NCG200521_Tier 1 Notification for Copper_20240819

Eplin, Jerry W
From: Rob Duffy <[e-mail]>
Sent: Monday, August 19, 2024 2:36 PM
To: Eplin, Jerry W
Cc: Chuck Griffin; Tony Tyson
Subject: [External] Keywell Metals, LLC - Matthews NC Plant -SW COC No NCG200521 - BMV
Exceedance
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Dear Mr. Eplin:
I am writing on behalf of my client, Keywell Metals, LLC(Keywell), as referenced, regarding a BMV exceedance for
total Copper.This was the first such occurrence and therefore a Tier I episode.
Keywell is an aerospace specialty metals recycler and therefore the operational methods tend to differ from most
of the industries associated with the general industrial stormwater permit in that their operations don't change.
Keywell has completed the required steps in accordance with the general permit... Keywell has reinspected and
didn't find any new issues or changes within their operations that could have attributed to the exceedance.
However,two possible reasons for the exceedance are suspected.The first and most likely is that the amount of
rainfall that has been experienced duringthe past several months has been above average. Keywell has
experienced similar conditions in the past that also resulted in elevated metals concentrations. Copper is a
naturally occurring element in the region and it is suspected that it is leaching from the soil and joining the surface
water flow.Though less likely, a second possibility is that a neighboring operation is contributing copper to the
stormwater flow that is crossing the Keywell parcel.To address the matter going forward, Keywell will attempt to
allow for the naturally occurring copper to stabilize in the soil by waiting for a prolonged dry period where the
absence of rainfall prior to collecting their 41"Quarter-2024 stormwater sample,which may have a significant
impact on the concentration. In addition, Keywell will attempt to identify an alternative sampling point to
investigate potential background or offsite sources.
If you have any questions or need any further information from us, please do not hesitate to contact me; or my
client that is copied on this email and reachable by phone at 704-234-8630.Also, if this email should be sent to an
alternate person/email address, please let me know.
Sincerely,
Rob Duffy
Rob Duffy
Aegis Environmental, Inc.
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www.aegisenv.com
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Richmond,VA I Greenville,SC I Charlotte,NC
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