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HomeMy WebLinkAboutWPO201500020 Review Comments WPO VSMP 2015-04-09�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: Charlottesville Catholic School, VSMP Plan preparer: Scott Collins, Collins Engineering [200 Garrett St., Suite K, Charlottesville, VA 22902, scott(gbcollins -en ing eering corn] Owner or rep.: H.M. Walker, Jr. /Albemarle Storage, LLC, P. O. Box 332, Charlottesville, VA 22902 Jo Higgins, Project Development LLC, 2564 Mt. Torrey Road, Lyndhurst, VA 22952 T: 434.326 -0334 1 musxitAaol.com Plan received date: 6 Apr 2015 Date of comments: 9 Apr 2015 Reviewer: John Anderson Note— SWM Plan approved under WP02005- 00012 /SDP2004- 00106. This Application does not revise SWM Plan approved with SDP2004- 00106. —Also, WPO bond information at: BND200500021 WP -SE, BND200500022WP- SW. Comments MINOR in nature — revise per comments /submit .PDFs. Approval requires .PDF review /approval. Project ranked top priority per project representative request. Other reviews delayed, but not significantly. Also, please ref. PROCESS, pg 6 -7. Recommendation to issue building permit not delayed, in this instance. 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. Number pages. 2. Revise Sequence of Construction, per comments, Sec. C., below. 3. Sec. 4, ESCP — Revise per comments, Sec. C., below. 4. Sec. 5, SWMP — Remove WW Associates sheets; WW Assoc is not party to SWPPP. Create Collins sheet/s that includes schematic and narrative data copied from WW design [Approved WP02005- 00012 /SDP2004- 00106]; include as 11" x 17" Exhibit. Reference approved SWM Plan [SDP2004- 00106]. Include elements in SWPPP. There is no need to revise WW Assoc SWM Plan. Rather, SWPPP requires VSMP- Authority approved plan. At Collins discretion, include full -size sheet with requested information in VSMP Application. ACCD recommends this approach as a way to aid inspection/construction, especially details concerning trap conversion to bioretention SWM facility. Otherwise, contractor /inspector will rely on Site Plan. Please include: a. Stormwater Narrative b. Bioretention details Engineering Review Comments Page 2 of 7 c. Limits of Temp Grading Easement: show Also on ESCP —Sec. C., item #6. d. Clear reference to SWM Plan Approved per WW Assoc design/SDP2004- 00106. Images, below 5. Sec. 6, PPP /C. — Revise Dewatering operations prevention practices /control measures — Delete `as shown on plan,' since not shown. 6. Sec. 6, PPP /C. — Vehicle & Equipment Washing prevention practices /control measures. Revise VSMP Plan sheet 2, per SWPPP, Sec. 6.C.: Show containment and filtering for all wash waters. — Sec. C., item #5. 7. Sec. 12, Inspection Logs /Standard Frequency— Revise consistent with VAR10, Part II.F.2.a.(1)(2): [p. I INAR10] —at least once every 5 business days, or at least once every 10 business days and no later than 48 hr following a measurable storm event. 8. Sec. 12, Inspection Logs /Increased Frequency — Revise, consistent with VAR10, Part I.B.4.d.(1): [p. 1- 2NAR10] —at least once every 4 business days, or at least once every 5 business days and no later than 48 hr following a measurable storm event. Data - Collins SWPPP /SWMP insert - Item #4 (a. -c., ), above: 1. STORMWATER NARRATIVE THE PROJECT SITE 1S WITHIN THE BEAVER CREEK RESERVOIR WATERSHED. STORMWATER MANAGEMENT WILL BE PROVIDED ONSITE IN ACCORDANCE WITH ALL FEDERAL, STATE AND LOCAL REQUIREMENTS. SURFACE RUNOFF WITHIN THE PROJECT SITE IS DIRECTED TO TWO DRAINAGE WAYS (UNNAMED TRIBUTARIES TO BEAVER CREEK). DRAINAGE SHED A IS COMPRISED OF APPROXIMATELY 1.71 ACRES ONSITE AND SURFACE DRAINAGE IS DIRECTED NORTH TO THE NATURAL DRAINAGE WAY ALONG THE NORTHERN PROPERTY L 4K AND THEN EAST OFFSITE, THE BXISITING CONDITIONS IN SHED A CONSIST OF AN EXISTING PARKING LOT THAT WILL 13E REDEVELOPED WITH A NEW SELF STORAGE FACILITY WITH TRAVEL WAYS. TIIBRE WILL BE NO INCREASE IN IMPERVIOUS AREA WITHIN DRAINAGE SHED A. THEREFORE, NO QUANTITY CONTROLS WILL BE PROVIDED. STORMWATER MANAGEMENT QUALITY CONTROLS (BMP) IN ACCORDANCE WITH ALBEMARLE COUNTY REQUIREMENTS FOR DRINKING WATER WATERSHEDS WILL BE PROVIDED BY A BIO- RETENTION FACILITY LOCATED TO THE NORTH OF NEW STORAGE BUILDING G. THE BIO- RETENTION FACILITY WILL PROVIDE 50 PERCENT REMOVAL OF THE TARGET POLLUTANT PHOSPHOROUS EXCEEDING THE REQUIRED 15 PERCENT REMOVAL. THE FACILITY WILL RF.15 FF." WIDE AND 194 FF?F:T I,ONG F.qI nPPF?D WITH A 25 -FC10T CRASSFTS 11Lil1 LLl.11NIV 1u1 W. 114-.1 {u\LNI.1111. N Is A. 111 L k%1 Ir 11• 1 -1. 11. 1- 1141V THE FACLITY. THE CONCENTRATED FLOW FROM THE CLOSED CONDUrF STORM DRAIN SYSTEM WITHIN SHED A IS DIRECTED INTO A VDOT CLASS I DRY RIP -RAP APRON PRIOR TO ENTERING THE BIO- RETENTION FACILITY TO RETARD DISCHARGE VELOCITY AND DISSIPATE ENERGY. THE FACILITY INCORPORATES A IO -FOOT W IDE BY I S -FOOT RM -RAP EMERGENCY OUTFALL APRON WITH THE INVERT SET AT ELEVATION 643.50 TO PROVIDE A MAXIMUM PONDED DEPTH OF ONE FOOT. THE BIO- RETENTION FACILITY IS DESIGNED WITH A BIO- FILTER CONSISTING OF LUCK RIO- FILTER Mil{ OR TESTED APPROVED EQUAL WITH THE UNDERDRAIN AND D.I. WITH 12" HPDE OUTFALL. TEIE BIO- RETENTION AREA WILL BE EQUIPPED WITH VEGE'T'ATIVE PLANTINGS IN ACCORDANCE WITH WR-14. THE 12 -INCH HPDE BIO-FILTER OUTFALL IS EQUIPPED WITH A 10-FOOT BY 10 -FOOT VDOT CLASS I DRY RIP -RAP OUTFALL. SUFFICIENT RIP -RAP APRONS ARE INCLUDED BELOW BOTH THE EMERGENCY OUTFALL AND THE BIO- FILTER OUTFALL TO DISSIPATE ENERGY AND RENDER OUTFALL VELOCITIES NON - EROSIVE PRIOR TO DISCHARGE INTO THE NATURAL DRAINAGE WAYS. Engineering Review Comments Page 3 of 7 DRAINAGE SHED B IS COMPRISED OF 7.09 ACRES, OF WHICH 3.66 ACRES ARE ONSITE AND 3.43 ACRES ARE OFFSITE. THE EXISTING CONDITIONS IN SHED B CONSIST OF AN EXISTING PARKING LOT AND OPEN SPACE, THE ONSITE AREA WILL BE REDEVELOPED WITH NEW SELF STORAGE BUILDINGS, ALONG WITH TRAVEL WAYS AND PARKING AREAS. APPROXIMATELY 0.40 ACRES OF ADDITIONAL IMPERVIOUS SURFACE WILL BE GENERATED IN SHED B. SURFACE RUNOFF IN SHED B WILL BE DIRECTED TO A BISECTING NATURAL DRAINAGE WAY THAT COLLECTS AND CONVEYS SURFACE RUNOFF SOUTHEAST AND EVENTUALLY OFFSITE. A COMBINATION SURFACE FACILITY WILL PROVIDE BOTH WATER QUALITY CONTROL AND EXTENDED DETENTION. STORAGE FOR WATER QUANTITY WILL BE PROVIDED TO ATTENUATE THE 2-YEAR AND 10-YEAR POST - DEVELOPMENT EVENTS, UTILIZING THE MODIFIED DIRECT METHOD, THE ALLOWABLE RELEASE RATE FOR THE POST - DEVELOPED 2-YEAR STORM IS 21,8 CFS, AND 283 CFS FOR THE 10 -YEAR STORM. ROUTED RELEASE RATES WERE 8.33 CFS FOR THE 2 -YEAR STORM, AND 14.19 CFS FOR THE I O -YEAR STORM. EXTENDED DETENTION VOLUME WILL BE PROVIDED FOR TWICE THE WATER QUALITY VOLUME, AS DETERMINED BY CAPTURING THE FIRST 'h INCH OF POST- DEVELOPED IMPERVIOUS SURFACE IN DRAINAGE SHED B. THE FACILITY IS DESIGNED WITH A MULTISTAGE OUTFALL STRUCTURE CONTAB41NG A Y NOTCHED WEIR TO CONTROL THE 2 -YEAR STORM EVENT. THE FACILITY OUTFALL Wn L BE PROVIDED WITH VDOT CLASS I DRY RIP -RAP TO RETARD PIPE EXIT VELOCITY BY DISSIPATING ENERGY AND RENDERING THE OUTFALL VELOCITY NON - EROSIVE PRIOR TO ENTERING THE NATURAL DRAINAGE WAY. DRAINAGE SHED C IS COMPRISED OF 0.50 ACRES ONSITE, THE EXISTING SURFACE CONDITIONS CONSIST OF AN ASPHALT DRIVEWAY AND OPEN SPACE. THIS AREA WILL BE REDEVELOPED WITH TRAVEL WAYS, PARKING LOTS, NEW SELF - STORAGE BUILDINGS AND AN OFFICE THAT INCORPORATES AN EMPLOYEE RESIDENTIAL APARTMENT. THIS AREA DRAINS BY OVERLAND SHEET FLOW TO THE ANALYSIS POINT (AT THE FACILITY B OUTFALL). DRAINAGE SHED D IS COMPRISED OF 2.64 ACRES ONSITE. THIS AREA CONSISTS OF UNDEVELOPED OPEN SPACE AND WILL REMAIN UNDEVELOPED OPEN SPACE. DRAINAGE OCCURS VIA OVERLAND SHEET FLOW TO ANALYSIS POINT B (DOWNSTREAM OF THE SWMBMP DETENTION FACILITY). NATURAL DRAINAGE SHEDS HAVE BEEN HONORED WITH THIS PLAN AND OUTFALLS HAVE BEEN RENDERED ADEQUATE AND IN COMPLIANCE WITH MS -19. IN SHED A THERE IS NO INCREASE IN RUNOFF AND WATER QUALITY CONTROL HAS BEEN PROVIDED IN A MANNER WHICH EXCEEDS THE REQUIREMENTS FOR DRINKING WATER WATERSHEDS. IN SHED B, WATER QUALITY CONTROL HAS BEEN PROVIDED TO ATTENUATE POST DEVELOPMENT RUNOFF RATES TO THAT LESS THAN THE PRE - DEVELOPED RATE, AND WATER QUANTITY CONTROL HAS BEEN PROVIDED IN A MANNER WHICH EXCEEDS THE REQUIREMENT FOR DRINKING WATER WATERSHEDS. THIS PRO3ECT (CHARLOTTESVILLE SELF STORAGE AT CROZET) IS IN COMPLIANCE WITH MS -19 IN THAT STORMWATER MANAGEMENT (SWM) QUANTITY CONTROL HAS BEEN PROVIDED ONSITE, WHICH ATTENUATES THE POST- DFVELOPED 2 -YEAR AND 10 -YEAR SURFACE RUNOFF RATE TO THAT BELOW THE PRE - DEVELOPED 2 -YEAR AND 10 -YEAR SURFACE RUNOFF GENERATED BY THE SITE. (SEE SWMBMP NARRATIVE.) Engineering Review Comments Page 4 of 7 PROV #7E CIEAVOOT AT 50' �r-wr Prnlrrr'rNy 7WrFRVA7S ANfl AT FNf73 OF PAVEMENT ­ '-0 r t — PREVENT i0 PREVENT C�A�+ Wrf H CLP a AP' RNT CAP' fT}`fYF'1 A4W° COVER I / KET OR TEST ED A#D ? APPROVED EGYLNALENT _,- 50X SAND /= TOPSOIL 20! LEAF IAIJLCN l' 1 Yf�ffRJT - (1NllICATED }, OR STONE WEIR DISCWGE TO STABLE CHANNEL R STORM DRAIN. TYPICAL BIOFILTER CROSS SECTION DETAIL NTS TEM- "'y / N- no' TREE LINE oRMIUGE �'^,� EXISnNG ORCH cus s u»D \ c / .� •� MR lTNTON r EASEMENT IRIP -RAP\ / OA. OUR£f STRUCTyRE P CLASS / INV OUT � 93]00 y Q%ER� 1 RIP RAP / ) _ yrumr � I VNDEPDONN GRAVEL eMS7IT0 M413, 1,yY 4'6 PERF ATED SCHEDULE i - i - NoNPERFORATED 40 PVC PLPE OR EUWVALENT PYC PfPE AT & SLOPE (KV) WRAPPED IN FILTER FABRV AT fX SLOPE mffi TO DIOR SmQ w oRAlk PROVIDE ACRM ENTME WLQTH AT 2170L. &VrXTER TO BE SEEDED MOTES: wrTl4 DIVE OAT. RED TOO OR WILDFLOWER ANY SWTAPLE 1. THE NEED FOR ADDITIONAL pAVEtAENT EROSION Flm %W-DITW TEGTI0.1 FRq QF„V NT .T 99 -r-rg a I �I�+ � 8N AN NATNE $RASSESJSE"5- WLLOFLOWER MCA" IN DIOI� L PFI()J ,4 BASIS. INDIVIDUAL PR{7JECT ffA515. PLANTED LN PLUGS ANN OR 50FILTEft SEEDED WITH HEAVY STRAY 2. PROVIDE l' -4" PENDING DEPTH TO THE CREST OF AN AMCLL CWEREO WITH EC2 OVERFLOW MUCTILRE. OVERFLOW STRUCTURE MAY EROSION CONTROL iIATTAW BE DI IN BIONELENTION ARCAy DI IN PAVED AREA (1NllICATED }, OR STONE WEIR DISCWGE TO STABLE CHANNEL R STORM DRAIN. TYPICAL BIOFILTER CROSS SECTION DETAIL NTS TEM- "'y / N- no' TREE LINE oRMIUGE �'^,� EXISnNG ORCH cus s u»D \ c / .� •� MR lTNTON r EASEMENT IRIP -RAP\ / OA. OUR£f STRUCTyRE P CLASS / INV OUT � 93]00 y Q%ER� 1 RIP RAP / ) _ Engineering Review Comments Page 5 of 7 B. VSMP: SWPPP: Stormwater Management Plan (WP0201500004) VSMP Regulation 9VAC25- 870 -108 requires the VSMP authority to approve or disapprove a SWMP. The SWM Plan for post - developed site conditions associated with ESC Plan submitted with this VSMP Application was approved as WP02005- 00012 /SDP2004- 00106. Prior approval and design are unaltered and unaffected under this VSMP Application, which proposes construction of remaining self - storage units, and converts sediment trap to SWM bioretention facility. Reference ACCD Files /SWPPP for prior- approved SWMP, or plan details. C. VSMP: SWPPP: Erosion Control Plan (WP0201500004) Virginia Code §62.1- 44.15:55 requires the VESCP authority to approve or disapprove an ESCP. This plan is disapproved for minor reasons provided in comments below. The erosion control plan content requirements can be found in County Code section 17 -402. All comments relate to sheet 2. 1. Please coordinate with Kevin Conner, PE, Gay and Neel, Christiansburg, VA —Tel: 540.381 -6011. Gay and Neel design for Emerson Commons (TMP 56- 67A/to NE) includes Sanitary Easement/ force main across TMP 56A3 -7 in same location as proposed 8' high chain link safety fence: 2. Include reference to SDP2004 -00106 in Project Description. 3. Sequence of Construction: a. Note 4 — Check/revise reference to existing curb (if not built). b. Notes 4, 6 — Reference to proposed and existing sediment trap; revised to ref. proposed. c. Note 7 — Delete reference to condominium units. d. Note 11 — Revise: "Once the construction activity has been completed and within 30 days after final site stabilization or after the temporary measures are no longer needed, and once the inspector has given approval, the Contractor can remove the erosion control measures. No item shall be removed unless the upstream areas are stabilized and the inspector gives permission." e. Note 13 — Revise: "Unless otherwise authorized by the local program administrator, trapped sediment and the disturbed soil areas resulting from the disposition of the temporary measures shall be permanently stabilized to prevent further erosion and Engineering Review Comments Page 6 of 7 sedimentation." 4. Indicate (initial) non - hazardous waste dumpster location. 5. Indicate drainage /containment for vehicle wash water /paved CE. 6. Revise limits of disturbance, or obtain construction easement for areas of disturbance proposed to lie beyond limits of temporary grading (compare sheet 2 with image /SDP2004- 00106, above). 7. ESOP, when approved, does not permit deviation from elements of approved site plan: dimensions of building F, for example (40' x 200'— SDP2004 -00106 vs. 50' x 200' —ESC Plan/sheet 2, scaled). 8. Provide Building F and G (L x W) dimensions. 9. Note: Review indicates 118.86 cy at wet storage elevation, 642' [(16.5' x 194.5' x 1') _ 27]. Also, review indicates 138.63 cy at dry storage elevation, 643' [(19' x 197' x 1') - 27]. In any case, design provides sufficient storage ( >111.9 cy). 10. 15" storm is shown as existing. Show as proposed, unless it exists. (GIS, 2013 photometric detail): 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 (.PDFs, as quick check, welcome). Engineering plan review staff is available 2 -4 PM on Thursdays, should you require a meeting to discuss this review. Plan reviewer is available at 434.296 -5832 -0069 should you have any questions. Process: After approval, county staff will need to enter project information in a DEQ database for state application Engineering Review Comments Page 7 of 7 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.orWdeptforms .asp ?department= cdengyMo File: WPO201500020_VSMP_Albemaric Storage Charlottesville self - storage 040915