical profile at this entrance seems to make this change unnecessary, however.) 7. Please provide a completed Bond Estimate Request Form to the county engineer to receive an ESC bond. A grading permit cannot be issued until a bond is posted. C. Stormwater Management Plan Review Comments (WPO- 2012 - 00039) The update to stormwater calculations for the intermittent pond BMP is acceptable. No modification to the existing SWM plan (WPO- 2010 - 00023) is warranted with this application. At the time of this plan's approval, two additional copies of Sheet C -18 will be necessary for me to include in the file. File: E1_rp ecp_PBC _ wpo- 2012 -00039 sub - 2012 -00043 District Ave Extended.doc