NCG120038_Tier III_20220527

DocuSign Envelope ID: 121A1065-FCF1-4B70-96E1-DB78D29AC513
SM ITHGARD N ER AOORESS TEL WEB
14 N,Boylan Avenue,Raleigh NC 27603 919.828.0577 www.smithgardneNnc.com
May 27, 2022
Zac Lentz, P.E.
Assistant Regional Engineer
NCDEMLR—Winston-Salem Regional Office
450 West Hanes Mill Road, Suite 300
Winston-Salem, NC 27105
RE: Phase 2 Pond 3 Tier 3 Corrective Action Plan
Davidson County Landfill
Certificate of Coverage#NCG120038
General Permit#NCG120000
Dear Zac,
The following is a corrective action plan prepared by Smith Gardner, Inc. (S+G) on behalf of
Davidson County (the permittee) to address the Tier 3 exceedances at the Phase 2 Pond 3
(Basin) Stormwater Discharge Outfall (Outfall) at the County's landfill facility (Landfill). The
Landfill is permitted to discharge stormwater under General Permit No. NCG120000 and
Certificate of Coverage No. NCG120038 issued July 1, 2021. A summary of exceedances and
corrective actions (both completed and proposed) are included below.
Fecal Co I iform
Based on the Representative Outfall Approval dated November 12, 2009 (attached), the Landfill
has been implementing tiered responses for Total Suspended Solids (TSS) and Chemical
Oxygen Demand (COD). As cited in the approval letter, "the Division concurs thatmore frequent
monitoring for fecal coliform at this site would be ineffective'.
S+G was notified on May 24th, 2022 this approval was deemed ineffective with the revised
General Permit issued July 1, 2021. At this time, the Outfall is in Tier 2 status for Fecal Coliform
following two (2) consecutive exceedances in the March 2022 and April 2022 monitoring periods.
Within the current monitoring period a total of three (3) samples above the benchmark limit
have been measured. S+G will begin implementing tiered response actions for fecal coliform
moving forward. Furthermore, S+G intends to prepare a revised fecal coliform alternate source
demonstration to be submitted to the Department of Energy, Mineral, and Land Resources
(NCDEMLR) for review.
Total Suspended Solids
Documentation and Inspections
Sampling was conducted on April 18, 2022, the results of which were received April 27, 2022.
Based on the results of this sampling, the Outfall has measured four (4) exceedances for TSS
within the current permit period and is subject to Tier 3 response actions. An overview of
historic sample results at Outfall within the current permit period is attached. The Outfall
entered Tier 3 status for TSS following the April 2022 sampling event. S+G notified NCDEMLR of
the Tier 3 exceedance on May 3, 2022.

DocuSign Envelope ID: 121A1065-FCF1-4B70-96E1-DB78D29AC513
Zac Lentz, P.E.
May 27, 2022
Page 2 of 3
Following receipt of sample results from the April 2022 monitoring event, an outfall inspection
was conducted at the Basin and Outfall on May 5, 2022 by Steven Sink, Operations Manager of
the Davidson County Landfill (attached). A subsequent inspection was conducted by Joan
Smyth, P.G. of S+G on May 26, 2022.
Previous Corrective Actions
Following the samples collected in the third quarter of 2021 (TSS=9090 mg/L), Pond 3 was
cleaned and new rip rap stone was added at the inlet and outlet structures. Additionally, No. 57
stone was added around the inlet riser to better filter discharging water.
Following the March 2022 sampling event, Tier 2 corrective actions were developed and
implemented at the Outfall on May 5, 2022. Corrective actions at the Outfall included
installations of silt fencing around the outfall riser structure and additions of#57 stone to the
upstream slope of the outlet filter berm. A summary of these actions were submitted to
NCDEMLR on May 12, 2022. Since the completion of these corrective actions, no discharge
events have been monitored at the Outfall.
Sources of Total Suspended Solids
The majority of the Basin drainage area consists of the north slope of the Phase 2 landfil I unit.
This area is near final grade with stabilized intermediate cover. Runoff is conveyed to the basin
via a grass lined perimeter channel with multiple drop inlets. There are currently no industrial
activities within the Basin drainage area, so there are no operational activities evaluated or
identified for modification. Potential identified sources of sediment into the Basin appear to be
from two (2) areas of erosion within the inner berm of the Basin (Photos 1 & 2).
Proposed Corrective Actions
As a result, corrective actions to reduce TSS concentrations discharging from the Outfall will
include stabilization (reseeding, matting, and/or rip rap) of all areas within the Basin with visible
erosion or sediment accumulation. This corrective action will be implemented over a period of
two (2) weeks following approval of the corrective action plan from NCDEMLR. As noted, the
Outfall riser structure currently has #57 stone at the base of the riser and a newly installed
perimeter of silt fencing following the March 2022 corrective actions (Photo 3).
Monitoring and Inspection
Future monitoring at the OutfaII wiI I continue to be conducted on a monthly basis and following
significant rainfall events. In an effort to maintain good housekeeping, all sediment erosion
control features, vegetated drainage areas, and stabilized erosion areas within the Basin will be
inspected weekly until vegetation has been established to limit erosion and future sediment
discharge from the Outfall. Cleaning of all erosion control features in the event of sediment
accumulation or clogging will be implemented on an as needed basis to ensure effective
sediment removal from the discharge.

DocuSign Envelope ID: 121A1065-FCF1-4B70-96E1-DB78D29AC513
Zac Lentz, P.E.
May 27, 2022
Page 3 of 3
If you have any questions, or require further information, please contact us at(919) 828-0577 or
by email.
�N CA,9
Sincerely, .% ® S� ��
SMITH GARDNER,INC.
SEAm
DocuSigned by: DocuSigned by: ® 021 27Z 022.-''-
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C4990A65989B4AD... 5B6631996A674D7... '��+ �+ �OB��Q�
Matthew M. Jones, E.I. Pieter K. Scheer, P.E.
Staff Engineer, ext. 153 Senior Engineer, ext.123
[e-mail] [e-mail]
Attachments: November 2009 Representative OutfalI Approval Letter
Phase 2 Pond 3 Historic Stormwater Data
Phase 2 Pond 3 Outfall Inspection Checklist
cc: Steven Sink, Davidson County
Joan A. Smyth, P.G., S+G
H:\Projects\Davidson County(NC)\02 DC Compliance\03 DC NPDES\2022\04-April\Tier 3 Corrective Action Plan\DavdCo Stormwater Ph-2 SB-3 Tier 3 Action
Plan.docx

DocuSign Envelope ID: 121A1065-FCF1-4B70-96E1-DB78D29AC513
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DocuSign Envelope ID: 121A1065-FCF1-4B70-96E1-DB78D29AC513
S+G ENGINEERS PHOTOGRAPHIC LOG
Client Name: Site Location: Project No.
Davidson County Davidson County Landfill DAVDCO-21-4
Photo No. Date:
._�'�-3a�._ X�€E•f-�� "�,,' 3"�-.,-�ti r 4' �''x=Yy"���e r <a, s t` �
+x'"-c,-��5�F� 1s�;3,D„+, E - -'• r �a�$�''�fr3. �c'yF €'t� ' ��
5/26/223
Direction Photo Taken:
Southeast `
Description:
Area of erosion within
the Phase 2 Pond 3
sediment basin. Area
was identified as a
source of sediment
resulting in elevated
TSS and will be
stabilized based on
proposed corrective
actions.
Photo No. Date:
2 5/26/22
Direction Photo Taken:
South
Description:
Area of erosion within
the Phase 2 Pond 3
sediment basin. Area
was identified as a
source of sediment
resulting in elevated
TSS and will be
stabilized based on
proposed corrective
actions.

DocuSign Envelope ID: 121A1D65-FCF1-4B70-96E1-DB78D29AC513
S+G ENGINEERS PHOTOGRAPHICLOG
Client Name: Site Location: Project No.
Davidson County Davidson County Landfill DAVDCO-21-4
Photo No. Date:
3 5/26/22
Direction Photo Taken:
Southeast
Description:
Phase 2 Pond 3 outlet
riser structure with #57
stone filter berm and
newly installed
perimeter silt fencing.

DocuSign Envelope ID: 121A1065-FCF1-4B70-96E1-DB78D29AC513WYWA
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NCDftEN
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves perdue Coleen H. Sullins Dee Freeman
Governor Director Secret,ary
i
November 12,2009
Davidson County Integrated Solid Waste Management
c/o Mr. Charles Brushwood
1242 Old US Hwy 29/70
Thomasville,NC 27360
Re: Request.for Representative Outfall Status and
Tiered Response.Requirements
Davidson County Solid Waste Facility
NPDES Permit#NCG120038
Davidson County
Dear Mr. Brushwood:
The Winston-Salem Regional Office(WSRO) staff has reviewed your request that 5 of 9 stormwater
discharge outfalls (SDOs) being monitored in accordance with permit#NCG120038, be given
representative outfall status. Based on the information and maps provided, as well as a site visit by
Jenifer Carter and myself on October 28, 2009, we are approving your request, with one modification. In
accordance with 40 CFR §122.21 (g)(7), you are authorized to sample outfalls Phase 2 SB 3 (as opposed
to Phase 2 SB 1, as requested), Phase 2 SB 4,Phase 1 SB 2, Phase 1 SB 4 and C&D SB 9. These outfalls
will represent the other outfalls as follows:
Outfall to be Monitored* Representative of:
Phase 2 SB 3 Phase 2 SB 1
Phase 2 SB 4 Phase 2 SB 2
Phase 1 SB 2 _ Phase 1 SB 1 and Phase 1 SB 3
Phase 1 SB 4
C &DSB9
*Due to the formal closure of Holly Grove Landfill, monitoring of outfall HG SB 1 is no longer required
to meet the Qualitative or Analytical monitoring requirements of the permit
This approval is effective immediately. Please note that representative outfall status applies only to
the Analytical Monitoring requirements of the permit; therefore, Qualitative Monitoring will still
need to be performed at all nine (9) remaining SDOs.
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DocuSign Envelope ID: 121A1065-FCF(1r-41B70-96E1-DB78D29AC513 yAy
Ear v N c .
nsIf changes in drainage areas, BMPs,
structures,processes, storage practices, or other activities occur that significantly alter the basis of this
approval, representative outfall status many no longer be valid, or may need to be updated. You should
either resume analytical monitoring of all SDOs, or reapply to this office for representative outfall status
based on updated information.
If you have any questions or comments concerning this letter,please contact Jenifer Carter at(336) 314-
1440.
Sincerely,
Steve W. Tedder
Surface Water Regional Supervisor
Winston-Salem Regional Office
Division of Water Quality
cc: is
SWP Central Files
Stormwater Permitting Unit
Ms. Joan A. Smyth, P.G. (Richardson Smith Gardner&Assoc; 14 N.Boylan Ave;Raleigh,NC 27603)

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DocuSign Envelope ID: 121A1065-FCF1-4B70-96E1-DB78D29AC513
NPDES Stormwater Outfall Inspection Checklist
Inspection Details Sample Details
Facility Davidson County Landfill Sampling Period April 2022
Permit No. NCG120038 Date Sampled April 18, 2022
Outfall ID Phase 2 Pond 3 Date Results Received April 27, 2022
Outfall Tier 3 Date DEQ Notified May 3, 2022
Date/Time 5/5/22 12:00 noon
Technician Steven Sink Exceedance?
TSS (mg/L) 177 Yes
Fecal (#/100 mL) 4,600 Yes
COD (mg/L) 28.3 No
TSS Outfall Inspection Yes Na ;' N/All
Is there deposition of sediment at or immediately below outfall? X
Is there visible erosion at or immediately below the outfall? X
Is there visible erosion within the embankments of the sediment basin? X
Is there visible eroded sediment entering the sediment basin? X
If Yes or other evidence New Rock was installed
of pollution provide Silt Fence installed along riser pipe
additional details:
Fecal Coliform Outfall Inspection Yes NO",,",' N/A
Is there evidence of wildlife excrement surrounding the sediment basin? X
Is there evidence of wildlife or wildlife present in the area of the sediment X
basin?
If Yes or other evidence
of pollution provide
additional details:
Chemical Oxygen Demand Outfall Inspection Yes Na N/A
Is there and discoloration of the water within the sediment basin? X
Is there any foaming observed within the sediment basin? X
Is there any oil sheening present on the water surface or at the X
embankments of the sediment basin?
Is there any windblown waste present within the sediment basin? X
Is there and visible leachate or non-stormwater discharging into the X
sediment basin?
If Yes or other evidence
of pollution provide
additional details:

Permit No. NCG120000
E-7. Tier Three Response: Four Benchmark Exceedances Within the Permit Term
The facility will remain in Tier Three status until three consecutive samples are under the
benchmark or are inside the benchmark range for all parameters.
(a) If any four sampling results within the permit term for any single parameter are above the
benchmark value at a sampled outfall,then the permittee shall respond in accordance with
Table 5 to identify and address the source of exceedances for that parameter at that outfall.
(b) The permittee shall prepare a written Action Plan and submit to the Division's Regional
Office for review and approval within thirty(30) days of receipt of the fourth analytic
monitoring data point that exceeds the benchmark value. At a minimum,the Action Plan
shall include:
i. documentation of the four benchmark exceedances,
ii. an inspection report that covers the industrial activities within the drainage
area of the outfall with the exceedances (including the date of the inspection
and the personnel conducting the inspection),
iii. an evaluation of standard operating procedures and good housekeeping
procedures,
iv. identification of the source(s) of exceedances,
V. specific actions that will be taken to remedy the identified source(s) with a
schedule for completing those actions,and
vi. a monitoring plan to verify that the Action Plan has addressed the source(s).
(c) The permittee shall keep the Action Plan in the SWPPP and document when each specific
action was carried out and by whom.
(d) The permittee shall contact the Division's Regional Office when all actions in the Action Plan
are completed.
(e) The Tier Three response shall be in accordance with Table 5 below.
Table 5: Tier Three Response for Four Benchmark Exceedances Within the Permit Term
Timeline From
Receipt of Fourth Tier Three Required Response/Action
Sampling Result
Continuously i. Document the exceedances and each required response/action in the
SWPPP in accordance with E-7(c) above.
ii. Implement or continue monthly monitoring for all parameters at the
subject outfall and continue until three samples in a row are below the
benchmark value.
Within two weeks iii. Notify the Division's Regional Office in writing of the affected outfall,
four exceedance dates and values.
iv. Conduct a stormwater management inspection.
v. Identify and evaluate possible causes of the benchmark exceedance.
Within one month vi. Prepare an Action Plan that should include specific, feasible courses of
action to reduce concentrations of the parameter(s) of concern
including,but not limited to, source controls, operational controls, or
physical improvements and submit to the Division's Regional Office for
review and approval.
Upon DEQ Approval vii. Implement the approved Action Plan.
Page 13 of 31

Permit No. NCG120000
Upon Completion of
Approved Action Plan viii.Notify the Division's Regional Office of Action Plan completion.
Page 14 of 31