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HomeMy WebLinkAboutWPO202000024 Review Comments WPO VSMP 2020-05-24COUNTY 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: Christopher -Shilling Residence - VSMP Project file#: WP0202000024 Plan preparer: Alan Franklin PE, Waterstreet Studio / 418 E. Main St. Charlottesville, VA A22902 [alanAalanfranklinpe.com ] Owner or rep.: Sally Christopher & Tanner Shilling / 817 Montrose Ave Charlottesville, VA 22902 [ ranllyshillophergamail.com ] Plan received date: 20 Apr 2020 Date of comments: 24 May 2020 Reviewer: John Anderson In speaking with Cailen von Briesen, 5/21/20, Engineering expressed commitment to review revised plans within 5 business days. A bit more time may be required, given range of comments, but within 10 days is the goal. In the interim, please consider whether this project will purchase credits, or place areas in forest /open space easement. 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. Complete Certification, p. 7, single family SWPPP. 2. Given scale of project, provide PPP Exhibit that shows: paved CE draining to trapping measure, rain gauge, solvent storage, stucco /paint clean-up area, concrete washout draining to trapping measure, on -site fueling with lined containment /berm sized for (stored volume of fuel + 10-yr rain event) x 1.1 (cf), non -hazardous solid waste dumpster, and portable sanitary facility. 3. Include reference to WP02020-00024 in revised single-family SWPPP title. B. Pollution Prevention Plan (PPP) — See item 2 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. SW.100 a. If (nutrient) credits are not available and a portion of the parcel is placed in forest /open space easement, easement deed and Maintenance Agreement must be recorded prior to VSMP plan approval. b. Design proposes concentrated (piped) discharge to each ELS; provide: i. V2-yr calculations Note: each LS sizing worksheet assumes 5 fps within pipes. This may be erosive. Engineering Review Comments Page 2 of 4 ii. Outlet protection, each ELS (1 — 4). Specify L x W x D outfall protection. Specify size (Cl. 1 riprap, etc.). Ensure velocities non -erosive at each ELS. iii. Specify VDOT end sections for each outfall pipe. iv. Provide profile for each outfall pipe. v. Ensure sufficient cover. vi. Check for conflicts. c. Outfalls to LS i. Label pipes: 1, 2, 3, 4 (or similar). ii. Provide pipe L, DIA ( similar to EC.102). d. Label residence, pool, pool house, garage, barn, parking, drive, etc. e. Recommend either permanent inlet protection, culvert B, or provide plan notes that emphasize need to maintain inlet protection at culvert B until barn drive ditch is completely stabilized. f. Provide V2_n barn drive ditch which conveys runoff from Zack Lane, over a 20' vertical interval. Provide soil stabilization blanket /similar, if needed. g. Notel: Nutrient purchase requires coordination with county (Ana Kilmer /tel. 434.296-5832 - x3246) prior to executing purchase documents since project specific information must appear in documents (Affidavit, bill of sale). h. Note2: Nutrient purchase must be completed prior to receiving a grading permit. In speaking with Cailen von Briesen, 5/21/20, speed is an objective, with project approval /grading permit as soon as possible. Either SWM water quality compliance strategy involves process: either purchase of nutrient credits or platting /recording Forest/Open Space Easement. Engineering supports either approach, consistent with program requirements. It is not too soon to initiate either process, either by exploring nutrient credit availability, and contacting Ana Kilmer, or committing to plat an area as Forest /Open Space Easement. An easement requires separate county application, fee, and review schedule that will add considerable time to grading permit issuance, likely, several months. Nutrient purchase may be a quicker path to grading permit issuance. 2. Include Construction Record Drawings (As -built) for VSMP on the plans; link: hqp://www.albemarle.org/upload/ima2es/forms_center/departments/Communi1y Development/forms/Engineeringand _WPO_Forms/WPO VSMP Construction_ Record_ Drawings Policy 23May2014.pdf 3. Include ELS periodic maintenance and inspection guidelines on the plans (see VA DEQ Spec. #2). 4. Include ELS construction installation guidelines on the plans (VA DEQ Spec. #2). Note: Although ELS are not installed for water quality, they are installed for quantity control, are SWM facilities, and installation, maintenance and inspection procedures are relevant and must appear on the plans. 5. 17-414 requires bond for ESC measures. 6. Engineering policy concerning single-family construction has evolved, and Albemarle does not now require SWM Plan bond for single-family residential SWM facilities, although mitigation plans and ESC measures do require bond. Although SWM facilities (ELSs) will not be bonded, ESC plan bond may not be released until ELSs are accepted. See item 2, above. An as -built drawing is required for each ELS. 7. A state permit is not required for single-family construction. (VAR10 CGP). D. Erosion and Sediment Control Plan (ESOP) Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESOP. This plan is disapproved for reasons listed, below. The erosion control plan content requirements can be found in County Code section 17-402. 1. Sign /seal plans. 2. Include reference to WP02020-00024 in plan title. 3. Depict existing conditions; provide existing conditions sheet. 4. Provide Stage 0 ESC Plan (1" =40' scale) that shows perimeter controls prior to clearing, or constructing improvements, consistent with construction sequence. May combine 3 and 4; i.e., existing conditions w/perimeter ESC controls /paved construction entrance (PCE). Engineering Review Comments Page 3 of 4 5. On Stage 0 ESC Plan: a. Show property boundary and label TMP #59-37D (Also, note, below). b. Provide ownership data for TMP#59-37D. Note: SW.100 indicates boundary line adjustment (BLA) will combine TMP 59-37C4 and -37D. BLA plat must be recorded prior to VSMP /WPO plan approval unless existing TMP 59-37D boundaries are shown. Also, timing of BLA may affect nutrient purchase or format of Forest /Open Space Easement. Please provide status on BLA application (submitted, reviewed, etc.). c. Show and label critical slopes. Use easily distinguishable hatching. d. Show /label ponds (image below). e. Stage 0 will not show proposed improvements. Once existing conditions, distances, slopes to SF perimeters are more nearly visible, Engineering anticipates one or more sediment traps will be needed. This 4.30 Ac. disturbance likely cannot be managed without diversions and sediment traps. f. If traps are required, provide required ST design data, including trap floor /weir dimensions, etc. 6. EC.141 a. Revise steep slopes label to critical slopes, since project is in the rural area. b. LS labels reading L.P. ELEV 531.5', for example, are unclear. Please clarify L.P. c. Provide roof /garage /barn leader line connections to piped systems. If roof discharge is to surface, label discharge to splash blocks. Consider erosion potential. Engineering recommends roof runoff collection with conveyance to piped systems. (Evaluate /consider critical slopes susceptibility to erosion.) d. Label temporary outlet protection dimensions at SE corner of lawn (L x W x D). e. Revise LS3 discharge pipe to 8" DIA. EC.103 /Level spreader -Typ. detail a. Include schematic representation of the ELS structure, concrete or timber. b. Provide x-sectional dimensions (L of each of 4 ELSs varies). c. See VA DEQ Stormwater Design Specification No. 2, FiT2.3, below. d. Include underdrain in EC.103 detail to prevent ponding /nuisance conditions; ref. Fig 2.3. e. Daylight ELS underdrain/s. (Although EC.103 detail is descriptive, it lacks structural element and underdrain. Recommend label EC.103 L.S. detail ( x 4)). Engineering Review Comments Page 4 of 4 Level 5preader Lp 3' Layer of Now Path.- 157 Stone � Rlpaflil Bufflf Or F12w S&V 1 Channel 3 ft Mae Underdram - 5aed ` Strip of For Site Sod Filtar Fabric Conditiom - Dram Appropriately 51zed Into 13ypa55 Swale Concrete Footer Figure 2.3: Plan and Cross Section of Engineered Level Spreader (ELS) (Hathaway 2006) Version 1.9, March 1, 2011 Page 5 of 20 The VSMP permit application and all plans may be resubmitted for approval when all comments have been satisfactorily addressed. Please provide digital version of revised plan /SWPPP with a completed application form. 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 2-4 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. If nutrient credit purchase is required, purchase documents must be executed prior to county issuance of a grading permit. Note: If forest /open space easement is required, plat /deed approval and recordation, which entail separate processes, must be complete prior to plan approval. If a boundary line adjustment is pending then BLA approval processes, including plat review and recordation, must be complete prior to plan approval, or existing parcel boundaries must be shown on the plan, consistent with current real estate records. After Maintenance Agreement, forest /open space easement BLA plat (as needed) are recorded, nutrient credits purchased (as needed), and ESC Plan bond posted, Albemarle can hold a pre -construction conference. Applicants must request a pre -construction conference (by completing form), and pay any remaining application fee. The form identifies the contractor and responsible land disturber, and 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; hLtp://www.albemarle.org/deptfonns.asp?department--cdengmTo WP0202000024_Christopher-Shilling resid 052420