Loading...
HomeMy WebLinkAboutWPO202100035 Review Comments WPO VSMP 2021-08-18V 401 McIntire Road, North Wing County of Albemarle Charlottesville, VA 22902-4579 COMMUNITY DEVELOPMENT DEPARTMENT Telephone:434-296-5832 WWW.ALBEMARLE.ORG VSMP Permit Plan Review Project: Airport Road Pump Station Project Project file number: WPO2021-00035 Plan preparer: Brad Weiss, PE, Project Engineer — Short Elliot Hendrickson, Inc. (SEH) bweiss(a),sehinc.com 3535 Vadnais Center Drive, St. Paul, MN 55110 Owner or rep.: Michelle Simpson, PE [ msimpson(a),,rivanna.mg ] Rivanna Water and Sewer Authority, 695 Moores Creek Lane Charlottesville, VA 22902 Plan received date: 30 June 2021 Date of comments: 18 Aug 2021 Reviewer: John Anderson, PE 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 reasons listed below. The VSMP application content requirements can be found in County Code section 17-401. A. Stormwater Pollution Prevention Plan (SWPPP) 1. 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 / Ref. p. 134 of 160p. initial plan submittal, request Applicant revise, as follows: a. SWPPP Sec. 1 / Registration Statement: Complete Registration Statement: i. Sec. I/A.,B.,C (Recommend check C. box `yes') ii. List Sec. II.B. Address for locational/navigational purposes as Berkmar Drive Ext., North Terminus iii. Complete Sec. IV.B. —Estimated project dates iv. Complete Sec. VI: Print /sign /date b. SWPPP Secs. 4-5: Update with revised plans c. SWPPP Sec. 6. i. A. -Exhibit /Please revise to clarify (initial) locations of. 1. Rain gauge 2. Solid waste dumpster (if any) 3. Portable sanitary facility (ports John) 4. Paved construction entrance (may not use Berkmar Drive Ext. as PCE) 5. On -site fuel storage (if any) ii. E. -Please name individual responsible for PPP d. SWPPP Sec. 8 - Please name individual responsible for SWPPP compliance inspections, may be qualified RWSA, SEH, or contractor personnel. Required to receive Grading Permit, but not required for WPO plan approval. e. SWPPP Sec. 9, Signed Certification: Provide title /sign /date. B. Pollution Prevention Plan (PPP) — See above, Sec. 6. The PPP content requirements can be found in County Code section 17-404. Engineering Review Comments Page 2 of 6 C. Stormwater Management Plan (SWMP) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This plan is disapproved for reasons listed below. The stormwater management plan content requirements can be found in County Code section 17-403. 1. C12,C13 a. Ref. Engineering review comments, SDP202100056 (8/4/21), and revise proposed grade accordingly. b. Add linework to graphically explicitly indicate upslope point where defined swale begins. c. Label bioretention basin, L x W, in plan view. d. Label length of stone pre-treatment, each end of basin. e. List W media required for bioretention basin construction. [ Recommend number pages of Calculation Packet, and reference relevant pg. in calc. packet.] f. Revise plan view of basin to show buried stone storage at south end of basin, similar to the way buried stone storage is shown along west edge of basin. g. Label all basin elevations, including base of 24" storage area, base of fill media, pea gravel, etc. h. Revise `bottom elevation' label to read `top of fill media.' i. Include Construction Record Drawings (As -built) for VSMP on the plans: https://www.albemarle.orp/home/showpublisheddocument/3381 /637327510536700000 j. Include BMP clearinghouse bioretention installation (8.2), construction inspection, first -year maintenance operations (9.2), and maintenance inspections (9.3) information on the plan. k. Include attached periodic bioretention inspection checklist on the plans. 1. Indicate locations of 3 trees and 15 shrubs in plan view, identify using planting legend symbols. 2. Note: A 160-p. composite document was submitted: Application, certification (Miles B. Jensen, VA PE), proprietary document (TOC, Site Description, ESC Plan, SWM Plan, Tables, Appendices). 20-sheet plan comprises last pp. of the document. a. Please divide this document into separate submittals: Application, Calculation Packet (incl. USDA-NRCS soils map, drainage map/s, pre- post -condition, etc.), SWPPP, WPO plan. b. Additional /specific: i. PG. 9 (of 160-p..PDF): Revise ref. at 3.1.1 to require a paved construction entrance, rather than a temporary stoned construction entrance. See comment/s elsewhere requesting ACDSM paved wash rack detail be placed on plans. ii. PG. 14: 4.2.2 Ref. to Flood Protection — East discharge to meeting requirements for 9VAC25-870-66.C.2.b. indicates discharge to a (manmade) storm conveyance system that experiences periodic flooding. As discussed 8/17/21 (Weiss -Anderson), it is unclear that proposed east discharge from the bioretention basin is to a manmade system. Please clarify (via narrative, note, graphic linework, labels) that bioretention basin discharge is to an existing manmade storm conveyance system that experiences periodic flooding. iii. Also, 4.2.2 makes ref to 2-yr storm event peak discharge of 0.92 cfs, with runoff velocity of 2.86 ft/s. Plan must indicate discharge is to a manmade conveyance system, and is non -erosive, or is to a defined channel (as indicated by field -run or GIS contours) or to a natural receiving stream. 2-yr event discharge of 0.92 cfs at 2.86 ft/s to undefined parallel contour slopes may result in near- or long-term erosion issues for downslope storage facility. Revise design to show discharge (to East) is to a manmade conveyance system. As discussed 8/17, RWSA site elevation is nearly 100' higher than U.S. Rte. 29. Engineering must evaluate possible impact of site discharge on downstream receiving properties. From county GIS: Engineering Review Comments Page 3 of 6 iv. A public drainage easement is required between SWM facility outfall and receiving manmade system, or to point site discharge reaches a receiving stream [Ref. 18-32.7.4.2]. v. PG.41 (Postcondition—East drainage) 1. Construction sequence: a. At item 1, and wherever plan references a gravel or stone construction entrance, edit to read paved construction entrance with spray wash. b. At item 4, revise sequence to clarify that bioretention basin cannot be constructed unless all upslope disturbed areas are stabilized. Items that follow item 4 include rough grading, grading, building and utility construction, each with land disturbance. 2. Erosion control: a. At item 6, delete reference to University of Virginia. b. Re. item 7, show stockpile area, graphically, provide temporary ESC measures to limit sediment transport from soil stockpile. 3. General notes: a. At item 1, please clarify. Why should basin require restoration? What VDOT specification supersedes VA DEQ design specification? b. At item 2, reference VESCH, not VDOT specification. c. At item 3, please reference VESCH, not VDOT. d. At item 3, grading beyond plan -approved limits of land disturbance is impermissible. If Applicant anticipates grading beyond plan LOD, recommend revise LOD to accommodate anticipated grading need. vi. PG. 42 (Postcondition -bioretention basin) a. Clarify note that reads `130 LF gravel basin access drive restore with erosion matting following removal.' Permanent SWM facility requires permanent access, which may be turf, 10' wide (Min.), 20% slope (Max.). b. `See Sheet C 12 for restoration details' label is confusing. Restoration suggests bioretention basin is damaged, in need of restoration. Clarify. c. Postcondition may claim forest /open space land cover only with deed of dedication of platted forest /open space easement. Submit easement plat application, or revise design, calculations, VaRRM.xIs to eliminate postcondition FOS land cover (0.16 Ac.). vii. PG. 44 (Postcondition—West drainage) Engineering Review Comments Page 4 of 6 1. Postcondition may claim forest /open space land cover only with deed of dedication of platted forest /open space easement. Submit easement plat application, or revise design, calculations, VaRRM.xls to eliminate postcondition FOS land cover (0.09 Ac.). viii. PG. 48 (VaRRM.xis) 1. Provide Site tab data /image from DEQ Virginia Runoff Reduction Method New Development Compliance Spreadsheet. ix. PG. 60/other SCS Graphical peak discharge computations that rely on VaRRM.YJs may need to be revised if VaRRM.xls is revised to eliminate postcondition forest -open space. x. PG. 64 /Required storage volume, (Vs) may increase if SCS graphical peak discharge values change. xi. PG. 68 pipe flawing full, storm drains at Laurel Park Ln: Clarify whether table values exclude any runoff expected to reach storm drains at Laurel Park Ln. That is, storm drains at Laurel Park Ln. were designed to serve separate, earlier development at HTC. Airport Road pump station analysis must include all sources that contribute runoff to the existing storm drains. Please provide explicit calculations that clearly identify sources of runoff to existing storm lines, and that indicate the existing storm drains at Laurel Park Ln. serve prior development and can accommodate additional Airport Road pump station runoff within the full -flow capacity of existing storm pipes to project limits of analysis, in an open -channel non -pressurized state. 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 for reasons listed, below. The erosion control plan content requirements can be found in County Code section 17-402. 1. Revise to include WPO-related sheets only, please remove sheets C14, DCO2, DC04. 2. Revise plan title to include reference to WPO202100035. 3. Provide conventional plan title sheet that includes: a. Adjacent parcel information, including: i. Deed book -page reference. ii. Vicinity map, and no greater than 1"=2,000' iii. Owner, related zoning (ZMA) or site (SDP) plan. b. PE -seal (sign /date) c. Note regarding future VDOT Berkmar Drive Ext. project. d. Note regarding proposed length and location /alignment of new 24" DI water main. e. Limits of disturbance (x.xx Ac.), to include the approximate linear Area of Land Disturbance associated with installation of approximately 4500 LF of 24" water main. f. Note: ESC measures require bond. ESC measures for linear portions (24" water main) on off -site parcels not owned by RWSA require those owners be party to the bond, unless a contractor posts the WPO plan bond. RWSA should plan accordingly, to either arrange signature information /signatures of owners (of all parcels 24" water main transits) on the WPO plan (ESC) bond, or, to require RWSA contractor post WPO plan bond (ESC/SWM). 4. Note: (Temporary construction) easements appear to be required to constructlinstall 24" DI water main beyond public RW, beyond RWSA tax map parcel 32-41A2. Acquire and record temporary construction easements, as needed, to install 24" DI water main. Provide Engineering copy of recorded easements. 5. C05: Please check label, which may require edit, or deletion. BBB BERKMAR DR BURY RYDRNLTWN ME RATED 4D.6 G V. A V B. CONNECT TOE NW 24' TEE 6 E REONLER Engineering Review Comments Page 5 of 6 6. C09: Please title this sheet `site layout' since a WPO plan cannot approve a site plan. 7. Reference and incorporate SDP202100056 Engineering review comments in revised WPO plan, see comments d. 8/4/21. 8. C10 a. Include paved wash rack detail from p.8, ACDSM, hfti)s://www.albemarle.org/Home/ShowDocument?id=270 b. Provide and acquire public drainage easement across 32-41H1 to such point that concentrated bioretention basin discharge reaches manmade pipe network, or a natural receiving stream. Proposed design shows discharge to parallel slope contours, without receiving channel, with 40-ft vertical interval to a downslope storage facility, with approximately half this distance across managed steep slopes. Routing ACSA pump station bioretention basin discharge across adjacent downslope parcel with no receiving or manmade pipe system is impermissible. Please notify Engineering of deed bk.-pg. of off -site public drainage easement, and include bk.-pg. ref on revised WPO plan. c. Please include more deliberate grade lines to clearly indicate a proposed ditch at 130 LF gravel basin access drive leading to bioretention basin (permanent SWM facility). d. A SWM facility cannot be built with initial grading, rather, permanent SWM facilities are built once all up -slope contributing drainage areas disturbed by construction, are stabilized. A sediment trap may be required (item discussed by county with Brad Weiss, 8/17/21). Show, provide and design a trap, if temporary sediment trap is warranted —likely best location is future location of bioretention basin. Include all relevant design criteria, for example: wet/dry storage required, provided, side slope (2:1, etc.), and area draining to tap (x.xx Ac.). If sediment trap is not proposed, confirm that upslope contributing drainage area does not exceed 100 LF slope/ft. silt fence. Note: Item discussed with Brad Weiss, 8/17, telecon, 3:10-3:50pm Q. Anderson). e. Revise p. 11 of 160-p. submittal (Erosion Control Sequence) to include narrative discussing coordination of bioretention basin installation (if retained with revised design) with site stabilization. f. Please remove bioretention basin (or other SWM facility) from ESC plan sheet/s. Show SWM facilities on a SWM plan sheet. g. Include note that bioretention basin may not be constructed until all upslope contributing drainage areas are stabilized. Include note on C13, as well. 9. C11 a. Show grading and required ESC measures and permanent stabilization sufficient to establish pads for anticipated future ground storage tank/s since these are immediately adjacent and just upslope of the proposed bioretention basin. If bioretention is installed prior to future tank grading, then future tank grading is likely to compromise (blind) soil medium, and SWM facility performance, which may contribute to avoidable effort and expense, in the future. b. Show soil stockpile location listed at p. 11, 3_3. Erosion Control sequence, item 3. of 160-p. initial submittal .PDF. Engineering Review Comments Page 6 of 6 Process: After approval, plans will have 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 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. Permanent SWM facilities and public drainage easements require deeds of dedication. Deeds must be recorded prior to VSMP/WPO plan approval. A separate easement plat submittal (Application) is required for public drainage or SWM facility easements, which, for the moment, are proposed with Airport Road pump station VSMP. 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 under engineering applications; httos: //www.albemarle. org/govemment/community-development/=Iy-for/engineering—anal ications Please feel free to call if any questions: 434.296-5832 -x3069 Thank you I Anderson WP0202100035_Airport Road Pump Station_081821