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HomeMy WebLinkAboutWPO202000051 Approval - County 2021-04-15Phone (4341296-5832 Project: Project file#: Plan preparer: Owner or rep.: Plan received date: (Rev. 1) (Rev. 2) (Rev. 3) Date of comments: (Rev. 1) (Rev. 2) (Rev. 3) Reviewer: COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902-4596 VSMP Permit Plan Review Boys and Girls Club, Driver's Ed — VSMP WPO202000051 Kim Reeser (Mellon), PE [kim.roeser(i0mmons.com ] Bryan Cichocki, PE [ bryan.cichocki(i�timmons.com ] Craig Kotarski, PE, Timmons Group — 608 Preston Ave, Suite 200, Charlottesville, VA 22903 [craia.kotarski(i�timmons.com ] Boys and Girls Club, 1000 Cherry Ave., Charlottesville, VA 22903 [ipierceAbeclubcva.ora ] 6 Nov 2020 12 Jan 2021 [ SWPPP, only] 6 Feb 2021 9 Apr 2021 21 Dec 2020 2 Feb 2021 26 Mar 2021 15 Apr 2021 - Approved John Anderson Fax (434) 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 approved. Note: 1.62 lb nutrient credit purchase is required np or to receiving a Grading Permit. Also, please note: Strict hierarchy listing of eligible banks applies to nutrient credits purchased after 1/l/2021. Engineering can provide guidance. Also, see Attached 4/13/21 internal email, which includes DEQ guidance. A. Stormwater Pollution Prevention Plan (SWPPP) (Rev. 3) Prior SWPPP comments addressed. 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. Submit SWPPP; use county template: httos://www.albemarle.ore/home/showpublisheddocument?id=166 Please ensure that SWPPP, once submitted: 1. Sec. 1, Registration Statement is complete. Complete Sec. 1 as condition of VSMP /WPO plan approval. a. Sec. IV. E., (MS4), Please leave blank. (Rev. 1) Addressed. b. Sec. VI, Certification: Please complete (print name, sign, date). (Rev. 1) Not Addressed. (Rev. 2) Not addressed. Certification is Sec. V of revised Registration Statement. c. New: Please submit revised Registration Statement, Eff. 1/l/21 [Also, email sent January 29, 2021 11:20 AM] (Rev. 2) Partially addressed. As follow- i. Sec. II, Construction Activity Information data is, with slight exception, incomplete. For example: 1. Sec. II, B,C,E,F,I should be complete at this point. Perhaps one item may change (item IIC.), which should list estimated LOD with current submittal. Engineering Review Comments Page 2 of 6 2. Sec. 4, 5: Include revised ESC and SWM plan sheets, once comments addressed. (Rev. 1, 1) Persists. 3. Sec. 6.A. / Exhibit: Indicate location rain gauge /other required PPP measures. (Rev. 1) Partially addressed. As follow-np: Please revise Phase 1 Exhibit to show vehicle wash waters draining to downslooe trapping measure; not a VESCH sediment trap per se, but a 1-2 backhoe scoop depression, or to concrete washout. (Rev. 2) Persists. 4. Sec. 6.E. —List named individual responsible for pollution prevention practices riD Or i0 project pre - construction meeting. (Rev. 1, D Persists. 5. Sec. 8. — List named individual qualified to perform compliance inspections prior to pre -construction meeting (prerequisite to receive Grading Permit). (Rev. 1, D Persists. 6. Sec. 9., Signed Certification: Individual who prepared SWPPP document must sign as condition of VSMP /WPO plan approval. Also, Albemarle cannot register project with DEQ until SWPPP Sec. 9 is complete. (Rev. 1) Not Addressed. A SWPPP may be signed by Timmons Group personnel, since prepared by TG. (Rev. 2) Not addressed. 7. Include 2019 Notice of Termination form. (Attached /.PDF). (Rev. 1) Addressed. 8. SWPPP title includes ref. to VSMP /WPO2020-00051. (Rev. 1) Not addressed. (Rev. 2) Addressed, B. Pollution Prevention Plan (PPP) —See above. (Rev. 3) Addressed. PPP Exhibit Approved. C. Stormwater Management Plan (SWMP) (Rev. 3) Prior SWM plan review comments addressed. VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This plan is approved. 1. Revise WPO plan per Engineering Initial Site Plan review comments (10-Dec 2020) items 2-4, 9-11, 12 (b, c, g, h). Ensure ISP review revisions carry over to WPO plan resubmittal. (Rev. 2) Addressed. Applicant (2/4/21 letter): `Plans have been coordinated to address all comments received from the County.' 2. C1.3: Provide VDOT ST-1, IS-1, PB-1 details on the plans (steps, inlet shaping, pipe bedding). (Rev. 2) Addressed, 3. C5.0 a. Clarify whether pipe 301 discharge is to surface or manmade subgrade structure. If discharge is to surface, ensure discharge is to a stormwater conveyance channel, as existing topography at pipe 301 discharge are evenly spaced contours without a defined channel. This slope will erode if concentrated flow is released with no proposed change in grade, to define a channel. (Rev. 2) Addressed. b. Align pipe 301 outfall with pipe. An outfall structure should not deflect direction of discharge. Provide MH structure at pipe 301 discharge to deflect discharge, unless design relies on ex. MIT. (Rev. 2) Withdrawn /NA. Note: The end section outfall was showing due to a printing error that has since been resolved. 4. C3.4: Label Ex. SWM facility (Mfr, wetland). (Rev. 2) Addressed, 5. C5.1 a. Recommend a vault -style cover with locking feature for underground detention access located in paved surface between loop and west wing of building. This point of access should be limited to authorized personnel only with no possibility of trespass by youth patrons of the facility. (Rev. 2) Addressed. LaneTM underground system access details (access riser, ME frame/cover, steel ladder) are shown on C6.5. b. With next submittal, provide tiered retaining wall TW BW elevations. (Rev. 2) Addressed. 6. C5.0. C5.1 a. Show and label SWM facility easements for underground detention systems. Label SWMI, SWM2. Ensure easement widths meet ACSM easement diagram guidance, p. 15 (https://www.albemarle.org/Home/ShowDocument?id=270 ). (Rev. 2) Addressed. Engineering Review Comments Page 3 of 6 b. Clarify via inset details the precise location /structure type/s that house SWM1, SWM2 weir plates. Precise detail is needed. (Rev. 2) Addressed. As follow-up: Please provide slope label (0.0% if none) on SWMI, SWM2 detention pipe profiles, C7 00 C7.1. 7. C6.3 a. Revise SWMI weir plate detail top of pipe elevation to 548'. (Rev. 2) Addressed. b. Provide small-scale plan views for SWMI, SWM2 weir plate structures that show access ladders, pipe penetrations, weir plates and manway clearances ( access to each side of each weir plate) to check for potential conflicts. Also, 8.d., immediately below. (Rev. 2) Addressed. c. Provide debris cage details for SWMI, SWM2 weir plate orifice openings, unless overlooked. (Rev. 2) Addressed. d. Provide additional weir plate details: steel gauge, manner of connection to housing (pre -fabricated, welded, etc.). (Rev. 2) Addressed. e. Provide UG detention system profile details (bedding, inv elevations, system slope, if any, min. depth of cover, etc.). (Rev. 2) Addressed. 8. C6.2 a. Consider and offset any effect of diminished treatment of existing stormwater facility. C3.4 depicts post -developed condition with no Drainage Area 1 concentrated runoff reaching Ex. SWM. C2.4 shows 24" RCP outfall removed with project. Please update design, VRRM.xls re- development worksheet, and /or calcs if current /existing condition DAI runoff reaches wetlands, which perform water quantity /quality functions, which may diminish in the post-dev condition. (Rev. 2) Addressed. Aplicant: `No runoff from DA 1 reaches the existing manufactured wetland in either the existing or proposed conditions. See response to comment 8_b. below.' b. Pre -developed drainage area map may be inaccurate in that it may underestimate volume of runoff or areas currently draining to ex. stormwater facility. Instead, the pre-dev DA map implies DAl does not route to Ex. SWM facility /wetlands, when linework shows concrete flume which appears to route a portion of runoff to this facility via 24" RCP outfall (removed with project). Ex. contours /riprap appear to indicate a portion at least of pre-dev DAl runoff reaches Ex. SWM (blue circle, image, below). If existing Mfr. wetland is overgrown or poorly maintained, pre-dev runoff analysis must assume a pre -developed condition with functional existing SWM facility. (Rev. 2) Partially addressed. Applicant: `Please see screen clip below, which is an as -built plan of the existing SWM facility provided by the County to illustrate the existing drainage patterns. The area circled represents and emergency spillway from the existing SWM facility to the existing concrete flume. All drainage that gets into the concrete flume via the northern outfall bypasses the existing SWM facility. See note that states "TRANSITION EXISTING SWALE INTO CONCRETE DITCH". It appears that the existing manufactured wetland was designed to serve the Ivy Creek School building and associated parking, not the driver's education course.' As ollow-up: Please revise Stormwater Management /Water Quantity Narrative, Cale. report, p. 3, consistent with comment response. [ Cale. booklet image removed with Rev. 3 comments. Top image, below, from 2/4/21 comment response Bottom image from review comment Memo [ Images removed with Rev. 3 comments] c. Label analysis point 2 on post-dev DA map. Additional comments possible. (Rev. 2) Addressed. Applicant: `Per response to 10.g., we have not modified the analysis points with this submission. See below for reasoning.' 9. Include construction installation (Mfr.) notes and periodic maintenance requirements for proposed underground detention, on the plans. (Rev. 2) Addressed. Applicant `Mfr, recommended installation notes have been provided with details on Sheets C6.4 — C6.5. Periodic maintenance requirements for underground detention have been provided on Sheet C 1.0.' Calculation booklet a. Revise cover to include WP0202000051. (Rev. 2) Addressed. Engineering Review Comments Page 4 of 6 b. Provide LD-204, I =6 in, for inlet capacity analysis. (Rev. 2) Addressed. c. Revise inlet length, Str. 202, to limit excessive spread (=12.093'). (Rev. 2) Addressed. d. Recommend increase inlet lengths, Str. 206 and 208, from 6' and 4', respectively, to allow drivers to exit vehicles to dry pavement ( recommend avoid 9.599' and 9.164' spread, respectively). (Rev. 2) Addressed. e. Revise 6' inlet length, Str. 402, to ensure spread (9.012') is < Yz travel lane width + 2' gutter pan, or, <8'. Drive aisle =24', two-way travel, this means Yz travel lane width =6'. (Rev. 2) Addressed. f. Revise narrative, p. 3, to include discussion of Ex. county SWM facility (mfr. wetland). Provide comprehensive description of quality /quantity benefits provided by existing on -site SWM, and in the proposed post-dev condition. Project narrative /SWM does not mention ex. SWM facility. (Rev. 2) Partially addressed. Applicant: `Narrative within the calculation booklet has been modified to include mention of the existing drainage patterns and existing SWM facility.' As follow-up: Please revise calculation booklet to clarify that the Mfr, wetland does not appear to capture or treat runoff from the proposed Boys and Girls Club development. Also, item 8.b., above. g. Narrative, p. 3, explains that `Two underground detention systems will be installed to meet stormwater quantity requirements. SWMI is 50 linear feet of 84" CMP while SWM2 is 220 linear feet of 96" CMP. Together, these pipes reduce the 1-year, 24-hour storm to meet the requirements of the energy balance equation.' Energy balance applies at each discharge point. Revise narrative or design to ensure energy balance is achieved at each post -developed discharge to natural conveyance. (Rev. 2) Withdrawn /NA. Applicant: `The outfall to SWMI has been fixed to clarify that it is discharging into an existing structure and through a series of existing pipes. Due to a printing error, it appeared in our previous submission that the proposal was to discharge via an end section above grade; but this is not the case. All downstream pipes have been checked for capacity. However, due to the fact that SWMI does not discharge to a natural conveyance, it is our understanding that this comment no longer applies.' Engineering appreciates /accepts this response. D. Erosion and Sediment Control Plan (ESCP) (Rev. 3) Prior ESC plan review comments addressed. Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESCP. This plan is approved. C3.0 Develop a more detailed, additional -phase ESC plan that: a. Shows proposed mass grading required to construct improvements (pavement, building, walls, etc.) (Rev. 2) Addressed. b. See detailed ESC Plan developed for WPO202000005, Boys and Girls Club Northside, for examples of interim mass -grading, ESC measures, etc. (Rev. 2) Partially addressed. As ollow- yp: [ VESCH image removed with Rev. 3 comments.] i. Please locate silt fence at least 5 to 7 feet beyond the base of disturbed slopes with grades greater than 7%. Ref VESCH, Std. & Spec. 3.05, p. III-20 (text, below). Note: Reviewers may not in the past have requested revision, but inspectors direct us to this item as frequent source of failure for SF located coincident with toe of slopes > 7%. ii. Also, please revise C3.0 Sequence Phase III Note 3 to include 5' -7' offset, rather than toe of slope. c. C3.3 i. Phase 1 shows no proposed grading, other than grading for STI, ST2, ST3. (Rev. 2) Addressed. See, below. ii. Label sediment trap floor dimensions. (Rev. 2) Addressed. Engineering Review Comments Page 5 of 6 iii. Shift ST2 slightly downhill so DD inflow to ST2 travels a farther distance, with increased residence time. DD runoff is introduced too close to ST weir outfall. (Rev. 2) Addressed. iv. Label ST2, ST3 weir riprap dimensions ( L x W x D). (Rev. 2) Addressed. v. Revise diversions to ST2 to avoid 90-deg turns. Concentrated runoff will likely break through bends. Recommend replace ST2 with separate STs, one at each 90-deg bend, with area in between these two smaller STs directed to drain to one, or the other. (Rev. 2) Addressed. vi. Coordinate location, size of all traps with mass grade plan, sequence of construction, and final improvements. STs must function for a period of time, must accommodate construction of walls, building, paved surfaces, etc. (Rev. 2) Addressed. vii. The proposed 2-phase ESC plan gives no clear understanding of how the site, or ESC measures, will progress from existing condition thru final stabilization /site buildout. (Rev. 2) Addressed. d. C3.0: Revise sequence of construction to provide additional specific ESC detail from existing condition thru final improvements (building, walls, athletic field, pavement /sidewalks). (Rev. 2) Addressed. e. C3.4 i. Consider additional ESC measures for 10' (vertical interval) steeply -graded slopes south of building. (Rev. 2) Addressed. ii. Label steepest portion of graded slope west of stairs from elevation 561 to 544 (2.5:1, 3:1, etc.). (Rev. 2) Addressed, but follow-up. Applicant: `The steepest portion of graded slopes have been labeled on Sheets C5.2 — C5.3, both adjacent to the stairs and south of the proposed basketball court.' Afollow- up:Recommend Notes on C5.2, C5.3 that reference L 1.2 Master Plant Schedule table, Groundcover Mixes for slopes steeper than 3:1 (Native non -grass species, lespedeza invasive so we recommend against this species.) iii. Provide /specify permanent groundcover (vegetative cover) hardier than grass for any proposed graded slope steeper than 3:1. (Rev. 2) Addressed. Applicant: `Slopes steeper than 3:1 are only proposed south of the basketball court. Hardy vegetation is proposed in this area. See Sheet L 1.2.' iv. Label proposed slopes steeper than 3:1' provide /reference plant schedule (specify species other than grass). (Rev. 2) Addressed. Applicant: `Slopes are labeled on Sheets C5.2- 05.3. Hardy groundcover is proposed in steep areas. See Sheet L1.2' 2. C5.1: Provide ditch detail /calc. velocity in ditch created by new/proposed contours south of building, west of tiered retaining walls downslope of building (blue arrow, image, below). (Rev. 2) Addressed. Applicant: `Channel sections and ditch calculations have been provided on Sheet C5.0 for all proposed drainage ditches.' [ Image removed with Rev. 3 comments.] Please submit 2 print copies of now -approved SWPPP and 2 full-size print copies of VSMP plan to CDD /Engineering Division under transmittal to my attention that states: `Not for review, for stamped approval.' 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 Engineering Review Comments Page 6 of 6 information. The completed foams 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 foam, and pay the remainder of the application fee. The foam 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, hftp://www.albemarle.orvJdeptforms.asp?department=cdengWo WPO20200005I Bov s and Girls Clab_ Drivers Ed 041521rev 3