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HomeMy WebLinkAboutWPO201800078 Review Comments WPO VSMP 2019-03-15COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902-4596 Phone (434) 296-5832 Fax (434) 972-4126 VSMP Permit Plan Review Project title: Keswick Hall Spa Project file number: WP0201800078 Plan preparer: Timmons Group, Craig Kotarski, P.E. craig.kotarski@timmons.com Owner or rep.: Historic Hotels of Albemarle, LLC, John Trevenen jrevenen@keswick.com Plan received date: 22 October 2018 Plan received date: 15 February 2019 (Rev.1) Date of comments: 16 November 2018 Date of comments: 15 March 2019 (Rev. 1) Reviewer: WW Associates, Inc. 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 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. SWPPP Section 1 — Please have the Owner execute the Registration Statement Certification and resubmit. Rev. 1 Response: The estimated start date has been revised accordingly. Rev. 1 Comment: Please provide Owner signature on the Registration Statement Certification prior to plan approval. 2. SWPPP Section 2 — Please provide a copy of the DEQ coverage letter when obtained. Rev. 1 Response: Acknowledged. Rev. 1 Comment: Comment was acknowledged by preparer. 3. SWPPP Section 9 — Please complete and sign the certification. Rev. 1 Response: Certification to be signed prior to final approval. Rev. 1 Comment: Noted. Please complete and sign the certification prior to plan approval. 4. SWPPP Section 10 — Per 9VAC25-880-70 Part K, provide the person with the authority to sign inspection reports or to modify the stormwater pollution prevention plan and have that person sign and date. Rev. 1 Response: Signatures to be obtained prior to final approval. Rev. 1 Comment: Noted. Please proved signatures prior to plan approval B. Pollution Prevention Plan (PPP) The PPP content requirements can be found in County Code Section 17-404. SWPPP Section 6 PPP meets Albemarle County Code Section 17-404 requirements. Rev. 1 Response: Acknowledged. Rev. 1 Comment: No further comment. Engineering Review Comments Page 2 of 5 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 project narrative in the design calculations booklet under Water Quality Compliance is to be expanded to reference phosphorus removal with on -site permeable pavement. Only purchase of nutrient credits is referenced. Rev. 1 Response: The calculation booklet has been revised accordingly. Rev. 1 Comment: Comment addressed. 2. Please correct the Stormwater Runoff Considerations under the E&SC Narrative on Sheet No. C3.0 to reflect the use of permeable pavement rather than bioretention. Rev. 1 Response: Stormwater Runoff Considerations have been revised accordingly. See Sheet C3.0. Rev. 1 Comment: Comment addressed. 3. The plan cover sheet and E&SC narrative indicate a disturbed/project area of 2.67 acres while the Water Quality Analysis area for VRRM indicates a disturbed/project area of 2.27 acres. Please reconcile the correct disturbed area and adjust BMP VRRM accordingly. Rev. 1 Response: The project limits of disturbance is 2.67 acres. Stormwater design and E&SC plans have been reconciled accordingly. Rev. 1 Comment: Comment addressed. 4. No VRRM spreadsheets provided in the Design Calculations and Narrative. Please note that the spreadsheets provided on the plans Sheet No. C6.3 BMP selection/practice is incomplete. BMP Practice No. 7 (Spreadsheet Item No. 3) information not reconciled for Drainage Areas A and B Summaries. Please provide. Please provide the complete VRRM spreadsheets in the Design Calculations and Narrative or delete Section 3 (VRRM Worksheet Summary) from the Table of Contents. Rev. 1 Response: Two (2) VRRM spreadsheets have been provided. Set titled "Keswick Hall — Spa Predeveloped Drainage Area Map" reflects curve number reduction calculations provided on Sheets C6.0 & C6.2. The second spreadsheet titled "Keswick Hall — Spa Postdeveloped" reflects the post development drainage area and associated quality/quantity treatment obtained from the use of the permeable pavement system. Runoff Volume and CN values are reflected on Sheets C6.0 & C6.2 as well. Rev. 1 Comment: Comment addressed. 5. Please provide a typical detail/section of the permeable pavement per the selected "Level Design". Please provide appropriate reservoir layer hydraulic design (i.e. storage for water quality treatment volume per Section 6.1 of VA DEQ SWM Design Spec. No. 7). Rev. 1 Response: See Sheet C6.1 for additional calculation information. Rev. 1 Comment: Comment addressed. 6. Provide a CDA calculation per Table 7.4 Permeable Pavement Design Criteria (VA DEQ SWM Design Spec. No. 7). Please include a drainage area map to delineate the drainage area directed to each of the permeable pavement surface areas. Also, the proposed permeable pavement surfaces to the east of SWM do not appear to treat any upgradient impervious areas and thus provide no treatment. Adjust VRRM BMP Drainage Area B accordingly. Provide on -site treatment or purchase additional nutrient credit. Rev. 1 Response: CDA design calculations have been provided on Sheet C6.1 alongside the permeable paver drainage area map. Permeable pavement surfaces of the SWM treat rainfall directly on the parking surface. Calculations have been revised accordingly and nutrient credit purchase amount updated. Rev. 1 Comment: Comment addressed. 7. Please annotate the Post Development drainage area map to denote which areas equal VRRM Engineering Review Comments Page 3 of 5 Spreadsheet Drainage Areas A and B. Rev. 1 Response: Annotation has been added accordingly. See Sheets C6.0 & C6.2. Rev. 1 Comment: Comment addressed. 8. SWM 4 denotes a routed 1-year water surface on plan Sheet No. C6.0 of 426.29 and 425.79 on page 6 of Section 5 of the Design Calculations and Narrative. Please reconcile. Rev. 1 Response: Water surface elevations have been revised accordingly on Sheet C6.0. Rev. 1 Comment: Comment addressed. 9. SWM4 on Sheet No. C7.1 denotes bottom/invert elevation of 424.00 while detail on Sheet No. C6.0 denotes 424.50. Please reconcile. Also, please add length of 48 inches CMP provided for SWM 3 and SWM 4 on Sheet No. C7.1 profiles. Rev. 1 Response: Detail on Sheet C6.0 has been revised accordingly. Lengths of SWM3 & SWM4 have been provided accordingly. Rev. 1 Comment: Comment partially addressed. Sheet C7.1 was not provided with submittal package. 10. The weir plate section for SWM 3 and SWM 4 on Sheet No. C6.0 denotes the use of a suppressed rectangular weir (i.e. without end contractions). The inputs for SWM 3 and SWM 4 on pages 11 and 13 of Section 5 of the Design Calculations and Narrative indicate that the weirs are end contracted. Please reconcile and adjust plans/calculations accordingly. Rev. 1 Response: HydroCAD calculations have been revised to remove weir end contractions and calculations have been revised accordingly. Rev. 1 Comment: Comment addressed. 11. The 10-year routed flow elevations for SWM 3 and SWM 4 on Sheet No. C6.0 do not match the elevations on page 31 (SWM 3) and page 33 (SWM 4) in Section 5 of the Design Calculations and Narrative. Please reconcile. Rev. 1 Response: 10 year flow elevations have been revised to match the 10 year HydroCAD calculations accordingly. Rev. 1 Comment: Comment addressed. 12. Please note that additional comments may be generated based on responses to the comments. Rev. 1 Response: Acknowledged. Rev. 1 Comment: Comment acknowledged. 13. Rev. 1 Comment: It appears that the proposed grading will direct runoff from the grassed areas onto the permeable pavers in several locations. Please provide pretreatment for the grassed areas draining to the permeable pavers to prevent sediment wash -on. 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 add WPO201800078 to the cover sheet of the plans, calculations, and SWPPP. Rev. 1 Response: WPO # has been added to the plans, calculations and SWPPP. Rev. 1 Comment: Comment addressed. 2. Land disturbing activities are proposed within the WPO buffer (landward 50 feet). The land disturbing activity will be permitted by the Albemarle County Program Authority provided that a Mitigation Plan satisfying the requirements of Albemarle County Code Section 17-406 to include fee is submitted to and approved by the Administrator. VSMP approval will not be issued until Mitigation Plan is approved. Rev. 1 Response: A mitigation plan has been provided for review along with fee and checklist. Rev. 1 Comment: A mitigation plan has been provided with this submittal. Please refer to additional comments. Engineering Review Comments Page 4 of 5 3. Place inlet protection on storm drain inlet structures 122 and 126 on Sheet No. C3.2. Rev. 1 Response: Additional inletprotection has been added. Rev. 1 Comment: Comment addressed. 4. Please label critical/steep slopes as managed steep slopes. Rev. 1 Response: CriticaUsteep slopes have been labeled accordingly. See plan sheets. Rev. 1 Comment: Comment addressed. 5. Please add limits of clearing and grading to the demolition plan. Rev. 1 Response: Limits of disturbance has been added to the demolition plan. Rev. 1 Comment: Comment addressed. 6. Please add a stockpile location. Rev. 1 Response: A stockpile location has been added on the southeast side of the development. See Sheet C3.1. Rev. 1 Comment: Comment addressed. 7. Please address whether cut or fill balances have 10,000 cubic yard deficit or more and, if so, a waste area onsite must be identified or another approved and permitted site will be required. Rev. 1 Response: This project will not produce cut or fill balance deficits of more than 10,000 cubic yards. Rev. 1 Comment: Comment addressed. 8. Please provide Contractor's staging and parking areas. Rev. 1 Response: A staging and parking area has been indicated on Sheet C3.1. Rev. 1 Comment: Comment addressed. 9. The sediment trap has been graded such that surface runoff will pond behind the 419 elevation along the northeast and east side of the trap. Provide grading to provide positive drainage to the trap. Rev. 1 Response: Sediment trap grading has been revised to ensure positive drainage. See Sheet C3.1. Rev. 1 Comment: Comment addressed. 10. The sediment trap H = 5 feet and Ho = 4.0 feet. Thus the embankment top width is to be 4.5 feet. Please adjust detail on Sheet No. C3.0 and grading on Sheet No. C3.1 to reflect 4.5 feet. Rev. 1 Response: The detail on Sheet C3.0 has been revised to reflect a 4.5 ft embankment width. Sediment trap grading has been revised as well. See Sheet C3.1. Rev. 1 Comment: Comment addressed. 11. Rev. 1 Comment: Please provide a signed seal on the mitigation plan. 12. Rev. 1 Comment: Please reference the WPO # for the project on the mitigation plan. 13. Rev. 1 Comment: Show the critical slopes on the mitigation plan in accordance with the checklist requirements. 14. Rev. 1 Comment: The mitigation area shall be double (2x) the disturbed area. It appears that a 1:1 ratio is provided. Please revise the plans accordingly. 15. Rev. 1 Comment: Please provide inlet protection on storm drain structure 136. 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 Engineering Review Comments Page 5 of 5 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. Please coordinate Nutrient Credit Purchase with the County's Management Analyst prior to purchase. Evidence of purchase of required level of nutrient credits is required prior to Applicant receiving a grading permit. 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 nutrient purchase, ideally) 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; htti)://www.albemarle.orii/dei)tforms.asD?dei3artment=cden2wi)o File: WPO201800078 Keswick Hall Spa 11-16-18.doc