NCG060220_Corrective Action Plan_20240416

DARLING
,wdhih. INGREDIENTS
Via Email [[e-mail]] Darling Ingredients
4221 Alexandria Pike
April 16, 2024 Cold Spring, KY 41076
North Carolina Department of Environmental Quality T 859 781 2010
Mooresville Regional Office darlingii.com
Attention: Ms. Kathryn Peterson, Regional Engineer
610 East Center Avenue, Suite 301
Mooresville, North Carolina 28115
Subject: Revised Stormwater Sample Action Plan
Darling Ingredients Inc. (dba Bakery Feeds)
NPDES Permit No.: NCG060000, Certificate of Coverage No. NCG060220
Ms. Peterson,
Darling Ingredients Inc. (dba Bakery Feeds) herein provides the North Carolina
Department of Environmental Quality (NCDEQ) with the revised Action Plan in accordance
with the subject NPDES Permit NCG060220 (Permit), Permit Condition (PC) E-7(b),
regarding stormwater sample exceedances of the benchmark concentration of 120
milligrams per liter (mg/L) for Chemical Oxygen Demand (COD). Darling received the
laboratory report on March 7, 2024, which identified an exceedance of the Permit identified
benchmark concentration for COD at Outfall 001.
As the NCDEQ is aware, this is Bakery Feeds' fourth sampling result within the permit
term for a single parameter above the benchmark value at Outfall 001. However, the
previous benchmark concentration exceedances last occurred on July 8th, August 315t and
October 28th of 2021. Since the benchmark concentration of COD at Outfall 001 has not been
exceeded since 2021, Bakery Feeds believes this sample result to be an outlier compared to
the most recent results. Following receipt of the most recent benchmark exceedance, Bakery
Feeds promptly collected a sample on March 22, 2024. Bakery Feeds has since received this
COD sample result and it showed a return to compliance with a result of 52.7 mg/L. Bakery
Feeds believes the February 23, 2024 COD result is not a true representative discharge
based upon the recent history of COD results.
Darling takes its environmental stewardship very seriously and sincerely appreciates
the NCDEQ's assistance in this matter. If you should have any questions concerning this
plan, please contact me at your convenience at the address or telephone number listed at
the top of the cover page, or you may contact me by e-mail at [e-mail].
Sincerely,
DARLING INGREDIENTS INC.
15,MZ66
Matthew Smith
Manager of Environmental Affairs
cc: Rick Speaks, Regional Vice President (email only)
Jon Thelen, Vice President of Bakery Feeds and Organic Fertilizer (email only)
Kelly Thomas, Director of Environmental Affairs (email only)
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9 akery Feeds
Stormwater Action Plan
Darling Ingredients Inc. (dba Bakery Feeds) - Marshville
General NPDES Permit No. NCG060000, COC No. NCG060220
Pursuant to Permit Condition (PC) E-7(b) in General Stormwater Permit NCG060000, an
Action Plan is required for any Stormwater Outfall where four consecutive benchmark results
are above permitted benchmark values.
Darling Ingredients Inc. (dba Bakery Feeds) - Marshville facility, COC NCG060220, receives
incoming raw materials consisting of bakery byproducts and restaurant and food grease
(RFG) are processed at the facility to produce Processed Fats, protein, and carbohydrate
supplements for animal feed. Bakery byproducts are blended, dried, and ground to
manufacture Cookie Meal©. RFG is processed by filtering and vacuum evaporation to
produce Processed Fats.
The stormwater conveyance system is broken into six discharge drainage areas: Outfall 001
(on the northeast side of the site), Outfall 002 (on the north side of the site), Outfall 003 (on
the north side of the site), Outfall 004 which is represented by Outfall 003 (on the west side
of the site), Outfall 005 which is represented by Outfall 003 (on the west side of the site)
and Outfall 006 which is represented by Outfall 003 (on the southwest side of the site).
Outfall 001 has entered into Tier III SW monitoring, as a result of four chemical oxygen
demand (COD) results being above the benchmark value during the permit term.
The following is a summary of the benchmark exceedances for Outfall 001 under the current
permit, which became effective July 1, 2021:
Date COD
Benchmark 120 mg/L
July 8, 2021 220 mg/L
August 31, 2021 650 mg/L
October 28, 2021 220 mg/L
February 23, 2024 123 mg/L
On March 20, 2024, and in response to receipt of the February 23, 2024 benchmark results,
Bakery Feeds evaluated the Outfall 001 drainage area which includes the Bakery Raw
Material Unloading Area, Vehicle Wash Area, Finish Product Storage Area and the Rail Car
Unloading Area. Mr. Gary Adkins, Assistant General Manager, and Mr. Doug Jones, Plant
Manager, inspected the area and evaluated the possible sources contributing to the elevated
COD concentration.
Waters from the Outfall 001 drainage area would flow to an oil/water separator prior to
being discharged through the outfall that is periodically cleaned out by a third party
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company. However, this area has a higher probability of being impacted by the raw material
transfer areas.
Current best management practices (BMPs) in the drainage areas leading to Outfall 001
include the following:
• Hay bale located at the drain by the Rail Car Unloading Area
• Periodic street sweeping of the paved areas
• Frequent inspection of raw material around the Bakery Raw Material Unloading Area
Proposed modifications and additions to these BMP's are as follows:
• Replace hay bale at the drain by the Rail Car Unloading Area as needed and add a
hay bale at the top of the outfall concrete structure
• Perform street sweeping once a week, or as needed, on the paved areas that
discharge to Outfall 001
• Conduct cleaning of the oil/water separator once a month, or as needed, that will be
completed by a third party contractor
• Retrain employees that manage the Bakery Raw Material Unloading Area, which
includes the following proper cleaning techniques:
o Housekeeping with general operational procedures
o All storage and work areas being kept clean and in well-organized manner
o Monthly, or as needed, inspection of surfaces for any areas needing additional
cleaning
o Monthly, or as needed, inspection of hay bales and replace if needed
Additionally, Bakery Feeds immediately initiated monthly monitoring in accordance with the
PC E-7(e)ii. Bakery Feeds intends to continue monitoring until three samples in a row are
received below the benchmark.
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