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Home My WebLink AboutWPO201400059 Review Comments WPO VSMP 2014-08-04�pF A vt�r�1Q COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902 -4596 Phone (434) 296 -5832 Fax (434) 972 -4126 Project: Briarwood — Gas Station WPO Plan preparer: Scott Collins; Collins Engineering [200 Garrett St., Suite K, Charlottesville, VA 22902, scott(abcollins -en in�g com] Owner or rep.: Wendell Wood and Nena Harrell [ulcwww @embargmail.com] Woodbriar Associates [P. O. Box 5548, Charlottesville, VA 22905] Plan received date: 13 June 2014 (Rev. 1): 24 July 2014 Date of comments: 14 July, 2014 (Rev. 1): 4 August 2014 —Ref. 1./7., below Reviewer: John Anderson Stormwater Management Plan (WP0201400059) 1. Comment applies to WP0201400059 [site], WP0201400030 [underground storage amendment], WP0201300072 [road plan WPO]): Furnish print or c -copy of state - issued Virginia Stormwatcr Management Program VPDES (General) Permit for Briarwood development. WPO technical review criteria depend upon General Permit status. We are in receipt of email explaining that project has VPDES permit; based upon Jul -8 email assurance, it is assumed that technical criteria listed at 9VAC25- 870- 93/ -99 (Part II C) apply, but criteria listed at 9VAC25- 870- 62/ -92 (Part 11 B) may apply, depending upon permit status. Further review and comment are contingent upon receipt of copy of VPDES GP. We have requested information of VDEQ as well. (Rev. 1) Comment acknowledged: "previously approved DEQ permit will be provided upon receipt of it" — Applicant response, 22- Jul -14. VSMP approval or approval of grading /land disturbance (18- 32.4.2.8.c.; 18- 8.5.5.4) are contingent upon receipt of copy of DEQ VPDES General permit covering activities associated with road, gas station, and underground detention construction. Please reference Code Sec. 17 -417, B. 2. As follow -up to conversation 25 -June, revised design will include 3.0" (min) DIA low -flow orifice at low point of 10' -DIA underground detention system. With this change, other system dimensions may change. SCS routing results may change. Please revise design, and provide revised routing calculations. Also, outfall control structure 1 should be modeled as an orifice with area equivalent to the circle segment shown in detail, sheet 4, rather than as a weir. (Rev. 1) Comment addressed. 3. Grading and proposed 48' -15" HDPE or CMP shown within VDOT RW require VDOT permit. Explain maintenance plan for this outfall. VDOT will not maintain structure or riprap. (Rev. 1) Comment addressed. 4. Provide specific depth, length, distance dimensions for Filterra -SWM detention system necessary to review, inspect, and construct these interconnected structures (supplement Americast typical detail on sheet 5). (Rev. 1) Comment addressed. 5. Note —ACCD is in receipt of correspondence dated 6 -Jun 2014 from Filterra to Collins Engineering. Letter affirms design and is included with file. (Rev. 1) Comment addressed. 6. Note - ACCD is in receipt of letters from Contech, dated 8 -Jul 2013 and 9 -Jun 2014, affirming designs of underground detention systems proposed north (WP0201400030) and south (gas station) of Briarwood Drive. Letters included with files. (Rev. 1) Comment addressed. 7. Note - Further plan review revision request must be accompanied by a VSMP GP registration form, revised application fee, and additional information listed on a new VSMP application (WPO Virginia Stormwater Management Program Application.pdf). SWM/ESC application used as recently as Jun -30, 2014 has been replaced. New application is listed at: hitp:/ /www.albemarle.org /deptforms .asp ?department= cdeng)Wo; it's the last in a list of .pdf files. (Rev. 1) Comment acknowledged. Engineering Review Comments Page 2 of 3 1. New -With respect to SWPPP dated 7/20/14 prepared by Collins Engineering for construction activities at Briarwood Commercial Lots, received 7/24/14: Registration Statement (General VPDES Permit) latitude /longitude do not match SWPP coordinates; please reconcile. - Estimate start- finish / installation - removal dates throughout the SWPPP. Revise inspection schedule (p. 26). Inspections are required at least once every 10 business days (plus additional requirements). [Ref. 9VAC25- 880 -70, Part II, Stormwater Pollution Prevention Plan, F., Inspections, 2., Inspection Schedule] - SWPPP, p. 26, identifies one individual responsible for inspection. Confirm that this individual accepts sole responsibility for scheduled inspections, reporting, recordkeeping, notification, and for directing corrective response relating to SWPPP proposed to cover all Briarwood Commercial projects. EXHIBrr TO SHOW CONCRETE WASH OUT, PORTA - JOHNS, AND FUELING AREA (7/21/14): Show concrete wash out area (not shown). Concrete wash out area/s may not drain to storm inlets. Propose treatment for concrete wash waters. [§ 17- 404.B.] - Show on -site dumpster. Provide treatment (or detention) of dumpster drain water. Dumpster runoff may contain contaminants that may not discharge freely downslope, to a storm inlet, or to any stream. Provide silt fence or earthen berm at porta johns as containment in event of spill. Furnish impermeable containment, a barrier to infiltration designed to hold the entire volume of stored fuel in event of spill, with freeboard measure of safety, for each fueling tank shown in the SWPP exhibit. 17- 404.B. La. Wash waters — "Minimize the discharge of pollutants from equipment and vehicle washing, wheel wash water, and other wash waters. Wash waters must be treated in a sediment basin or alternative control that provides equivalent or better treatment prior to discharge." Propose treatment for wash water. - Construction entrance with wash rack to the north does not drain to a sediment basin; propose treatment. Label construction entrance on plan sheets as Paved CE, with wash rack [ref. WP0201300072, E &S Sequence of Construction Note 3]. Provide detail found at p. 27 of ACDSM —link: htW: / /www. albemarle. org/department. asp ?department= cdd &relpage =4447 - Transfer SWPPP best management practices to project plan sheets: practices or narrative listed/shown in SWPPP and on WPO plans should mirror each other. Revise SWPPP, SWPPP plan sheets, and corresponding WPO plan sheets. 2. New - Furnish letter of coverage, VDEQ General VPDES Permit —see #1 /p. 1, above. Please feel free to call 434- 296 -583, ext. 3069 to discuss comments, especially #1 or 7. Erosion and Sediment Control Plan (WP0201400059 /plans dated 12- Jun -14) 1. Comment applies to WP0201400059 [commercial site], WP0201400030 [underground storage amendment], WP0201300072 [road plan WPO]): MS -19 — please reference Briarwood Channel Adequacy Report, Nov -4, 2013, rev Jun -9, 2014 (Also, e -mail, Michelle Roberge, April 4, 2014, 11:19AM). For portions of natural terrain that lie between outfalls of existing 24" CMP (MS -19 Cross Section #1) and existing 18" concrete pipe (MS -19 Cross Section #3) beneath U.S. Rte. 29 and Herring Branch: a. Photos indicate erosion down slope of pipe outfalls, an indication that receiving channels are inadequate. The computations should reflect this, and appropriate measures should be specified to correct the problem. The computations (roughness and velocities) appear to indicate conditions of adequacy that do not exist. (Rev. 1) Addressed via Briarwood Channel Adequacy Report, revised July 21, 2014. 2. Show SF / SAF along south edge of Briarwood Drive. (Rev. 1) Comment addressed. 3. Furnish perimeter control at NW corner of site. If site is developed prior to road (ref. SUB201400066), ESC is needed to prevent runoff at the NW corner. (Rev. 1) Comment addressed. 4. Furnish sediment traps at low end of each diversion dike that ends at inlet (DI) of pipe beneath Briarwood Drive. IP alone is insufficient. Jul -7 -14 site visit indicates DI of pipe beneath Briarwood Drive is elevated well above existing grade, so runoff skirts this DI. Add note to modify existing grade at DI of pipe beneath Briarwood Drive to ensure that runoff from site development and road construction reaches inlet without bypassing onto paved surface of U.S. Rte. 29 (photos available). (Rev. 1) Comment addressed. 5. Furnish IP at proposed relocated DI in the median of Rte. 29. (Rev. 1) Comment addressed. 6. Show MU for areas to be mulched. (Rev. 1) Comment addressed. Engineering Review Comments Page 3 of 3 7. Show IP at existing inlet on the north side of Briarwood Drive, sheet 7. (Rev. 1) Comment addressed. 8. Show crest of stone weir elevation, sheet 8 (detail), as 427'. (Rev. 1) Comment addressed. 9. Land disturbance in VDOT RW requires VDOT permit. (Rev. 1) Comment acknowledged. 10. Remove Stormwater Runoff Considerations note, sheet 6 (applies to WPO201300072). (Rev. 1) Comment addressed. File: WPO201400059- briarwood -gas station- 080414rev -1