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Home My WebLink AboutWPO202100042 Review Comments WPO VSMP 2021-09-17�q off nig 401 McIntire Road, North Wing Charlottesville, VA 22902-4579 County of Albemarle Telephone: 434-296-5832 COMMUNITY DEVELOPMENT DEPARTMENT WWW.ALBEMARLE.ORG �tBGIN�P' VSMP Permit Plan Review Project title: VSMP Plan Bamboo Grove Project file number: WPO2021-00042 Plan prepares Shimp Engineering, 912 E. High St., Charlottesville, VA 22902 Keane Rucker, FIT, keane(a),shimp-engineering.com Justin Shimp, PE,Iustin(a),,shimp-engineering.com Owner or rep.: Bamboo Grove LLC 92 Oak Forest Circle Charlottesville, VA 22906 Plan received date: 2 Aug 2021 Date of comments: 17 Sep 2021 Reviewer: 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. 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. Revise SWPPP title page to include correct TMPs (05500-00-00-068C0; 05500-00-00-068D0) and Project Name (Bamboo Grove VSMP). 2. Include ref. to WPO202100042 in SWPPP title. 3. Revise Owner to Bamboo Grove Development, LLC, consistent with Sec. 9 Certification Statement. 4. Sec. 1 -Registration Statement a. Sec. I.A. -Please revise Operator Name to Bamboo Grove, LLC, consistent with Sec. 9. b. Sec. ILF. —Leave blank since parcels are not located within Albemarle County MS4. 5. Sec. 4, 5 -Update to reflect ESC /SWM plan revisions. 6. Sec. 5: Please remove HydroCAD routings from SWPPP. Routings in Calc. booklet are sufficient. 7. Sec. 6.A. /Exhibit: Locate rain gauge within parcel boundaries, outside public RW. 8. Sec. 6.E.: Person responsible for PPP must be identified prior to pre -construction, but not for WPO plan approval. B. Pollution Prevention Plan (PPP) —see SWPPP item 7., above The PPP content requirements can be found in County Code section 17-404. 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. C13 a. Note: Project proposes to meet water quality requirements with combination of forest -open space easement and 0.51 lb. nutrient credit purchase. Forest -open space easement must be recorded prior to plan approval and requires separate plat application and review /approval process. 2. C14 Engineering Review Comments Page 2 of 4 Nutrient credit purchase is not required for plan approval but is required to receive a Grading Permit. Please coordinate nutrient credit purchase with Ana Kilmer prior to finalizing purchase, as both bill of sale and affidavit must list project specific information (WPO#, project name, project HUC, 0.51 lb. of credits, etc.) Please coordinate with Ms. Kilmer at earliest convenience (434.296-5832-x3246, akilmer(a)albemarle.org ). Please find easement plat application at: hfos: //www.albemarle. org/home/Showoublisheddocument/ 1052/637624089314100000 . b. Include (image of) Construction Record Drawings (As -built) for VSW on the plans, link: httos://www.albemarle.org/home/Showoublisheddocument/3381 /637327510536700000 . c. Provide reference to dry detention pond design criteria. d. Label dry detention pond floor dimensions L x W. e. Provide detailed profile for pond structures. i. Riser ii. Riser base elevation iii. Existing /proposed grade iv. Pond floor v. Pond structures /see hydroCAD routings 1. 18" culvert (primary spillway) 2. 8" orifice 3. 5' DIA riser 4. Emergency spillway (dimensions /material) f Plan view of dry detention pond is missing linework, labels, leaders, etc. Provide complete plan view design with level of detail required to evaluate design, estimate bond amount, construct, inspect, and operate this facility. g. Provide dry detention pond installation steps on the plan. h. Provide periodic dry detention pond inspection guidelines on the plan. i. Include notes /guidelines to convert sediment trap to dry detention pond. a. Pre- /post -developed offsite overland sheet flow is intuitively an identical longest path. This may be a misconception, but whatever sheet flow path is shown for upslope offsite runoff, it is a single path perpendicular to existing contours, and is unaffected by on -site downgradient development, or change to on -site contours. When offsite sheet flow encounters altered site grading, that would appear to be the point pre- /post-dev storm runoff may diverge in pre- /post condition (sheet, shallow concentrated, concentrated). Please identify longest off -site sheet /SC flow paths and represent these as pre- /post-dev runoff condition, and revise graphics /calculations, as needed. Else, correct misconception. b. Please update 1-yr, 10-yr page references to Calculation booklet; pp. 16, 22, 36, 55 appear inaccurate. c. Check 1-yr, 10-yr values against Calculation booklet, for example: Calc. booklet reports 24-hr 1- yr Qw=3.48cfs, while plan list 3.74cfs. Calc. booklet reports 24-hr 10-yr Qpr=13.64cfs, while plan list 14.35cfs. Please check plan v. calculation booklet values for consistency. Revise energy balance equation and plan table values, as needed, to correspond with booklet HydroCAD routing values. d. 3-A7 profile: provide label /note specifying subgrade compaction for pipes /structures. Entire pipe -structure network is in fill. 3. Cl: Tax Map parcels appear to correspond with HTC development, please revise. 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. Engineering Review Comments Page 3 of 4 1. C9 a. Revise CE label to PCE (paved construction entrance), provide ACDSM paved wash rack detail on sheet C 12 (p. 8 /ACDSM). b. CWD appears to concentrate sheet flow (offsite clean runoff) and divert it toward Orchard Drive; design relies on slight swale to route it beneath (paved) construction entrance. Provide barrier to prevent higher -than -anticipated concentrated /channelized diverted flow from causing flooding in Orchard Drive (provide an earth berm, more pronounced grade, etc.). c. Project proposes ESC measures within public right of way and a diversion immediately adjacent to edge of pavement. VDOT land use permit is required. d. Provide construction entrance culvert IP. e. Provide grade required to install construction entrance culvert in ESCP Phase 1. f. Label trap outfall /weir riprap L x W dimensions. g. Label sediment trap. 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 are 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. This project requires separate easement plat application, review, and approval. Once plat is reviewed and comments are addressed, Engineering will format template deeds (SWM / public drainage) to be recorded with the plat. Please submit [forest -open space /SWM /public drainage] easement plat application at earliest convenience. Note: easement plat with deeds must be recorded prior to receiving a Grading Permit. Also: plan proposes 0.51 lb. nutrient credit purchase. Although nutrient credit purchase is not required for WPO plan approval, it is required prior to pre -construction, to receive a Grading Permit. After ^9^ ea, eFage is issued, via the eavoFago lotteF, 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 stab, 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 Applications: Engineering Review Comments Page 4 of 4 httos: //www.albemarle. orgIgovernmenticommunity-develoomentlaooly-for/engineering-anal isations Thank you. Please call if any questions — tel. 434.296-5832-x3069, or email 4anderosn2(a),albemarle.org. WPO202100042—Bamboo Grove-091721