20131200 Ver 6_Email NOV Response_20200807

Moore, Andrew W
From: wayne watkins <[e-mail]>
Sent: Friday, August 7, 2020 1:11 PM
To: Moore, Andrew W; Davidson, Landon
Cc: Aiken, Stan E; [e-mail]; [e-mail]; David Odom;
[e-mail]; [e-mail]; [e-mail]; Pete
Dickerson
Subject: [External] TIEC - DWR NOV 2020-SS-0014 response
Attachments: TIEC response letter to DWR NOV 2020-SS-0014 08-05-2020.docx; COVERED ARENA
MASTER -BYPASS STREAM STABILIZATION (2).pdf
External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]
Andrew, please see the attached response to Notice of Violation — 2020-SS-0014 issued August 4, 2020. The response is
made on behalf of Tryon International Equestrian Center. Additionally, see attached detail of the proposed energy
dissipator stabilization plan. The action items are already in process.
Thank you for your attention to this matter. Please feel free to call on me with any questions.
Best regards,
Wayne Watkins, CPESC
Odom Engineering, PLLC

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Odom
Engineering
60" BYPASS OUTFALL
AUGUST 06, 2020
STREAM BANK
PLLC
169 Oak Street, Forest City, N.C. 28043
ph: 828.247.4495 fax: [phone]
STABILIZATION DETAIL
(FIGURE 1)
SCALE: N.T.S.

Odom
Engineeringpuc
August 5, 2020
Mr. Andrew W. Moore P.G.
North Carolina Department of Environmental Quality
Division of Water Resources
Asheville Regional Office
2090 U.S. Hwy 70
Swannanoa, North Carolina 28778
Dear Mr. Moore:
169 Oak Street • Forest City, NC 28043
office 828.247.4495 • fax [phone]
Re: Response to NOV 2020-SS0044
Project: Tryon International Equestrian Center
Address: 4066 Pea Ridge Road
Mill Spring, NC 28756
Odom Engineering, PLLC is submitting the required response and action plan on behalf of Tryon International
Equestrian Center as requested in your Notice of Violation letter dated August 4, 2020. Each violation item is detailed
below as stated in the Notice along with the required action to remedy the violation. Efforts to complete the removal
of deposition in the stream (KA), restoration of the energy dissipator at the stream by-pass and the inspection of
stormwater retention systems is already in progress. Documentation and reporting will follow as soon as the work is
complete.
It is important to note the occurrences of flooding during the week of May 18, 2020; in particular, May 19,
2020 when more than (7-inches) of rainfall occurred in less than a twelve-hour period. Therefore, an event greater
than the 50-year, 12-hour rainfall occurred. Areas previously stable including native woodlands were severely
eroded throughout the entire drainage basin. The constructed erosion control devices remained in working condition
while natural ground with woodland cover eroded into the stream mentioned in your Notice of Violation.
Our position is that the damage was caused by extensive rainfall and flooding, a "natural act" and not a matter of
negligence. Please see our responses below.
I. Other Waste (In -Stream Sediment) —15A NCAC 02B .0211(12) —Title 15A NCAC 026.0211 (12) requires that "Oils,
deleterious substances, colored, or other wastes: only such amounts as shall not render the waters injurious to public
health, secondary recreation, or to aquatic life and wildlife, or adversely affect the palatability of fish, aesthetic
quality, or impair the waters for any designated uses." Approximately 50 feet of an unnamed tributary of White Oak
Creek (Class C) was impacted by sediment and gravel deposition from the 60-inch bypass outfall failure.
Response action 1: The 50 lineal feet of the unnamed tributary impacted by sediment and gravel deposition adjacent
to the discharge of the 60-inch by-pass outlet will be cleaned by shovel and bucket method. The deposition will be
removed in the dry while by-pass pumping is utilized. Deposition materials will be removed from the project area to a
suitable site on property away from watercourses.
II. Removal of Best Usage — 15A NCAC 02B .0211 (2) —Title 15A NCAC 02B .0211 (2) requires that "The waters shall be suitable for
aquatic life propagation and maintenance of biological integrity, wildlife, secondary recreation, and agriculture. Sources of water
pollution that preclude any of these uses on either a short-term or long-term basis shall be considered to be violating a water
quality standard." The sediment and gravel deposition within the stream channel results in a removal of use.
ODOM ENGINEERING, PILLC - -1
169 Oak St., Forest City,
North Carolina, 28043
http.-Ilwww.odomengineering.com

Response action 2: The sediment and gravel deposition in the 50 lineal feet of unnamed tributary will be removed as
stated above in response action 1.
III. Turbidity —15A NCAC 02B .0211 (21) —Title 15A NCAC 02B .0211 (21) requires that "Turbidity: the turbidity in the receiving
waters hall not exceed 50 Nephelomet ricTurbidity Units (NTU) in streams not designated as trout waters and 10 NTU in streams,
lakes, or reservoirs designated as trout waters; for lakes and reservoirs not designated as trout waters, the turbidity shall not
exceed 25 NTU; if turbidity exceeds these levels due to natural background conditions, the existing turbidity level shall not be
increased." The water sample collected from KB (Class C) upstream of the stormwater discharge was 45 NTUs. The water sample
collected from KB downstream of the stormwater discharge was 190 NTUs.
Response action 3: The Contractor immediately ceased the activity and replaced the berm that was temporarily
removed to access the construction area for backfilling of the concrete modular wall. Sediment fence will be utilized
to provide additional sediment and erosion control while the work progresses and remain until all disturbed areas are
stabilized. Training has been provided to those performing the work on behalf of the Owner.
IV. Individual 401 WQC Condition Violations — Tryon Equestrian Partners, LLC submitted a North Carolina Individual 401 WQC
modification request dated April 27, 2018. DWR issued an approval letter for the modifications on November 16, 2018. The WQC
issued for the project impacts specifies the activities must follow all conditions listed therein. The following condition violations
were noted:
Conditions # 5 - No waste spoil, solids, or fill waters, or riparian areas beyond the footprint of the impacts depicted in the
application for this project. All construction activities, including the design, installation, operation, and maintenance of sediment
and erosion control Best Management Practices shall be performed so that no violations of state water quality standards, statutes,
or rules occur.
Condition #6—Sediment and Erosion Control. Erosion and sediment control practices must be in full compliance with all
specifications governing the proper design, installation, and operation and maintenance of such Best Management
Practices.
Condition #8—Construction Stormwater Permit NCG010000. An NPDES Construction Stormwater Permit is required for
construction projects that disturb one (1) or more acres of land. This Permit allows stormwater to be discharged
during land disturbing activities as stipulated in the conditions of the permit. If your project is covered by the permit, full
compliance with permit conditions including the erosion and sedimentation control plan, inspections and maintenance, self -
monitoring, record keeping and reporting requirements is required.
Response action 4 (condition #5, #6 and #8): Sediment and erosion control devices shall be implemented while land -
disturbing activity progresses and remain in -place in working condition until all disturbed areas are permanently
stabilized. Erosion control devices shall include but not be limited to; sediment fence, diversion berms, wattles, drop
inlet protection, inlet and outlet protection, rock check dams and other Best Management Practices as needed along
with temporary and permanent vegetation of disturbed areas. All erosion and sedimentation control activities shall
follow the design standard, specifications, and approved permit guidelines. Erosion control practices shall be
inspected per permit requirements along with record keeping, self -inspection and monitoring.
Sediment Removal and Stabilization Plan response:
Approximately 50 feet of stream (KA) located below the existing outlet of the 60" by-pass pipe shall be
manually cleaned by shovel and bucket method to remove sediment and gravel. Manpower from TIEC
and/or specialty contractors will utilize hand equipment only. Deposition removed from the stream will be
transported to other areas on the property and disposed of upland and away from watercourses. The
proposed schedule to remove the deposition shall be scheduled as soon as possible and is partially
influenced by Contractors availability. Completion of deposition removal should occur within two days.
Turbidity standards will be met by working in the dry utilizing sandbagging and by-pass pumping of the N
stream flow.
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ODOM ENGINEERING, PILLC - -1
169 Oak St., Forest City,
North Carolina, 28043
http.-Ilwww.odomengineering.com

Stabilization of the 60" RCP outfall pipe and existing dissipator narrative:
The deposition in -stream as noted in the violation was caused by a rainfall and flooding which exceeded the
50-year, 12-hour rainfall interval. Areas previously stabilized by placement of rip -rap and modular concrete
wall components as energy dissipaters remained stable. Areas of natural ground between the end of the
dissipator and the re -constructed rock toe eroded with some loss of native soil and woodland vegetation
material to the stream.
Energy dissipator stabilization narrative:
• Install temporary sandbag coffer dam and by-pass pump system to pump stream flow around the work area
and work in the dry.
• Leave the existing rock toe in -place along with boulders. Remove damaged coir matting and debris from the
damaged area.
• Construct a uniform compacted sub -grade (foundation) from edge of the existing rock toe to the intersection
with the stable rip rap energy dissipator.
• Install a protective woven geotextile product on the compacted sub -grade (foundation).
• Place stepped rows of 2'x'2'x4' concrete modular wall units from the edge of the existing rock toe to the
intersection with the existing rip rap dissipator. Construct an 8 ft. wide center channel section (2) blocks
wide. Construct the outside blocks of each row at (12") higher elevation to create a 4 ft. raised shoulders on
each side. Each row of concrete modular block units will create a 16 ft. wide stepped channel. Approximate
length is 12 feet. The design concept includes six stepped rows of four modular blocks that will create a
stable stepped energy dissipator joining the rock toe at stream side.
• Stabilize sides adjacent of the new channel by seeding with riparian seed mixture and cover with coir fabric.
Secure coir fabric with wooden stakes.
• Install live stakes upon availability in the next growing season.
• Clean the stream of deposition as mentioned in the sediment removal and stabilization plan.
• Provide cross sections to DWR data by survey and overlay on the as -built data.
• Provide 3-year monitoring.
401 Water Quality Certification Condition and Turbidity Violations plan:
• All stormwater retention structures including (Isolator row and Stormtech systems) will be inspected for
sediment accumulation. Photo and video documentation will be provided to DWR.
Provide removal of sediment in retention systems. Removal of sediment shall be conducted in accordance
with the approved stormwater management plans for all WQC issued for the project. Removal of sediment
shall be documented in written form along with photo/video documentation and provided to DWR.
Inspection and maintenance logs for the last three years for all approved stormwater BMPs in the project
area will be provided.
Please consider this correspondence as the required response requested in your letter dated August 4, 2020, As
previously mentioned the work to correct the violations is already in process and we look forward to working with
you to resolve these matters in very timely fashion. Please feel to contact me if you have any questions concerning
this submittal.
Sincerely,
a a i,--
David Odom, P.E.
Attachment: Detail drawing — 60" RCP energy dissipator stabilization plan.
ODOM ENGINEERING, PILLC - -1
169 Oak St., Forest City,
North Carolina, 28043
http.-Ilwww.odomengineering.com