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HomeMy WebLinkAboutWPO201900047 Review Comments WPO VSMP 2020-09-25Cil 1T COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902-4596 Phone (434) 296-5832 Fax VSMP Permit Plan Review Project title: Hampton Inn VSMP Project Tile number: WPO201900047 Plan preparer: Bohler Engineering VAABohlerEng.com [ Iwright(cr�,bohlereng.com ] Owner or rep.: PT Hotel, LLC Plan date: 2 Aug, 2019 (Rev 1.) 11 Sep, 2019 (Rev. 2) 3 Jan 2020 (Rev. 3) 20 Aug 2020 Plan received date: 14 Aug 2019 (Rev. 1) 16 Sep 2019 (Rev. 2) 8 Jan 2020 (Rev. 3) 21 Aug 2020 Date of comments: 27 Aug 2019 (Rev. 1) 25 Sep 2019 /rev. 2-Oct 2019/Alb. County (Rev. 2) 21 Feb 2020 (Rev. 3) 25 Sep 2020 Reviewer: WW Associates, Inc. (initial /Rev. 1) / Rev. 1, 2, 3 (J. Anderson) 972-4126 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 for several reasons outlined in D. (ESCP) at items 9. 12, 13, below (max. retaining wall height / easements). 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. Registration Statement: a. Section IV E states that the discharge is to an MS4. This appear correct for program compliance purposes since project is located within Alb. County MS4 boundary. b. Section IV F requires the provision of a 6" order HUC. Please provide the 12-digit code, or the 2- letter, 2-digit number code. (Rev. 2) Addressed. c. Section VI: the Certification must be signed and dated. (Rev. 2) Comment persists. (Rev. 3) Addressed. 2. Provide the Notice of Permit Coverage, once issued. (Rev. 2, 3) Comment persists. B. Pollution Prevention Plan (PPP) The PPP content requirements can be found in County Code section 17-404. This plan is disapproved. 1. Please provide an I I" x 17" plan sheet that shows the second construction entrance, with settling pit for washdown. (Rev. 2) Partially addressed. As ollow-up: Please show settling pit for washdown. Show initial rain gauge, chemical /solvent storage, and concrete washout locations. (Rev. 3) Addressed. 2. Show fueling in Table C of Section 6. (Rev. 2) Addressed. (Incl. at Table B.) 3. Provide the responsible person prior to Grading Permit issuance. (Rev. 2) Revise Section F. to comply with 9VAC25-880-70, Part II, section A.4.e. (Rev. 2) Addressed. Engineering Review Comments Page 2 of 6 4. Revise Section G to comply with 9VAC25-880-70, Part II, section A.4.f. This requirement is focused on training personnel, not the construction or inspection/duties of personnel. (Rev. 2) Addressed. 5. Section 7 states that bacteria are a TMDL basis for the Rivanna River. State here the measures that will be taken to ensure that fecal coliform bacteria do not leave the site. (Rev. 2) Addressed, 6. Section 8: Qualified Personnel must be identified prior to Grading Permit issuance. (VSMP /WPO Plan must be approved prior to approval of the Final Site Plan /FSP.) (Rev. 2) Comment persists. Applicant response: `Acknowledged.' (Rev. 3) Persists. Applicant response (8/20/20 letter): `Qualified personnel shall be identified prior to Grading Permit issuance.' 7. Section 9: The signed certification must be submitted prior to Grading Permit issuance. (Rev. 2) Comment persists. Applicant response: `Acknowledged.' (Rev. 3) Addressed. 8. Section 10: The Delegation of Authority should be provided prior to Grading Permit issuance. (Rev. 2) Comment persists. Applicant response: `Acknowledged.' (Rev. 3) Persists. Applicant: `The Delegation of Authority will be determined prior to Grading Permit issuance.' 9. Provide a legend for the hashmark symbols used in the port-a-john, dumpster, fuel pan and materials stockpile areas. (Rev. 2) Addressed. C. Stormwater Management Plan (SWMP) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This plan is disapproved. The stormwater management plan content requirements can be found in County Code section 17-403. Note items 1. 3, below, this section, then skip this section (since comments addressed, or if they persist, are required to be met prior to Grading Permit issuance, not VSMP /WPO plan approval) and go to Sec. D. Erosion and Sediment Control Plan since several comments there more nearly pertain to the SWM Plan than the ESC Plan. Please address items 9. 12, 13 (Sec. D.) for SWM Plan and VSMP /WPO plan approval. 1. Nutrient [credits] must be purchased before final VSMP plan approval. Section 17-502 provides the requirements for acquisition of offsite nutrient credits. Provide required documentation for purchased credits. Please coordinate with Ana Kilmer (434.296-5832-x3246) prior to purchase, else purchase documents may require revision. (Rev. 2) Comment persists. Applicant response: `Nutrient purchase documents have been provided on Sheet C-901. Nutrient purchase will occur prior to plan approval, once all stormwater management comments have been addressed and no further revisions are required.' Also: in addition to providing documents on the plan, it is imperative to coordinate with Ms. Kilmer prior to nutrient credit purchase. (Rev. 3) Comment revised to read: Nutrient credits must be purchased prior to Grading Permit issuance, but purchase is not required for VSMP plan approval. 2. Provide a maintenance and inspection schedule for the permanent stormwater control practices, detention and isolator row. Also, items 6 and 13, below. (Rev. 2) Addressed. 3. Coordinate a stormwater control maintenance agreement with Ana Kilmer as soon as possible. Agreement is required under 17415, and is prerequisite to both Grading Permit and FSP approval. (Rev. 2) Comment persists. Applicant response: `Acknowledged.' (Rev. 3) Persists. Applicant: `The Stormwater Control Maintenance Agreement shall be coordinated prior to final plan approval.' As follow-up: Engineering encourages coordination as soon as possible since Maintenance Agreement must be recorded prior to easement plat approval, and easement plat approval is required prior to VSMP /WPO plan approval. 4. Stormwater conveyance piping sizes not specified. Provide for review. (VDOT LD-204. LD-229) (Rev. 2) Addressed, 5. Show pre- and post -development Tc calculations. (Rev. 2) Partially Addressed. As follow- Cannot locate pre -development Tc calculation on sheet C-900. Please guide reviewer to this information. (Rev. 3) Addressed. 6. The Isolator Row is a Practice 17 filtering device. Please correct the VRRM spreadsheet, line 14b. Also, include with plans pg. 34-37 (portion of O&M Manual) of .PDF file at: hays://www.swbmp.vwrrc.vt.edu/wp- content/uploads/2017/10/Filter Application StormTech-Isolator-Row Item- l.pdf# ap ee=34 ). (Rev. 2) Addressed. New: (10/2/19) Engineering Review Comments Page 3 of 6 7. Recommend project site area and limits of disturbance be listed on C0.0. (Rev. 2) Addressed, 8. Since storm runoff releases to a natural conveyance downslope of pipe outfall, compliance requires energy balance, which is provided. Given this, channel protection analysis is complete at riprap section at outfall. No need to evaluate at POI-1, or discuss POI-L Likewise, recommend revise SWM Narrative to reflect flood protection is met using 9VAC25-870-66.C.2.b, in which case, POI -A analysis is not required. (Rev. 2) Addressed, 9. C-900: Water Quality BMP Analysis makes ref. to Isolator Row. Provide isolator row plan /profile details, as well as installation details for this stormwater quality -related BMP. Plan -profile -details required for adequate installation, and construction inspection. (Rev. 2) Addressed, C-901 10. Stormwater Detention System — Outlet Structure Detail: If this is (sheet C-202) Str. STM A-30 revise detail caption to clarify this is the case (if outlet structure detail is STM A-20, please revise detail to clarify). Also: (Rev. 2) Addressed. a. Low flow orifice < 3" DIA is prone to blockage. Engineering requires 3" Min orifice diameter. Revise weir plate design, detention system design, and routings, as needed. (Rev. 2) Withdrawn. b. Provide weir plate data: material, gauge, connection to MH wall (pre -fabricated /field -built, etc.) c. Ensure weir plate connection with MH /outlet structure is watertight. Provide notes /specifications, as needed. d. Provide low -flow orifice trash rack, and detail. e. Label critical elevations of 45" StormTech ® MC-3500 detention system profile. For example: underdrain, stone chamber beneath system, top of chamber, final grade, etc. 11. Operation of bypass is unclear. Provide plan /profile design information for bypass /bypass structures. Clarify whether weir plate is located in STM A-20 or A-30. Clarify location and elevations of bypass pipes. Show bypass pipes in profile. Provide schematic detail aligned /consistent with C-203 Sequence, Phase I, Note 7, where bypass pipes are introduced. Explain how permanent bypass of a portion of post - developed storm runoff works. Clarify post -developed bypass runoff via narrative and schematic detail. (Rev. 2) Partially addressed. Please consider possibility underground detention may become obstructed (consider site runoff routed to system, not State Farm Blvd. off -site runoff that bypasses the site). Engineering recommends design allow bypass of on -site runoff of the underground detention system in event system experiences obstruction or unanticipated issue. (Rev. 3) Withdrawn. Applicant: `Recommendation acknowledged. The bypass pipes have been oversized to ensure adequate capacity and limit the potential of obstruction. In the event that the bypass were to be obstructed, the underground detention system would back up from the two inlets at the northwest side of the development and overtop the curb, flowing down grade to the outfall location, providing overland relief for the proposed building.' 12. Consolidate SWM details, as much as possible. For example, only plan -view schematic of StormTech system is an outline of the system on C-202, which is insufficient. Include plan -view of detention system on SWM plan sheet, rather than ESC plan sheet. Label overall L x W of detention system. (Rev. 2) Addressed, 13. It is unclear after reviewing plan and technical information whether the entire extent of the MC-3500 system is an isolator row, or if only a portion is. Clarify using linework, notes, labels, etc., extent and location of isolator row. Ensure plan provides sufficient detail to guide installation of inspection ports, non -woven fabric, etc. (Rev. 2) Addressed. 14. Provide calculation using L x W of StormTech system to show VaRRM.xls required volume is provided: 5,842.49 FV. (Rev. 2) Partially addressed. As ollow-: Details on C-903 (* footnote) appear to indicate 12" stone above a 9" stone foundation, or 21" stone total is required to provide design treatment volume. Please confirm minimum installed storage meets required (VaRRM .xls) treatment volume. (Rev. 3) Addressed. Applicant: `The SWM detention elevations have been confirmed to match the engineering design, conforming with the VaRRM values shown.' Engineering Review Comments Page 4 of 6 D. Erosion and Sediment Control Plan (ESCP) — Comments addressed with Rev. 2, 3 in light grayscale text. Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESCP. This plan is approved, yet review comments listed in this section with prior reviews relate to SWM plan more than the ESC plan, and several persist. Please note items 9, 12, 13, below, and address for SWM Plan and VSMP /WPO plan approval. 1. Intentionally blank 2. Provide the name of the certified land disturber. Also See. B., above, PPP. Listed on plan sheet C-101. 3. A waiver is required for the proposed disturbance within the critical slope area. Please provide evidence that a waiver has been obtained for this disturbance. (Rev. 2) Withdrawn, review error. Proposed grading on managed slopes is a permitted use, and is complaint with 18-30.7.5. New: (10/2/19) C-201 4. Remove silt fence unless parallel with contours. 5. Provide alternative ESC measures for SF removed at item 4' DD, for example. 6. Label floor dimensions of sediment trap. Label ST weir dimensions. (Also, item 22, below). 7. DA upslope of silt fence may not exceed 100', which appears to be the case at the N comer of LOD. Revise SF design consistent with VESCH, Yd Edit, 1992, 8. Revise CE label to read PCE. VA Uniform Coding System legend is fine, but project requires a paved construction entrance. Revise Legend to include Mulch (MU). Revise sheet C-202, as well. C-202: 9, Note: PE -sealed geotechnical retaining wall design is required for Site Plan approval. (Rev. 2) Comment persists. Applicant response: `Acknowledged. PE -sealed geotechnical retaining wall designs will be provided prior to Site Plan approval.' (Rev. 3) Partially addressed. As follow-up: Hillis -Carnes Engineering Associates retaining wall design titled Hampton Inn Charlottesville, d. 8/12/20 (10 sheets) indicate at least at one location along each of four (4) walls, labeled Walls 1, 2, 3, 4, where wall ht. from base of wall (proposed grade) to top of wall exceeds maximum ht. allowed for retaining walls located on managed steep slopes. Max. In. does not exceed max. allowable (wall) ht. by much, but each wall appears to, for example: a. Wall 1, Sta. 1+20, 10-block ht., or —7.33' ht. b. Wall 2, Sta. 0+80, 10-block ht., or —7.33' ht. c. Wall 3, Sta. 0+90, 9-block ht., or —6.66' ht. d. Wall 4, Sta. 1+10, 10-block ht., or —7.33' ht. Note: Height in excess of 6' could, as an option, be addressed with a 5r' wall, which itself may not exceed 6' max. ht. if located on managed steep slopes. Revise design to ensure max. wall ht. of each stepped retaining wall located on managed steep slopes does not exceed 6'. 10. Show /label SWM Facility Easement (detention /isolator row). Provide SWM Facility Access Easement that extends to public RW (State Farm Blvd). (Rev. 2) Partially addressed. As follow-up: SWM Facility easement linework is show. Please label linework (SWM Facility Access Easement is labeled.) (Rev. 3) Addressed. Applicant: `SWM Facility easement is labeled with SWM keynote as described on Sheet C- 103.' 11. Provide, show and label public drainage easement for permanent stormwater conveyance downstream of detention system. (Rev. 2) Partially addressed. As follow- Easement linework is show. Please label linework. (Rev. 3) Addressed. Applicant: `The drainage easement has been labeled with a keynote as described on Sheet C-103.' 12. Submit easement plat application for items listed at 10 and 11, above. Ensure easement width for detention system conforms with drainage easement diagram at ACDSM, p. 15, link to Design Manual: (Rev. 2) Engineering Review Comments Page 5 of 6 Comment persists. Applicant response: `An easement plat will be provided prior to plan approval.' http://www.albemarle.orglupload/images/fonns center/departments/community development/forrns/desi�n standards manual/Albemarle County Design Standards Manual 2015-04-25 draft.pdf (Rev. 3) Persists. Applicant: `Easement plat shall be submitted under separate cover.' 13. Note: Recorded deed of easement (deed /plat) is required prior to VSMP /WPO plan approval. (Rev. 2) Comment persists. Applicant response: `Acknowledged. The recorded deed of easement will be provided prior to plan approval.' (Rev. 3) Persists. 14. Dimension riprap (L x W x D) at storm pipe outfall near west corner of site. 15. Add labels that correlate this sheet with C-203, VII, Sequence, Phase I, Note 7., bypass pipes (proposed and existing 2 1 " bypass). C-203 16. Sequence of Construction, Phase I, Note 7: Label 21" RCP pipe on C-202. (Rev. 2) Comment appears to persist. Reviewer cannot locate label. (Rev. 3) Withdrawn; review error. "Per the sequence of Construction, the existing 2 1 " RCP bypass pipe is to be removed in Phase I, following installation of the proposed 24" RCP re-routed bypass pipe. As the existing 2l" bypass is to be removed in Phase I, it is not shown in the Phase H E&S Control Plan on Sheet C-202.' 17. Include county Construction Record Drawing (As -built) policy on VSMP plan; link to policy: http://www.albemarle.ore/upload/images/forms center/departments/Community Development/forms/En ine eeriniand WPO Forms/WPO VSMP Construction Record Drawings Policy 23Mav2014.pdf 18. Provide /include manufacturer -specific installation and periodic inspection guidelines on the plan. Also, comment at C.6., above. 19. Provide additional sequence /text description of transition from Phase I to Phase II, especially measures required once sediment trap is removed, but before site is stabilized and detention system is on-line. (Rev. 2) Partially addressed. As ollaw-W: It appears Note 7 should precede Note 51 since it appears the 24" permanent (bypass) pipe must be installed prior to the sediment trap. Also, please see Engineering review comments on Hampton Inn FSP (SDP2020-00004), d. 14 Feb 2020. (Rev. 3) Addressed. Applicant: `The sediment trap has been revised to remove the conflict with the proposed 24" RCP bypass pipe.' 20. Provide additional sequence that details how /when detention system is brought on-line, relative to site stabilization. (Rev. 2) Partially addressed. As follow-up: Revise Note 9 to clarify that the StormTech system (underground stormwater detention facility) may not be connected and should remain isolated from upstream storm conveyance pipes until all contributing upslope areas are stabilized (stone /pavement, etc.). Also, revise Note 8 to indicate that contractor may not remove sediment trap (or any active ESC measure) without county ESC inspector approval. (Rev. 3) Addressed. Applicant: `The Sequence of Construction has been revised to provide additional clarification on the installation of the underground stormwater detention facility and removal of the sediment trap.' C-204: 21. Include VDOT standard details, including: ST-1, IS-1, MH-1. 22. Show sediment trap floor dimensions on C-201 (Also, item 6, above). 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. Since print submittals must be quarantined, however, Engineering welcomes and encourages .PDF preview of plans or Hillis -Carnes retaining wall design. eewew. Staff not available for in person meetings during pandemic, but available for MS Teams video -conference. Process: After approval, plans will have to be bonded. The bonding process is begun by submitting a bond estimate request Engineering Review Comments Page 6 of 6 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 have to be completed by the owner and submitted along with cash, certificates or sureties for the amounts specified. The agreements will have to be approved and signed by the County Attorney and County Engineer. This may take 24 weeks to obtain all the correct signatures and forms. Stormwater Management Facilities Maintenance agreements will also have 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 have to be submitted along with court recording fees. After bonding and agreements are complete, county staff will 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 have 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 must 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, httD://www.albemarle.orpJdei)tfonns.aSD?deDartrnent�dengwDo WPO201900047 Hampton Inn 092520 rev1doex