HomeMy WebLinkAboutWPO201600063 Review Comments 2017-02-17 .0 GARRETT ST, SUITE K CHARLOTTESVILLE VA 22902
COLLINS =,;,,:l ‹ , ,,
(434.293.3719 PH 434.293.2813 FX
www.colIins-engineering.corn
TRANSMITTAL
❑ FAX ❑ MAIL X DELIVERY
FROM:GRAHAM MURRAY,P.E.
COMPANY:ALB. COUNTY ENGINEERING DATE:2/17/17
(Community Development)
FAX: TOTAL NO.OF PAGES INCLUDING COVER:
PHONE NUMBER: SENDER'S PHONE NUMBER:434-566-3011
PROJECT/SUBJECT:
NORTHTOWN IIB- EARLY GRADING PERMIT
WPO 201600063
PLEASE FIND ENCLOSED:
NO.COPIES DATE DESCRIPTION
4 2/17/17 CONSTRUCTION PLANS
1 2/17/17 COMMENT RESPONSE LETTER
1 2/17/17 GEOTECHNICAL ENG. LETTER
NOTES/COMMENTS:
THE PREVIOUSLY SUBMITTED PLANS WERE REVIEWED AND CONDITIONALLY APPROVED PENDING
THE FINAL RESOLUTION OF A FEW ADMINISTRATIVE ITEMS,MEANING THE CONSTRUCTION PLANS
WERE NOT REQUIRED TO BE REVISED AND RESUBMITTED FOR APPROVAL PER AN E-MAIL
CORRESPONDENCE BETWEEN MR.WENTLAND AND MR.MURRAY DATED 1/30/17.FOLLOWING THIS
CORRESPONDENCE,THE DEVELOPER ELECTED TO SUBMIT A FINAL SITE PLAN FOR THIS PARCEL,
WHICH IS BEING COMPLETED CURRENTLY.THE ATTACHED VSMP PLANS AND CALCULATIONS
INCORPORATE MINOR CHANGES THAT HAVE RESULTED FROM THE CREATION OF THE FINAL SITE
PLAN.THESE SUBTLE CHANGES WILL ALLOW THE APPLICANT TO UTILIZE THIS VSMP PLAN FOR THE
PROPOSED FINAL SITE PLAN'S CONSTRUCTION,AND WILL HOPEFULLY AVOID HAVING TO SUBMIT AN
AMENDMENT WITH THE REVIEW OF THE FINAL SITE PLAN.
SHOULD YOU HAVE ANY QUESTIONS DURING YOUR REVIEW/CONDITIONAL APPROVAL,PLEASE FEEL
FREE TO CONTACT THE APPLICANT VIA E-MAIL(GRAHAM@COLLINS-ENGINEERING.COM)OR VIA HIS
CELL PHONE(434.566.3011).
RESPECTFULLY,
GRAHAM MURRAY,P.E.
RECEIVED BY:
SIGNATURE DATE
COLLINS *vara GARRETT ST, SUITE K CHARLOTTESVILLE VA 22902
434.293.3719 PH 434.293.2813 FX
www.collins-engineering.corn
February 17,2017
Matt Wentland, P.E.
Department of Community Development
401 McIntire Road
Charlottesville,VA 22902
RE: Northtown Phase IIB(WP0201600063)
Thank you for your comments dated January 30, 2017 on the above-referenced project. The updated plans reflect
changes to address your comments as described below:
A. Stormwater Pollution Prevention Plan(SWPPP)
1. The final, County signed plans will be inserted into the SWPPPP prior to the first inspection:This is
comment is acknowledged.
B. Pollution Prevention Plan (PPP)
NO f",rther;.,„�o:>rq;,�
C. Stormwater Management Plan(SWMP)
1. This comment is acknowledged.The preserved open space areas wilt need to be bonded prior to the
issuance of a grading permit:
2. This comment is acknowledged. Nutrient credits will need to be purchased prior to the issuance of a
grading permit.
3. Comment previously addressed:
4. Comment previously addressed.
S. The applicant has provided a letter from a third party consultant confirming the proposed basin and its
design will not adversely impact the existing wall.
D. - Erosiu l crista
1. No further comments
Should you have any questions, please feel free to contact me at graham@collins-engineering.com.
Sincerely,
Graham Murray, PE
Collins Engineering
Circeo CIRCEO GEOTECH
Geotechnical 5956 Buckland Mill Road
Engineering, P.C. Roanoke, Virginia 24019
Office: (540)366-2379
Mobile: (540)354-3260
Fax: (540)904-6200
Geotechnical Explorations-Foundation Explorations-Retaining Wall Design
February 17, 2017
Scott Collins,P.E.
Collins Engineering
200 Garrett Street,Suite K
Charlottesville, VA 22902
Re: Engineering Report-Existing Redi-Rock Retaining Wall Evaluation
Northtown Center II8
Albemarle County,Virginia
C6E Project No. RW-1841
bear Scott:
Circeo Geotechnical Engineering, P.C. has completed the engineering evaluation of the existing Redi-
Rock retaining wall (designated Wall 1) with respect to the proposed building and detention pond
adjacent to the wall for the proposed Northtown Center -Phase IIB in Albemarle County, Virginia.
Existing Redi-Rock Wall 1
The Redi-Rock retaining wall was designed by D.R. Johnson& Associates, LLC, Project No. 125-13-03,
dated April 3, 2013, for Northtown Center - Phase IIA. For Wall 1, the wall design was based on a
maximum wall height of 34.5 feet, including embedment, and overall length of 716 linear feet. The
wall utilized 28" Redi-Rock units, reinforced with MiraGrid 5XT, 8XT and 10XT, with geoconnectors,
and use of drainage aggregate (VDOT No. 57 Stone) and compacted granular fill in the reinforced
zone up to EL. 449.5, and a gravity wall (unreinforced) for the final four (4) courses (6 feet in
height) up to the top of wall at EL. 455.5. The longest geogrid length was 22 feet, with the top
geogrid length of 25 feet.
For design purposes, the reinforced fill was based on a unit weight of 120 pcf, internal friction angle
of 28 degrees and zero cohesion. A live load surcharge of 250 psf was assumed at the top of the
wall. The maximum allowable soil bearing pressure was 3,000 psf.
Proposed Building
The proposed building will be constructed within 15 feet of the wall face. In this area, the geogrid
reinforcement were 14 to 16 feet in length, with the top geogrid layer at 16 feet to 18 feet. The
top geogrid layer was EL. 449.5. The grade at the building is approximately EL. 460, with an
estimated building footing grade at EL. 458. The imposed building structural loads where
Engineering Report-Northtown Cdkit„r+IIB-Evaluation of Ex.Redi-Rock Retaining Wall
CGE Project No.RW-841
February 17,2017
determined to be outside the zone of the influence of the wall, and does not adversely impact the
retaining wall performance.
Proposed Detention Pond
The proposed detention pond with be constructed with the embankment crest to match the top of
the wall with the pond bottom at EL. 450.5, with a pond depth of 5.5 feet above the top of the wall.
In the pond area, the geogrid lengths were 22 feet in length, with the top geogrid layer at 25 feet.
The top geogrid layer was EL. 449.5,and no geogrid in the upper 6 feet unreinforced. Bottom of the
pond is approximately 12 inches above the top geogrid layer. The bottom and sides of the pond
should be protected with a minimum 12" thick compacted impervious clay liner or synthetic (rubber)
membrane to prevent water infiltration into the reinforced fill. It is understood that a 24"
diameter RCP standpipe and trashrack with orifices will be provided to allow for slow release of
stormwater into the existing storm structure and outfall pipe at the base of the wall for the 100-
year storm.
Certification
Based on review of the project construction documents for Northtown Center IIA, construction
inspection report and site photos during the construction, the wall construction was determined to
be installed in accordance with the structural engineering plans. The proposed Grading & Drainage
Plan, Northtown Center IIB, Sheet No. 4, dated February 6, 2017, prepared by Collins Engineering,
construction of the proposed building and installation of the proposed detention pond will not
adversely impact the structural performance for the retaining wall system. With the exception of
the recommended incorporation of a compacted clay liner or synthetic rubber membrane to prevent
water infiltration into the reinforced zone, no modification to the existing Redi-Rock retaining wall
is warranted. The building loads of the proposed structures are outside the zone of influence of the
retaining wall,and should not impact the structural integrity of the wall.
Let me know if you have any questions.
CIRCEO GEOTECHNICAL ENGINEERING, P.C.
Michael R.Circeo,P.E. Q ,
President
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MICHAEL R. ' r->
No. 021245
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2
COUNTY 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: Northtown Phase IIB
Project file number: WPO -2016-00063
Plan preparer:
Collins Engineering
Owner or rep.:
First Gold Leaf Land Trust (Wendell Wood)
Plan received date:
17 October 2016
(Rev. 1)
16 December 2016
Date of comments:
1 December 2016
(Rev. 1)
30 January 2017
Reviewer:
Matt Wentland
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
rationale is given in the comments below. 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 ESOP, (3) a SWMP, and (4) any TMDL measures necessary.
1. The SWPPP will need to be updated with the ESC, SWM, and PPP sheets. This can be done once
the plans are ready to be approved. (Rev. 1) Comment partially addressed. The ESC and SWM
sheets were not found in the SWPPP. These will need to be in the SWPPP prior to the first
inspection.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
1. The PPP exhibit will need to be included in the SWPPP. (Rev. 1) Comment addressed.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a
SWMP. This plan is disapproved, and the reasons are provided in the comments below. The
stormwater management plan content requirements can be found in County Code section 17-403.
1. The Forest and Open Space Area used in the VRRM worksheet will need to be platted or bonded
prior to issuing a grading permit. (Rev. 1) Response acknowledged.
2. The nutrient credits will need to purchased prior to issuing a grading permit. (Rev. 1) Response
acknowledged.
3. Provide the calculations for the IIC Flooding compliance. [9VAC25-870-98] (Rev. 1) Comment
addressed.
4. Provide the proposed square footage of the impervious area on TMP 45-111C to show how it
Engineering Review Comments
Page 2 of 3
compares to the estimated available treatment area of 7,815sf shown on the amendment to
WPO201300002. (Rev. 1) Comment addressed.
5. Provide a signed and sealed confirmation from a Geotechnical and Structural Engineer that the
proposed pond and embankment will not adversely impact the existing wall prior to plan approval.
(Rev. 1) Response acknowledged.
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, and the reasons are provided in the comments below. The erosion control
plan content requirements can be found in County Code section 17-402.
1. The ESC plan appears to be acceptable at this time.
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.
County forms can be found on the county website forms center under engineering;
http://www.albemarle.org/deptforms.asp?department=cden.gwpo
Engineering Review Comments
Page 3 of 3
File: WPO201600063 Norlhlown Phase IIB Rev 01-30-17.doc
'sok GARRETT ST, SUITE K CHARLOTTESVILLE VA 22902
COLLINS softio,
434.293.3719 PH 434.293.2813 FX
www.collins-engineering.com
TRANSMITTAL
❑ FAX ❑ MAIL X DELIVERY
TO:MR.MATT WENTLAND,P.E. FROM:GRAHAM MURRAY,P.E.
COMPANY:ALB. COUNTY ENGINEERING DATE: 12/16/16
(Community Development)
FAX: TOTAL NO.OF PAGES INCLUDING COVER:
PHONE NUMBER: SENDER'S PHONE NUMBER:434-566-3011
PROJECT/SUBJECT:
NORTHTOWN IIB- EARLY GRADING PERMIT
WPO 201600063
PLEASE FIND ENCLOSED:
NO.COPIES DATE DESCRIPTION
1 12/16/16 COMMENT RESPONSE LETTER
4 12/16/16 CONSTRUCTION PLANS
1 12/14/16 SWM CALCULATIONS PACKET
1 12/16/16 SWPPP REPORT WITH A PPP
NOTES/COMMENTS:
THE APPLICANT MADE SIGNIFICANT EFFORTS TO FULLY ADDRESS ALL OF THE REVIEWER'S
COMMENTS,WITHOUT CONTEST,AND THE APPLICANT BELIEVES THIS PLAN CAN BE APPROVED.
SHOULD YOU HAVE ANY QUESTIONS DURING YOUR REVIEW,PLEASE FEEL FREE TO CONTACT THE
APPLICANT VIA E-MAIL(GRAHAM@COLLINS-ENGINEERING.COM)OR VIA HIS CELL PHONE
(434.566.3011).
RESPECTFULLY,
GRAHAM MURRAY,P.E.
RECEIVED BY:
SIGNATURE DATE
COLLINS ou, X110 GARRETT ST, SUITE K CHARLOTTESVILLE VA 22902
434.293.3719 PH 434.293.2813 FX
www.collins-engineering.com
December 16,2016
Matt Wentland, P.E.
Department of Community Development
401 McIntire Road
Charlottesville,VA 22902
RE: Northtown Phase IIB(WP0201600063)
Thank you for your comments dated December 1, 2016 on the above-referenced project. The updated plans
reflect changes to address your comments as described below:
A. Stormwater Pollution Prevention Plan(SWPPP)
1. The applicant appreciates the reviewer's prior lack of an objection to the SWPPP.The SWPPP has been
updated with the current ESC,SWM and PPP sheets for what will hopefully be a final approval.
B. Pollution Prevention Plan(PPP)
1. The SWPPP was revised to include the PPP.
C. Stormwater Management Plan(SWMP)
1. This comment is acknowledged.The preserved open space areas will be need to be bonded prior to the
issuance of a grading permit.
2. This comment is acknowledged. Nutrient credits will need to be purchased prior to the issuance of a
grading permit.
3. In a phone conversation between Mr.Wentland and Mr. Murray of Collins Engineering on December 13th
this developments'prior agreed upon compromise for meeting MS-19 requirements was discussed.And
at the conclusion of the conversation it was agreed this plan could satisfy this comment if the 2-and 10-
year post-development design outfalls were less than the pre-development 2-and 10-year design outfalls.
As a result,the detention basin was expanded to increase its volumes so that the post-development flows
would be less than the pre-development flows. Please see the attached SWM calculations packet and
sheets 7 and 8 for evidence of this compliance.
4. During the aforementioned phone conversation it was determined that if the proposed impervious areas
on TMP 45-111C are to exceed 7,815 sf then an amendment to WPO 201300002 would be required. It
was also conveyed that the specifics of this parcel's development were not known at this time.And since
the intent of this plan is to allow the developer to obtain a grading permit,and a final site plan for this
parcel is required to construct any impervious areas,the plans have been revised to include a note that
reads,
5. This comment is acknowledged.The applicant is currently working with a consultant to obtain this
confirmation.
D. Erosion and Sediment Control Plan(ESCP)
1. The applicant appreciates the reviewer's prior approval.
Should you have any questions,please feel free to contact me at graham@collins-engineering.com.
Sincerely,
Graham Murray, PE
Collins Engineering
COUNTY 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:
Northtown Phase IIB
Project file number:
WPO -2016-00063
Plan preparer:
Collins Engineering
Owner or rep.:
First Gold Leaf Land Trust (Wendell Wood)
Plan received date:
17 October 2016
Date of comments:
1 December 2016
Reviewer:
Matt Wentland
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
rationale is given in the comments below. 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 ESOP, (3) a SWMP, and (4) any TMDL measures necessary.
The SWPPP will need to be updated with the ESC, SWM, and PPP sheets. This can be done once
the plans are ready to be approved.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
1. The PPP exhibit will need to be included in the SWPPP.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a
SWMP. This plan is disapproved, and the reasons are provided in the comments below. The
stormwater management plan content requirements can be found in County Code section 17-403.
1. The Forest and Open Space Area used in the VRRM worksheet will need to be platted or bonded
prior to issuing a grading permit.
2. The nutrient credits will need to purchased prior to issuing a grading permit.
3. Provide the calculations for the I1C Flooding compliance. [9VAC25-870-98]
4. Provide the proposed square footage of the impervious area on TMP 45-111C to show how it
compares to the estimated available treatment area of 7,815sf shown on the amendment to
WP0201300002.
5. Provide a signed and sealed confirmation from a Geotechnical and Structural Engineer that the
proposed pond and embankment will not adversely impact the existing wall prior to plan approval.
D. Erosion and Sediment Control Plan (ESCP)
Engineering Review Comments
Page 2 of 2
Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESOP.
This plan is approved, and the reasons are provided in the comments below. The erosion control
plan content requirements can be found in County Code section 17-402.
1. The ESC plan appears to be acceptable at this time.
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.
County forms can be found on the county website forms center under engineering;
ht!p://www.albemarle.or,-/deptforms.asp?department=cden,izwpo
File: WP0201600063 Northtown Phase IIB 12-01-16.doc