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Home My WebLink AboutWPO201400074 Review Comments WPO VSMP 2018-03-20COUNTY 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: Riverside Village WPO Amendment 1 Project file number: WP0201400074 — WPO1 Plan preparer: Justin Shimp, Shimp Engineering [Justin@shimp-engineering.com] Owner or rep.: Chris Henry [chenry@stonypointdb.com] Plan received date: Rev 1 — Feb 61", 2018 Rev 2 — March 111, 2018 Date of comments: Rev 1 — Feb 271h, 2018 Rev 2 — March 20", 2018 Reviewers: Rev 1 & Rev 2 - Bobby Jocz 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. 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. Include WPO number [WP0201400074] and project description [WPO Amendment 1] on the title page, calculations booklets and SWM plan. Rev 2 — Partially addressed. Include WPO Amendment 1 in title on cover sheet. PE seal and signature should be provided on calculations booklets and SWM plan. Rev 2 — Addressed B. Pollution Prevention Plan (PPP) The PPP content requirements can be found in County Code section 17-404. No objection C. Stormwater Management Plan (SWMP) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This plan is denied, and the reasons are provided in the comments below. The stormwater management plan content requirements can be found in County Code section 17-403. This project does not qualify under Part II C [9VAC25-870-96] as indicated on sheet C6. Note that per grandfathering regulations [9VAC25-870-48], "if the plan for the grandfathered project is modified after approval, there can be no increase in the volume rate of runoff above that in the previously approved plan". Please ensure compliance under part IIB requirements [9VAC25-870- 63]. Rev 2 — Addressed Engineering Review Comments Page 2 of 4 Drainage area map and VRRM spreadsheet identify different impervious and total project acreages. The VRRM spreadsheet states the project limits are 2.14 acres with impervious area of 1.3 acres, whereas the water quality map provides a total project limit of 2.41 acres and an impervious area of 1.47. Please correct Rev 2 - Addressed Purchase of nutrient credits must occur prior to final approval. Rev 2 — Acknowledged, 2.63 lbs of credit must be purchased prior to final approval. 4. Catchment area identified for catchment A4 is inconsistent between calculations packet, drainage map, and LD-204 spreadsheet. Please correct. Rev 2 — Not addressed, inconsistent values for the curb opening length, catchment area, and runoff coefficient for structure A4 still presented. Please correct. 5. Provide throat lengths for all inlet structures on stormsewer profiles. Rev 2 - Addressed Structure A9 is indicated as existing on the stormsewer profiles, but is called out as currently a MH structure in the current conditions. Please clarify. Rev 2 — Addressed 7. Provide analysis proving post development 10yr 24hr storm is confined within the conveyance system. The LD-347 shows that the I Oyr-24h storm is contained within the stormsewer pipe network, but does not prove containment within SSC-A1. Rev 2 — partially addressed. Cross section presenting ditch depths not provided as discussed via email 2/28. Additional Rev 2 Comments 1. [Sheet C5] Correct channel geometry presented in ditch section detail. The depth identified is not possible with the side slope and width identified. 2. [Calculations packet and sheet C61 For ditch design table provide context for the number presented (3.246) to the right of the 2-year flow for ditch Al. 3. Discharge into reach A4-A4A does not include flow from BWC/underground detention. Please correct. 4. Provide inlet calculations for structure All. 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 approved pending minor edits identified below. The erosion control plan content requirements can be found in County Code section 17-402. 1. The north diversion dike takes too sharp of curve towards the sediment trap and may result in overtopping of diversion. Please soften the curve. Rev 2 — Addressed. 2. The temporary culvert discharges too close to the outlet of the sediment trap causing short circuiting of the trap. In addition the pipes proximity to the outfall may cause structural issues. Confirm outlet elevation of the pipe to evaluate potential conflict with existing 18" HDPE stormsewer pipe. Rev 2 — Addressed. 3. Ensure existing biofilter adjacent to project site will not be contaminated from construction Engineering Review Comments Page 3 of 4 activities related to block 1. Rev 2 — Addressed 4. For E&S Phase II, silt fence should be provided below 2:1 slope on the east side of the property until final stabilization can occur. Rev 2 — Addressed. 5. Provide engineering detail for temporary diversion. Rev 2 — Addressed. Additional Rev 2 Comments 1. [Sheet C4] Construction entrance is listed twice in the key, should be replaced with dust control. 2. Provide measures to ensure construction traffic only utilizes construction entrance for site access. 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 plan review staff are available from 2-4 PM on Thursdays, should you require a meeting to discuss this review. Process; After approval, plans will need to be bonded. The bonding process is begun by submitting a bond estimate request form and fee to the Department of Community Development. One of the plan reviewers will prepare estimates and check parcel and easement information based on the approved plans. The County's Management Analyst will prepare bond agreement forms, which will need to be completed by the owner and submitted along with cash, certificates or sureties for the amounts specified. The agreements will need to be approved and signed by the County Attorney and County Engineer. This may take 2-4 weeks to obtain all the correct signatures and forms. Stormwater Management Facilities Maintenance agreements will also need to be completed and recorded. The County's Management Analyst or other staff will prepare the forms and check for ownership and signature information. The completed forms will need to be submitted along with court recording fees. After bonding and 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. Engineering Review Comments Page 4 of 4 County forms can be found on the county website forms center under engineering; http://www.albemarle.or /g deptforms.asp?department=cdeng"oo Bobby Jocz Albemarle County Community Development — Engineering rjocz@albemarle.org (434) 296-5832 ext. 3283