Loading...
HomeMy WebLinkAboutWPO201400002 Review Comments 2014-01-15Review Comments Project Name: Agnor Hurt Elementary School Renovations And Ad Erosion and Sediment Control Ply Date Completed: Wednesday, May 14, 2014 Revievrer: Frank Pohl Department "Di vi9ion1.Agency: Office Facilities Development Reviews Comments: Review Status: Approved F-1 Rage: 11 County of Albemarle !On: 1211'U2014 Review Comments Project Name: Agnor Hurt Elementary School Deno +rations And Ad Erosion and Sediment Control Ply Date Completed: lWednesday, April 23: 2014 Revievrer: Frank Pohl Department "Divi9ion1.Agency: I Office Facilities Development Reviews Comments: Review Status: I Requested Changes I ' I routed to the Page: 1 Counts of Albemarle Cn: 191 2014 Review Comments Project Name: Agnor Hurt Elementary School Penovations And Ad Erosion and Sediment Control P� Date Completed: lWednesday, April 23: 2014 Revievver: I Frank Pohl F-I D e p a rtm e nt,D ivi 9 i o n.1.Ag e n cy Office Facilities Development F-I Reviews Comments: Review Status: IRequested Changes F-I Page: 1 Counts of Albemarle Cn: F191--V2014 *�TT__v COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road Charlottesville, Virginia 22902 WPO Plan Review Project: Agnor -Hurt Elementary School Renovations and Additions Plan submittal date: 15 January 2014 Number: WP0201400002 Date: 24 February 2014 Reviewer: Max Greene Phone: 296 -5832 ext. 3283 This is an abbreviated review comment notice. We are doing one round of comments and then handing the file over to Frank Pohl in OFD for any further review and approval. To schedule, please call Frank Pohl for an appointment. Erosion & Sediment Control: Adequate (Code Chapter 17, Article H) g Not Adequate Y N • State standards followed, and Design Standards Manual notes and details • Adequate limits and perimeter measures out of work areas • All stages protected adequately • Adequate channels 1. Please submit a request for a modified inlet protection for the files. 2. Please state on the plans the date of topography. If topo is more than 1 year old, then please note on plan that topo was visually field verified by Engineer and date of verification. 3. Please locate at least 1 bench mark on the plans that will be utilized throughout the duration of the site work. 4. Inlet protection shown is for toe of slope installation due to lack of emergency overflow and can cause erosion problems when installed in other location. Please show inlet protections suited for each application. 5. Please place a note next to the sediment trap "Sediment control structure removals shall be approved in writing from WPO inspector." 6. Cleanwater diversion appears to dump a large area of drainage into back of building with no outlet. Please explain how stormwater is to be handled at the outlet of the Cleanwater Diversion. 7. Cleanwater diversion near Woodburn Road is within the proposed grading and will need to be moved back if water is to remain clean. 8. Cleanwater diversion will require a lining to prevent erosion of the berm. 9. Cleanwater diversion across critical slope will require a lot of grading to install. Please show grading required to install Cleanwater diversion in conformance with Std. & Spec 3.17 — Stormwater conveyance Channel. 10. Please clarify drainage path from sediment basin and detention facility. 11. Inlet protection along Woodburn Road appears too shallow and may cause the stormwater to overflow down the slope into the Cleanwater diversion. Please show a detail of how this will be constructed. 12. Mountable berm appears to be draining in the wrong direction. 13. Several inlet protections may be exceeding the 1 acre drainage area limit. Please show corresponding drainage areas for each sediment control structure including roof drains. (Inlets draining to sediment basin with overland relief flows into basin are exempt from 1 acre rule.) 14. Please show inlet protection on the existing inlet in the parking lot on the South side of the site. This may not be required unless the WPO inspector requires it. 15. Please show curb and gutter along 11 space parking area to reduce erosion on new slope. 16. Diversion into basin from building does not appear to be a stable proposal and could blow -out in a storm event. Please clarify the construction and stability of the diversion across the existing swale area. Please consider extending basin over existing swale. 17. Please show Albemarle County detail for temporary paved construction entrance on the plans. Adequate [ 17- 204.fJ An application for an erosion and sediment control plan that requires modifications, terms, or conditions to be included in order for it to be approved shall be deemed to be withdrawn if the owner fails to submit a revised plan addressing the omitted modifications, terms or conditions within six (6) months after the owner is informed of the omitted information as provided under paragraph (B). Stormwater Management: X Not Adequate (Code Chapter 17, Article III) Y N Enough capture and treatment for on -site areas Enough detention storage for on -site areas Sealed hydrologic and hydraulic computations provided 1. Could not find details for cartridge filter system stated in submittal. 2. Please submit 4 copies of the WPO plans and computations with original signatures on seal for each. 3. Please show access ports to each cell of the underground detention facility for insnection and maintenance. Does not annear to be a serviceable system. My comments on the swm are below. I could not find verification of water quality treatment for the new entrance and bus loop area. - Better explanation needs to be provided for the area /volume curve used in the routings. It appears as though the modeling for the stone field voids and the arches may be counting some portion of storage areas double, which erroneously helps results. - I did not find anything regarding MS -19, and we know this is a problem area with the channel and grate inlet next to Berkmar. - The storage chamber system is not recommended for a county maintained infrastructure. Plastic chambers under a heavily loaded bus loop may have structural problems in the long term. The system is very difficult to inspect and clean out, and as proposed, has no reasonable access. It is recommended that a surface pond, or reinforced concrete storage chamber system be considered, and not placed directly under the bus route. Glenn Brooks, P.E. County Engineer Albemarle County Mitigation: N/A (Code Chapter 17, Article III) Adequate Not Adequate Y N m Buffers and disturbed areas adequately shown m Adequate plantings at 2:1, or other mitigation provided This review attempts to encompass the larger compliance questions. County staff does not assume responsibility for any calculation or plan details, and cannot cover the intricacies of every plan submitted. Each plan and calculation must have a professional seal and signature to assume these responsibilities. This plan is Approved (please see attached Approval Fact Sheet) X Not Approved [ 17- 204.fJ An application for an erosion and sediment control plan that requires modifications, terms, or conditions to be included in order for it to be approved shall be deemed to be withdrawn if the owner fails to submit a revised plan addressing the omitted modifications, terms or conditions within six (6) months after the owner is informed of the omitted information as provided under paragraph (B).