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HomeMy WebLinkAbout20211126 Ver 2_HB-0001 Nationwide Tyrrell_Dare August 31, 2022_20220831Alligator River Bridge Project Geotechnical Borings
A private engineering firm will be selected to conduct the geotechnical subsurface investigation for the
project with approximately 222 Standard Penetration Test (SPT) borings to be performed. These 222
borings will be performed in the corridor shown on the attached site map. We anticipate 149 bridge
borings will be located within the Alligator River to the north of the existing Alligator River Bridge and be
accessed using barge mounted drilling equipment. Approximately 40 roadway and 3 bridge borings will
be performed along the western bridge approach and 27 roadway and 3 bridge borings will be
performed along the eastern bridge approach and accessed using ATV mounted drilling equipment.
The bridge borings in the Alligator River will be advanced utilizing geotechnical drilling rigs mounted to
self-propelled floating barge or jack -up barge platforms. The floating barge platforms will be used closer
to the eastern and western shores of the river, or in shallow water as needed, and will be stabilized at
the boring locations using aluminum or steel spuds dropped into the river bottom to hold the barge in
place during drilling. Additional spud casing can be added or removed depending on the water depth
and will be extended well above the working platform to allow the barge to float up or down with
changing water levels (tidal changes). The jack -up barges will mechanically lower stabilizing spuds to the
river bottom at the boring locations and will then be used to raise the barge platform completely out of
the water and provide a stable working platform during drilling operations unaffected by changing water
levels. Each boring will advance 3-inch or 4-inch diameter steel outer casing from the barge platform to
the mudline and into the subsurface by rotation or driving creating minimal disturbance to the river
bottom. This temporary casing will be advanced as needed into the subsurface to provide borehole
stability. The drilling and sampling of the borings will be completed within the steel casing utilizing mud -
rotary drilling methods. Drill fluids consisting of a water-bentonite slurry will be circulated from a mud
tub on the barge platform through the drill tools and drilling bit and recirculated to the mud tub on the
barge platform through the outer steel casing. Drilling cuttings (spoils) will be captured in the mud tub,
removed as necessary to facilitate drilling and sampling operations, and temporarily stored in metal
drums on the barge platform until boring termination is achieved. Upon boring termination, any stored
drill cuttings will be shoveled back down the steel outer casing and into the subsurface and the
temporary casing will be removed. Stored drill cuttings unable to be returned to the subsurface will be
brought to shore and deposited on land outside of wetland areas. The barge drilling platforms will be
launched and recovered from the marina/boat ramp shown on the attached site map. It is expected
that each bridge boring will be advanced to a depth of approximately 150 feet and will take two days to
complete. We anticipate having up to three barge mounted drilling rigs in operation and estimate
approximately 6 months to complete these borings.
The roadway and bridge borings located on land along the bridge approaches will be advanced utilizing
geotechnical drilling rigs mounted to rubber -tired, tracked, or marsh -buggy ATV platforms as needed
based on actual ground conditions. Drilling and sampling operations will be performed as described
above using mud -rotary drilling methods and tools. Movement of the ATV drilling rigs will be confined
to the proposed alignment corridor as much as possible to minimize ground disturbance accessing these
locations. Access to the alignment corridor will be from existing access points, roads, or right-of-way. If
a proposed boring location is inaccessible to ATV drilling equipment, hand tools consisting of hand
augers and/or muck probes will be utilized to characterize the subsurface conditions
at those locations. It is expected the roadway borings will be advanced to depths ranging from 10 to 50
feet below existing ground surface and will be performed concurrently with the barge drilling
operations.
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STATE OF NORTH CAROLINA
DEPARTMENT OF TRANSPORTATION
Roy COOPER
GOVERNOR
August 25, 2022
J. ERIC BOYETTE
SECRETARY
NC Division of Water Resources US Army Corps of Engineers -Wilmington District
Transportation Permitting Branch Washington Field Office
1617 Mail Service Center 2407 West Fifth Street
Raleigh NC 27699-1617 Washington, NC 27889
ATTN: Ms. Amy Chapman, Supervisor Mr. Kyle Barnes,
Transportation Permitting Branch NCDOT Project Manager
Subject: NCDOT Response to Notice of Violations STIP HB-0001, Bridge 7 on US 64 over the
Alligator River, Tyrrell and Dare Counties.
NCDWR Project No. 20211126
USACE Action ID SAW-2021-01091
References: NCDWR NOV-2022-PC-0389 Dated July 26, 2022
USACE NOV Dated August 11, 2022
Dear Madam and Sir:
This letter is in response to the Notice of Violation (NOV) letters received from the NC Division of Water
Resources (NCDWR) (2022-PC-0389) issued on July 26, 2022 and the US Army Corps of Engineers
(USACE) Action ID SAW-2021-01091 issued on August 11, 2022. Included with this letter are
responses addressing items from each of the agencies' letters, mapping showing the impacted areas, as
well as a letter from the geotechnical subcontractor.
NCDWR NOV-2022-PC-0389
The NCDWR NOV was issued due to failure to secure a written 401 Water Quality Certification (WQC)
as well as 401 WQC condition violation for NCDOT STIP HB-0001, the replacement of Bridge No. 7 on
US 64 over the Alligator River in Tyrrell and Dare Counties.
As requested, responses to the questions from the NCDWR NOV are provided below:
o What led to the observed wetland violations
While collecting geotechnical data, the subcontractor Wood PLC cleared trees in the wetlands though
original intent was no clearing would be necessary and that if an area was inaccessible, a smaller low
ground pressure personnel carrier would be used in combination with muck probes or hand augers to drill
shallow holes that do not require clearing. Additionally, mats were not utilized to prevent rutting that
occurred throughout much of the footprint.
• During the Monthly Project Status Meeting on 6/27/2022, NCDOT was notified by the
subcontractor that the LGP boring equipment had been stuck.
Mailing Address: Location:
NC DEPARTMENT OF TRANSPORTATION Telephone: (919) 707-6000 1000 BIRCH RIDGE DRIVE
ENVIRONMENTAL ANALYSIS UNIT Customer Service: 1-877-368-4968 RALEIGHNC 27610
1598 MAIL SERVICE CENTER
RALEIGH NC 27699-1598 Website: www.nedot.gov
• Paul Williams emailed Garcy Ward with NCDWR and Kyle Barnes with USACE on 6/27/22
informing them of the stuck equipment.
• Paul Williams met Garcy Ward at the site on 6/28/22.
• NCDOT staff from; Division 1, Geotechnical Engineering Unit, Environmental Analysis Unit,
Garcy Ward, Kyle Barnes, and Wood PLC met on 7/11/22.
• Kyle Barnes visited the site on 7/12/22.
• Paul Williams and Randy Midgett provided Kyle Barnes and Garcy Ward an update on 7/14/22.
o List any actions necessary to remediate the violation and prevent it from happening again
Compensatory mitigation was discussed during a call on August 19, 2022 between staff from NCDOT,
NCDWR, and USACE. As a result of the meeting, NCDOT's current proposal is to provide
compensatory mitigation for 0.343 ac of impacted wetlands considered as mechanized clearing at a 1:1
ratio via the NC Division of Mitigation Services (NCDMS). Additionally, a 0.010 ac area outside the
potential future footprint of the project would be restored via limited earthwork to fill in ruts and
replanting. This 0.010 ac restoration would not commence until the parcel is acquired or permission is
granted from the current property owner. Additionally, annual monitoring would not be required by the
agencies for the 0.010 ac restored area.
NCDOT and the geotechnical subcontractor, Wood PLC, regret this incident occurred. We have met with
the contractor, subcontractor, and NCDOT personnel involved with the project and discussed measures to
prevent such impacts from happening on future projects. This will include but not be limited to better
scoping on future projects for the expected and potential impacts to perform geotechnical borings; better
training of drilling firms for the conditions/requirements listed in the Nationwide 6 by making periodic
site visits while the work is being performed and other issued permits; better oversite by NCDOT
personnel that field activities conform to the permit requirements and reiterating the importance of
adhering to the work proposed to the regulatory agencies as well as all conditions accompanying the
permits.
USACE NOV Action ID SAW-2021-01091
During the USACE's site visit they found that General Condition #11 of the Nationwide Permit 6 was not
adhered to. This condition states Heavy equipment working in wetlands or mudflats must be placed on
mats, or other measures must be taken to minimize soil disturbance. As a result, NCDOT must propose
either a restoration plan for the site or provide a compensatory mitigation plan to replace the functional
loss to wetlands.
As stated above in the response for NCDWR's second item, NCDOT's current proposal for compensatory
mitigation for the impacted areas considered as mechanized clearing includes obtaining credits from
NCDMS as well a small area of restoration at the impacted site.
NCDOT will submit an Individual WQC application as well as coordinate with the USACE to determine
if a permit modification request of the previously issued permit verification for Nationwide Permit 6.
Additionally, NCDOT has initiated advanced right-of-way acquisition for the property on which the
impacts occurred. This process is in the early stages and could take a minimum of nine months to be
finalized. There is also a possibility that the acquisition process may not be successful and if so, NCDOT
will coordinate the NCDWR and USACE to determine what other action would be necessary.
Please know that we take these actions very seriously and efforts will be made to ensure such deficiencies
do not occur again. If you have questions or would like to discuss further, please contact Chris Rivenbark
at crivenbark@ncdot.gov or (919) 707-6152.
IDocuSigned by:
MA44 C. P,4t4,1" III
AAAD1248B309416...
for Philip S. Harris III, P.E., C.P.M.
Environmental Analysis Unit Head
ec:
Garcy Ward, NC Division of Water Resources
Monte Matthews, US Army Corps of Engineers
John Conforti, REM, NCDOT Project Management Unit
Jennifer Evans, PE, NCDOT Project Management Unit
Paul Williams, NCDOT Division 1
David Herring, LG, PE, NCDOT Geotechnical Unit
Jason Dilday, NCDOT Environmental Analysis Unit
wood.
August 18, 2022
Three Oaks Engineering, Inc.
324 Blackwell Street
Suite 1200
Durham, North Carolina 27701
Attention: Mr. Craig Young, PE
Subject: Wood response to Notice of Violations
STIP No.: HB-0001
Tyrrell and Dare Counties
Wood E&IS Project Number: 6234-21-0242
References: NCDWR NOV-2022-PC-0389 Dated July 26, 2022
USACE NOV-SAW-2021-01091 Dated August 11, 2022
Dear Sir:
This letter is in response to the NC Division of Water Resources Notice of Violation (2022-PC-
0389) issued on July 26, 2022, due to failure to secure written 401 Water Quality Certification
(WQC) as well as 401 WQC condition violation; and the United States Army Corps of Engineers
Notice of Violation (SAW-2021-01091), issued on August 11, 2022, violation of General Condition
#11 of the Nationwide Permit #6 for NCDOT STIP HB-0001, Replacement of Bridge No. 7 on US
64 over the Alligator River in Tyrrell and Dare Counties.
As requested by the NCDOT and in support of the NCDOT response to the above Notice of
Violations (NOVs), a timeline of the work performed, activities that led to the NOVs, and planned
changes to future work processes are provided below.
Timeline of Site Activities:
5/23 to 5/26: The geotechnical drilling rig mounted to a Marsh Buggy ATV carrier and a
smaller Marsh Master personnel carrier mobilized to the Dare County side of the project
site and moved into the woods/marsh to begin the planned geotechnical roadway and
land -based bridge borings on this end of the project. The first boring was completed near
station -L- 234+00. While moving to the next boring location at -L- 232+00 the Marsh
Buggy became stuck in very soft ground. It was determined that a second Marsh Buggy
would need to be brought to the site to extract the stuck drill rig and continue the
geotechnical boring work.
5/31 to 6/3: Second Marsh Buggy rig arrives onsite 5/31 and work begins to extract the
stuck rig. A second entry path was made into the site to facilitate removal of stuck rig.
Correspondence:
Wood Environment & Infrastructure, Inc.
4021 Stirrup Creek Drive, Suite 100
Durham, North Carolina 27703
Tel (919) 381-9900
Fax (919) 381-9901
Woodplc.com
HB-0001 Wood Response to NOVs
Wood Project 6234-21-0242
August 18, 2022
Page 2
Some hand clearing was performed with a chain saw to create a second entry point into
site and facilitate removal of the stuck rig. The stuck Marsh Buggy was freed and removed
to the staging area for demobilization from site.
6/6 to 6/9: Boring work continued with the second Marsh Buggy and the team completed
the boring near -L- 232+00. While moving to the next boring location at -L- 230+00, the
marsh master support vehicle broke down (engine failure). The boring was drilled at -L-
230+00, then the Marsh Buggy was used to tow the marsh master out of woods/marsh
and a third entry path was made into site to facilitate removal of broken-down marsh
master. Some hand clearing with a chain saw was performed to create third entry point
and to facilitate the tow and removal of marsh master from site. The marsh master was
demobilized from site to get repaired.
6/13 to 6/17: Mobilized replacement marsh master support vehicle to site and continued
boring work. Borings at -L- 228+00 and -L- 226+00 were completed. Some hand clearing
with chain saw was required to access these locations in areas of thick brush and woods
(trees too closely spaced to move between them or too close together to push through).
The team encountered very dense areas of small trees with some larger trees while
moving to boring at -L- 224+00, and hand clearing with a chain saw was required to create
path for marsh buggy and marsh master to access boring location (unable to "push
through" with Marsh Buggy/marsh master). Hand clearing and chain saw use was limited
as much as possible to trees with diameters of 5" inches or less at chest height, though a
few trees of diameters up to 10" were cut due to the density of trees and to avoid the larger
trees at the site. On 6/15 we had a call from property owner regarding the multiple entry
points to the site and chainsaw clearing. We discussed issues of the rig getting stuck and
equipment breakdown and the unanticipated clearing required to get unstuck, remove the
broken-down equipment, and access the boring locations. Property owner requested we
limit access to site from third entry point for remainder of work and limit hand clearing/chain
saw use as much as possible. Work continued and completed borings at -L- 224+00 and
-L- 222+00, with hand clearing of trees as described above performed as needed to
access these locations. Extra effort by the field drilling crew was made to find the "path of
least resistance" while staying within the proposed right-of-way limits of the project and
limit the amount hand clearing required to continue accessing the site and proposed boring
locations.
6120 to 6/24: Work continued as above, with hand clearing as needed to access the
proposed bridge boring locations. Completed bridge boring EB-2.
6/27 to 7/1: Work continued as above, with hand clearing as needed to access boring
locations. Completed bridge boring B-133. During the HB-0001 monthly status meeting on
6/27 the above events were conveyed to the project team. We provided a timeline for the
completing the remaining geotechnical boring work to the team. NCDOT personnel visited
the site on 6/28 to evaluate the site conditions of the drilling operation. Due to the difficult
conditions experienced up to that point, it was considered unfeasible and would cause
additional damage to the site to create alternative access paths to access the remaining
deep borings for the proposed bridge.
7/5 to 7/8: Work continued as above, with hand clearing as needed to access boring
locations. Completed bridge boring B-131, returned to EB-2 location to collect Shelby tube
HB-0001 Wood Response to NOVs
Wood Project 6234-21-0242
August 18, 2022
Page 3
samples at offset boring location adjacent to EB-2, and started moving Marsh Buggy and
marsh master out of woods/marsh.
7/11: Marsh Buggy and marsh master equipment moved out of woods/marsh to staging
area and prepared for demobilization from site. GoToMeeting held with USACE, NCDWR,
and NCDOT to discuss the wetland impacts.
Activities Leading to the NOVs:
• The consequences of getting the initial Marsh Buggy drilling equipment stuck, breakdown
of the marsh master support vehicle, and the subsequent actions required to safely extract
and remove this equipment from the woods/marsh, along with the density of the woods
we encountered accessing much of the site resulted in the use of hand clearing with chain
saws to access many of the boring locations on this side of the of the project site.
The thickness or closely spaced nature of the immature woods along with groves of larger
trees was unanticipated, interspersed with areas of soft ground, marsh, and wetland
prevented the equipment from pushing through the brush and small trees as we had
anticipated and experienced on the west end of the project (Tyrrell County side).
At the request of the landowner, our access to the Dare County side of the project site
was limited to one path in and out of the site, which was utilized multiple times per day by
the marsh master support vehicle during drilling operations. The soft ground combined
with the repeated/overuse by the support vehicle resulted in rutting of the ground (areas
characterized as "mechanical clearing") in portions of the site, in the area where the Marsh
Buggy got stuck, where the broken marsh master had to be towed out of the woods/marsh,
and portions of the site that had surficial/standing water.
Planned Changes to Future Work Processes:
Future work processes will include a more thorough evaluation of site conditions during
the scoping phase of the project and will include more input from subcontractors to better
assess the capabilities of the drilling platforms to access the proposed sites and boring
locations. These evaluations will provide better understanding of the potential site
environmental impacts and will include consideration of worst -case scenarios or
unintended consequences from geotechnical boring operations.
On future projects, the NCDOT will be immediately notified if difficulties arise in the
performance of the scope of work that could lead to unpermitted impacts to jurisdictional
resources.
• Better collaboration with those involved in the environmental permitting for these types of
projects so that those involved with securing the permit and those performing the work
have a clear and mutual understanding of the conditions/limitations contained within the
permit, what the thresholds are for a changed condition, and to temper best -case or overly
optimistic evaluations of site conditions with operational experience.
HB-0001 Wood Response to NOVs
Wood Project 6234-21-0242
August 18, 2022
Page 4
If we can be of further assistance to the NCDOT in responding to these NOVs or if you would like
to discuss further, please do not hesitate to contact us.
Sincerely,
Wood Environment & Infrastructure Solutions, Inc.
Michael B. Lear, L.G.
Associate Geologist/Project Manager
Registered, North Carolina 1927
(919) 610-5066
Michael.lear@woodplc.com