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HomeMy WebLinkAboutWPO201500047 Action Letter 2015-08-06�pF A COUNTY 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: The Pants Project —VSMP Plan preparer: Justin Shimp, Shimp Engineering, 201 E. Main St. Suite M, Charlottesville, VA 22902 fiustin(a,shimp -en ineering com] Owner or rep.: Grey Preservation Society LLC P. O. Box 7143, Charlottesville, VA 22906 Plan received date: 16 Jul 2015 Date of comments: 6 Aug 2015 Reviewer: John Anderson 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. B. VSMP: SWPPP: Stormwater Management Plan (WP0201500047) VSMP Regulation 9VAC25- 870 -108 requires the VSMP authority to approve or disapprove a SWMP. This plan is disapproved for reasons provided in comments below. The stormwater management plan content requirements can be found in County Code section 17 -403. Comment sections (SWPPP & VSMP SWMP) have been combined since, while we understand design intent, site forces conceptual reconsideration. We believe conceptual redesign has potential to lessen expense and yet provide adequate post - construction storm runoff control. Recommend break project into thirds: a. Lower reach of driveway, if driveway existed prior to current improvements ( -ref image, below; disregard if no there was not a pre - existing drive). If a driveway existed prior to improvement (now - existing driveway), treat sections that keep or kekt) to pre- existing alignment as maintenance. VESCPNSMP will not apply to these maintenance sections. Identify, label, and eliminate section acreage from SWM design. Also, see Attached guidance. While difficult to apply this guidance to impervious cover, DEQ linear project guidance is informative. (Attached) Engineering Review Comments Page 2 of 3 ono ­ — –... ", h a 4 *fay &a0 ±vo b. Remaining drive endinu at build site envelope / Area of disturbance. Elev. 872'± (sheet C3 VaRRM .xls: consider total load (TP) reduction required based on post - construction land cover, this section. This section is impervious driveway width + ditches. Drainage area =Area of disturbance for ditches /driveway. For example: if drive + ditch width =16' and L =2722 LF, enter 1 Ac. impervious. This value returns load reduction requirement =1.76 lb. Next, recommend place forest -open area in conservation/preservation easement. If, for example, willing to place 4 Ac. in easement, enter this value (if enter 4 Ac., for example, xls. returns load reduction =0.48 lb.; 6 -Ac. eliminates load reduction altogether, for 1 Ac. impervious area.) Options exist. This may address water guali t requirements for driveway. For water quantity, level spreaders (ELS) may convert concentrated flow to sheet flow (ref. 9VAC25- 870- 66.D.). Other options exist —for example, combine this driveway section with building site in Energy Balance equation. Note: ELS may not work; installation or construction impacts may outweigh any perceived advantage. Also, ELSs must be maintained in perpetuity if relied upon to comply with 9AVAC25- 870 -66. c. Build site. Use VaRRM .xls to calculate phosphorus load reduction; provide energy balance, provide SWM quality/quantity control. 2. Note: Advantage of splitting project is that it eliminates expense and difficulty of constructing a pond at proposed location. Comment: Pond will likely not be approved at this location. This location receives /treats post - construction runoff that passes 700' through undisturbed woods (and arguably merits no treatment), while not collecting/treating ditch runoff, which is the more critical from a pollutant perspective. Eliminate pond at this location, or redesign to receive and treat ditch runoff. There is an issue with this, however. Drive ditches are apparently constructed. Plans appear to indicate that there are culverts spaced along drive that convey runoff into woods (please confirm). If this is the case, eliminate pond since design does not collect/treat ditch runoff. There are advantages to combining driveway with preservation/conservation easements to reduce phosphorus load reduction requirement associated with site access runoff. 3. Explain post - development drainage map abbreviations. While this map is carefully detailed, cannot interpret `MGD'. Legend would be helpful. SF, IMP, AF, make sense –MGD? Conceptual issues are significant, anticipate additional comments following revision. Welcome .PDF preview. Please feel free to call, or request plan review meeting. Also, urge Applicant contact Geoff Elsie, 434.270 -3471. VSMP Application includes signed cover sheet for single family residence SWPPP dated 22- Apr -2015 (signature date, 7/15/15). Geoff Elsie will need a complete copy of the single family residence SWPPP –the entire document. Engineering Review Comments Page 3 of 3 C. VSMP: SWPPP: Erosion Control Plan (WP0201500047) Virginia Code §62.1- 44.15:55 requires the VESCP authority to approve or disapprove an ESOP. This plan is disapproved for reasons provided in comments below. The erosion control plan content requirements can be found in County Code section 17 -402. C3 — Label ditch sections to correspond with Stormwater Management Report Modified LD -268 ditch labeling convention. LD -268 table —Add note to make protective lining design intent clear. C4 — Provide stockpile silt fence. Engineering plan review staff are available from 2 -4 PM on Thursdays, should you require a meeting to discuss this review. Plan review staff are also available at 434 - 296 -5832 (- x3069) should you have questions. 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 request a pre - construction conference by completing a 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.or /g deptforms .asp ?department--cdengMTo Thank you - 434.296 -5832 —x3069 File: WP0201500047 Pants Project VSMP_080615