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HomeMy WebLinkAboutWPO202000009 Review Comments WPO VSMP 2020-05-28COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902-4596 Phone (434) 296-5832 Fax (434) 972-4126 VSMP Permit plan review Project title: SRTS Greer/Jouett Bicycle & Pedestrian Improvements Project file number: WP02020-00009 Plan preparer: Brian McPeters [ brian.mcpeters(a,kimley-horn.com ] Michael Mitchell / Kimley-Horn Associates Owner or rep.: Matt Wertman [ mwertmankalbmemarle.org ] Plan received date: 24 Feb 2020 Date of comments: 9 Apr 2020 Reviewer: John Anderson 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 for reasons listed, 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. 1. Provide a SWPPP including registration statement. (Rev. 1) Not addressed. Please provide SWPPP at earliest convenience. (Rev. 2) Comment persists. Also see email sent, 11/15/2019 12:39 PM. Use county template; link:_ httD://www.albemarle.orL'/UDload/imaaes/forms center/departments/Community Development/forms/Eneineerin 2 and WPO Forms/Stormwater Pollution Prevention Plan SWPPP temnlate.ndf Kimley-Horn has provided a SWPPP (including Registration Statement) for County review. 1. Revise title to ref. WP0202000009. Kimley-Horn has revised title sheet to reference WPO number. 2. Sec. 1 /Registration Statement: Sec. VI. Certification — print /sign /date. Matt Wertman may sign. Kimley-Horn will coordinate with Matt Wertman to sign SWPPP certification upon approval of SWPPP contents. 3. Sec. 3 /Nature of Activity: Include as first item, first 3 paragraphs of p. 4 of Hydraulic Design Report. Kimley-Horn has added the first three paragraphs of pg. 4 of the Hydraulic Design Report to Section 3 of the SWPPP. 4. Sec. 4, 5: Update ESC and SWM plan sheets, once comments addressed. Kimley-Horn has updated the ESC and SWM plan sheets after addressing comments. 5. Sec. 6.E.: Person responsible for pollution prevention practices must be provided prior to receiving a Grading Permit. Kimley-Horn has noted that the person responsible for pollution prevention practices will be a member of the general contractor's team, is TBD, and will be determined prior to acquiring a Grading Permit. The contractor is unknown at this time, since the project has not been advertised. Once a contractor is selected, this section will be updated to provide specific names and contact information. No pollution prevention practices are necessary until construction begins by the general contractor. 6. Sec. 8: List named individual responsible for inspections —if TBD, list TBD and provide name of the individual responsible for inspections prior to receiving a Grading Permit. Kimley-Horn has noted that the person responsible for inspections will be a member of the general contractor's team, is TBD, and will be determined prior to acquiring a Grading Permit. The contractor is unknown at this time, since the project has not been advertised. Once a contractor is selected, this section will be updated to provide specific names and contact information. No inspections are necessary until construction begins by the general contractor. 7. Sec. 9: Signed Certification: Please complete. Matt Wertman (county representative) may sign. Kimley-Horn will coordinate with Matt Wertman to sign SWPPP certification upon approval of SWPPP contents. 8. Sec. 10: Engineering encourages FES-FPC /County of Albemarle schools to delegate environmental compliance responsibility /liability to contractor (once selected) via Delegation of Authority form. Kimley-Horn will coordinate with Albemarle County and the general contractor (once selected) to get Delegation of Authority form signed by contractor. B. Pollution Prevention Plan (PPP) (Rev. 2) Comment persists. See email sent 11/15/2019 12:39 PM. The PPP content requirements can be found in County Code section 17-404. Provide a PPP (11 x 17" Exhibit) —Recommend revise figure, p. 8 /SWPPP to show: a. Rain gauge location b. Concrete washout location c. Solid waste dumpster location, if any d. On -site fuel storage location, if any e. Portable sanitary facility location Kimley-Horn has added a PPP exhibit at the end of Section 6 to depict proposed locations of Rain Gauge, Concrete Washout, and Sanitary Facilities. All components are subject to change by general contractor (once selected). Engineering Review Comments Page 2 of 5 C. Stormwater Management Plan (SWMP) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This plan is disapproved for reasons listed, below. The stormwater management plan content requirements can be found in County Code section 17-403. 1. Revise Plan Title to include ref. to WP0202000009. Kimley-Horn has revised title sheet to reference WPO number. 2. Imo): Water quantity summary, energy balance, detention summary tables are visually clear displays, but it is difficult to interpret between them, in context of Hydraulic Design Report. For example: a. Post -development 1-yr Q, outfall A, appears in separate locations as 4.17 (into BMP A), 0.99 (from BMP A), 1.17 (Energy balance [Outfall A]), and 8.41 cfs (summary table). To clarify: 4.17 cfs is total runoff entering BMP A, 0.99 cfs is total runoff leaving BMP A, 1.17 cfs is undetained runoff from site only reaching Outfall A (not including offsite runoff), 8.41 cfs is total combined runoff reaching Outfall A (combination of discharge from BMP A and bypass) b. Post -development 1-yr Q, outfall B, appears in separate locations as 1.32 (into BMP B),0.66 (from BMP B), 0.29 (Energy balance [outfall B]), and 23.06 cfs (summary table). To clarify: 1.32 cfs is total runoff entering BMP B, 0.66 cfs is total runoff leaving BMP B, 0.29 cfs is undetained runoff from site only reaching Outfall B (not including offsite runoff), 23.06 cfs is total combined runoff reaching Outfall B (combination of discharge from BMP B and bypass) c. Post -development 1-yr Q, outfall C, appears in separate locations as 1.02 (into BMP C), 0.78 (from BMP C), 0.12 (Energy balance [Outfall C]), and 0.78 cfs (summary table). To clarify: 1.02 cfs is total runoff entering BMP C, 0.78 cfs is total runoff leaving BMP C, 0.15 cfs is undetained runoff from site only reaching Outfall C (not including offsite runoff), 0.78 cfs is total combined runoff reaching Outfall C (in this case, discharge point of BMP C is same as Outfall C) d. For clarity, to aid review and minimize confusion, please provide a separate new table to this sheet correlating each compliant -relevant 1-, 2-, or 10-31 _Q to a specific hydrograph (provide Hyd. No. _). If Report pagination holds steady, please provide pg.# ref. to 189-p..PDF. Examples: Report p. 32 correlates Hyd. No. 1, 2, 5, 6, 9, 10 with plan sheet IF(1) Energy Balance (Outfalls A, B, C pre- post-) values. Water Quality Summary table Outfall A QD, ,eloped (8.41 cfs) is from Report p. 112 (summary) /Avnx. E., Hyd. No. 4., but a table index for 1-, 2-, 10-yr compliant -relevant Q values is needed. Additional comments are possible. Kimley-Horn has clarified the hydrograph references for the Detention Summary table and added a hydrograph reference table for the Water Quantity Summary. e. Provide caption or narrative to supplement Energy Balance Summary table to guide review to precise outfall locations (A, B, C) where energy balance equation is performed. It is unclear. Kimley-Horn has added a note clarifying the analysis provided by the Energy Balance Summary table. This analysis is looking at site runoff only to determine the 1-year improvement needed when analyzing the combined runoff in the other tables. Please confirm outfalls depicted on IF(2) and table data on IF(1) indicate compliance with water quantity requirements should: a. Base bid only be awarded (sta. 304+27.08 - 316+66.26) b. Additive bid item 1 be awarded in addition to a. (sta. 300+45.68 - 304+27.08) c. Additive bid item 2 be awarded, in addition to b. (sta. 316+66.26 - 202+82.07) d. Additive bid item 3 be awarded, in addition to c. (ref. sheet 1) Note: Engineering must ensure whatever portion of the project is built complies with stormwater quantity regulations. Also, ref. sheet 5D (base bid only inset). Kimley-Horn has provided stormwater quality and quantity analysis for the scenario in which all phases depicted in the plans are constructed. This is the scenario in which the maximum amount of development and land disturbance is present at each outfall. In all other scenarios referenced in the comment above, the SWM impacts would diminish or disappear altogether at each outfall. Therefore, the most conservative analysis was provided to achieve SWM compliance under all scenarios. Engineering Review Comments Page 3 of 5 2Cf 11 4. Stormwater runoff considerations note mentions both outfalls, whereas plan mentions outfalls A-F, elsewhere. Please revise note consistent with multiple outfalls. Kimley-Horn has revised the note to reference Outfalls A-F. 5. Adjacent Areas Note: `Route 10' may be relic text from a separate project. Kimley-Horn has revised the note. 6. Off -site Areas Note: If offsite borrow or waste areas exceed >10,000 SF, an ESC plan will be required for the off -site area. Off -site area must be identified prior to Engineering issuing a Grading Permit. Kimley-Horn has revised the note. No offsite areas are proposed to be disturbed by the Engineer as part of this project. Contractor to provide ESC plan for offsite areas if needed for construction. 7. Sequence /Maintenance Note, c.: Revise to read `...inspector must be notified of the offsite borrow or spoil location at the on site pre -construction meeting to be held at county office building. Kimley-Horn has revised the note. 8. 2C(3), 2DQ) —Label a. road /sidewalk Kimley-Horn has added labels for roadway and shared use path. b. stone feature and provide I x w x d dimensions of this feature at Str. 4-2. Kimley-Horn has added label, surface area, and thickness callouts for riprap near structure 4-2. 9. Report, p. 9: Caption beneath return period table list Min proposed pipe slope=0.30%. Albemarle drainage plan review checklist, p. 2, item 3., specifies pipe slope at 0.5% min. Consider slope more nearly approaching 0.5% rather than 0.2% min listed at VDOT Drainage Design Manual, 9.4.8.6. Repeat experience /outcomes favor construction installation error if design grade <0.5%, though with daily inspection, As -built and acceptance requirements typical of VDOT-county projects, concern abates. Kimley-Horn has revised the caption to note a minimum proposed slope of 0.67%. The exception as noted is the detention pipes (minimum proposed at 0.32% to maximize storage provided and detention time). 10. Report, p. 7: Outfall B, 1 It primary bullet: possible typo ref. to Outfall A. (Unclear how BMP B relates to BMP A). Kimley-Horn has revised the typo. 11. 2D(1): Add flow lines to storm sewer system pipes, Str. 4-1 thru 4-5, and Str. 4-6 to 4-5 similar to flow lines shown on 4B. Kimley-Horn has added pipe flow lines. Engineering Review Comments Page 4 of 5 12. 5 D : Confirm that existing trailer access ramp may be relocated. The trailer is a series of nine trailers connected to form a rectangular classroom complex. The ramp proposed to be relocated provides a second ADA-point of access to the complex (constructed 2016), and may be required for fire safety (2nd exit point). The existing nine trailers are configured with entrances south and north, both ADA. Please examine the issue and revise design if ramp proposed to be relocated cannot be relocated. Note: If relocated to west face of trailer/s, for example, to west end of north -most trailer, a relocated complex entrance /exit would open into a classroom, not the central corridor. Check to see if this meets local /state ADA- or fire -access requirements. Examine /confirm that a plan exists to locate a 2nd entrance meeting local and state access requirements, since locations along east and west appear problematic. If east face, existing ramp at north end of complex turns at the NE corner of north -most trailer, and bears south along this face of the complex, so east side of the trailers does not offer a ramp relocation option if sidewalk is built as depicted on 5D (if additive bid item 2 is not constructed). Comment #12 has been withdrawn per email correspondence on 4/9/2020. 0 'f jlq�TURIILrl 2 L ,t°sru a FA:PHALT B—250�RT LT � EASTrlyG C F 7RARER ACCESS RAMP 2.50'Rr RELOCATED �QT ,�] 4�T $Y OTHERS � s6L�x � �D 19 fl 25' 50, 13. Sheet titling ends with 21)(4). Recommend sheet titles from sheet 3 onward to the last plan sheet. Kimley-Horn has provided sheet titles as required per VDOT CADD standards (does not include plan sheets, profile sheets, etc.). Sheet titles for all sheets are provided in the Index of Sheets. Engineering Review Comments Page 5 of 5 14. 3A: Provide ditch flowline to indicate that runoff from southern roadside of Lambs Lanes (between Sta. 305+00 and 306+25) is diverted from Outfall F to Outfall A, avoiding detention needs at Outfall F. (Report, p. 7, Outfall A, primary bullet 4) Note: Flow is not diverted to Outfall A via ditch. Flow is captured in proposed curb and gutter and a flowline is created across the entrances at 306+25 and 307+50 so that runoff reaches BMP A. 15. Report, p. 8: Methodology explains grate inlets analyzed manually via a spreadsheet using 4 inch /hr. intensity. Unless mistaken, inlet capacity calculations require 6.5 inch / hr. reference event. Revise, as needed, per VDOT inlet methodology (especially for Outfall C since Str. 3-3 is to serve as a control structure in a detention pipe system (BMP Q. Kimley-Horn has revised the grate inlet computations to account for a check storm intensity of 6.5 in/hr. 16. Appendix C, p. 26: It appears untenable that pre -redevelopment land cover includes 0.92 Ac. undisturbed, protected forest/open space or reforested land, out of land disturbance total of 2.11 Ac. Lambs Lane /Rd. corridors and proposed disturbances occur on nearly exclusively existing managed turf, per DEQ definitions. Provide exhibit identifying 0.92 Ac. Forest/Open Space, or revise VaRRM.xls and nutrient purchase required for stormwater quality compliance. Kimley-Horn considers the overgrown, forested area surrounding the site of BMP to be closer to forest / open space runoff conditions in the pre -development condition. This is area will be converted to managed turf in the post -development condition. Please see attached exhibits documenting presence of forested area. 17. Report, p. 28 /Appendix D: Ref. SWM comment item l.d., above, and provide additional table to correlate stormwater outfall table compliant -relevant 1-, 2- and 10-yr values to a specific hydrograph. Kimley-Horn has added an additional table referencing page numbers of compliant hydrographs in the Outfall Summary table. 18. Report p. 29 —Similarly, provide correlation between compliant -relevant energy balance summary table values and a specific hydrograph. List title (Hyd. No. ) and report (.PDF) pg=#, if possible. Additional comments are possible as follow-up to SWM review comments l.d., 17, 18. Kimley-Horn has added an additional table referencing page numbers of the Detention Summary hydrographs in Appendix E. 19. 21)(1), 21)(3): Label floor dimensions of BMP A, BMP B (L x W). Kinley-Horn labeled floor dimensions of BMP A and BMP B. 20. 2D(2) 21)(4): Recommend increase scale to 1" =10" since images are quite reduced. Kimley-Horn increased scale from 1" = 10' to 1" = 5'. 21. 2D 3 : Provide dimensions for riprap emergency spillway. Kimley-Horn added dimensions for emergency spillway. 22. 2D(2): Provide riser structure base and rim elevations. Kimley-Horn added callouts for riser base and rim elevations. 23. 21)(3), 21)(4), 5 (BMP B): Confirm 25-yr event will not inundate Lambs Road (SR 657). Note: BMP B emergency spillway elev.=561.00 while 10-yr WSE=561.24' (spillway activated). The BMP B emergency spillway discharges into a paved ditch and combines with offsite bypass from the Albemarle High School parking lot. Then the runoff passes through an existing culvert and combines with more offsite bypass from the Lambs Road roadside ditch as it reaches Outfall B (existing culvert underneath Lambs Lane at the intersection). Per SWM calculations provided in the design storm (10-yr), a reduction in peak discharge is achieved at the Lambs Road roadside in the Post -Development condition. The contributing runoff from BMP B is approx. 6% of the total runoff reaching Outfall B at the Lambs Road roadside (see attachment). Therefore, not only does the runoff from BMP B insignificantly contribute to the headwater adjacent the Lambs Road roadside, but the BMP improves the existing situation. 24. 4: Recommend extend ditch flowline arrows (between shared -use path and Lambs Ln.) from Sta. 312+75 to BMP A. Kimley-Horn has added a callout noting that existing ditch between BMP A and 312+75 is to be cleaned out. Flowline arrows are not provided because existing ditch is already present and is not intended to be graded with new inverts or foreslopes. 25. 4: BMP A presents an approx. 5.5' vertical drop from EP, Lambs Lane, and presents risk. Provide runoff protection barrier for vehicles. Runoff protection is not provided since all slopes adjacent Lambs Lane within BMP A are 4:1 or flatter Engineering Review Comments Page 6 of 5 (traversable and recoverable) and all hazards (drainage structures) are located outside the roadway clear zone. 26. 5: Propose landscaping or fixed visual barrier between EP, Lambs Lane, and BMP B. Kimley-Horn has added landscaping barrier of shrubs between Lambs Lane and BMP B. 27. 663,): Recommend one or two 2" DIA holes in floor of Str. 3-3 upstream of weir wall to alleviate nuisance pending or overcome error of installation that may favor nuisance ponding. Kimley-Horn has added callout for two 2" diameter holes in bottom of structure in front of weir to prevent pending. 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 for reasons listed, below. The erosion and sediment control plan content requirements can be found in County Code section 17-402. 1. 2C(11: List 2.11 Ac. estimated area to be disturbed with Erosion and Sediment Control Narrative. Kimley-Horn has clarified total disturbed area on Sheet 2C(1) as 2.35 acres. 2.11 acres is SWM-applicable disturbance (includes redevelopment only, excludes maintenance activities). 2. 4B: Provide existing contour labels south of TSB -I. Kimley-Horn has added existing contour labels south of TSB -I. 3. 4B: Provide SAF between TSB-1 and Lambs Ln. during ESC Phase. Kimley-Horn has added SAF between TSB-1 and Lambs Lane is ESC plans. 4. 4B: Where proposed drainage grates are close to edge of new shared -use path, provide notes to ensure walk has adequate area nearly flat leading to 3:1 or flatter grade downslope to edge of grate (recall issue at sidewalk grate issue on Barracks Rd project). Design against mis-step leaving pedestrian unbalanced on slope. A nearly flat shared -use path shoulder is essential in areas adjacent to BMPs or drainage grates given young and middle -school students' tendency to veer from the path. Kimley-Horn has designed the shared use path roadside per VDOT Standards, providing a 2'-wide shoulder (at 2% slope) adjacent a 2:1 slope that has less than a 4' drop-off (see attachment for cross section at Station 102+50). This roadside is not considered a hazard per the standard. Therefore, neither a wider shoulder nor handrail is required. The structure is also a DI-5, so the grate will conform to the finished grade of the ditch as shown in the cross section. This is the same scenario at Station 103+25. 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 review staff is unable to meet with the public due to the covid-19 pandemic, until further notice. Please call if any questions. J. Anderson, 434.296-5832 -0069 Engineering Review Comments Page 7 of 5 Process; After 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; h!t2://www.albemarle.oriz/deptforms.asp?del2artment=cdenaMMo OUTFALL E tiJ / (OUTFALL E) J / OUTFALL D j-LF—j / I / C OUTFALL 41 411 \ � s 6 OUTFALL F S66 OUTFALL B f � v OUTFALL OVERALL AREA (acres) OVERALL CN Tc (minutes) SITE AREA (acres) SITE CN A 10.55 69.3 12 1.36 57.0 8 8.40 89.2 10 0.49 61.0 C 0.38 82.3 5 0.14 61.0 D 3.21 73.9 5 0.03 61.0 E 1.54 81.2 5 0.03 61.0 F 0.54 75.3 5 0.07 77.9 588 ,t "