20100603 Ver 1_Email_20130402

Ridings, Rob
From: Ridings, Rob
Sent: Tuesday, April 02, 2013 8:30 AM
To: Murray, Christopher A
Cc: Alsmeyer, Eric C SAW; Earwood, Aaron V; Tharrington, Emmette B; Montague, Heather W;
Pearson, Donald R
Subject: RE: Construction issue on Bridge No. 19 on SR 2000 over Neuse, River (B -4660) in Wake
County
Chris,
Due to no other good options, I agree that instead of the boardwalk that some pipe fill under the greenway would be
the reasonable way to handle this, along with rip rap at the outlet.
A revised plan sheet showing all this will be needed for the record'when you're able to get one - -- including showing a
non - erosive velocity for the water entering the river - -- but I do not think you need a whole revision to your DWQ
certification.
Let me know if you have any Questions,
Rob Ridings
From: Murray, Christopher A
Sent: Monday, April 01, 2013 5:52 PM
To: Ridings, Rob
Cc: Alsmeyer, Eric C SAW; Earwood, Aaron V; Tharrington, Emmette B; Montague, Heather W; Pearson, Donald R
Subject: Construction issue on Bridge No. 19 on SR 2000 over Neuse River (B -4660) in Wake County
NCDENR -DWQ Project No 01006
USACE Action ID Number 2006 -40799
Rob,
Stormwater from the southern portion of the project was to be discharged from a 36 inch pipe structure (and rip rap
outlet pad) into an existing drainage swale that converged with the Neuse River. The project design incorporated
construction of a timber boardwalk over the existing drainage swale (see attached image) that would be part of the City
of Raleigh pedestrian trail. The original design of the timber boardwalk required installation of driven wooden piles on
10 foot spacing. The purpose of the boardwalk with wooden piles on 10 foot spacing was included in our plan to avoid
direct impacts to the existing drainage Swale (cost: $60,140).
Once construction commenced on the project, it was determined that bedrock was observed within the limits of the
boardwalk. The engineering firm that completed the original boardwalk design came up with Revision Number 1. This
design involved construction of a rock anchor to tie the wooden piles to the bedrock and keep the wooden piles on 10
foot spacing (cost: $90,149). Construction of the rock anchor would have required impacts to the flow line of the
existing drainage swale . I was concerned about construction of Revision Number 1 as it would result in direct
construction impacts to the existing drainage swale (which is what I was trying to avoid).
The engineering firm has recently presented Revision Number 2. This design involved construction of a wooden piles on
a 25 foot span that would have avoided impacts to the flow line and banks of the existing drainage i wale (cost:
$160,892).
In light of the rising costs, a site visit was conducted last week with Division personnel to review all construction
options. We have previously observed a 2 foot wide and 2 foot deep hole in the existing drainage swale within the
proposed limits of the boardwalk. Insertion of a steel rod into the ground in several areas at this location leads us to

HSB 9 — This basin looks good overall with some vegetation in the bottom. The area around the outlet needs to
be cleaned out to allow for better drainage.
HSB 10 — Looks good overall. There is a baffle around the outlet which should be removed. The area inside the
baffle needs to be cleaned up, removing sediment piles, rock, and the pallet.
HSB 11— The basin looks good overall. One edge of the level spreader has been breached and has water piping
around the level spreader. This should be fixed such that the device is not short circuiting.
HSB 12 — Basin looks good overall; however, some slumping of the bank was noticed in the corner near the
road which should be fixed and stabilized. The level spreader should be lowered as it appears to match the
height of the inlet pipe and is probably not functioning correctly.
HSB 13 — The basin itself looks good. However, there are some issues with the outlet. The outlet does not drain
as intended. There was an attempt to fix this by excavating a drainage ditch to the edge of the buffer; however
this attempt appears to have been unsuccessful. Additionally, no level spreader has been constructed on the
outlet of the basin. A device which will create diffuse flow prior to the discharge reaching the 50 foot buffer is
required. While on site, several elevation shots were taken to determine if proper drainage would be feasible.
The measurements seemed to indicate that elevation between the outlet pipe and the buffer may be an issue.
One solution briefly discussed was perhaps modifying the outlet structure and pipe by raising it, thereby
allowing for a higher outlet elevation and better drainage of the discharge, but his may not be a practical
solution as this would probably not allow proper drainage of the basin. NCDOT agreed to consider
opportunities to modify the outlet structure to get better drainage and also to investigate the possibility of
installing a level spreader. If a properly functioning level spreader cannot be installed, then the NCDOT will
need to submit in writing a justification as to why it is not possible to do so. Other means of obtaining diffuse
flow may need to be considered if this proves to be the case.
HSB 14 — This basin contained approximately 4 -6 inches of accumulated sediment which needs to be cleaned
out.
- The level spreader at ramp 2B looks good.
- The buffer area replanted near ramp 2B looks good and seems to be vegetated nicely with all trees surviving.
- There is a drainage ditch line located on the outside of ramp 2B that needs to have accumulated sediment
cleaned out. Also, there was some erosion on the banks that need to be addressed. It is also recommended
that the channel be lined with rip rap to help prevent future erosion in the channel.
- There is a stormwater drainage feature that drains into a stream near HSB 6 that currently has a rock check
dam installed. The feature drains into a jurisdictional stream and has had sediment deposited into the stream
in the past. The slope is steep and could have future erosion issues due to the slope and the soils. It is
recommended that when the check dam is removed the line of drainage be rip rapped to help avoid any
future erosion and sedimentation issues. The area can be lined down to the edge of the retaining wall, but be
sure to keep rock out of the thalweg of the stream.
- Several of the level spreaders have waddles on the back side of them. These should be removed at the
appropriate time.
General Comments:
- Most of the HSBs have one or more sandbags located near the outlet. All sandbags should be removed when
they are no longer needed.
- All HSBs should be seeded with appropriated vegetation type when conditions allow.
The NCDWQ appreciates you taking the time to review this project with us. I would like to arrange a time to
review the HSBs in a few months, after any deficiencies have been addressed, the basins have been seeded, and
preferably prior to the project being opened to traffic. If you have any questions or require additional information,
please contact David Wainwright at (919) 807 -6405 or [e-mail].

Ridings, Rob
From: Ridings, Rob
Sent: Tuesday, April 02, 2013 8:30 AM
To: Murray, Christopher A
Cc: Alsmeyer, Eric C SAW; Earwood, Aaron V, Tharrington, Emmette B; Montague, Heather W;
Pearson, Donald R
Subject: RE. Construction issue on Bridge No. 19 on SR 2000 over Neuse River (B -4660) in Wake
County
Chris,
Due to no other good options, I agree that instead of the boardwalk that some pipe fill under the greenway would be
the reasonable way to handle this, along with rip rap at the outlet.
A revised plan sheet showing all this will be needed for the record when you're able to get one - -- including showing a
non - erosive velocity for the water entering the river - -- but I do not think you need a whole revision to your DWQ
certification.
Let me know if you have any Questions,
Rob Ridings
From: Murray, Christopher A
Sent: Monday, April 01, 2013 5:52 PM
To: Ridings, Rob
Cc: Alsmeyer, Eric C SAW; Earwood, Aaron V; Tharrington, Emmette B; Montague, Heather W; Pearson, Donald R
Subject: Construction issue on Bridge No. 19 on SR 2000 over Neuse River (B -4660) in Wake County
NCDENR -DWQ Project No 01006
USACE Action ID Number 2006 -40799
Rob,
Stormwater from the southern portion of the project was to be discharged from a 36 inch pipe structure (and rip rap
outlet pad) into an existing drainage swale that converged with the Neuse River. The project design incorporated
construction of a timber boardwalk over the existing drainage swale (see attached image) that would be part of the City
of Raleigh pedestrian trail. The original design of the timber boardwalk required installation of driven wooden piles on
10 foot spacing. The purpose of the boardwalk with wooden piles on 10 foot spacing was included in our plan to avoid
direct impacts to the existing drainage Swale (cost: $60,140).
Once construction commenced on the project, it was determined that bedrock was observed within the limits of the
boardwalk. The engineering firm that completed the original boardwalk design came up with Revision Number 1. This
design involved construction of a rock anchor to tie the wooden piles to the bedrock and keep the wooden piles on 10
foot spacing (cost: $90,149). Construction of the rock anchor would have required impacts to the flow line of the
existing drainage swale . I was concerned about construction of Revision Number 1 as it would result in direct
construction impacts to the existing drainage swale (which is what I was trying to avoid).
The engineering firm has recently presented Revision Number 2. This design involved construction of a wooden piles on
a 25 foot span that would have avoided impacts to the flow line and banks of the existing drainage Swale (cost:
$160,892).
In light of the rising costs, a site visit was conducted last week with Division personnel to review all construction
options. We have previously observed a 2 foot wide and 2 foot deep hole in the existing drainage swale within the
proposed limits of the boardwalk. Insertion of a steel rod into the ground in several areas at this location leads us to

believe that the only thing holding up the ground in the area is the numerous tree roots. There is a large void in the
ground directly under the flow line of the existing drainage Swale. The area is completely unstable at this time and will
only get worse if the boardwalk is constructed per any of the revisions.
We were aware that the design of the City of Raleigh pedestrian trail adjacent to our project included installation of
numerous pipes to convey stormwater under the trail. We now think that the best option is to construct a similar
system on our project. This would involve installation of an approximately 30 foot long 42 inch pipe structure (with
headwall and endwall) within the limits of the previously proposed boardwalk. This would allow the contractor to open
up the open hole /void in the existing drainage swale and backfill with suitable fill. The pipe structure would then be
installed along with a Class II rip rap pad that would extend to the banks of the Neuse River (cost: $54,198).
The presence of the open hole /void in the existing drainage swale and the rising costs of other options leads me to
believe that this is the best option for long -term stability. As noted above, this is the same design that has been utilized
on the City of Raleigh pedestrian trail within 200 feet of our project. Please review this information and advise if you
agree with our proposal to eliminate the boardwalk and install a pipe structure to convey stormwater runoff at this
location.
Thanks,
Chris Murray
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** Can't Build Due to Rock ,
3) Revision Number 2: Longer span to avoid bed and bank of Swale
1) Boardwalk Original -Per original plan
Quantity
LC
Description Quantity
Unit Price
Mobilization
Total
4
48" Rail 120
$ 55.00
$
6,600.00
5
Boardwalk 60
$ 500.00
$
30,000.00
6
Posts 330
$ 58.00
$
19,140.00
7
Approach 2
$ 2,200.00
$
4,400.00
$
4,950.00
LOM - Lumber
$
60,140.00
** Can't Build Due to Rock ,
3) Revision Number 2: Longer span to avoid bed and bank of Swale
LC Description
Quantity
Unit Price
Total
Mobilization
1
$
14,000.00
$
14,000.00
Excavated Pile Foundation
64
$
740.00
$
47,360.00
Boardwalk
45
$
1,230.00
$
55,350.00
4 Rail
90
$
55.00
$
4,950.00
LOM - Lumber
256
$
56.00
$
14,336.00
LOM - Hardware
1064
$
7.50
$
7,980.00
LOM - Brackets
28
$
65.00
$
1,820.00
Excavator Rental
1
$
8,250.00
$
8,250.00
Loader Rental
2
$
623.00
$
1,246.00
Labor
30
$
20.00
$
600.00
Office
50
$
100.00
$
5,000.00
$
160,892.00
2) f
LC
4
5
6
7
140
LC

tevision Number 1: Use rock anchor due to bedrock in area.
Description
Quantity
Unit Price
Total
48" Rail
120
$ 55.00
$
6,600.00
Boardwalk
60
$ 500.00
$
30,000.00
Posts
0
$ 58.00
$
-
Approach
2
$ 2,200.00
$
4,400.00
Revised Foundation
1
$ 43,190.79
$
43,190.79
Rip Rap
$
4,000.00
$
2,000.00
Grading Work
785.00
$
$
4,000.00
256
$
56.00
$
90,190.79
1,
I
E
4)
Pipe w/ Headwalls
Description
Quantity
Unit
Price
Total
42" Pipe
30
$
100.00
$
3,000.00
Rip Rap
$
2,000.00
Grading Work
$
4,000.00
Endwall
7.6
$
785.00
$
5,966.00
LOM - Lumber
256
$
56.00
$
14,336.00
LOM - Hardware
1064
$
7.50
$
7,980.00
LOM - Brackets
28
$
65.00
$
1,820.00
Excavator Rental
1
$
8,250.00
$
8,250.00
Loader Rental
2
$
623.00
$
1,246.00
Labor
30
$
20.00
$
600.00
Office
50
$
100.00
$
5,000.00
$
54,198.00
1,
I
E