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Home My WebLink AboutWPO201600009 Approval - County 2016-10-28COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902-4596 Phone (434) 296-5832 Fax (434) 972-4126 VSMP Plan review Project: Old Trail Village Blocks 10, 16 & 17/18 (SWM, ESC, Mitigation Plan) Plan preparer: Jeremy Fox, Ammy George, Bill Ledbetter —Roudabush, Gale & Assoc, Inc 914 Monticello Road, Charlottesville, VA 22902, jfoxgroudabush.com; ageorgeAroudabush.com; bledbetternroudabush.com Owner or rep.: March Mountain Properties LLC [1005 Heathercroft Circle, Suite 100] Dave Brockman, dave(a)oldtrailvilla eg com Reviewer: John Anderson — En ink eering Emily Cox (Rev. 2) Stream Buffer Mitigation Plan (RGA Received date: 7 Jun 2016 (Rev. 1) 22 Jun 2016 (Rev. 2) 21 Oct 2016 Date of comments: 20 Jun 2016 (Rev. 1) 12 Jul 2016 Approval vending Attorney's Office Quidance relative to Easements (Rev. 2) 27 Oct 2016 — Approved SWPPP, SWMP. ESCP not reviewed with these comments -NA WP0201600009 A. Stormwater Pollution Prevention Plan (SWPPP) — NA B. VSMP: SWPPP: Stormwater Management Plan (WP0201600009) — NA C. VSMP: SWPPP: Erosion Control Plan (WP0201600009) — NA D. Mitigation Plan (WP02016-00009) — Approved 1. Include `WP0201600009' in Mitigation Plan title. (Rev. 1) Addressed. 2. Mitigation Area labels: misprint (Mitigation) —please revise. (Rev. 1) Addressed. 3. Ensure Area 132-1 will not be impacted by Slabtown Branch Sanitary Sewer Extension project. (Rev. 1) Addressed. 4. Recommend signs visible to the public that advertise March Mountain Properties' stream buffer impact minimization, and stream buffer preservation, conservation, and restoration efforts. (Rev. 1) Addressed. 5. Add Note (Mitigation Area 132-1 site): "Area 132-1 will not be planted until Slabtown Branch Sanitary Sewer Extension project is complete. Area 132-1 should be planted in the fall of the year of completion of the sanitary sewer extension project, or the spring of the following year. Land disturbance associated with WP0201600009 must be stabilized (per Approved ESOP) without regard to Mitigation Plan in any area that may be affected by Slabtown Branch Sanitary Sewer Extension project." Contact Engineering Div. if any questions (Frank Pohl, County Engineer). (Rev. 1) Addressed. Engineering Review Comments Page 2 of 3 6. Ensure vehicular access to SWM Facilities L-2, L-3, S-3, S-12 will not create additional stream buffer impacts, or affect proposed mitigation areas (especially Areas Al, A2, A3, 132-1, C1). (Rev. 1) Addressed. 7. Recommend include plant totals for each plant schedule table. (Rev. 1) Addressed. 8. Add Note: "Minimum survival required after two growing seasons is 490 plants per Acre, or 1,299 plants. This plan establishes nine Mitigation Areas. 1,299 is a plan -wide figure. 70% plant survival does not apply to any single Mitigation area. Provided 1,299 plants survive at the end of two growing seasons, the plant survival requirement is met. Mitigation plan bond amount may be reduced for plants that survive two growing seasons. Mortality that reduces survival to less than 1,299 plants must be replaced with tree or shrub container -grown seedlings, per plant and planting requirements (specifications) listed at Stream - buffer Mitigation General Planting Notes (sheet 3). These notes apply to replacement plants, as well as initial plants." (Rev. 1) Addressed. 9. Add Note: "County access to each Mitigation Area during normal business hours to inspect or execute mitigation measures (re -plantings, for example) will be provided through Easements." (Rev. 1) Addressed, but without reference to easements. (Also, items 10, 11, 12, below). 10. Establish (Mitigation Plan) Easements that correspond with and preserve Mitigation Areas identified in the plan. (Rev. 1) Not Addressed. Applicant's comment response referred to County Attorney's Office. (Rev. 2) Addressed. 11. Establish Access Easements that grant (county) access to each Area identified in the plan. This does not mean vehicular access, but near -vehicle approach with remaining terrain traversable by an individual of median age in good health. Access easement terrain should not be rugged. (Rev. 1) Partially Addressed. Applicant's response referred to County Attorney's Office. (Rev. 2) Addressed. 12. Submit Easements for legal review and approval prior to and as condition of Final Site Plan approval, or Final Plat approval, for Lots /units in Old Trail Village, blocks 10, 16, 17, 18 & 30. (Rev. 1) Not Addressed. Referred to County Attorney's Office [email: 7/12/2016 7:28 AM]. (Rev. 2) Addressed. 13. Note —It is important to limit replanting cycles. 1,299 is a fixed end -of -2" -growing -season requirement. If, for example, the total at the end of the second season is 1,249 (shortfall =50), then 50 replacements must survive, meaning it may be best to plant more than 50 to ensure that, in the example, at least 50 survive at the end of the second replacement growing season. Please call Frank Pohl, County Engineer -434.296-5832 —x7914, if any questions. (Rev. 1) Addressed. 14. Note —Mitigation Plan must be bonded. (Rev. 1) Acknowledged. Engineering plan review staff are available from 2-4 PM on Thursdays, should you require a meeting to discuss this review. File: WP0201600009_OTV_blocks 10, 16, 17, 18 VSMP_Mitigation only_] 02716-rev2 Engineering Review Comments Page 3 of 3 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; hLtp://www.albemarle.or2/deptfonns.asp?department--cden2no File: W002016000090TV blocks 10, 16, 17, 18 VSMP Mitigation only_102716-rev2 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 Plan review Project: Old Trail Village Blocks 10, 16 & 17/18 (SWM, ESC, Mitigation Plan) Plan preparer: Bill Ledbetter —Roudabush, Gale & Assoc, Inc [BLedbetterkroudabush.com] 914 Monticello Road, Charlottesville, VA 22902 J. Glenn Muckley —Stantec /5209 Center Street Williamsburg VA 23188-2680 Glenn.muckley@stantec.com Owner or rep.: March Mountain Properties LLC [1005 Heathercroft Circle, Suite 100] Dave Brockman, davekoldtrailvilla eg com Reviewer: John Anderson —behalf of Engineering SWM Plan (Stantec) Received date: 23 May 2016 (Rev. 1) 29 Jun 2016 Date of comments: 19 Jun 2016 —Conditionally -Approved (Rev. 1) 20 Jul 2016 —Approved SWPPP, ESCP and Mitigation Plan not reviewed with this correspondence -NA WP0201600009 A. Stormwater Pollution Prevention Plan (SWPPP) —NA B. VSMP: SWPPP: Stormwater Management Plan (WP0201600009) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This plan is approved. (19 Jun 2016) SWMP Conditionally -Approved. 20 -Jul 2016 —All prior review comments addressed with revision. See Stantec comment response (booklet/file -Attu. Todd Shifflett, 28 -Jun 2016). Plan is Approved. [Review comments /Conditional Approval also sent as email, 6/19/2016 5:07 PM] Prior comments removed for simplicity. See CountyView (CV) system for 19 Jun 2016 Engineering review comments. C. VSMP: SWPPP: Erosion Control Plan (WP02016-00009) —NA D. Mitigation Plan (WP02016-00009) —NA Process: After approval, plans need to be bonded. The bonding process is begun by submitting a bond estimate request form and fee to the Department of Community Development (received). One of the plan reviewers will prepare estimates Engineering Review Comments Page 2 of 2 (provided by RGA) and check parcel and easement information based on the approved plans. The County's Management Analyst will prepare bond agreement forms (in process), 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. VAR100043 was modified by VDEQ on 16 -Mar 2016 to include blocks 10, 16 & 17/18, 27.13 Ac. area of disturbance. Gotmty and Applioant have discussed that once Old Trail Stofmwater- Master- Plan d. 5 Feb 2016 is r-evised in response to discussion 17 Mar-, is subsequently r-eviewed and accepted by County and Mar -ch Mountain Propei4ies, that a pre constFuction meeting may be r-equested to receive a Cir-ading PeFmit for blooks 10, 16 & 17/18. Initial site plan (SDP201500028) for these blocks was approved 7/24/15. Old Trail Village Stormwater Master Plan (MP) refines Zoning Application (ZMA200400024) plan grading. Once County and Applicant accept revised MP, 18-8.5.5.4 allows County to issue a Grading Permit for site preparation. Pre -requisites to Grading permit include 6 items: i) Parks & Recreation Easements presumed by MP to locate L-3 (or perform grading) on Alb. County property; ii) rev. 5 -Feb 2016 MP; iii) SWPPP; iv) slight revisions listed at #9, #21, and #24; v) ESC bond; and, vi) estimated date that detailed final SWM designs for L3, 553, S-12 will be submitted. (21 Jun 2016) Early Grading: Ref. email 5/26/2016 10:03 AM: D. Brockman to J. Anderson. Also: email, County to Dave Brockman, Bill Ledbetter, and Leslie Tate: 6/16/2016 7:48 AM. Early Grading is unfortunately not an option. [Review error.] WP0201600009 ESCP is approved. Mitigation plan: Approval pending Attorney's Office guidance relative to Easements. Also, email: J. Anderson to County Attorneys' Office, 7/12/2016 7:28 AM). Once Mitigation Easement review /recordation meet county attorney's requirements; ESOP, SWMP, Mitigation bonds are posted; and LRB pro -rata fee is paid, Applicant may request a pre -construction conference by completing a form —all state fees have been paid. The form identifies the contractor and responsible land disturber, and remaining fee to be paid (county portion). 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 so that work may begin. County forms can be found on the county website forms center under engineering; hqp://www.albemarle.oriz/dgptfonns.asp?department--cdenMUo Thank you New teL # : 434.872-4501 —x3069 File: WP0201600009_OTV_blocks 10, 16, 17, 18_VSMP_SWMPonly 072016revl-Approv 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 Plan review Project: Old Trail Village Blocks 10, 16 & 17/18 (SWM, ESC, Mitigation Plan) Plan preparer: Jeremy Fox, Ammy George, Bill Ledbetter —Roudabush, Gale & Assoc, Inc 914 Monticello Road, Charlottesville, VA 22902, jfox(&roudabush.com; a e�orge(a�roudabush.com; bledbetter ct,roudabush.com J. Glenn Muckley —Stantec /5209 Center Street Williamsburg VA 23188-2680 Glenn. muckley(a,stantec. com Owner or rep.: March Mountain Properties LLC [1005 Heathercroft Circle, Suite 100] Dave Brockman, davegoldtrailvilla eg com Reviewer: John Anderson—beha!LofEn inQ eering SWM Plan (Stantec) Received date: 23 May 2016 Date of comments: 19 Jun 2016 —Conditionally -Approved ESC Plan (RGA Received date: 11 Feb 2016 (Rev. 1) 18 Mar 2016 (Rev. 2) 13 May 2016 Final 23 May 2016 Date of comments: 6 Mar 2016 (Rev. 1) 3 Apr 2016 (Rev. 2) 21 May (e-mail: 5/21/2016 9:20 PM) Final 21 Jun 2016 —Approved Stream Buffer Mitigation Plan (RGA) Received date: 7 Jun 2016 Date of comments: 20 Jun 2016 WP0201600009 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. Please submit SWPPP for blocks 10, 16 & 17/18 —include SWPPP Exhibit. Pattern after prior SWPPP submittals, prior blocks. Permit Registration Statement and VAR100043 are current and incl. 27.13 Ac. area of disturbance proposed with these blocks. Please call if any_questions. (Final) Addressed. Ref B. Ledbetter email: 5/23/2016 10:20 AM Attached /Also, OTV SWPPP at: L•\DEPT\Community Development\Engineering Division\anderson\documents_MayJun20l6 Engineering Review Comments Page 2 of 9 B. VSMP: SWPPP: Stormwater Management Plan (WPO201600009) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. Final SWM Plan dated May 20, 2016 was received May 23, 2016 (SWMDesign Summary, East Side /Stantec, Williamsburg, VA) Stormwater management plan content requirements can be found in County Code section 17-403. (19 Jun 2016) SWM Plan Conditionally -Approved. Please address comments below for Final Approval: [Review comments /Conditional Approval also sent as email, 6/19/2016 5:07 PM.] 1. Title sheet a. Recommend list VAR100043 on this /future SWM Plan Title sheets. DEQ SWCGP database lists VAR100043 details, and this permit must be modified to include any Additional land disturbance projects at Old Trail (except Slabtown Sewer Ext. project —A linear project). Note: SWCGP CGP VAR100043 details: Comment ("Total and disturbed area increased from 91.71 ac."); Est. Area to be disturbed (110.83 Ac.*); Application complete date (03/08/2016); Expiration date (06/30/2019); Technical Criteria (Part 2 C — Previously Permitted); Permit Writer (DEQ — Shantelle Nicholson); Modified on 03/16/2016; Additional (Record created 03/04/2016 by John Anderson). Note*: 03/16/2016 Modification includes Area of Land Disturbance for blocks 10, 16, 17, 18, and 30. Blocks 5, 20, and 21 are not (at this time) covered by VAR100043. b. Revise Project Narrative, 2 /2.1 —Existing 2.11% impervious area (ZMA) yields load =37.32 lb (TP) per year. Part IIC applies. Part IIC requires SWM design (via Master Plan) limit post - developed (development -wide) discharge to the Average Watershed (16%), or 104.98 lb TP/yr. Proposed impervious Area (Ave. for 237.35 Ac.) =43.45%. Proposed pollutant load (43.45%) =238.66 lb TP/yr. Master Plan design removes 133.68 lb TP/yr, to comply with state stormwater Part IIC (water quality) requirements. See Table 7, Master Plan. 2. Sheet 2: Recommend DISCLAIMER: Area (Ac) and Curve Numbers for this plan vary slightly from Master Plan Appendix C Hydrology Support Information d. April 4, 2016. Slight variation in Area /CN values relates to slightly imprecise analysis possible with Master Plan (MP) estimate of future development (See Old Trail Stormwater Master Plan Update, Accepted Apr. 12/Signed: Apr. 25, 2016). This and future reviews should not expect Areas /CNs for distinct development blocks to align with the MP precisely. Applicant cannot force values that do not match, to match. Rather, Stantec presents with this SWMP (blocks 10, 16, 17, 18, 30) the most accurate information available. Review recognizes that slight variation between SWMP and MP DA or CN values (DA IDs 1013, 1213, 1513) has no effect on compliance. CNs are virtually identical: 61.54, 61.00, 60.71 (SWM Plan: 1013, 1213, 1513) vs. 61.00 (each DA) in the MP. Reviewers should be alert to effect on compliance if discrepancies exist between Master Plan and SWM plans submitted for discrete blocks. 3. Sheet 8 —L-2 Retention basin DA listed as 23.93 Ac.; Compliance tracking ledger submitted with this Plan: 23.81 Ac. —Revise for consistency. 4. Sheet 4 —Label Rowcross St. to orient those unfamiliar with Old Trail Village. 5. Sheet 4 —Detail, S-3 High Flow Bypass Structure detail: While image is useful, this series of images and text are adapted from VA stream restoration design guide. Reference to streambed, streambank, bank full, meander, head boulders, vane, scour pool, and VSRDM (VA Stream Restoration Design Manual?? —LINK: http://www.deq.virginia.gov/Portals/0/DEQ/Water/Publications/BMPGuide.pdf ) will utterly confuse. It is not possible to adapt this stream restoration detail to SWM purposes and expect contractors, inspectors, or even bypass to succeed. Provide revised High Flow Bypass Structure detail that supports design aims (including but not limited to): type /size material/s; plan /profile; construction specifications; construction guidelines; design elevations. 6. Sheet 4 —Show and label existing contours at least 50 -ft beyond property line. S-3 lies in close proximity to PL. 7. Sheets 4, 6, 8, 10 —5-3, 5-12, L-2, L-3 Grading & Layout: Provide show and label vehicular SWM Facility Access. Provide smooth non -curb mount unimpeded off-street access /parking /turnaround. Ref. ACDSM, Sec. 5 (text image, below) 8. 9. 10 11 12 13 14 15 16 17 18 19 20 21 Engineering Review Comments Page 3 of 9 Rcst N1anage mcnt Practices Fpr Stormwatcr Management: All practices must have adequate vehicle access: 10' width graded at less than 20%. Anything over 20% must be surfaced with gravel or pavement. Access must be to all structures and Forebay cleanout areas. Easements must be provided over all access and facilities, to accompany deeds and agreements as available on the county website; http;//www. al bemarle.urg/deptforms. asp?depanment--cdena"po Sheets 4, 6, 8, 10 —Provide permanent aesthetic physical barrier to trespass. Provide signs that prohibit trespass swimming. Warn of drowning hazard at each detention /retention facility. Each facility must be clearly posted: SWM Facility. Private Property. No Trespassing. Etc. Sheet 5 —Provide S3A-S3A' profile elevations for: bioretention /detention basin floor, Elev. of each riser base ( X 2 risers). Please review /provide elevations for design features that may be required for water quality -quantity treatment, inspection, or construction. Please coordinate with RGA on ESC Plan. Sheet 4/5 —Provide dimensions for outlet protection to aid review, bonding, construction, and inspection — Ref. to VESCH Std. & Spec. 3.18 is inadequate (S-3-1, S-3-2, S-3-3). Sheet 6 —S-12 High Flow Bypass Structure —Revise per comment #5., above. Sheet 6 —Label Rowcross St. to orient /aid review. Sheet 6/7 —Provide dimensions for outlet protection to aid review, bonding, construction, and inspection — Ref. to VESCH Std. & Spec. 3.18 is inadequate (S-12-1, S-12-2, S-12-3). Sheet 6/7 —Recommend SWM -1 Riser Elevation match ESCP Sediment Basin #3 Crest Elev. =647.20, if possible. Reviewer is positioned to Approve ESCP (blocks 10, 16, 17, 18 & 30). Though Riser elevations needn't match, if possible, it simplifies construction and may minimize expense. Sheets 5'7 " 7, 11 —Each detention basin profile includes identical SWM -1 Riser label. For separate facilities, this is confusing. Recommend distinct Riser labels for each facility. Sheet 7 —Provide S 12A -S 12A' profile elevations for: bioretention /detention basin floor, Elev. of each riser base ( X 2 risers). Sheet 7 —Top of berm, S-12 detention basin, is =650.00'. WP0201600009, RGA ESCP top of dam, sediment basin 3 =650.20'. Revise top of berm to match top of dam since sediment basin (RGA, sheet 4) and S-12 (Stantec, sheet 6) grading are otherwise nearly identical. Sheet 7 —Revise profile DI -1 (biofilter) Riser crest elevation to 648.5'. 664 �.noenoroseo ria s 2.857 SF SIORETENTION FACILITY . . . . . . . ROPOSEO GRADE PIOMTER FLOOR =648 FT . . .660 30INCii RCA 644 2 YR. ME 640 EVEL SPREADER PROPOSED RIPRAP OUTLET PROTECT $,12.1 636 P@RvESCH M. AND$PEC. 91S - .. •! •. - .� CLASS I RiPRAP 121NCH RCP MM. LEPTN=7.7 FT y i _ T — INV OP•Md33 FT �--.-• INV DOM MWOO FT 632 PROPOSED CONCRETE � e / CyZBrF F Sheet 8 —L-2 Drop Structure ap) —Revise per comment #5., above. Also: this detail appears to apply to structures S-1 through S-4. Replacement detail should clarify which plan view structures are detailed. Sheet 9 —No splash rocks or armoring is shown downstream of Structure S5. Recommend armor to prevent erosion at this point. Erosion at this point may migrate upstream and undermine Structures S 1 —S4. Sheet 9 —Provide L2A-L2A' profile elevations for: Each of 4 step pools, retention basin floor, elev. of riser base, elev. of 8" drain pipe (if known). NV IJP+ 651.60 ISTING GRADE INV DOWN = 549.10 FT 654 DIA RISER TOP OF WALL •651.90 FT CREST ELEVATION - 656 FT 652 ERM ELEV -660-00 FT 10OYR. WSE 648 j 7 100 YR. WSE 10 YR. ME 644 2 YR. ME 640 EVEL SPREADER PROPOSED RIPRAP OUTLET PROTECT $,12.1 636 P@RvESCH M. AND$PEC. 91S - .. •! •. - .� CLASS I RiPRAP 121NCH RCP MM. LEPTN=7.7 FT y i _ T — INV OP•Md33 FT �--.-• INV DOM MWOO FT 632 PROPOSED CONCRETE � e / CyZBrF F Sheet 8 —L-2 Drop Structure ap) —Revise per comment #5., above. Also: this detail appears to apply to structures S-1 through S-4. Replacement detail should clarify which plan view structures are detailed. Sheet 9 —No splash rocks or armoring is shown downstream of Structure S5. Recommend armor to prevent erosion at this point. Erosion at this point may migrate upstream and undermine Structures S 1 —S4. Sheet 9 —Provide L2A-L2A' profile elevations for: Each of 4 step pools, retention basin floor, elev. of riser base, elev. of 8" drain pipe (if known). Engineering Review Comments Page 4 of 9 22. Sheet 9 —Label existing grade (L2A-L2A' profile). Note: Existing grade is shown using solid line type on Sheets 5 and? (S3A-S3A' and S12A-S12A') —this is ok, but dash line conventional. 23. Sheet 8/9 —Provide dimensions for outlet protection /stone step complex pools to aid review, bonding, construction, and inspection (L-2-1; 4 stepped pools). 24. Sheet 10 —Label one or more streets. 25. Sheet 10 —Ref. WP0201600009, RGA, sheet 6. Although County is positioned to approve WP0201600009 ESCP today, RGA may provide slip sheet/s at Applicant's discretion without review at no expense to revise 92.00' L 7.61% 30" RCP shown on ESCP sheet 6. If pipe were instead 93' L w/ invert IN =628.00' (3' lower) and invert OUT =622.00' (2' lower), then ESCP and SWMP would match. With routings dependent on 1-6" orifice at @ 630.00' (will not work with ESCP pipe design), it may be simpler to revise ESCP than the SWMP. Recommend revise ESCP to match SWMP, if possible. Note: if revise to match Stantec plan, rev. ESCP pipe slope (30"RCP) =6.45%. 26. Sheet 10/11 —Provide dimensions for outlet protection (L-3-1, L-3-2). 27. Sheet 10 -110' L 36" RCP between MH -1 and MH -1 [please re -label one MH as MH -2], 11desip—ned to route high-flow, must be shown in profile with sufficient detail to review /evaluate design effect, and to understand high flow bypass. 28. Sheet 10 —Provide bioretention sizing calculation —Ref. sheets 4, 6. Also, check calculation as 4,019 S.F. (required) appears slightly high (3,866 S.F. /review check). 29. Sheet 20 —Revise VSMP Compliance Summary 2 /2.1 —Also, see #l.b., above. 30. Sheet 20—SWM/BMP Maintenance Agreement: Not typically seen on SWM Plans. If retain, recommend parenthetical: (Summary, for information only. Maintenance Agreement exists as separate legal document, and is recorded elsewhere). Stormwater Management Design Summary —East Side (3 -ring binder + e -document) 1-i (e-aoe) —tvpo —Now snouta react no Floodplain V Nnw4loodp€ain impacts are impacts are not WATER s aDDD a propo.'UA. Cut spillway implicitly 0.00 channels to tie facility approved in the outfalls are, the only work master plan -- proposed Mthin the Encroachment floodplain per into Floodplain? understanding of prior discussions ivith Albemarle County staff. Impacts) b. p. 17 e-doc —DA 12B —Area SF values should be revised listed as 0.000) fbR£STiD a aaoa 55 a�4 OPEN SPACE B 6.Dt]a dl GM WATER s aDDD 9$ 0.00 sum ODOO 0.00 CW NDIV{DI Routings: L-2 10 -yr (POST) —SUMMARY Proposed Peak =16.83 cfs : Appendix C* /routing: =16.98 cfs —please Reconcile. * Appendix C: Hydrology Support Information Engineering Review Comments Page 5 of 9 C. VSMP: SWPPP: Erosion Control Plan (WP0201600009) Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESOP. This plan is approvedpending follow up request for slight r-evisions at items �i1ta1. (Rev. 2) Partially addressed. Ref. email 5/21/2016 920 PM; #21, #24 Addressed. (Final) Addressed. Note: With decision to reference Master Plan for Old Trail (OTV MP), with CGP (VAR 100043) valid through 2024 (w/renewal in 2019), and with initial SWM Application for blocks 10, 16, 17, and 18 expected soon, it may be possible to approve this ESCP (w/revisions), process ESC bond, and issue a Grading Permit prior to final detailed SWM facility design approval. Much depends on timing and form of initial SWM Application: substantial deviation from OTV MP could derail any effort to issue a Grading Permit prior to SWMP approval for these blocks. If SWMP bears close similarity to OTV MP and if County/Applicant are close to agreement on OTV MP, then it may be possible to issue a Grading Permit prior to SWMP Approval for blocks 10, 16, 17, 18. This may help, or be offer of limited benefit given required level of coordination with Parks and Recreation and agreements likely necessary to locate permanent SWM facilities on County Parks and Recreation property (TMP# 55E -01-H). Easements may exist, but additional deeded access from County to Applicant may be required for SWM facilities L2/L3. Further, withfinal detailed SWM plan design approval a prerequisite to Site Plan (SDP201600006)/Final Plat approval for blocks 10, 16, 17, and 18; with Variance to ZMA200400024/GDP sheet 3 a prerequisite to County ability to apply OTV MP, a series of steps is required prior to sale of Lots in these blocks. Engineering will try to expedite review. .PDF preview is available for limited design checks. It is possible up to 5 plans may be under review at once: Final Site/Final Plat, WPO, ROAD, and Zoning Variance Exhibit; this, in Addition to OTV MP -print plans are essential to help avoid errors and mistakes. fGIS/Approx. Location OTV MP BMPs LL 2, L-3 (TMP# 55E -01-H)] Note: Irl may not serve blocks 10, 16, 17, and 18 -reference to L-2 may be misplaced. (Rev. 1) Acknowledged. Water Quantity Compliance Summary NODE Existing Peak Discharge (cis) Proposed Peak discharge Nsj Percent Difference 10 2 -YR 10 -YR I 1OD-YR 2 -YR 10 -YR I 1DD-YR 2 -YR M -YR 10D -YR L-2 6,04 18.69 48.54 5.34 16.83 108.75 -11.6% -10496 124.196 L-3 4.71 14.32 36.64 1.91 7.14 45.03 -59.4% -50.1% 22.9% S-3 3.65 11.52 30.GG 3.G0 11.48 41.41 -1.4% -0.3% 35.1% 5.12 1.17 3.63 9.48 0 81 2.24 22.50 -30.8% -38.3% 131.396 C. VSMP: SWPPP: Erosion Control Plan (WP0201600009) Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESOP. This plan is approvedpending follow up request for slight r-evisions at items �i1ta1. (Rev. 2) Partially addressed. Ref. email 5/21/2016 920 PM; #21, #24 Addressed. (Final) Addressed. Note: With decision to reference Master Plan for Old Trail (OTV MP), with CGP (VAR 100043) valid through 2024 (w/renewal in 2019), and with initial SWM Application for blocks 10, 16, 17, and 18 expected soon, it may be possible to approve this ESCP (w/revisions), process ESC bond, and issue a Grading Permit prior to final detailed SWM facility design approval. Much depends on timing and form of initial SWM Application: substantial deviation from OTV MP could derail any effort to issue a Grading Permit prior to SWMP approval for these blocks. If SWMP bears close similarity to OTV MP and if County/Applicant are close to agreement on OTV MP, then it may be possible to issue a Grading Permit prior to SWMP Approval for blocks 10, 16, 17, 18. This may help, or be offer of limited benefit given required level of coordination with Parks and Recreation and agreements likely necessary to locate permanent SWM facilities on County Parks and Recreation property (TMP# 55E -01-H). Easements may exist, but additional deeded access from County to Applicant may be required for SWM facilities L2/L3. Further, withfinal detailed SWM plan design approval a prerequisite to Site Plan (SDP201600006)/Final Plat approval for blocks 10, 16, 17, and 18; with Variance to ZMA200400024/GDP sheet 3 a prerequisite to County ability to apply OTV MP, a series of steps is required prior to sale of Lots in these blocks. Engineering will try to expedite review. .PDF preview is available for limited design checks. It is possible up to 5 plans may be under review at once: Final Site/Final Plat, WPO, ROAD, and Zoning Variance Exhibit; this, in Addition to OTV MP -print plans are essential to help avoid errors and mistakes. fGIS/Approx. Location OTV MP BMPs LL 2, L-3 (TMP# 55E -01-H)] Note: Irl may not serve blocks 10, 16, 17, and 18 -reference to L-2 may be misplaced. (Rev. 1) Acknowledged. Engineering Review Comments Page 6 of 9 0 o Heo Moe. s--1, -ofl This is an ESCP —please remove labels SWM -1, SWM -2, and SWM-3/all sheets. (Rev. 1) Addressed. Replace Ex. SWM -2 labels with Ex. SB2/all sheets. (Rev. 1) Addressed. Replace SWM -1, SWM -3 labels with SB1, SB3/all sheets. (Rev. 1) Addressed. Sheet 2: 5. Show/label 50 -ft distance and 100 -ft WPO stream buffers for Lickinghole Creek and Slabtown Branch. (Rev. 1) Addressed. 6. Recommend reference Stantec Old Trail Village Stormwater Master Plan/5 Feb 2016 on Overall Plan sheet. (Rev. 1) Addressed. 7. Recommend add Future BMP L-2 to Existing Sediment Basin WPO #201300082 label. (Rev. 1) Addressed. 8. Revise sediment basin profile titles (sheets 6, 7, 8) to read SB 1, SB2/Modified, SB3, respectively. (Rev. 1) Addressed. 9. Revise routing data block text (sheets 6, 7, 8) to eliminate reference to SWM; instead ref, sediment basins. (Also, see item #33) (Rev. 1) Addressed. As follow-up: Please edit sheet titles to read Sediment Basin rather than Stormwater Basin. (Rev. 2) Not addressed. (Final) Addressed. 10. Note: SWMP routings when submitted may reference detention/retention basins, and ideally reference L_3, SS31 5-12, consistent with OTV MP. (Rev. 1) Addressed. 11. Sheet 3: Provide trapping device, E side Fielding Run, opposite Claire Mill Circle (>100'L slope). SF alone is insufficient. (Rev. 1) Addressed/discussed 9 -Mar. 12. Sheet 3: Provide diversion dike upslope of SF, E of Fielding Run opposite 5 lots at N end of the street. (Rev. 1) Addressed. Sheets 3, 4: 13. Provide SAF, each sediment trap/basin. (Rev. 1) Addressed. 14. Revise CE symbol to read PCE (paved CE), consistent with detail, sheet 5. (Rev. 1) Addressed. 15. Revise Limits of Disturbance labels to include 27.13 Acres. (Rev. 1) Addressed. 16. Provide additional existing contour labels. (Rev. 1) Addressed. Sheet 4: 17. Proposed contour labels difficult to read; increase pitch. (Rev. 1) Addressed. 18. Revise drainage divide around SB3; show divide at Elev. 650±. [ref. profile/sheet 8] (Rev. 1) Addressed. 19. Provide SF, E side Fielding Run Drive, Sta. 31+40 - 33+40±. (Rev. 1) Addressed. Engineering Review Comments Page 7 of 9 20. Revise drainage divide E of Fielding Run Drive, beginning Sta. 31+40± ; divide is shown running east, parallel with contours; revise to show running NE along ridge (proposed contours). (Rev. 1) Addressed. 21. Provide diversion (250'±) to direct runoff along proposed contours, N edge limits of disturbance into SB -1. (Rev. 1) As follow-up —Please provide diversion in alternate location: if view sheet 4 physically, request diversion extend from approx. mid -point of plan sheet revisions block down (East) to scale block. (Rev. 1 diversion provided may be removed.) Apologize for any confusion please call if any questions. (Rev. 2) Addressed. 22. Reference sediment basin outfall/riprap protection details on sheets 6, 7, 8 (OP1A, OP2A, OP3A). (Rev. 1) Addressed. 23. Shift diversion/DV out of sidewalk, NW corner, intersection Golf Drive and Fielding Run Drive. (Rev. 1) Addressed. 24. Consider/provide SB -1 baffle, if necessary, to increase flow path of runoff entering from S to prevent short- circuiting. (Rev. 1) Addressed. Asfollow-up: Please show SB 1 riseribarrel in plan -view. (Rev. 2) Addressed. 25. Eliminate `SWM POND (See Master Plan)' Note. Provide Title sheet or Sheet 2 reference to Master Plan. (Rev. 1) Addressed. 26. Proposed sediment basin embankments, berm elevations, contours, outfall pipe locations, INV elevations, pipe lengths/DIA, primary riser locations/Eley., and grading should match OTV MP BMP LL3, S-3, S-12 design parameters, if possible. Avoid need to replace/relocate through -dam pipe outfalls requiring embankment tear -down to convert sediment basins to permanent SWM facilities. (Rev. 1) Addressed. 27. Sheet 5: Silt Fence drainage installation detail: revise detail to provide gap in SF downslope of sediment basin pipe outfall/riprap protection. Place stone in gaps. SF/stone should not be required downslope of SB outfall protection, but perimeter SF/stone is appropriate at these points until slopes stabilize. (Rev. 1) Addressed. Sheets 6, 7, 8: 28. Profiles/All sheets: Show dewatering device, dry storage/clean-out elevation [Ref. VA DSWC detail]. (Rev. 1) Addressed. 29. Provide conventional flat/level top of embankment; anticipate berm will provide vehicular access. Eliminate prism berm design. (Rev. 1) Addressed. 30. Provide 10' -wide berm if embankment to provide facility (Maintenance vehicle) access. (Rev. 1) Addressed. 31. Design/show pipe collars: Calc. saturated length; provide number of required collars and dimensions. (Rev. 1) Addressed. 32. Label slope (3:1, 4:1, etc.) —left -side slope/each profile view. Match LL=3, 55=3, S-12 design, if possible. (Rev. 1) Addressed. 33. Remove HydroCAD detailed routings data from plan sheets 6, 7, 8; provide Q2,-10,-25 yr. summaries, instead. Provide detailed routings/data as supplemental document. (Rev. 1) Addressed. 34. Sheet 6: Recommend OPA1 Q25 design, since no emergency spillway. OPA1 must provide adequate protection. OTV MP shows pipe outfall located 50 -ft. from Lickinghole Creek. (Rev. 1) Addressed. 35. Sheet 6: Toe of dam —620.00 appears inconsistent with profile. (Rev. 1) Addressed. 36. Sheet 7: Recommend revise top of dam Elev. to 657.20, and INV out —649.97 to INV out —651.5, consistent with MP. Goal is to avoid reconstruction during conversion to SWM facility. Adjust INV in — and riser data, as necessary. [Ref OTV MP Fig. 15] (Rev. 1) to be addressed with detailed final SWMP. 37. Sheet 8: Recommend facility outfall pipe DIA, L, location match MP. MP pipe DIA =18", L=120'±. INV out is identical w/ OTV MP. [Ref OTV MP Fig. 16] (Rev. 1) to be addressed with detailed final SWMP. Sheet 9: 38. Design notes/details should reflect concerns expressed during review of blocks 11, 14, 12, 15 Amended, WP0201500066. There is trace reference to critical geotechnical aspects of design; nothing on sheet 9. (Rev. 1) Addressed. Engineering Review Comments Page 8 of 9 39. Ref. VSMH, First Edit., 1999, Min. Std. 3.01, Earthen Embankment —Specify embankment design. Design/show cutoff trench, drains, impervious core, etc., in profile view. (Ref. VSMH, Fig. 3.01 -la/ -Ib (homogenous/zoned)). (Rev. 1) Addressed. D. Mitigation Plan (WPO2016-00009) (Also, email: J. Anderson to A uny George, 6/20/2016 6:24 AM) The mitigation plan content requirements can be found in County Code section 17-406. 1. Include `WPO201600009' in Mitigation Plan title. 2. Mitigation Area labels: misprint (Mitigtaion) —please revise. 3. Ensure Area B2-1 will not be impacted by Slabtown Branch Sanitary Sewer Extension project. 4. Recommend signs visible to the public that advertise March Mountain Properties' stream buffer impact minimization, and stream buffer preservation, conservation, and restoration efforts. 5. Add Note (Mitigation Area B2-1 site): "Area B2-1 will not be planted until Slabtown Branch Sanitary Sewer Extension project is complete. Area 132-1 should be planted in the fall of the year of completion of the sanitary sewer extension project, or the spring of the following year. Land disturbance associated with WPO201600009 must be stabilized (per Approved ESCP) without regard to Mitigation Plan in any area that may be affected by Slabtown Branch Sanitary Sewer Extension project." Contact Engineering Div. if any questions (Frank Pohl, County Engineer). 6. Ensure vehicular access to SWM Facilities L-2, L-3, S-3, S-12 will not create additional stream buffer impacts, or affect proposed mitigation areas (especially Areas Al, A2, A3, B2-1, C1). 7. Recommend include plant totals for each plant schedule table. 8. Add Note: "Minimum survival required after two growing seasons is 490 plants per Acre, or 1,299 plants. This plan establishes nine Mitigation Areas. 1,299 is a plan -wide figure. 70% plant survival does not apply to any single Mitigation area. Provided 1,299 plants survive at the end of two growing seasons, the plant survival requirement is met. Mitigation plan bond amount may be reduced for plants that survive two growing seasons. Mortality that reduces survival to less than 1,299 plants must be replaced with tree or shrub container -grown seedlings, per plant and planting requirements (specifications) listed at Stream - buffer Mitigation General Planting Notes (sheet 3). These notes apply to replacement plants, as well as initial plants." 9. Add Note: "County access to each Mitigation Area during normal business hours to inspect or execute mitigation measures (re -plantings, for example) will be provided through Easements." 10. Establish (Mitigation Plan) Easements that correspond with and preserve Mitigation Areas identified in the plan. 11. Establish Access Easements that grant (county) access to each Area identified in the plan. This does not mean vehicular access, but near -vehicle approach with remaining terrain traversable by an individual of median age in good health. Access easement terrain should not be rugged. 12. Submit Easements for legal review and approval prior to and as condition of Final Site Plan approval, or Final Plat approval, for Lots /units in Old Trail Village, blocks 10, 16, 17, 18 & 30. 13. Note —It is important to limit replanting cycles. 1,299 is a fixed end -of -2"d -growing -season requirement. If, for example, the total at the end of the second season is 1,249 (shortfall =50), then 50 replacements must survive, meaning it may be best to plant more than 50 to ensure that, in the example, at least 50 survive at the end of the second replacement growing season. Please call Frank Pohl, County Engineer -434.296-5832 —x7914, if any questions. 14. Note —Mitigation Plan must be bonded. Engineering Review Comments Page 9 of 9 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 (received). One of the plan reviewers will prepare estimates (under courtesy review /draft ESCP bond estimate shared with Applicant, 20 -Jun) 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. 6/20/2016 6:24 AM VAR100043 was modified by VDEQ on 16 -Mar 2016 to include blocks 10, 16 & 17/18, 27.13 Ac. area of disturbance. County and Applioant have disetissed that onee Old TFail SWR:nwater- Master- Plan d. 5 Feb 2016 is revised in response to disetission 17 Mar-, is s4seqiiently r-eviewed and aecepted by County and Mar -eh Nloiintain Pr-apeFfies, that a pre eans"etion fneeting fnay be r-equested to r-eeeive a Grading Pefmit for- blooks 10, 16 & 17,119. Initial site plan (SDP201500028) for these blocks was approved 7/24/15. Old Trail Village Stormwater Master Plan (MP) refines Zoning Application (ZMA200400024) plan grading. Once County and Applicant accept revised MP, 18-8.5.5.4 allows County to issue a Grading Permit for site preparation. Pre -requisites to Grading permit include 6 items: i) Parks & Recreation Easements presumed by MP to locate L3 (or perform grading) on Alb. County property; ii) rev. 5 -Feb 2016 MP; iii) SWPPP; iv) slight revisions listed at #9, #21, and #24; v) ESC bond; and, vi) estimated date that detailed final SWM designs for L3, S3, S-12 will be submitted. (21 Jun 2016) Early Grading: Ref. email 5/26/2016 10:03 AM: D. Brockman to J. Anderson. Also: email, County to Dave Brockman, Bill Ledbetter, and Leslie Tate: 6/16/2016 7:48 AM. Early Grading is unfortunately not an option. [Review error.] WP0201600009 ESCP is approved Also, email: county to Applicant, May 23, 2016 9:07 AM). WP0201600009 SWMP (Stantec) is Conditionally—Approved (19 Jun 2016). Mitigation plan: under review. Once WP0201600009 receives Final Approval, once ESCP, SWMP, and Mitigation Plan bonds are posted, Applicant may request pre -construction conference by completing a form —all state fees have been paid. The form identifies the contractor and responsible land disturber, and remaining fee to be paid (county portion). 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 so that work may begin. County forms can be found on the county website forms center under engineering; hLtp://www.albemarle.org/dotforins.asp?departtnent--cdengmTo Thank you New tel. # : 434.872-4501 —x3069 File: WP0201600009 OTV blocks 10, 16, 17, 18 VSMP Junl9-21,2016