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HomeMy WebLinkAboutWPO201600033 Review Comments WPO VSMP 2016-11-18Phone (434) 296-5832 OF Alga. VtRGSry�P COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902-4596 VSMP Permit plan review Fax (434) 972-4126 Project title: U. of Va. Foundation Golf Facility Project file number: WP0201600033 Plan preparer: Dewberry Engineers [dkeeler@dewberry.com] Owner or rep.: University of Virginia Real Estate Foundation [cds7c@virginia.edu] Plan received date: (Rev. 1) (Rev. 2) Date of comments: (Rev. 1) (Rev. 2) Reviewer: 4 May 2016 10 October 2016 17 May 2016 18 November 2016 David James (ext. 3273) 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 ESOP, (3) a SWMP, and (4) any TMDL measures necessary. 1. Item appears adequately addressed for approval. (Rev. 1) B. Pollution Prevention Plan (PPP) The PPP content requirements can be found in County Code section 17-404. L Item appears adequately addressed for approval. (Rev. 1) 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. Please submit a VRRM spread sheet for redevelopment. SWM requirements will be verified/reviewed for approval once all documentation has been received. (Rev. 1) DewBerry Response: VRRM spread sheet for redevelopment shall be updated to the year 2013 (version 3.0) and shown on sheet C6.03. An excel file shall be provided to Mr. Greene via email. (Rev. 2) Addressed. 2. SWM plan was not apparent in submittal. Please clarify. (Rev. 1) DewBerry Response: SWM plan (Sheets C6.01-C6.09) shall be included in this submission. Previously submitted stormwater report calculation package. (Rev. 2) Addressed. 3. SWM Plan — Show contributing drainage areas to each SMF; Provide maintenance requirements for all SWM facilities on drawings. (Rev. 2) 4. C6.03 — Provide a concise narrative describing the stormwater management strategy, BMP used and level design, describing how the practice fits into the overall plan, and stating all assumptions made in the design. (Rev. 2) 5. Permeable Pavement (SWM plan) — Provide manufacturer cut sheets and maintenance requirements. Show location of observation well(s). (Rev. 2) 6. Permeable Pavement (design) — Show that any contributing DA will not exceed twice the SA of the permeable pavement; Pavement slope to be 0% (1% with an underdrain). (Ref. Section 5). Verify that the pavement will drain within 48 hours following a storm. Provide the results of soil infiltration rate testing to confirm a subsoil infiltration rate of at least 0.5-inch/hour for level 2 design. (VADEQ SW Design Spec. 7). (Rev. 2) 7. Confirm the depth to seasonal high groundwater table and bedrock (minimum 2 ft. below the design bottom of the facility). (Rev. 2) 8. Bioretention basins (SWM plan) — Provide scaled plan & cross sections of BMPs. Show facility area, embankment area, area of site getting treated for water quality calculations. Show the top -of - bank and basin bottom elevations. Show the location of underdrain & cleanouts. In the details (C5.02): Provide 12" (MIN) stone sump below the invert of pipe underdrain; Show max design storm elevations (2-yr/10-yr); Indicate 5:1 (MAX) slope of grass filter strip to BMP. (Rev. 2) 9. Bioretention (design) - Indicate the type and level design used; Slope of CDA to be between 1-5%; A pre-treatment cell is needed for any piped inlets; Provide the results of soil infiltration rate testing to confirm a minimum subsoil infiltration rate of > 0.5 in/hr (> 1 in/hr in order to avoid the use of an underdrain). The number of infiltration tests is based on the scale of the planned infiltration facility area (Ref. Tables 9.2 and 9.3). Planting plan: Ponding depths greater than 6" will require a specific planting plan. [NOTE: The maximum contributing drainage area for a micro- bioretention facility (e.g., rain garden) is 0.5 acre (3% of the CDA or 5% of the roof area for Level 1 or 4% of the CDA or 6% of the roof area for Level 2); for an urban bioretention facility is 2,500 sq. ft., and for a conventional bioretention facility is 2.5 acres.] (VADEQ SW Design Spec. 9). (Rev. 2) 10. Provide calcs for pipe outlet from bioretention. Show that site meets Part II(B) requirements for channel and flood protection by meeting the design 1-yr 24-hr storm using Energy Balance, or 2- yr/10-yr 24-hr storms & Limits of Analysis (VSMP Regulation 9VAC25-870-66). (Rev. 2) 11. Provide maintenance access easement to SWM facilities. Access easement may be required (Ref. Design Manual, Sect. 5). (Rev. 2) 12. Provide the condition of existing storm infrastructure, and if any measures are needed for repair. (Rev. 2) 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. There does not seem to be a connection between the phase 1 and phase 2 erosion and sediment control protection plans. Example: Sheet C2.06 shows a basin and diversion across the middle of the page and no proposed grading, sheet C3.16 shows proposed grades and two bio-retention structures and no diversions. Basins and traps are required for all phases of construction. This office recommends combining the two phases into one comprehensive erosion and sediment control plan. Conversions from sediment traps and basins can /should be on the SWM plans. Conversions are performed after the site is stabilized and SWM structures are protected from sediments. (Rev. 1) DewBerry Response: Sheets shall be updated and SWM Sheets added. Recommend a simplified plan layout with smaller scale, but not required. (Rev. 2) 2. Sediment traps and basins are required for land disturbances >1 acre per VESCH. (Rev. 1) DewBerry Response: Sediment traps and basins shall be in design to comply with VESCH standards. Addressed. (Rev. 2) 3. Silt fence will need to be moved/shown outside the proposed disturbance. (Rev. 1) DewBerry Response: Silt fence shall be moved outside of limits of disturbance. Addressed. (Rev. 2) 4. Diversions should be shown in place of silt fence that runs down slope. The diversions will need a sediment trap or basin at the outlet. (Rev. 1) DewBerry Response: Diversions shall be shown in place of silt fence that runs down slopes. Design shall be updated to show diversions to sediment basin. Partially addressed — diversion on north part of site is shown going outside limits of disturbance, include diversion within LOD. Also, remove diversions from cut/fill areas unless these can be protected during earthwork activities (VESCH 3.09). (Rev. 2) 5. Match lines do not appear to work on all pages. Plans could not be pieced together per match lines for review. Please revise. (Rev.1) DewBerry Response: Refer to key plan on sheet C0.05 for match line reference. Addressed. (Rev. 2) 6. E&SC plan - Indicate staging area, any stockpiles, and show dust control symbols (DC); Show callouts for proposed SWM features (permeable pavements, stormwater pipes, ditches, MHs, etc.). (Rev. 2) 7. Show existing drainage divides; Show pre -/post -drainage area, including offsite areas draining to sediment basin. (Rev. 2) 8. Temp. Sediment Basin - Show design calcs for proposed basin that meet the design criteria; Missing details for some of the SB components; Mention details on how riser will tie-in to existing 24" pipe; Install baffle to prevent shortcutting; Side slopes should be maximum 2'/2 :1 (VESCH 3.14). (Rev. 2) 9. E&SC Phase II sheets - Show 24" pipe; Show construction entrance. (Rev. 2) 10. C5.01 - A paved wash rack is required; include detail (Ref. Design Manual, Sect. 6). (Rev. 2) 11. C5.01 - Show detail for Nyoplast IP, remove IP detail of curb gutter; Consider capping Nyoplast inlets until site is stabilized; The (title) heading should match the pictures for check dam (VESCH 3.20). (Rev. 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. 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; http://www.albemarle.org/deptforms.asp?departinent--cdengmTo