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HomeMy WebLinkAboutWPO201800085 Review Comments WPO VSMP 2019-02-25Phone (434) 296-5832 Project title: Project file number: Plan preparer: Owner or rep.: Plan received date: Date of comments: Reviewer: COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902-4596 VSMP Permit plan review TMP 18-34171-G Residence WP0201800085 Justin Shimp Mark Lyons Nov 13, 2018 Jan 18, 2019 Dec 13, 2018 (Rev.1) Feb 25, 2019 (Rev.2) David James Fax (434) 972-4126 U ustin@shimp-engineering. com] [mlyonsivy@gmail.com] [dj ames@albemarle. org] 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. The rationale is given in the comments below. The application may be resubmitted for approval if all of the items below are satisfactorily addressed. 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. Please complete sections prior to pre -construction meeting. Update reduced plan inserts for SWPPP when plan is finalized. (Rev.2) Comment still valid. B. Pollution Prevention Plan (PPP) The PPP content requirements can be found in County Code section 17-404. 1. (Rev.1) Show any proposed clearing/grading activities, paving operations, landscaping operations, E&S controls, staging, stockpile, borrow, fueling, waste disposal, vehicle/equipment washing, concrete washout locations on the PPP. (Rev.2) Under Section 6, Part B & C - Show locations these pollutant generating activities on the PPP as noted in the boxes. C. Stormwater Management Plan (SWMP) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This plan is disapproved, and the reasons are provided in the comments below. The Stormwater management plan content requirements can be found in County Code section 17-403. (Rev. l) ,K (Rev.2) Addressed. 2. (Rev. 1) Show a `SWM facility' easement around the level spreaders & detention basin. (Rev.2) Level spreader easement should extend to include any protected vegetative buffer where required. 3. (Rev. 1) A conserved open space or vegetated filter strip must be shown downwards from the level spreader to function as a permanent measure. This `management' area should extend to the edge of property or floodplain and be labeled as such. (Rev.2) Design must meet the length requirements to function as a permanent SWM facility, see #7 below. 4. (Rev. 1) SWM easements to be recorded with a deed & plat prior to VSMP plan approval. (Rev.2) Comment still valid. 5. (Rev. 1) I don't believe the detention basins proposed meet any ESC/SWM spec. Show design calcs meet spec. (i.e. for drainage area, vol., shape, wet pool, drawdown, etc.). Basins should meet the 25-yr design/spec. The riser structure should have a trash rack. (Rev.2) Design of detention basin should meet spec., Drainage area equal to or greater than 3 acres . eeds a permanent pool to settle out sediment Design for Principal Spillway (see DEQ SWM HB, MS 3.02) 6. (Rev. 1) Detention design - It looks like the orifice is located between riser and 15" pipe. No stagnant pools. (Rev.2) Needs permanent pool; Design for principle spillway. 7. (Rev. 1) The level spreader design should follow the SWM design specs. It appears from county GIS that there's existing forest buffer, so the equation would be 40' length for every cfs. So, level spreader (LS) A would be = 1.47*40', LS B = 3.74*40' (exceeds max), and LS C = 1.28*40'. The minimum length is 13', max 130'. The maximum sheet flow length of either also must be satisfied (see VADEQ SWM Design Spec.2, Table 2.2). The LS needs to discharge to a well vegetated area with <10% slope. (Rev.2) Design should follow SWM guidance shown in design manual, Length of ELS lip = 13 lin. ft. per each 1 cfs of inflow (min. 13 lin. ft.; max 130 lin. ft.) for vegetated filter strips or for undisturbed conserved open space with at least 90% veg. cover (per Section 6.2 of the Design Specification) Length of ELS lip = 40 lin. ft. per 1 cfs for forested or reforested filter areas Size ELS for the 10-yr storm Overland flow from ELS will not concentrate in 150' or will enter protected buffer (forest/open space/wpo) or vegetated filter strip or enter into defined natural channel 8. '(Pt-, t) t""mtd di(c1b6n 4. 1'4"m ide dcsiaoo (Rev.2) Currently addressed. 9. (Rev.2) Include this checklist on the plan set. http•//www.albemarle.org/upload/images/forms center/departments/Community Develop ment/forms/Engineering and WPO Forms/"TO VSMP Construction Record Drawings Policy 23May2014.pdf 10. (Rev.2) Show that outfall from SWM basins go to a natural channel or extend outlet protection to a natural channel. 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, and the reasons are provided in the comments below. The erosion control plan content requirements can be found in County Code section 17-402. (Rev.2) Acknowledged. 2. (Rev.1) Sheets C3/C4: a. Show critical slope areas. (Rev.2) Not addressed. There are critical slopes (see County GIS overlay). b (Rev.2) Addressed. Cannot find private street easement of 5059/405. Please provide plat. (Rev.2) Not addressed; not able to find DB/PG. Show a temp. construction easement for disturbance in adjacent parcel 18-13F2. �� �1�f 2} x f ..ro - f. „ z F fb.i F �� lk.�t a�, �lac�� 4Eltk���� ��' . ,�E�. fnl` �ltc' „K c•e�€tfsr� t �: lxs .�� �t�a.:1ie l�>w�E�l��s:� @� ,� .,If € N� E (Rev.2) Addressed. (Rev.2) Acknowledged. 4. (Rev.1) Sheet C8: :i. k1ko Oh €he cid` (-0' f rWfOe,,. €kwl Tlr; (W1 kl;rolt k III& (Rev.2) Addressed. }. 4;bo%, i11.ii (._' % OP k ;0'ell l,"O N, Ov'' ign( El. Ime. 10 aplicar to hw 1ti1? qt w'- .f ',Pr the ,!,op- (Rev.2) Addressed. 5. (Rev.l) Sheet C9: *k.11di-S' (Rev.2) Addressed. b. Show SR/ST symbol and design computations for the detention. Show a phased plan — ESC-1 sheet for perimeter controls, ESC-2 sheet for grading & additional controls based upon your construction sequence. (Rev.2) There is not enough drainage area going to these detentions to classify them as a detention basin. 3 acres D.A. (min) for a sediment basin. (Rev.2) Addressed. d. Show grading (road, etc.), show all existing contours. (Rev.2) Sheets C5,C9,C10 — Show existing contours that are missing on the (( property. 6. i f i) �xhm 1f b t t (Rev.2) Currently addressed. 7. (Rev.1) Show ST/detention calcs., the design meets spec, and provide ST detail. (Rev.2) Partially addressed. The det. basin design will need correction to make it meet spec. (Rev.2) Addressed. 9. (Rev.2) Cover - Parcel is listed as 18-13F1 for the TMP# according to County GIS. 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. 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. After bonding and agreements are complete, county staff will need to 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 need 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 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 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; http://www.albemarle.org/deptforms.asp?department=cden�ywpo