Loading...
HomeMy WebLinkAboutWPO201300052 Correspondence 2014-05-01 Name cur aCT®mac. . Ib COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road,Room 227 Charlottesville,Virginia 22902-4596 Phone(434)296-5832 Fax(434)972-4126 Project: Old Trail Village, Block 1B & 3C Plan preparer: Roudabush,Gale&Assoc., Inc [914 Monticello Road, Charlottesville, VA 22902,cmulligan @roudabush.com] Owner or rep.: JA-ZAN LLC [1150 Pepsi Place, Charlottesville VA 22901, dave@oldtrailvillage.com] Plan received date: 15 April 2014 Date of comments: 01 May 2014 Reviewer: Glenn Brooks, John Anderson A. Stormwater Management and Mitigation Plan(WPO201300052) 1. Separate out the WPO plans. They cannot be approved as part of a road plan or site plan set. The plans have been split into a Site Plan,A Road Plan & a WPO plan to illustrate the approved outfall under Old trail Drive. 2. These plans indicate the off-site pond across Old Trail Drive will provide stormwater management. This is fine as long as this plan gets runoff and discharge to that location. Please provide current plans and profiles for the complete pipe run to the pond, indicating accurate current elevations of ground, road, road substructure, and pond in the 2 and 10 year storms. This must be included fully on this plan,to be bonded with this plan. The pipe run cannot decrease in size as indicated on sheet 16. It appears the entire run should be 42"diameter. The originally approved pipe profile and design information has been included into the WPO plan,as requested; please recognize that much of the storm sewer system is existing construction,which would include the temporary 24" outfall pipe into the existing Sediment Basin,and existing structures are shown as dashed to indicate. The Sediment Basin design information has been included herein for reference. 3. Please clarify and provide inlet computations for existing inlets that are receiving flow from this development. Also,the tables do not appear to be clearly separating sump and on-grade inlets(see VDOT LD-204). Please ensure all drainage inlets will capture the 10 year storm to carry runoff to the stormwater management pond. Please clarify which pipes are existing(13,-16) The Storm Sewer Design table appears to indicate capacity issues, for example: from Ex. 106 to Ex. 108, from Ex. 114 to Ex. 116, and 7 other pipe sections. Please review and revise as necessary. The existing pipes were as-built,analyzed and included per direction given. Existing structures & pipes are shown as dashed. All computational references to inlets or pipes not specifically relevant to this plan have been removed. The site disturbance exists within an improved Old trail Village Block where an existing storm sewer system originally designed and sized for this phase of the development. This would include the BMP design,the storm water Engineering Review Comments Page 2 of 3 conveyance and control,as well as the Phase 1 Erosion Control. The inlet computations include the 6.5" inlet spread computations which indicate full containment within the curb section. The additional inlet information has been omitted to clearly indicate the on-grade or sump conditions. B. Erosion Control Plan(WPO201300052) 1. Separate out the WPO plans. They cannot be approved as part of a road plan or site plan set. The WPO plans were separated from the Site Plan as requested,and the Phase 1 Erosion Control Information from the Block 3A plans has been included herein for reference. 2. Provide clear limits of disturbance. The limits of Land Disturbance has always been clearly labeled on the Phase 2 Erosion Control Plan. The limits of disturbance are isolated by the existing pavement surrounding this phase of construction,and the existing storm sewer conveys the water to the existing sediment basin located behind the Pool(Block 3A). 3. Provide perimeter controls for the initial stage of construction. The plan shows only inlet protection. Inlet protection cannot be installed until the drainage system is installed. This is too late. The perimeter EC measures include Silt Fence,as well. The majority of the drainage system is existing,whereas the proposed structures are clearly illustrated in the Storm Structure& Storm Pipe Schedules. 4. The pipe run to the pond must be included. Show all measures to install the pipe run to the pond. The original Collins plan design for the Upper Ballard pond outfall, including the pipe plan and profile have been removed from the site plan and were utilized to the create the newly requested WPO plan. Upon stabilization of the design watershed and closure of the existing sediment basin,the outfall for Upper Ballard pond shall be constructed to meet the perpetual SWM requirements for the development of this area originally sized,designed and approved with Block 3A plans,WPO-2008-0014 "OLD TRAIL VILLAGE BLOCK 3 STORMWATER MANAGEMENT PLAN". 5. The plan note on sheet 9, note 1 on the sequence, and sheet 16, indicate an outfall into a sediment basin. This sediment basin is not part of this erosion control plan as shown. It cannot be considered, as it may be removed with other plans. All controls must be shown and detailed on the plan, and within the limits of disturbance. Since this area was originally designed and approved for Land Disturbance under the original WPO,the Sediment Basin cannot be removed until the entire Land Disturbance area is stabilized per the EC inspector. The existing sediment basin plan design information was replicated herein for reference,and the actual drainage area, based on current field conditions was included. 6. Update the narrative. This plan has not proposed any checkdams or basins. The narrative does not propose construction of the existing dam or basin measures, but does reference their maintenance requirements and functionality procedures for repair, prior to land disturbance. 7. Revise the sequence of construction. Item#1 is not valid. Item #7 appears to be a carryover from prior plans. Item#2 is not possible, as many inlets have yet to be installed. °Iwo, Noe Engineering Review Comments Page 3 of 3 C. Road plans We are awaiting a subdivision application and fee for the Ashlar Avenue road plans. This was conveyed in an e-mail on 17 Apr 2014. Items 1 &2 are valid, per the existing storm sewer, existing sediment basin and approved Phase I EC plan for this area. Additional information about the existing measures has been included. Item #7 has been removed. D. Site Plan (SDP201300044) Comments as posted to County View system on 3/25/14. Previous comments from Michael Koslow appear to be addressed with this submittal. However,there are still outstanding issues with WPO plan. Remove the WPO and road plans. They cannot be approved as part of a site plan set. Per the latest direction,we have separated the WPO plan form the Site Plan. As the system logged correctly,these plans should have already have been approved,as all items were addressed adequately per the current discussions& direction given at that time. Hopefully,this will satisfy any remaining concerns. E. Final Plat(SUB201400065) A complete review of the final plat will be performed when road, site and WPO plans are approved, and can be matched against the final plat. The following preliminary comments are provided; 1. Easements will need to be recorded for drainage through lots and to the off-site pond. 2. A maintenance agreement will need to be in place for the pond. A copy of a recorded document should be provided to verify. 3. A Lickinghole Basin pro-rate share fee will be computed with final approval, and this will need to be paid. 4. Road plans will need to be approved. 5. Bonds will need to be posted. Bond estimate can be requested when plans are approved. Forms are available on the county website. ;1 Vk l'i -.ti{°°,; --�-{ l 8,4!i-111111 1 !-i1;,2311=,. laaam `..•., John Anderson • From: Dave Brockman [dave @oldtrailvillage.com] Sent: Tuesday, April 15, 2014 9:27 AM To: 'don franco'; Glenn Brooks Cc: 'Chris Mulligan'; 'Bill Ledbetter'; Max Greene; Michelle Roberge; John Anderson Subject: RE: Old Trail Stormwater Hi Glenn, Thanks for you quick responses.As Don mentioned we will meet shortly and get back with you to keep this momentum going. Without making any implied message of our position (and reiterating what Don said), I would like to state for the record that if any of our written correspondences, between us, are interpreted as any form of"County Determination" on this issue,then we want to reserve the right to appeal, and that these conversations/correspondences are a "work in process" between the two parties in hopes of achieving a common goal. My intent is that we continue with cooperative dialog until we find a solution. Thanks, Dave Brockman From: don franco [mailto:donfrancoiii @gmail.com] Sent: Tuesday, April 15, 2014 8:53 AM To: Glenn Brooks Cc: Dave Brockman; Chris Mulligan; Bill Ledbetter; Max Greene; Michelle Roberge; John Anderson Subject: Re: Old Trail Stormwater Thanks for the feedback, let us digest this and see if we can come up with a reasonable strategy. As you can guess, your interpretation of the ponds, intending to provide quality and quantity,basically means we can have very little released untreated. This may prove challenging given the lay of the land. We'll be back with an overall stormwater management plan or, if we need be, with a formal request for a written determination or rezoning. Thanks again. Don Franco don@community-results.com Community Results 471 Panorama Road Earlysville, VA 22936 434.974.9285 (o) 434.249.9641 (c) On Apr 15, 2014, at 8:38 AM, Glenn Brooks <GBROOKS(2Ialbemarle.org>wrote: I did not sum the blue areas, but if they are 100 acres as you say, that sounds OK. From: don franco [mailto:donfrancoiiagmail.com] Sent: Friday, April 11, 2014 2:29 PM To: Glenn Brooks Cc: Dave Brockman; Chris Mulligan; Bill Ledbetter; Max Greene; Michelle Roberge; John Anderson Subject: Re: Old Trail Stormwater OK, I think I'm following your logic,but want to verify-this extension since its pertinent to the Block 2 WPO. We have 64.5 acres to be treated and by my quick estimate 100 acres going to the ponds (treated and detained). So our water quality metric is really 164.5 acres going through to a bioretention, extended detention or a pond? (i.e., we're not required to treat using to bioretention,but we are required to provide 50%removal)? Don Franco don@community-results.com Community Results 471 Panorama Road Earlysville,VA 22936 434.974.9285 (o) 434.249.9641 (c) On Apr 11, 2014, at 1:25 PM, Glenn Brooks <GBROOKS(a,albemarle.org>wrote: Here are my answers to your questions after careful examination of the rezoning plan; 1. Is the accounting of stormwater management based on acreage to biofilters OK (Michael and Bill settled on around 64-65 acres.) ? Yes. This must also be in context of what is discussed below. 2. Does extended detention satisfy the intent of the ZMA where bioretention is called for? This is framed as a theoretical question on whether extended detention is the same as bioretention from a water quality standpoint. I think the state guidelines establish this. What seems to be more to the point is the ponds. Does 50%removal in the ponds suffice to meet the intent of the biofilter treatment? No. The intent of the plan appears to be to treat those areas which could not drain to the ponds. See below. Most of the areas which are not captured by the ponds are designated to be treated by potential biofilters (in red). The intent of the plan appears to be to capture these areas so they are not released into conservation areas (in green)untreated. 3. Is detention compliance at Slabtown and Lickinghole at the edges of the property sufficient? The development must follow the general plan below. The blue areas were intended to go to the ponds. It appears they were intended to be treated and detained. The red areas were not going to the ponds. So, in the context of the plan, you could over-detain the blue areas to provide detention for the red areas. I don't think using the two points, Lickinghole and Slabtown, at the edges of the property would meet this intent. 2 4. Can some areas not be detained? ..1 I think this is answered in question 3. <image001.jpg> Glenn Brooks, P.E. County Engineer Albemarle County From: donfrancoiiigmail.com [mailto:donfrancoiii©gmail.com] Sent: Sunday, April 06, 2014 1:14 PM To: Glenn Brooks Cc: Don Franco; Dave Brockman; Chris Mulligan; Bill Ledbetter Subject: Old Trail Stormwater Glenn: I hope you had some quality time off and are refreshed and ready to get back into the swing of things. As you know, it is always challenging to interpret general ZMA statements into engineering specifics. Our goal is to consolidate the multiple approvals at Old Trail into an overall stormwater management approach, simplifying the bonding, SDP process and ZMA compliance review. In response to Michael Koslow's 1.7.2014 Memo to Bill Ledbetter, we prepared a detailed summary of approved WPO-SWM Plans based on bonding information and the plans received from Engineering under our recent FOI request. We located the approved WPO facilities on an as-built map of the ZMA area, delineating their individual as-built watersheds. While we haven't finalized the map, we believe the draft map reflects our current status with respect to ZMA compliance and helps to highlight the questions we need addressed in order to proceed. The specific questions which we would like you to weigh in on are: 1. The ZMA water quality metric for monitoring compliance is acreage. Specifically, 64.5 acres of the PUD needs to be treated (per Michael Koslow 1.7.2014). Do you agree? 2. The WPOs approved to date have included both bioretention and extended detention facilities. Michael's memo seemed to suggest the 64.5 acres needed to be treated through a bioretention facility. Since both treatments provide an estimated 50%removal, we feel both treatments satisfy the intent of the ZMA requirement. Do you agree? 3. Water quantity compliance, while part of the ZMA, needs to be reviewed at specific locations. We suggest where Slabtown Branch and Lickinghole exit our property or at the downstream confluence of the two streams. Do you have a preference? Keep in mind that we understand that compliance with MS-19 requirements will need to be demonstrated along these creeks. 4. Our strategy for meeting detention requirements will likely include a combination of over-detained and un-detained areas. Do you agree that not all areas need to be detained? Also,please review the general form of the map we provided you at the meeting. We are not asking you to verify the specific acreage or plan details,just the general form. 3 Finally,keep in mind that our goal Sis to determine where we have common ground and where we may need additional information or have differing opinions. To that end, I have tried to keep the questions focused and have intentionally not provided a full discussion of each of the above questions. Should we need to get a written interpretation on the ZMA, we will request it under a separate letter. Should you wish to discuss further, please do not hesitate to contact me. We stand ready to finalize the requested information and submit an overall stormwater management plan for your approval once we have the requested clarification. Thanks, Don Franco Community Results 471 Panorama Road Earlysville, VA 22936 434.974.9285 434.249.9641 don(a,community-results.com 4