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HomeMy WebLinkAboutWPO201900062 Correspondence 2022-03-2330 Scale, LLC 871 Justin Drive, Palmyra, VA 22963 Ph. 434.242.2866 mikea.30scale.com SCALE 3 1 N E E R I N G March 17, 2022 Mr. Matthew Wentland Department of Community Development 401 McIntire Road Charlottesville. VA 22902 RE: Southwood — Phase 1 - Clean Earth Fill Plan — North Area WPO 2019-00062 Amendment TM 90A1-1D -Albemarle County, Virginia Dear Matt, To accompany our electronic resubmission of the referenced WPO plan and H&H Computations, the below describes how we have addressed your comments (Rev. 1) dated March 9, 2022: 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. Will the existing DEQ permit be used to cover this area? If so, please provide a completed and signed DEQ Registration Statement modification if the area increased from the original permit, or a new Registration Statement if not. (Rev. 1) Response noted. A grading permit cannot be issued until the modification has been processed by DEQ. RESPONSE: Yes. The existing DEQ permit for Southwood Redevelopment — Village 1 (VAR10P133) will be used to cover this area. A completed and signed DEQ Registration Statement modification application has been included with the resubmission. The existing Village 1 SWPPP will need to be updated once this plan is approved or a separate SWPPP provided. (Rev. 1) Response noted. RESPONSE: The Village 1 SWPPP will be updated with the DEQ Registration Statement modification, a copy of the approved VSMP Plans for the Clean Earth Fill, and an updated PPP to include the new 1.01-acres of disturbed area. B. Pollution Prevention Plan (PPP) The PPP content requirements can be found in County Code section 17-404. 1. The existing Village 1 PPP will need to be updated once this plan is approved. (Rev. 1) Response noted. RESPONSE: Acknowledged. The existing Village 1 PPP will be updated once the plan is approved. SCALE ENGINEERING 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. This plan cannot be approved until the 0.43 Ib/yr of nutrient credits have been purchased. Please contact Ana Kilmer prior to purchasing credits. Since this project drains to impacted streams, the credits will need to be purchased from the Ivy Creek or Rivanna River credit banks, since they are located in the same HUC8. [9VAC25-900-91.13] (Rev.1) Please note that the credits will need to be purchased from the Ivy Creek or Rivanna River credit banks. RESPONSE: A letter of availability for 0.20 lbs. of nutrient credits from the Ivy Creek credit bank has been included on the plans and in the H&H Calculations Booklet. 2. A SWM maintenance agreement will be required. Please contact Ana Kilmer to begin this process. (Rev. 1) Comment withdrawn, a new agreement is not needed. RESPONSE: Acknowledged. 3. Land used as Forest and Open Space in the VRRM (post -development) will need to be protected by an easement and cannot be disturbed during construction. Show this area on the plans. Forest and Open Space will require a plat and deed. (Rev. 1) Comment addressed. RESPONSE: Acknowledged. 4. The maintenance access to the pond should not exceed 15% slope and will need to provide access to the riser structure. [DEQ BMP Specs.] (Rev. 1) Comment addressed. RESPONSE: Acknowledged. 5. Remove 'private' from the SWM easement label. A plat and deed will be required for the SWM easement. (Rev. 1) Comment addressed. The plat and deed will need to be recorded prior to LOR approval. RESPONSE: Acknowledged. 2 1 P a g e SCALE ENGINEERING 6. Since the pond is being used for water quality, provide details on how it meets the design requirements in DEQ BMP Spec. 15. This includes the pretreatment requirements in section 6.4. (Rev. 1) Comment partially addressed. Per section 6.4, the forebay should be at least 4' deep and have an aquatic bench. The bench should be a minimum of 4' wide at a depth of 18" below the water surface. RESPONSE: As discussed, the ED Pond has been revised to be a SWIM Pond. As such, the SWIM pond provides stormwater detention to address channel erosion and flooding, and does not provide water quality. As a result, the forebay design requirements per Section 6.4 do not need to be met. However, the forebay as designed will remain to facilitate future cleanout of accumulated sediment from the forebay/pond. The 0.09 lbs. of phosphorus removal credited to the ED Pond will be purchased. Refer to the Letter of Availability to purchase all of the required 0.20 Ibs/yr of nutrient credits. Provide a landscaping plan per Spec. 15 section 6.7. (Rev. 1) Comment addressed. RESPONSE: Acknowledged. S. The maximum side slopes allowed by the County inside a basin is 3:1. (Rev. 1) Comment addressed. RESPONSE: Acknowledged. 9. The height of the fill is not to exceed 8' above natural grade, which is the existing grade. (Rev. 1) Comment addressed. RESPONSE: Acknowledged. 10. Show more detail on the swale that is being created next to Mobile Home #780. It appears that the fill is encroaching onto the corner of the home and past the limits of disturbance. Ensure all runoff is directed away from the home. (Rev. 1) Comment addressed. RESPONSE: Acknowledged. 11. Show existing utilities on the profiles. (Rev. 1) Comment addressed. RESPONSE: Acknowledged. 31 ENGINEERING 12. The sanitary sewer will need to be outside of the SWM pond. There is also over 10' of cut proposed over the sanitary line and does not appear feasible. (Rev. 1) Comment addressed. RESPONSE: Acknowledged. 13. The plan is currently under Zoning review and may generate additional comments. (Rev. 1) Comment addressed. RESPONSE: Acknowledged 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. Revision 1 comments 1. Include silt fence along Bitternut Lane at the toe of the proposed slope. RESPONSE: Silt fence has been added along Bitternut Lane at the toe of the proposed slope. We thank you for your time to review this request. Please contact me if you have any questions or require additional information to complete your review. Sincerely, CFM Cc: Mr. Andrew Vinisky, Habitat for Humanity of Greater Charlottesville Mr. William Thiessen, Habitat for Humanity of Greater Charlottesville Mr. Bryan Rieckmann, P.E., Faulconer Construction Company Mr. Bryan Cichoki, P.E., Timmons Group Mr. Clint Shifflett, P.E., Timmons Group 4 1 P a g e