HomeMy WebLinkAboutSUB201500100 Correspondence 2015-08-06 „h. ,.......
PROJECT MANAGEMENT
SFIIMP CIVIL ENGINEERING
LAND PLANNING
ENGINEERING
August 6, 2015
Ms. Michelle Roberge
Senior Civil Engineer
County of Albemarle
Department of Community Development
Regarding: Free State Run—Final Site Plan P 2015000
WPO201500015
Dear Mr. Newberry,
Thank you for your review of the preliminary site plan for Free State Run. We have revised
the plans per NDS comments dated July 16, 2015. Please find below a detailed comment response letter
describing the changes we have made to each of your comments.
1. The E &S sheets as well as the SWM detail sheet have been removed from the final site plan.
2. We are now installing a groundwater detention system near the location of the spring, and it will collect
any groundwater via the use of an underdrain.
3. Comment addressed.
4. Comment addressed.
5. We understand that disturbance of the preserved slopes requires rezoning but we will not be disturbing
any of the preserved slopes, see VSMP comment response.
6. Comment addressed.
7. Comment addressed.
8. Comment addressed.
9. Drainage easements are now being shown on all SWM facilities.
10. We have replaced the drainage flume with a drainage inlet and pipe to the bio retention pond, so we
will no longer need a runoff easement.
11. We have adjusted the pond near Lot 24 so that it does not cross property line.
12. Access easements to SWM facilities now being shown.
13. Comment addressed.
14. Comment addressed.
15. A separate road plan has been provided to be bonded.
16. Comment addressed.
17. Comment addressed.
18. Comment addressed.
19. VSMP comment response addresses this.
20. Comment addressed.
21. Comment addressed.
22. Outlets have been updated so that the velocity does not exceed 15 fps.
23. Comment addressed.
24. End sections/outlet protection has been provided on the requested profiles.
25. Comment addressed.
26. Comment addressed.
A. Stormwater Pollution Prevention Plan (SWPPP)
1. The SWPPP onsite will have E&S and SWM plans included.
2. Final SWM calculations will be signed, sealed and dated.
3. Comment addressed.
4. Comment addressed.
5. Comment addressed.
6. Comment addressed.
7. Comment addressed.
B. Pollution Prevention Plan
1. There is a 11x17 PPP in the SWPPP that includes locations of concrete washouts etc.
C. Stormwater Management Plan (SWMP)
1. We have changed the title to say VSMP and removed Sheet C12 from final site plan.
2. Comment addressed
3. The points of analysis have been simplified to the two existing swales that lead to the pond below
the site.
4. The underground storage pipe has been removed from underneath the residential lots, and into the
private road.
5. We have been in contact with Army Corp to obtain letter of approval for stream disturbance.
6. Preserved Slopes
a)The level spreader before the preserved slopes, instead the outflow pipe from the detention facility
will be routed between Lots 10 and 11.
b)There will be minimal grading behind Lots 5-8. The basement elevations of the units are within a
foot of existing grade.
c)As shown in Erosion Plan, we will stake a safety fence which is not to be crossed. We are happy
to have a County inspector verify that the slopes are undisturbed. We realize this will be more
expensive, but it is the builder's responsibility.
7. Comment addressed.
8. Comment addressed.
9. Curb inlet at B3A has been replaced with a DI-7, thus bypassing water away from the bio retention
pond.
10. Credits have not yet been purchased, but the amount is specified in the SWM cover letter.
11. The Type II 24 hour storm has been updated in the pre and post development HydroCad analysis.
Page 12
12. There is no intention to divert water around bio retention 2. There is no longer a spillway, all water
will be contained within the pond (while maintaining 1' ponding depth) and then will flow through
the D3 pipe to detention.
13. The toe of spillway from bio retention 1 is connected to the adjoining riprap.
14. Comment addressed.
15. Underdrains
a)The underdrain has been removed from the pre-treatment area for bio retention 1.
b)Biofilter mix has been removed from bio retention 1 pre-treatment.
16. Comment addressed.
17. We have provided a pre-treatment cell that then spills into a gravel diaphragm before entering bio
retention pond. Runoff from Lots 1 and 2 will flow from roofdrains into the sewer that flows into
pre-treatment cell.
18. Bio Retention 1
a) As stated previously, we are still waiting for a response from the Army Corp.
b) We will have one swale that is intersected by a berm then routed to the pre-treatment cell.
We have provided a detail of the area on the grading plan to create a clearer vision of our
intentions for this area.
c) We have replaced curb inlet with DI-7 and to allow runoff to bypass biofilter.
d) See b)above.
e) We have provided a pre-treatment cell as well as a gravel diaphragm in our plans.
Bio Retention 2
a) We will provide underdrains for bio retention pond 2.
b) Again, there is no intention to divert runoff from biofilter 2, it has been sized to take in
runoff from Lots 22 and 23 and maintain 1' of ponding depth until piped through storm sewer
D3.
c) We removed the drainage swale and replaced with a pipe that flows into the bio retention
pond 2. That's why no more information was given for it.
d) Bio retention pond has been shifted so that it is not in Lot 24 and the easement has been
adjusted accordingly.
e) This is a level 1 bio retention facility, thus requiring one form of pre treatment which is
provided in the form of a pretreatment cell, in which we softened the 90 degree bend.
New SWM Comments:
19. The underground detention at entrance has been resized, but still remains large to detain 1 and 10
year storms.
20. Perc tests will be provided.
21. We have added access manholes to the detention pipe.
22. We have replaced the 48" pipe with an 84" pipe.
23. It is supposed to be a rectangular trench with stone, and pipe laid within it. See detail 9, sheet
C12.
Page 13
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24. We have labeled the contours for the bio retention pond.
25. We have dimensioned the bio retention pond on sheet C12.
26. The contours for the embankments on both bio retentions have been labeled on sheet C12.
27. Cleanouts are being shown.
28. The side slopes have been clarified on sheet C12.
29. The length of the culvert exiting the biofilter has been labeled.
30. We have labeled the spillway elevation and provided its dimensions on bio retention 1.
31. New biofilter elevation is 405.5 and it has been labeled.
32. We have removed the wall from the bio retention pond. It is no longer necessary since we must
maintain 1'of ponding depth.
33. We have also removed the control structure.
34. We have verified that the invert out for bio retention 1 matches calculations.
35. Pipe labels and calculations have been double checked for consistency.
36. SWM easements are present on the plan.
37. We have created a new HydroCad model that matches the new simplified analysis within the site.
D. Erosion and Sediment Control
1. Comment addressed.
2. Comment addressed.
3. Comment addressed.
4. Comment addressed.
5. Comment addressed.
6. The safety fence has been adjusted to be within the limits of disturbance.
7. We have added notes about the DD's on erosion sheet. The diversion dikes will stay in
place until the curb gutter and sewer pipes are installed. After that, the silt fence will be
sufficient.
8. Comment addressed.
9. We have shifted the diversion dike 10'away from sanitary sewer.
10. Comment addressed.
11. Riprap sizing has been labeled on the outlet protection.
12. The detail title has been corrected.
13. Inlet protection is shown for all inlets now.
Page 14
Nur' `owe
Planning Division
1. The end of Free State Drive complies with the specified County Code sections. WE have extended
the ROW and the road to the property line as close as possible and we have coordinated with VDOT
on the requirements for a temporary turn around and none are required for SSAR regulations. It
seems that we can extend it further, but our road grading would be a lot more steep in order for the
grading to tie in to existing contours at the property line.
2. We have revised the street tree spacing to get closer to compliance.
3. Space constraints on Free State Drive will not allow us to extend the sidewalk all the way to Free
State Road. Also, we did not provide the sidewalk on the northern side of Free State Road, because
we stopped it short of the piece of land within uncertain ownership. In addition, we do not feel that is
necessary to provide a sidewalk where there are no houses on the northern side of Free State Road.
If you have any questions please feel free to contact me via e-mail at Morgan(a)shimp-engineerinq.com or
Justin Shimp at JustinAshimp-engineerinq.com or by telephone at 434-227-5140.
Sincerely,
Morgan Bell
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Ir
PROJECT MANAGEMENT
SHIMP CIVIL ENGINEERING
LAND PLANNING
ENGINEERING
C___.,
October 12, 2015
Mr. Justin Deel
Civil Engineer
County of Albemarle
Department of Community Development
Regarding: Free State Run—Road and Drainage Plan SUB2015.00100
Dear Mr. Deel,
Thank you for your review of the road and drainage plan for Free State Run. We have
revised the plans per County comments dated September 1, 2015. Please find below a detailed comment
response letter describing the changes we have made to each of your comments.
1. Per our most recent conversations, aerial topo can be utilized if it's more accurate. As the steep slopes
ordinance is written, the slopes boundary is limited to the GIS layer and can only be reduced. The
aerial survey that was provided to us for this site has a scale of 1"=50'with 2' contour intervals with an
accuracy of+1- 1'. This is more accurate than the field survey provided by the county. We have
evaluated the survey and determined that there are not any areas that are steeper than 25%that
remain unmarked as"preserved".
2. According to Sec. 14-410.0 we are not required to provide a temporary turnaround, because we are
less than 300'from the intersection and the road is only serving 2 houses. However, we have provided
a hammerhead turn-around at the end of Free State Drive. Also, Free State Drive has not been
extended to the abutting property line due to grading restraints.
3. Farrow Hill Court has been adjusted to have a 6%turn-around. Although we took the radius from the
edge of pavement, we have still provided more than the minimum required radius of 60' by providing a
66'diameter from EOP.
4. Road stationing per 50' interval has been provided on sheets C7-C9.
5. We have provided sealed retaining wall details on sheet C12.
6. We do not believe that the relocation of this crosswalk is necessary because the required sight
distance for Free State Drive has been provided and the crosswalk is in clear view.
7. We believe that a guardrail is not necessary due to the fact that the outside curve of Free State Road is
uphill and will not cause a major concern.
8. I have adjusted the labels and leaders to make the asphalt layers clear. There is also another
pavement detail on sheet C11.
9. See Road Plan cover sheet for general construction notes for private roads.
10. We have provided a pavement design document separately in the Drainage Calculation Packet. Trip
Generation was provided on the cover sheet.
11. Slopes greater than 2:1 have been labeled on the Landscape Plan and the areas have been hatched.
See sheet C10 notes for groundcover specifications.
12. A Drainage Calculation packet will be submitted with this updated Road Plan.
If you have any questions please feel free to contact me via e-mail at Morgan(c�shimp-enqineerinq.com or
Justin Shimp at Justin(c�shimp-engineerinq.com or by telephone at 434-227-5140.
Sincerely,
Morgan Be
Page 12
PROJECT MANAGEMENT
SHIMP CIVIL ENGINEERING
LAND PLANNING
ENGINEERING
November 19, 2015
Mr. Justin Deel
Civil Engineer
County of Albemarle
Department of Community Development
Regarding: Free State Run—RP SUB 2015-00100
Dear Mr. Deel,
Thank you for your review of the VSMP for Free State Run. We have revised the plans per
County comments dated October 19, 2015. Please find below a detailed comment response letter describing
the changes we have made to each of your comments.
1. We will provide a signed and sealed topographic survey showing compliance with Section 30.7.4b
2. Comment addressed.
3. We have adjusted the offset cul de sac to be 6%.
4. Comment addressed.
5. The stacking block retaining walls have been replaced with concrete, the retaining wall calculations
have been provided.
6. The 225'sight distance has been indicated on the site plan to show there are no obstructions to view
of the crosswalk. Please note that there is also a 15 mph speed limit at this location.
If you have any questions please feel free to contact me via e-mail at Morgan anshimp-enqineerinq.com or
Justin Shimp at JustinAshimp-enqineerinq.com or by telephone at 434-227-5140.
Sincerely,
Morgan Bell
Justin Deel
From: Justin Deel
Sent: Wednesday, January 06, 2016 2:31 PM
To: 'Justin Shimp, P.E.'
Cc: Jess Achenbach
Subject: RE: Planning Application Review for SUB201500100 Free State Run - Road Plans.
Thanks,Justin. This takes care of the remaining comments in my 5 January Review Letter. I am ready to approve this
plan pending recommendation from VDOT and ACSA.
I noticed that the drainage computation package that I left for you to copy had not been updated since early October.
Please update this so that it is consistent with the approved VSMP plan and provide a copy for the County and VDOT.
Thanks,
Justin
From:Justin Shimp, P.E. [mailto:justin@shimp-engineering.com]
Sent:Wednesday,January 06, 2016 11:32 AM
To:Justin Deel<jdeel@albemarle.org>
Cc:Jess Achenbach<jess@reddirtdev.com>
Subject: Re: Planning Application Review for SUB201500100 Free State Run - Road Plans.
Hello Justin,
As discussed, the sight lines are shown for the cross walk on sheet C4. More critically the mid-block cross walk
is at the crest of the hill and pedestrians will have clear visibility both directions.
Concerning the retaining wall, the design takes into account the site specific application and we have reviewed
the need for the pipe to cross through the wall and can confirm that this condition can be accommodated within
the wall as designed. A handrail is assumed on the detail and is also required by building code for the height of
this wall and it will be provided.
Thanks!
Justin Shimp, P.E.
434-953-6116
On Jan 5, 2016, at 3:08 PM, Justin Deel <jdeelgu,albemarle.org> wrote:
The Review for the following application has been completed:
Application Number= SUB201500100
Reviewer=Justin Deel
Review Status = Requested Changes
Completed Date =01/05/2016