NCG120038_Tier III_20220526

DocuSign Envelope ID: EBEOB42B-29C8-44BO-8E72-59B2EBF14845
SMITH GARDNER WORE55 TEL NEB
14 N.Boylan Avenue,Raieigh NC 27603 919.328,0577 www.smithgardnednc.com
6i 61NEERS -
May 24, 2022 NC Department of
Environmental Qjaiity
Zac Lentz, P.E. Recpk/e>d
Assistant Regional Engineer MY 2 6 70?
NCDEMLR - Winston-Salem Regional Office Winston-Salem
450 West Hanes Mill Road, Suite 300 Regional Office
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 an action plan completed by Smith Gardner, Inc. (S+G) on behalf of the Davidson
County Landfill (Landfill) and Davidson County (the permittee) to address the Tier 3
exceedances at the Phase 2 Pond 3 Stormwater Discharge Outfall (SDO). The Landfill is
permitted to discharge stormwater under General Permit No. NCG120000 and Certificate of
Coverage No. NCG120038 issued July 1, 2021. The Landfill is currently subject to tiered
responses for Total Suspended Solids (TSS) and Chemical Oxygen Demand (COD). Outfalls at
the Landfill are not subject to Fecal Coliform exceedances due to site wide alternate source
approval due to wildlife activity.
Sampling was conducted on April 18, 2022, the results of which were received April 27, 2022.
Based on the results of this sampling, the Phase 2 Pond 3 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 Phase 2 Pond 3 within the current permit period is
attached.
Total Suspended Solids
Phase 2 Pond 3 entered Tier 3 status for TSS following the April 2022 sampling event. S+G
notified the Department of Energy, Mineral, and Land Resources (DEMLR) of the Tier 3
exceedance on May 3, 2022. Following the March 2022 sampling event, Tier 2 corrective actions
were developed and implemented at the Phase 2 Pond 3 Outfall on May 5, 2022, the results of
which were submitted to DEMLR on May 12, 2022. Since the completion of these corrective
actions, no discharge events have been monitored at the Phase 2 Pond 3 Outfall.
Corrective actions at the outfall included installations of silt fencing around the SDO riser
structure and additions of #57 stone to the upstream slope of the outlet filter berm. Future
sampling will be conducted at the downstream slope of the outlet filter berm to address TSS
discharge from the structure. Future monitoring will be conducted to determine the
effectiveness of the currently implemented corrective actions prior to implementation of
additional sedimentation and erosion control measures.

DocuSign Envelope ID: EBEOB42B-29C8-4460-8E72-59B2EBF14845 ,
Zac Lentz, P.E.
May 24, 2022
Page 2 of 2
In the event of future exceedances, additional corrective actions will be implemented to reduce
TSS discharge from the Phase 2 Pond 3 Outfall. Additional erosion control measures will follow
the following sequence:
1. Stabilize (reseeding, matting, and/or rip rap) all areas within the basin with visible
erosion or sediment accumulation.
2. Remove silt fence around riser structure and replace with a rip rap filter berm including
#57 stone on the upstream slope of the berm.
3. Assess the Phase 2 Pond 3 drainage area for potential sediment migration to Phase 2
Pond 3 and revegetate as required.
If you have any questions, or require further information, please contact me at [phone] or
by email.
Sincerely,
SMITH GARDNER,INC.
DocuSigned by: DocuSigned by:
E�i��,c,w dl�t.. ,�at�,c,s E���S�1�---
C499�Ao596964AD.. 53u53t996A674D7.
Matthew M. Jones, E.I. Pieter K. Scheer, P.E.
Staff Engineer, ext. 153 Senior Engineer, ext.123
macfdsmithgardnerinc.com pieterfdsmithgardnerinc.com
Attachments: Phase 2 Pond 3 Historic Stormwater Data
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

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