HomeMy WebLinkAboutSDP201800061 Review Comments Minor Amendment 2018-09-10COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
Phone (434) 296-5832 Fax (434) 972-4126
Site Plan Review
Project title:
ACSA Admin & Ops Center —Minor Amendment
Project file number:
SDP201800061
Plan preparer:
Dewberry Engineers / 4805 Lake Brook Drive, Suite 200
Glen Allen, VA 23060
Owner or rep.:
Alexander J. Morrison, PE /ACSA[aorrison(abserviceauthority.org]
Plan received date:
7 Aug 2018
Date of comments:
10 Sep 2018
Plan Coordinator:
Andy Reitelbach
Reviewers:
John Anderson
SDP201800061
1. A separate standalone VSMP permit is required. Please remove the following from the Minor Site
Plan Amendment: C0.2; portion of C2.0 related to ESC; C5.0, C5.1, C6.2, C6.3.
2. Recommend revise title of Minor Site Plan Amendment to include `SDP201800061, Minor Site
Plan Amendment' and to delete `100% submission.' (Engineering recommendation only).
3. Title VSMP Plan: `Albemarle County Service Authority Operation Center Expansion Parking Lot
Expansion, VSMP /WP02018-XXXXX.' Note: once WPO# assigned, will provide # for final
VSMP Plan title sheet revision.
4. Ref. Albemarle County Code, Chapter 17, Sec. 17-401 thru 17-405 for VSMP Application form
and content requirements (incl. SWPPP, PPP, ESC /SWM plans + Application /fee requirements).
Link:
http://www.albemarle.or¢Lupload/images/Forms_Center/Departments/County Attorney/Forms/AlbemarleC
ounty_Code _Ch17 Water_Protection.pdf
5. C3.1 —Label ditch and ditchline slope on upslope side of retaining wall.
6. C3.1 — Recommend revise description of Str. 20 (in data arranged as table) to include 48" diameter.
7. C3.2 — Proposed retaining wall design problematic:
a. Proposed design must meet each applicable standard listed at 18-30.7.5.a.1-3, b.l-4;
please call if any questions.
b. Eliminate proposed 2:1 slope at base of wall, an impermissible approach to limiting
height to 6'.
c. Provide stepped walls, max. ht. W, with 3' separation between walls.
d. Consider constructability /possible need for off -site temporary construction easement.
e. Proposed design (w/ 2:1 slope at toe, to be eliminated) requires 6' horizontal space; 4.5'
is available between face of wall and property line.
f. Show property line (accurate scale) in profile view.
g. It appears possible to reconfigure wall design and parking lot to meet design standards
listed at 18-30.7.5 while still providing 18 parking spaces. Reviewer is unaware of any
waiver process, or relief from design standards at 18-30.7.5.
C4.0
8. Revise STM 24 MH-1 label (typo) —diameter should read 60".
9. Provide Note that steps are required for MH depth > 4.0'.
10. Compare inside crown of pipe elevation, 375.75 (INV IN, STM 20), with 10-yr event elevation,
Engineering Review Comments
Page 2 of 2
376.52. Detention pipe must be sized to contain a 10-yr event without exceeding interior elevation
(of top of pipe, at lowest point). Avoid pressurized system. Recommend examine next larger pipe
diameter.
11. STM20 - Provide ref to weir plate detail, sheet C5.3.
12. C4.1 - Conduit flex table slope and length values for Node # 25, 30 do not match profile labels,
C4.0, C4.1. Review /revise for consistency.
13. 5_2 - Recommend detail for handrail post, since detail provided assumes handrail set in retaining
wall. Proposed handrail is not on wall, but behind wall, in fill section. Also note: handrail design
must prevent easy access to top of wall. If rail slopes down with grade behind wall, ensure design
provides suitable deterrent to trespass /prevents access to top of wall.
14. C5.3 - Show MH steps schematically in top view of weir plate MH detail, to limit conflict and
guide installation during construction.
15. C5.3 - Provide VDOT ST-1 (MH step) detail.
16. C5.3 - Provide trash rack, 4" orifice.
VSMP (preview comments); additional comments likely, once VSMP Application submitted:
17. C0.2, ESC Maintenance /Note. 2: Revise to specify paved construction entrance. Provide paved
CE detail. Ref. ACDSM /p. 8 -link:
http://www.albemarle.org/upload/images/forms center/departments/community development/forms/design s
tandards manual/Albemarle County Design Standards Manual 2015-04-25 draft.pdf
18. C0.2, ESC Sequence item 4 must come prior to item 3; install silt fence prior to clearing /grubbing.
19. C2.0 -Revise CE label to read PCE (Incl. PCE in ESC legend).
20. Provide schematic depicting Phase 2, once retaining wall constructed and STM25 installed. See
ESC Sequence note 6 (storm structure #25). Provide phased ESC schematic.
21. In Phase 2 ESC schematic, specify VESCH blanket stabilization for ditch behind (upslope side of)
retaining wall to limit proximate effect on adjacent property, should erosion develop in this area.
22. C5.0 - Provide paved construction entrance detail -ref p. 8, ACDSM; also, comment 17, above.
23. C6.2 - Coordinate nutrient credit purchase with Ana Kilmer, Management Analyst, CDD, prior to
purchase. Legal must review documents prior to sale. Ms. Kilmer: 434.296-5832 -x3246
/akilmer@albemarle. org.
24. C6.2 -Provide stormwater quality /quantity narrative to outline and demonstrate compliance.
25. C6.3 -Energy balance is incomplete, and confusing. Provide RV(1-yr, Pre- /post -development)•
26. C6.3 -Provide routing for 1-year event, pre -development; provide model input /hyrdrograph.
27. Use county SWPPP template.
Link:
hitp://www.albemarle.orgLupload/images/forms center/dgpartments/Community_ Development/forms/Engine
ering and WPO_Forms/Stormwater_Pollution _Prevention _Plan _SWPPP_template.pdf
Thank you.
J. Anderson 434.296-5832 -0069
SDP201800061 ACSA Admin Parking 091018.docx