HomeMy WebLinkAbout20190189 Ver 1_NOV Response Submittal 2020-10-13_20201014Advantage Civil Engineering, PA
October 14, 2020
Mr. Landon Davidson, P.G.
Regional Supervisor
Water Quality Regional Operations
Asheville Regional Office
Dear Mr. Davidson:
34 Big Bear Trail
Asheville, NC 28805
Phone: 828-545-5393
NC Firm # C-2849
RE: Notice of Violation (NOV) Response
Lance Road Subdivision
(DWR Project No. 20190189)
Stream and Wetland Violation
401 WQC Conditions
Buncombe County
The following is a point by point response to your comments dated August 28, 2020 regarding the NOV
for Lance Road Subdivision in Buncombe County.
Documents provided as requested:
Sediment Removal Location Map
Attachment A - Representative photographs depicting the site are
Stream and Wetland Standard Violations
Required Response 1: "Please explain why these impacts occurred without prior authorization."
The impacts were due to improperly operated and maintained sedimentation and erosion control measures
(SECM) and large unexpected storm events that were exceeded the normal design storms used to size
sedimentation and erosion control.
Required Response 2: "Please provide documentation (including a detailed site map/survey) depicting all
jurisdictional water features (e.g. streams and wetlands) on the site. This documentation should describe and
quanta the impacts to those jurisdictional features and should include plans to avoid further stream and wetland
impacts on the site. "
A Preliminary Jurisdictional Determination was issued for the project by the U.S. Army Corps of
Engineers on December 14, 2018 (map attached). ClearWater Environmental Consultants, Inc. (CEC)
conducted a site visit on September 29, 2020. During this visit the streams and wetland were evaluated for
sediment impacts. CEC identified and flagged areas of sediment deposition. A Sediment Removal
Location Map depicting these locations has been included in this response. All erosion control measures
have been properly maintained and Super Silt Fence has been installed and/or repaired around the
perimeter of all jurisdictional waters to avoid further stream and wetland impacts.
Required Response 3: "Please submit a Sediment Removal Plan (Plan) to this office for review and approval. The
Plan must address removal of accumulated sediment from all surface waters. This
office recommends you secure an environmental consultant experienced in stream
restoration to assist you with developing your Plan. The Plan should include:
• The amount (depth) of material that has been deposited in the stream and wetland. This information
should be depicted on a map you provide.
• A narrative explaining how disturbed areas will be stabilized to prevent the discharge
of sediment to the streams.
• A narrative explaining how sediment will be removed including techniques,
manpower, and tools to be used. It is recommended that you used hand labor
(buckets, shovels, and wheelbarrows) to remove deposited sediment from the stream
and wetland.
• A proposed schedule with dates that indicate when you expect to begin and complete
the removal of sediment.
• A narrative explaining how and where the removed sediment will be disposed and
stabilized.
• A narrative explaining how turbidity will be minimized during the sediment removal
work.
Once the works is complete, a final report documenting the results of the sediment removal
activities should be submitted to Andrew Moore."
CEC identified and flagged areas of sediment deposition on September 29, 2020. Sediment was observed
in pockets throughout the unnamed tributary to Avery Creek (UT-2) ranging from 2-8 inches in depth. A
Sediment Removal Location Map depicting the amount and the location has been included in this
response. Representative photographs depicting the site are included as attachment A.
Erosion control measures have been repaired and improved since the violation to prevent ongoing and
continuing sedimentation impacts. The contractor is much more sensitive to the need for proper
maintenance of the SECM needs for the site to protect the waters of the state since the NOV was received.
Sediment will be removed from UT-2 by hand via the use of shovels, buckets, and wheelbarrows. This
work is expected to take place over the course of one to four weeks weather pending. Sediment removal
will begin at the origin of UT-2 and will progress downstream as shown in the Sediment Removal
Location Map (approximately 565 linear feet). In areas where there is new green growth sediment will
not be removed based on these being stable areas. Sediment removed will be relocated to onsite upland
locations at least 30 feet from jurisdictional waters. Sediment will be contained by a silt fence perimeter
and a layer of straw seeded with annual rye grass will be applied to all sediment spoil piles if it is not able
to be used in graded areas on the site.
CEC proposes the installation of a temporary coir check dam below the impacts associated with UT-2.
The check dam placed in the unnamed tributary would trap re -suspended sediment for removal at the end
of the project. This measure would be maintained throughout the restoration process and be removed
after final approval by DWR.
Sediment removal efforts, utilizing the aforementioned techniques, will be initiated immediately upon
approval by the NCDWR. It is anticipated that sediment removal from UT-2 will be complete within 30
days of NCDWR approval. A final report will be submitted within 30 days of completion of the
remediation efforts.
DWR noted sediment impacts up to 4 inches in the wetland adjacent to UT-2. Wetland systems are
capable of handling some sediment accumulation, and CEC advises sediment removal from a wetland
only if the accumulation is such that the wetland system is essentially unable to recover through natural
processes. During the September 29, 2020 site visit CEC noted that wetland hydrology remains present,
and hydrophytic vegetation has reestablished itself within the wetland. It is the opinion of CEC that this
wetland is recovering and that the sediment within the wetland should remain in place.
401 Water Quality Certification Condition Violations
Required Response 1 - Condition II. 2: "Submit the Sediment Removal Plan."
Sediment will be removed utilizing the aforementioned techniques mentioned within the Stream and
Wetland Standard Violation Required Response 3.
Required Response 2 - Condition II. 5: "Please provide documentation (including a detailed site map/survey)
depicting all jurisdictional water features (e.g. streams, wetlands, buffers) on the site. This documentation should
describe and quantify the impacts to those jurisdictional features, and should include plans to avoid further
stream and wetland impacts on the site."
See Stream and Wetland Standard Violation Required Response 2.
Required Response 3 - Condition II. 11: "Explain how you are going to bring the reinforced concrete box culvert
into compliance with the noted condition:"
It was determined during a site visit with a representative from the Army Corps of Engineers that since this case
included removal and replacement of an existing culvert that was elevated well above the stream normal water
level that nothing at this time is needed for the concrete culvert and it can remain as is.
All the above information is from a collaboration between professionals representing ACE and CEC. If
you should have any questions or need any additional information during your review, please do not hesitate to
contact us.
Sincerely,
Michael Lovoy, P.E.
and a layer of straw seeded with annual rye grass will be applied to all sediment spoil piles if it is not able
to be used in graded areas on the site.
CEC proposes the installation of a temporary coir check dam below the impacts associated with UT-2.
The check dam placed in the unnamed tributary would trap re -suspended sediment for removal at the end
of the project. This measure would be maintained throughout the restoration process and be removed
after final approval by DWR.
Sediment removal efforts, utilizing the aforementioned techniques, will be initiated immediately upon
approval by the NCDWR. It is anticipated that sediment removal from UT-2 will be complete within 30
days of NCDWR approval. A final report will be submitted within 30 days of completion of the
remediation efforts.
DWR noted sediment impacts up to 4 inches in the wetland adjacent to UT-2. Wetland systems are
capable of handling some sediment accumulation, and CEC advises sediment removal from a wetland
only if the accumulation is such that the wetland system is essentially unable to recover through natural
processes. During the September 29, 2020 site visit CEC noted that wetland hydrology remains present,
and hydrophytic vegetation has reestablished itself within the wetland. It is the opinion of CEC that this
wetland is recovering and that the sediment within the wetland should remain in place.
401 Water Quality Certification Condition Violations
Required Response 1 - Condition II. 2: "Submit the Sediment Removal Plan."
Sediment will be removed utilizing the aforementioned techniques mentioned within the Stream and
Wetland Standard Violation Required Response 3.
Required Response 2 - Condition II. 5: "Please provide documentation (including a detailed site map/survey)
depicting all jurisdictional water features (e.g. streams, wetlands, buffers) on the site. This documentation should
describe and quanta the impacts to those jurisdictional features, and should include plans to avoid further
stream and wetland impacts on the site. "
See Stream and Wetland Standard Violation Required Response 2.
Required Response 3 - Condition II. 11: "Explain how you are going to bring the reinforced concrete box culvert
into compliance with the noted condition:"
It was determined during a site visit with a representative from the Army Corps of Engineers that since this case
included removal and replacement of an existing culvert that was elevated well above the stream normal water
level that nothing at this time is needed for the concrete culvert and it can remain as is.
All the above information is from a collaboration between professionals representing ACE and CEC. If
you should have any questions or need any additional information during your review, please do not hesitate to
contact us.
Lance Hill Subdivision (+/- 36.5 AC)
Att. .'
, 1"1
40\
Project Boundary
Legend
Coir Log Check Dam
- Approximate Stream
Culvert
Sediment Impact
Approximate Wetland
Project Boundary
Conturs 4ft
Drawn by: BWY 10.2.20; CEC Project# 1134
Sediment Impact Summary:
+/- 565 Linear Feet of UT-2
Pockets of Sediment Ranging
2-8 inches Deep
Begin Removal
Buncombe County,
North Carolina
CLearWaLer
Sediment Removal
Location Map
32 Clayton Street
Asheville, North Carolina 28801
Attachment A
Photo 1: Perched metal culvert within UT-1 prior to box culvert installation.
View looking downstream toward Avery Creek.
Photo 2: Reinforced concrete box culvert that replaced the perched metal culvert
View from right bank of Avery Creek looking upstream.
Photo 3: Flag S 1, 4 inches of sediment accumulated in stream bed.
To be removed. View downstream.
Photo 4: Flag S2, 6 inches of sediment accumulated on bank.
To be removed. View upstream.
Photo 5: Flag S2, 6 inches of sediment accumulated on bank.
To be removed. View toward left bank.
Photo 6: Flag S3, 8 inches of sediment accumulated in stream bed.
To be removed. View downstream.
Photo 7. Flag S4, 5 inches of sediment accumulated in stream bed.
To be removed. View upstream.
91,202
Photo 8. 0-4 inches of sediment accumulated in wetland adjacent to UT2.
Wetland hydrology persists, and hydrophytic vegetation has reestablished itself within the wetland.
It is the opinion of CEC that this sediment should remain in place.
Photo 9. Super silt fence and straw matting have been installed in order
to stabilize the site and prevent the discharge of sediment to streams and wetlands.