NCG030650_Email RE Benchmark Exceedances_20230212

Georgoulias, Bethany
From: Nicole Johnston <[e-mail]>
Sent: Sunday, February 12, 2023 6:55 PM
To: Eplin, Jerry W
Cc: Chandler, Jeffrey A; Khan, Zahid; Georgoulias, Bethany; Cook, Brittany
Subject: [External] Copper and TSS Exceedances for Outfall #003 CommScope, Claremont for
January 2023
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Jerry,
Per the general permit for CommScope, Inc. (NCG030000) Claremont Facility (under COC NCG030650), sampling was
completed on ROS Outfall 003 for the site on Wednesday, January 25th, 2023 with a rainfall even totaling 0.54" of rain.
received results from the laboratory (Statesville Analytical) on Friday, February 3rd, 2023. For this event, all parameters
were below the benchmark EXCEPT for Copper and TSS.
Please note the following for the January 2023 results:
1) The benchmark for Copper under General Permit NCG030000 is 0.010 mg/L. The result obtained for Copper
for Outfall #003 was 0.037 mg/L, which exceeded the benchmark of 0.010 mg/L.
2) The benchmark for TSS under General Permit NCG030000 is 100 mg/L. The result obtained for TSS for
Outfall #003 was 180 mg/L, which exceeded the benchmark of 100 mg/L.
3) As completed recently in the past, I grabbed a rainwater sample on that same day in a small bucket and had
copper, lead, and zinc analyzed as well. The results from the analyses obtained for the stormwater bucket
sample were the following:
Copper: <0.002 mg/L— Non -Detect
Lead: <0.0005 mg/L
Zinc: 0.016 mg/L
4) The rainwater sample was utilized to try and investigate background levels and determine other influences
on benchmark exceedances. These results do not really provide any background levels to consider for the
copper benchmark exceedance (and neither for TSS as this was not analyzed for the stormwater bucket
sample).
5) As we noted last month, we thought that it may be possible for the copper exceedance due to displaced
metal being stored in an open dumpster utilized by the contractor completing construction for some new
storage buildings. I am still working to see what may have caused this exceedance for the copper and now
for the TSS. We may need some assistance to assess what needs to occur now. Please note that I was able
to grab samples on Thursday, February 2nd, 2023, and these samples looked much better and much clearer
than those collected in January; so, again, we are hopeful that we have corrected the issue with the copper
and now for the TSS. We will know further in the next couple of weeks when the data results come back
from the lab for the February 2nd samples.
6) This benchmark exceedance for copper will be documented in the SWPPP, and corrective action steps will
be implemented to reduce such occurrences. Furthermore, best management practices will be utilized to
assist with reducing the copper with exceeding its respective benchmark value.
Please note that rainfall totals for the Claremont CommScope site are obtained from the National Weather Service.
Please contact me on my cell at [phone] if you need any further information. Thank you.

Nicole Johnston