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Home My WebLink AboutSUB201400207 Review Comments Road Plan and Comps. 2015-04-24Al vr�N1Q COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road Charlottesville, Virginia 22902 -4596 Phone (434) 296 -5832 Fax (434) 972 -4126 Project: Cascadia Blocks 1 —3 Final & Road Plan Plan preparer: Dominion Engineering Owner or rep.: Cascadia Development LLC Plan received date: 20 Mar 2015 Date of comments: 24 Apr 2015 Reviewer: Michelle Roberge Engineering has completed the review of SDP201400075 and SUB201400207. Please address the following comments. Final Site Plan 1) On sheet SP4, there should be a diversion from the sec to pond 2. [Revision 11 Comment addressed. 2) On SP4, show the remaining managed slopes. [Revision 11 Comment addressed. The remaining managed slopes are shown on the parcels to be developed. 3) Show dumpster pad detail. [Revision 11 Comment partially addressed. Applicant has shown the dumpster enclosure detail. Please add a note for the dumpster pad to be "a minimum of 4" stone base and 6" concrete of 3000 psi at 28 days or stronger, reinforced with a minimum grid of wire reinforcement or #4 bars at 12" on center." 4) There is a 6' wide min sidewalk requirement for sidewalk in front of bldg. Please dimension. [Revision 11 Comment addressed. 5) The northern parallel parking in the commercial area will be difficult to maneuver. Please address. [Revision 11 A SU truck can maneuver into the commercial area, but please describe movement to exit this area. 6) Label CG -2 on commercial parking. Show detail. [Revision 11 Comment partially addressed. Show CG -2 detail in sheet SP34. 7) Relocate spot elevation for dumpster pad to be legible. The site shall be designed so that stormwater does not run through, and drains away from, areas where dumpsters are located in order to minimize the potential for contaminating stormwater runoff due to contact with solid waste. [Revision 11 Comment addressed. Engineering Review Comments Page 2 of 5 8) It appears another wall will be necessary behind lots 18 and 19 to avoid grading over sanitary sewer mh. However, it also appears the geogrid will extend beyond bldg foundations for lots 16- 19. Please address. [Revision 11 Please discuss with ACSA to let them know of the change. I just need to document that they are okay with the revision. 9) The geogrid appears to extend beyond bldg foundation of lot 22. Please address. [Revision 11 Comment addressed. The applicant has shown the geogrid location. It is still close to the house and caution is necessary when constructing bldg foundation. 10) All retaining walls facing Rte 20 will require ARB approval. [Revision 11 Comment acknowledged. 11) Show a crosswalk at entrance of commercial area. [Revision 11 Comment addressed. 12) Show low maintenance ground cover, not grass, for all areas with 2:1 slopes. See the following areas: Area near str 14C, slopes adjacent to stairs, north of lot 6 near retaining wall, near lot 22, near north of commercial bldg, within Park A, etc. This can be shown with landscaping plan. [Revision 11 Comment addressed. The "site plan" sheets labels the 2:1 slopes. 13) It does not appear you are meeting Proffer 1 (G) and (H). Please verify and address. [Revision 11 Comment addressed. 14) Show calcs for existing 7A and downstream stormsewer, where 43 ties into. Verify that existing 24" HDPE is adequate. Do the same for existing 5. [Revision 11 Comment addressed. 15) 15" pipes are the minimum requirement. Revise 12" stormsewer pipes. [Revision 11 Comment addressed. Applicant has provided pipe capacity analysis for the 12" pipes. Also, pipes will be privately maintained and will convey runoff from lots to the public stormsewer system. 16) 58A will be prone to clogging. How will it be constructed with the SCC? Also, the grate will not capture entire runoff and area is subject to erosion. Divert excess runoff to an adequate outlet. Can existing sediment trap be converted to a permanent BMP? Show access road to BMP. [Revision 1]Applicant has shown structure 58A to be in a sump condition. The water surface elevation for the10 yr storm has also been determined. I recommend sizing sump area slightly larger in the event the grate is clogged and with back to back storms. I recommend designing with an assumption that grate is 50% clogged 50. 17) Profile and calculations should match. Please address for downstream pipes after str 37, 36, 31 and 30. [Revision 11 Comment addressed. 18) Please show profile for 46A -46. [Revision 11 Comment addressed. 19) For str 32 -31, show drainage easement on lot 59. [Revision 11 Comment addressed. Engineering Review Comments Page 3 of 5 20) For str 1413-14 A, revise drainage easement to include pipes. [Revision 11 Comment addressed. 21) For str 62 -ex 5, show drainage easement. [Revision 11 Comment addressed. 22) For str 9 -ex 3, show drainage easement on lot 37. [Revision 11 Comment addressed. 23) Show existing SWM easement and access easement for pond 1. [Revision 11 Comment addressed. 24) Remove plantings on drainage easements. For example, see str 22 -23. Verify for other locations. [Revision 11 Comment addressed. 25) Match Ex 2 and Ex 3 downstream pipes with approved site plan from Blocks 4 -7. Please verify they match. [Revision 11 Comment addressed. There is a field revision for 4 -7 to incorporate blocks 1 -3 design. 26) Show details for nyoplast dome grates. [Revision 11 Comment addressed. 27) Verify direction of flow change in each drainage structure is 90 degrees or greater: 48- 46, 45 -44, 27A -26, 21 -19, and 8A -7. [Revision 11 Comment addressed. 28) Show all DI structure details. [Revision 11 Comment addressed. 29) It appears you are showing grinder pumps. Please show a private onsite central sewerage system for those lots. Then it can be pumped to tie into the public sewer system. Please discuss with [Revision 11 Engineering recommends approval of grinder pumps even though it is the Engineering Dept's opinion that grinder pumps will be a burden to the homeowners in the event of a power outage and when the grinder pumps need maintenance. ACSA has expressed their concern and believes a private pump station would present more of a public health issue in the event of a failure. It appears ACSA will not provide a plan approval for any developments that propose a private pump station within their jurisdicational area. Road Plan 30) Per proffer 2, VDOT approval is required for proposed 20' additional public R/W along the edge of existing Rte 20 right of way. The owner shall dedicate to address future potential improvements along Rte 20. [Revision 1] I defer to VDOT. It appears to be addressed, but I need verification. 31) The interconnection for Broadus Baptist Church is shown. The 30' wide easement is centered along the trail. If a future connection is to be made, how will an adequate driveway be built if the retaining wall from the commercial building abuts the trail? Also, slope east of pond 2 will need to Engineering Review Comments Page 4 of 5 be regraded, but it is already at 2:1 slope. If a wall is built, it will be subject to ARB review. Please address. [Revision 11 Applicant has adjusted 30' easement to be centered along trail. It appears unlikely for a private drive to be constructed here. 32) It appears Knoll Lane is proposed as a one way road since it cannot meet VDOT sight distance requirements for vehicles turning into Delphi Lane. I recommend ending Knoll Lane with a cul de sac and adding landscaping for screening. Also, increase road width to 24' wide with 2% cross slopes (typical VDOT cross - section) with no parking signs on both sides. Discuss with Fire Rescue. R = 34 fl mi- JnPaved Area F � Offset S u l b CUVde—sac 33) Please remove the perpendicular parking on Knoll Lane. [Revision 1]Comment addressed. 34) If the subdivision plats will be phased, note the road plans will need to be delineated to match phasing plan with proper turnarounds. We have a policy that one road plan with appropriate title should correspond with subdivision plat phase. [Revision 1]Comment acknowledged and phasing plan is shown. 35) Label all signs on road plan. [Revision 1]Comment partially addressed. a) Please label stop sign at the intersection of Terrace Ln and Delphi Dr. b) Move street sign on intersection of Terrace Lane and Delphi Lane. Same comment for Knoll Lane and Delphi Lane. 36) Show intersections within a road profile. Label elevation and station. [Revision 1]Comment addressed. 37) Show sidewalk detail per VDOT standards. [Revision 1]Comment addressed. 38) Road plans shall be approved by VDOT, Fire Rescue, and ACSA. [Revision 1]Comment acknowledged. New comments: 39) Show sight distance profile for Knoll lane that we discussed via email. 40) Scale is wrong for sheet SPSA. 41) The stubout should be revised to a cul -de -sac per our discussions. Engineering Review Comments Page 5 of 5 Current Development Engineering is available from 2:30 -4:00 PM on Thursdays to discuss these review comments. Please contact Michelle Roberge at 434 - 296 -5832 ext. 3458 or email mrobergegalbemarle.or� to schedule an appointment.