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HomeMy WebLinkAboutWPO201900035 Review Comments WPO VSMP 2019-07-12COUNTY 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: 2265 Decca Lane — VSMP (Single -Family) Project file number: WP02019-00035 Plan preparer: Kurt Gloeckner kurtgloeckner(&amail.com; Mike Myers: mike(a,30scale.com 1980 Fox Run Lane, Charlottesville, VA 22901 Owner or rep.: Leigh and Craig Johnson 2265 Decca Lane, Charlottesville, VA 22901 craigjohnson3Aicloud.com Plan received date: 3 Jun 2019 Date of comments: 12 Jul 2019 Reviewers: John Anderson 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. ( Please also see county email: initial VSMP /WPO plan review comments, 7/12/2019 6:37 AM.) Note: Engineering welcomes (.PDF) preview prior to print re -submittal for final approval. Also, Applicant (plan preparer /Gloeckner) and Engineering are scheduled to meet 16-Jul to review print plans (and plat /SUB201900097) prior to final print plan /plat submittal. 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. Sec. 1: provide 2019 Registration Statement. Information virtually identical to information furnished on 2014 Registration Statement. Link to form: httD://www.albemarle.ore/uDload/imaees/forms center/deDartments/Community DeveloDment/forms/Enein eering_and _WPO_Forms/CGP_Registration_ Statement _2019_FINAL _201904.pdf . Note:.PDF scan of form is fine; email janderson2(iDalbemarle.ore, charris(&albemarle.org. 2. Sec. 6.: Provide with 11" x 17" Sec. 6 SWPPP Exhibit: a. Rain gauge location b. On -site fuel storage; lined containment with storage Vol. > Qio-24 hr event ( 5.57"), stored fuel Vol. + 10% (fuel + Qio Vol.). c. Non -hazardous solid waste dumpster /covered d. Portable sanitary (porta John); downslope SF e. Concrete wash -out /contained f. Solvent /chemical storage /contained 3. Sec. E.: List named individual responsible for Pollution Prevention Practices; recommend RJ Cooper. 4. Revise title: Include ref. to WP02019-00035. B. Pollution Prevention Plan (PPP) The PPP content requirements can be found in County Code section 17-404. 1. Anticipate addressed via SWPPP. Engineering Review Comments Page 2 of 4 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 in comments, below. The stormwater management plan content requirements can be found in County Code section 17-403. 1. Revise Title Sheet (Plan) title to include: VSMP /WP02019-00035. 2. Please delete Site Plan from VSMP /WPO Plan title. 3. Sheet 2: Include note: `No grading or fill will occur in FEMA mapped floodplain.' 4. Sheet 4 a. Although Wet Pond is designed for quantity control only, include note that VA DEQ Stormwater Design Specification No. 14 construction and inspection standards apply.' b. Revise LS length to 40'. Also, item 6., below. c. Revise label ref. to 20' LS. Revise to 40' LS length. d. Recommend 1" =20' text, to accompany graphic scale. e. Provide additional inset cross-section profile for emergency spillway; include WSL for Q2, 10, too events (water depth) in spillway. Profile should indicate Qioo does not overtop pond embankment. Note: QIoo depth is 473.77'; 100-yr event is contained within emergency spillway. f Provide spillway riprap dimensions (L X W X D). g. Provide wet pond floor dimensions (L X W X D). 5. Revise VaRRM (.xls) to include all disturbed area, that is, 3.20 Ac. 2-.0 1.5 Ac. forest /open space (hydrologic soil group B) E sails, 0.15 Ac. impervious, 3.05 Ac. turf, is an approach that meets water quality requirement (9VAC25-870-65). Note: Please do not include Wet Pond in forest /open space. Ref. 2016 DEQ guidance Memo, p. 12, table, Forest & Open Space, bullet 5. Link: htWs://www.deq.vir ig niaia.izov/Portals/O/DEQ/Water/StonnwaterManagement/VRRM/GM14- 2001%20Virginia%20Runoffl/o20Reduction%20Method V3.pdf Image, CDD estimate Forest/Open Space required to meet 3.20 Ac. LOD development; VaRRM.xls, v. 3.0 (ALSO: see Attached NRCS web -soil survey report; all soils within LOD are hydrologic soil rrg_oun: B) DEQ vi gm, Runoff Reduction Method New Development Compho-spreadsheet - Version 3-0 r2011BMPStandardsand Specifiratiore 02013Daft BMPStandardsand Specifications Project Name: 2265 Dacca lane, WPO2019-00035, prelim Date: 7/12/19 (CDDI BMP Design Speciif-tuna List: 2013 Draft Stds & Specs T ISite Information final results 9 Post -Development Project Jreakment Volume and Loajls) ,o Jj / 111Land Cover iacres) 12 A ils Bsoila cAoils I Dsoils I r-Is rest/open spane(acres)--undisturbed, 13 proteaetl forest open space or reformed land 1.50 1.50 Managed Turf (aaresl-disturbed, graded for 14 yardsor other turf to be mowed/managed 3.05 3.05 15 impewiouscover (xresl 0.15 D.15 16 toresy penspur areas mustdeprorectedin acco with thevi,ginia xunoJ reduction method 4.20 1T 1a Constants Runoff Coefficients IRvI 19�AnnusI lieinfall linchesl 43 zo Target namtan Event pnchesl 1.00 21 Total PhosphoruslTPI EMC(.yJQ 0.26 A Soils BSoils Csoils DSoila Eorest/open space 0.02 0.03 0.04 0.05 Managed Turf 0.15 D.20 0.22 025 impendouscover 0.95 0.95 0.95 0.95 TP Load Reduction Required Ilb/vrl I 31 I 6. Engineering recognizes level spreader (LS) disperses concentrated flow to sheet flow, but relies on design std. provided with VA DEQ Stormwater Design Specification No. 2, Sheet Flow to Veg. Filter Strip, p. 3, table 2.2, 13 LF /cfs to size LS. Engineering Review Comments Page 3 of 4 a. Provide 40' length to accommodate Q10 flow =3.11 cfs. b. Provide (Typ.) LS detail: include Fig. 2.6 (Clearinghouse Spec. No. 2; pg. 8). This is a SWM plan detail. c. Provide LS dimensions (L x W x H) and material type. 7. Provide two (2) clean outs at first 2 bends in 8" PVC (nearest house), and provide four (4) std. VDOT MH- 1 (or Alt.) at the next four (4) downslope bends in 8" storm drain. Also, ESC Plan item l.b./c., below. S. Provide 8" storm line profile. 9. Include on the plans VA DEQ Stormwater Design Specification No. 14 (Wet Pond) construction sequence and inspection steps listed at Sec. 8.1 and 8.2; Link: ho2s://www.swbLnp.vwrrc.vt.edl/ - content/uploads/2017/11/BMP-Spec-No-14_WET-PONDS _vl-9_05112015.pdf Note: although wet pond is being utilized for quantity control only, construction sequence and inspection are identical for quantity control, except that with this design, Sec. 8.1 steps 7 and 13 are NA. Riser (principal spillway) inspection, also NA. 10. Include on plans periodic maintenance inspection for wet ponds. Ref. Attached. 11. Related to 5, above: SWM Forest /Open Space Easement plat with a Deed of Dedication is required prior to VSMP Plan approval (under review /SUB2019-00097). Note: Engineering will format Deed of Dedication template for Applicant once SWM Maintenance Agreement is recorded (please see Process section, below). 12. A SWM Facility Maintenance Agreement is required prior to final VMSP Plan approval. Please coordinate Maintenance Agreement with Ana Kilmer, CDD Management Analyst (tel. 434.96-5832-x3246). 13. Include Note acknowledging SWM Facility As -built requirement/s apply to Wet Pond, pond spillway LS. 14. Include text of WPO NSMP Construction Record Drawings Policy on Plans (Link (.PDF): htW://www.albemarte.org/upload/images/forms_center/departments/Community Development/forms/Engin eering_and _WPO_Forms/WPO_VSMP Construction_ Record Drawings Policy 23Ma.2�pdf). 15. SWM and ESC plan bonds must be posted prior to project receiving a grading permit (at pre -con meeting). 16. Submit VSMP bond estimate request form. A SWM Plan bond is required for wet pond: spillway, plunge pools (stone), earthwork, LS, etc. Link: hops://www. google.com/url?q=htips://www.albemarle.org/�pload/images/forms_center/departments/Community_Deve lament/forms/bonds/Bond_Request _to Establish a Bond.pdf&sa=U&ved=OahUKEwiX4d- i25zeAhVikeAKHYDbAxkOF g¢GMAE&client=internal-uds- cse&cx=013641561590022973988:g3cwisrdbli&use=AOvVawO70B-uOuTu_Fa 5WrzNXdB). 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 in comments, below. The erosion control plan content requirements can be found in County Code section 17-402. 1. Sheet 5 a. Revise labels: i. Revise steep slopes to critical slopes. ii. Revise 20' LS length to 40'. iii. Revise proposed 0.90 Ac. proposed forest /open space easement to 1.5 Ac., or value sufficient to meet 9VAC25-870-65 requirement. b. Show /label 8" clean -outs at first 2 bends in 8" PVC storm drain pipe (nearest house). c. Provide, show, label four (4) VDOT MH-1 at next four (4) downslope bends in 8" PVC pipe. Or, as discussed 7/12 (11 AM tel. call), provide Nyloplast ® vertical access instead of VDOT MH-1. d. Provide Nyloplast detail/s. e. Provide trapping measure (reasonable volume) at downslope end of each clean -water diversion. Alternatively, as discussed 7/12, provide LS parallel to contours as a temporary measure. If LS provided, include VESCH, 3' Edit., 1992, Plate 3.21-2 on plans (ESC plan detail). VESCH Std. & Spec. 3.21 specifies Min. L =10'. Engineering Review Comments Page 4 of 4 2. Sheet 6 a. Provide paved construction entrance detail. See ACDSM, p. 8. Link. http://www.albemarle.orgLunload/images/forms center/departments/communityy development/form s/design standards manual/Albemarle County Design Standards Manual 2015-04-25 draft.pdf b. Include VESCH Table 3.32D on plans (permanent vegetation /Piedmont). 3. Sheet 7 a. Pre -Post runoff composite CN values may be revised to reflect only hydrologic soil group `B', but this is not a requirement (Ref. Attached websoil survey report). b. For pre- or post areas and area listed in composite CN tables, please report a single acreage. Acreage may vary from pre- to post, but within predevelopment or post -development condition, please list a single pre- or post -development acreage, as discussed 7/12. c. Label Mechums River. 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. (.PDF preview welcome). 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. Stormwater Management Facility, SWM Facility Access, Forest /Open -Space Easements must be recorded prior to final approval. This means a Grading Permit may be issued prior to recordation of VSMP-related easements. After bonding and agreements are complete, and easement recorded, Albemarle County can hold a pre -construction conference. Applicant 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 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; htt2://www.albemarle.org/deptforms.asp?departrnent--cdengMo WP02019-000035 2265 Decca Lane 071219