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HomeMy WebLinkAboutWPO201500064 Review Comments 2016-06-09Short Review Comments Report for: WPO201500064 SubApplication Type: Davis Residence Driveway - VSMP Stormwater Management/BMP Plan Erosion and Sediment Control Plan Date Completed:09/25/2015 Reviewer:Justin Deel CDD Engineering Review Status:Denied Reviews Comments:The VESCP application is used for projects that are exempt from the Virginia Stormwater Management Program, VSMP, and the DEQ General Permit. However, the proposed project is not exempt from the VSMP. Section 17-303 of the Albemarle County Code lists land disturbing activities that are exempt from the VSMP. The total land disturbance for this project (1.74 acres) is more than 1 acre; therefore, a VSMP application must be submitted. See Section 17-401 for the requirements of the VSMP application. Additionally, this project proposes a stream crossing. Stream crossings require a mitigation plan consisting of the re-establishment of stream buffer vegetation at a 2:1 ratio. Refer to Section 17.604.C for the minimum criteria for stream crossings and Section 17-406 for contents of a mitigation plan. The mitigation plan may be included with the VSMP plan. Lastly, this plan only includes the driveway to the home site. If the home site construction is expected to meet or exceed 1 acre of land disturbance it is recommended that it be included in the VSMP application for the driveway, as disturbance over 1 acre will require another VSMP application. Division: Date Completed:11/23/2015 Reviewer:Justin Deel CDD Engineering Review Status:Requested Changes Reviews Comments: Division: Date Completed:03/11/2016 Reviewer:Max Greene CDD Engineering Review Status:See Recommendations Reviews Comments:Requested a meeting with the consultant to discuss the erosion and sediment control portion of the VSMP. The trap as shown does not protect the stream. The silt fence shown down slope is just a diversion. The silt fence should be shown to follow elevations as needed or replaced with a diversion that leads into a sediment trap. Division: Date Completed:06/09/2016 Reviewer:Max Greene CDD Engineering Review Status:Administrative Approval Reviews Comments: Division: Page:1 of 1 County of Albemarle Printed On:February 10, 2017 NP February 23,2016 County of Albemarle Department of Community Development 401 McIntire Road Charlottesville, VA 22901 C/O: Justin Deel RE: Davis Residence Driveway (WPO-2015-00064) VSMP Plan Revisions Dear Mr. Deel: Please find attached the revisions to the plan based on your comments dated November 23, 2015. I have listed each comment individually with the response on how the comment was addressed. A. Stormwater Pollution Prevention 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) A SWPPP was not included with this submission. Please provide. Response:A SWPPP has been included with this submission. B. Pollution Prevention Plan(PPP) The PPP content requirements can be found in County Code section 17-404. 1) A PPP was not included in this submission. Please provide. Response:A PPP has been included(part of the SWPPP). C. Stormwater Management Plan(SWMP) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP.This plan is disapproved,and the reasons are provided in the comments below.The stormwater management plan content requirements can be found in County Code section 17-403. 1) The Virginia Runoff Reduction Method Instruction &Documentation (March 28,201 1) states that "all areas that will be considered forest/open space for stormwater purposes must have documentation that prescribes that the area will remain in a natural,vegetated state". Please provide this documentation for the 0.75 acres of forest/open space included in the provided VRRM spreadsheet. Note that the County Attorney's office is currently working on a means of prescribing areas to remain in a natural,vegetated state for purposes of VRRM compliance. Response:A revised VRRM has been included. The revised acreage for the conservation area is 1.35 acres(provided). Sheet S-1 of the plans shows the conservation area and the areas used for calculating sheetflow for Specification #2 of the design criteria. 2) You are showing the conversion of the sediment trap to a biofilter,yet the biofilter is not included in your VRRM,please clarify.Additionally,the biofilter cannot be within the WPO buffer, as 680 IVY FARM DRIVE • CHARLOTTESVILLE. VIRGINIA 22901 • PHONE: (434) 531-7387 • Davis Residence Driveway Pith (WPO 2015-00064) . Page 2 February 23,2016 permanent stormwater management facilities are not listed among the activities that may be authorized within the WPO buffer[17-603&-604]. Response:The biofilter has been deleted from the plan.All criteria will be met with a conservation area as shown on the plans(1.35 acres). 3) The provided typical biofilter details are no longer acceptable. Please remove and provide actual to scale detail(s) and cross-section(s) for SWM facilities. Response:The biofilter has been deleted from the plans. The details have been removed. 4) Please change plan set title to say Virginia Stormwater Management Program (VSMP) plan,as opposed to WPO plan. Response:The plan title has been changed to VSMP plan. 5) Please show areas that are sheet flowing to a conservation area,so that the design criteria in Specification No.2 can be verified. Response:The area that sheet flows to the conservation area has been shown on sheet S-1. 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, and the reasons are provided in the comments below.The erosion control plan content requirements can be found in County Code section 17-402. 1) Please adjust silt fence so that it is not running parallel to the grade change;which has shown to be ineffective, leading to undermining and blowouts.Alternatively,please stagger-step silt fence so that it is perpendicular to the grade change. Response:The silt fence has been adjusted to parallel grade change.This will need to be field verified for installation. E. Mitigation Plan This plan is disapproved, and the reasons are provided in the comments below.The mitigation plan content requirements can be found in County Code section 17-406. 1) Plan shows a biofilter inside WPO buffer, please remove.See SWM comment#2. Response:The biofilter has been deleted from the plans and hence removed from the buffer. I trust that the above comments are adequately addressed for the minor site plan amendment. Should you have questions regarding the revisions, please call me at (434) 531-7387. Sincere 4 ! , Nat Pes, P.E. .,. m..w ,..w. 680 IVY FARM DRIVE •wCHARLOTTESVILLE VIRGINIA 22901 • PHONE: (434) 531-7387 • Justin Deel To: nat.perkings@gmail.com; davisbnd@gmail.com Subject: Planning Application Review for WPO201500064 Davis Residence Driveway-VESCP. The Review for the following application has been completed: Application Number=WPO201500064 Reviewer=Justin Deel Review Status = Denied Completed Date =09/25/2015 The VESCP application is used for projects that are exempt from the Virginia Stormwater Management Program, VSMP, and the DEQ General Permit. However, the proposed project is not exempt from the VSMP. Section 17-303 of the Albemarle County Code lists land disturbing activities that are exempt from the VSMP. The total land disturbance for this project(1.74 acres) is more than 1 acre; therefore, a VSMP application must be submitted. See Section 17-401 for the requirements of the VSMP application. Additionally, this project proposes a stream crossing. Stream crossings require a mitigation plan consisting of the re-establishment of stream buffer vegetation at a 2:1 ratio. Refer to Section 17.604.0 for the minimum criteria for stream crossings and Section 17-406 for contents of a mitigation plan. The mitigation plan may be included with the VSMP plan. Lastly, this plan only includes the driveway to the home site. If the home site construction is expected to meet or exceed 1 acre of land disturbance it is recommended that it be included in the VSMP application for the driveway, as disturbance over 1 acre will require another VSMP application. If you have any questions please feel free to contact me. Justin Justin Deel, EIT Civil Engineer 11 Department of Community Development County of Albemarle,Virginia 434.296.5832 ext. 3565 1 �pF A vt�r�1Q 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 title: Project file number: Plan preparer: Owner or rep.: Plan received date: Date of comments: Reviewers: VSMP Permit Plan Review Davis Residence Driveway WPO- 2015 -00064 NP Engineering Benjamin Davis 12 November 2015 23 November 2015 Justin Deel County Code section 17 -410 and Virginia Code §62.1- 44.15:34 requires the VSMP authority to act on any VSMP permit by issuing a project approval or denial. This project is denied. The rationale is given in the comments below. The application may be resubmitted for approval if all of the items below are satisfactorily addressed. The VSMP application content requirements can be found in County Code section 17 -401. A. Stormwater Pollution Prevention 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. A SWPPP was not included with this submission. Please provide. B. Pollution Prevention Plan (PPP) The PPP content requirements can be found in County Code section 17 -404. 1. A PPP was not included in this submission. Please provide. C. Stormwater Management Plan (SWMP) VSMP Regulation 9VAC25- 870 -108 requires the VSMP authority to approve or disapprove a SWMP. This plan is disapproved, and the reasons are provided in the comments below. The stormwater management plan content requirements can be found in County Code section 17 -403. 1. The Virginia Runoff Reduction Method Instruction & Documentation (March 28, 2011) states that "all areas that will be considered forest/open space for stormwater purposes must have documentation that prescribes that the area will remain in a natural, vegetated state ". Please provide this documentation for the 0.75 acres of forest /open space included in the provided VRRM spreadsheet. Note that the County Attorney's office is currently working on a means of prescribing areas to remain in a natural, vegetated state for purposes of VRRM compliance. 2. You are showing the conversion of the sediment trap to a biofilter, yet the biofilter is not included in your VRRM, please clarify. Additionally, the biofilter cannot be within the WPO buffer, as permanent stormwater management facilities are not listed among the activities that may be authorized within the WPO buffer [17 -603 & - 604]. 3. The provided typical biofilter details are no longer acceptable. Please remove and provide actual to scale detail(s) and cross - section(s) for SWM facilities. Engineering Review Comments Page 2 of 3 4. Please change plan set title to say Virginia Stormwater Management Program (VSMP) plan, as opposed to WPO plan. 5. Please show areas that are sheet flowing to a conservation area, so that the design criteria in Specification No. 2 can be verified. D. Erosion and Sediment Control Plan (ESOP) Virginia Code §62.1- 44.15:55 requires the VESCP authority to approve or disapprove an ESCP. This plan is disapproved, and the reasons are provided in the comments below. The erosion control plan content requirements can be found in County Code section 17 -402. 1. Please adjust silt fence so that it is not running parallel to the grade change; which has shown to be ineffective, leading to undermining and blowouts. Alternatively, please stagger -step silt fence so that it is perpendicular to the grade change. E. Mitigation Plan This plan is disapproved, and the reasons are provided in the comments below. The mitigation plan content requirements can be found in County Code section 17 -406. 1. Plan shows a biofilter inside WPO buffer, please remove. See SWM comment #2. The VSMP permit application and all plans may be resubmitted for approval when all comments have been satisfactorily addressed. For re- submittals please provide 2 copies of the complete permit package with a completed application form. Engineering plan review staff are available from 2 -4 PM on Thursdays, should you require a meeting to discuss this review. Process; After approval, plans will need to be bonded. The bonding process is begun by submitting a bond estimate request form and fee to the Department of Community Development. One of the plan reviewers will prepare estimates and check parcel and easement information based on the approved plans. The County's Management Analyst will prepare bond agreement forms, which will need to be completed by the owner and submitted along with cash, certificates or sureties for the amounts specified. The agreements will need to be approved and signed by the County Attorney and County Engineer. This may take 2 -4 weeks to obtain all the correct signatures and forms. Stormwater Management Facilities Maintenance agreements will also need to be completed and recorded. The County's Management Analyst or other staff will prepare the forms and check for ownership and signature information. The completed forms will need to be submitted along with court recording fees. After bonding and agreements are complete, county staff will need to enter project information in a DEQ database for state application processing. DEQ will review the application information based on local VSMP authority approval. At this time, the DEQ portion of the application fees will need to be paid directly to the state. For fastest processing, this is done electronically with the emails provided on the application. DEQ should notify applicants with instructions on how to pay fees. When DEQ approves the application, they will issue a permit coverage letter. This should be copied to the county. After DEQ coverage is issued, via the coverage letter, the County can hold a pre - construction conference. Engineering Review Comments Page 3 of 3 Applicants will need to complete the request for a pre - construction conference form, and pay the remainder of the application fee. The form identifies the contractor and responsible land disturber, and the fee remaining to be paid. This will be checked by county staff, and upon approval, a pre - construction conference will be scheduled with the County inspector. At the pre - construction conference, should everything proceed satisfactorily, a joint VSMP and grading permit will be issued by the County so that work may begin. County forms can be found on the county website forms center under engineering; hlt2://www.albemarle.ora/deptforms.ap?department--cdengmTo File: WPO201500064 VSMP Review.doc Justin Deel From: Justin Deel Sent: Friday, September 25, 2015 10:19 AM To: 'nat.perkins @gmail.com'; 'davisbnd @gmail.com' Subject: RE: Planning Application Review for WPO201500064 Davis Residence Driveway - VESCP. The Review for the following application has been completed: Application Number = WPO201500064 Reviewer = Justin Deel Review Status = Denied Completed Date = 09/25/2015 The VESCP application is used for projects that are exempt from the Virginia Stormwater Management Program, VSMP, and the DEQ General Permit. However, the proposed project is not exempt from the VSMP. Section 17 -303 of the Albemarle County Code lists land disturbing activities that are exempt from the VSMP. The total land disturbance for this project (1.74 acres) is more than 1 acre; therefore, a VSMP application must be submitted. See Section 17 -401 for the requirements of the VSMP application. Additionally, this project proposes a stream crossing. Stream crossings require a mitigation plan consisting of the re- establishment of stream buffer vegetation at a 2:1 ratio. Refer to Section 17.604.0 for the minimum criteria for stream crossings and Section 17 -406 for contents of a mitigation plan. The mitigation plan may be included with the VSMP plan. Lastly, this plan only includes the driveway to the home site. If the home site construction is expected to meet or exceed 1 acre of land disturbance it is recommended that it be included in the VSMP application for the driveway, as disturbance over 1 acre will require another VSMP application. If you have any questions please feel free to contact me. Justin Justin Deel, EIT Civil Engineer II Department of Community Development County of Albemarle, Virginia 434.296.5832 ext. 3565 County of Albemarle Department of Community Development County Engineer's Commentary Number 5: Erosion and Sediment Control for Roads Across Streams 11 Mar 2008 Question: Do I have to put in a basin? Can I put in traps instead? Can I just use silt fence? Background: While these may sound like the same questions asked on every project for every erosion control plan, I am referring specifically to roadway stream crossings, usually with culverts and fill. The county review generally follows a form like this; 44-4..473 **** _.*. Submittal 1: The culvert crossing with silt fence protection. This is usually seen as the least destructive solution. It has the smallest footprint, assuming the fill comes from another part of the roadway. Unfortunately, it does not meet minimum standards. There is no protection for the stream when the pipe is being placed. Most of the silt fence is useless, because it is running with the grade, and blowouts occur on either side of the pipe inverts. County comments ask for revision, requesting a basin. Albemarle County Community Development ' County Engineer's Commentary#5 Page 2 of 6 Submittal 2: After county comments, a second submittal might look something like this. The designer usually replies that the culvert area is too big for a basin to be practical. It is also easier to design traps, and cheaper and quicker to build them. Unfortunately, the culvert drainage area is too big for the CIP also, and this solution, like the one before, only operates after placement of the pipe. County comments are repeated, requesting a basin, but recognizing a basin may never be provided, and so also offering a silt trap solution, with four traps around the pipe inverts. - � , s ( � Submittal 3: At this point, the designer has taken the silt trap recommendation, but still faithful to the first submittal, is keeping only silt fence for the smaller drainage areas. The county will usually insist that the silt fence is not adequate, and point out that the drainage area to ST-2 exceeds the maximum. The drainage area to ST-i also might be exceeded during the initial land disturbance (this is discussed later). Albemarle County Community Development County Engineer's Commentary#5 Page 3 of 6 r--) (..,_ e -- Submittal 4: The four-corner compromise: At this point, the plan is usually approved. The county has given up on obtaining a sediment basin, and a compromise has been reached to provide traps at the four points of drainage concentration. Where areas are too big for traps (bottom left, ST-4), diversions have been provided to direct "clean" water around the trap. Commentary: There are a number of problems with the four-corner compromise. For designers and reviewers, it takes about four revisions to get here, and that wastes everybody's time. For inspectors and contractors, it does not work well in the field. It is difficult to get these traps dug into the hillsides, and it is even more difficult to maintain. A stream crossing and diversion are still needed to install two of the traps, and the pipe. From the Program Authority perspective, there is still a period of time when the two traps downstream have drainage areas above the maximum, before the road fill cuts off the upper areas, and so the project does not meet minimum standards. During the life of the project, one or more of these traps typically fails, and the "clean" diversion is usually dirty, at least temporarily. Lastly, owners often do not see the sense in providing traps uphill of the project, and complaints and confusion result. In order to avoid these problems, it appears necessary to set some rules on what the county will accept. The basin is still the preferred solution, both for ease of maintenance and inspection, and for performance. However, some point must be recognized when it is a greater disturbance and headache to build a large basin than to fool around with the four-corner compromise. Likewise, at some point the disturbance or drainage area is small enough that a basin or trap is unnecessary. Lastly, there are often objections from DEQ or the Army Corps to basins on some jurisdictional streams. It seems logical to base rules on expected performance, drainage areas, and consideration for the potential for damage, based on the amount of proposed disturbance and fill. The following tiered approach is proposed; Albemarle County Community Development ' County Engineer's Commentary#5 Page 4 of 6 1. For drainage areas less than 50 acres, and road fills greater than 4' in height, a basin must be used. (50 acres is an arbitrary number chosen at approximately 4 times what the four-corner trap arrangement could protect, 12 acres) Live streams must be pumped around, or diverted with temporary piping and an off-line culvert placement, or some other strategy. Basins cannot be placed in the live flow. q C/ •• .. 2. If the culvert drainage area is above 50 acres, or the road fill is less than 4' in height, the four- corner trap arrangement may be used. Clean water diversions must be built with a fabric liner. Down-stream traps must be designed to the largest drainage encountered during the life of the project. For example, looking at trap ST-1, most designers use this drainage area; I ti _ y F Yy F I -` Albemarle County Community Development County Engineer's Commentary#5 Page 5 of 6 However, during the initial stages of construction, before fill is in place, the drainage may be something like this; s 0 2 The use of basins in the corners may need to be considered in some cases. Uphill, where drainage areas may be less than 0.25 acres, wire reinforced silt fence may be used alone. In the example, this may be the case with trap ST-3, which could be removed; 1 ( \ n�'� -_.s N• wv. ,. carer �',�:,.4r. .. a- r, Notice the silt fence is placed along the contour as much as possible, to catch sediment instead of diverting it. Every project is a unique fingerprint to some extent, and these proposals may not always work, but this should catch the majority of situations. Please let me know if you have Albemarle County Community Development County Engineer's Commentary#5 Page 6 of 6 concerns with these proposals, or suggestions for improvement.