NC0083321_Response to NOV-2022-TX-0005_20220208

RECEIVED 4
• FEB 112022 ONWASA
onwasa om
Water Sciences Section 228 Georgetcv,-n Rd
Jacksorviile, NC 2E540
February 8, 2022
Cindy Moore, Aquatic Toxicology Branch Supervisor
Division of Water Resources, NCDEQ
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
ATTN: Zach Thomas, Environmental Senior Specialist
RE: NPDES Permit No. N00083321/001
Hubert Water Treatment Plant
Onslow Water and Sewer Authority, Onslow County
Dear Mr. Thomas:
This letter is sent in response to a Notice of Violation (NC NOV-2022-TX-0005) issued to
the above-referenced facility on January 19, 2022, due to a failure to pass Whole Effluent Toxicity
(WET) testing for the November 2021 sampling event.
• ONWASA does not dispute the findings of the NOV, as it was self-reported, and we take
seriously compliance with NPDES permit requirements. As of the date of this letter, we are
extending an existing task order contract with a professional engineering consulting firm (W.K.
Dickson & Company, Wilmington Office) who is partnering with an analytical/testing sub-
consultant (Shealy Consulting, LLC of Batesburg-Leesville, SC) to develop and implement an
expanded effluent testing program with the goal of identifying the cause(s) of the Acute Toxicity
Test failures.
We have also discussed the situation with the firm that performs our WET tests,
Envirochem Analytical Laboratories of Wilmington, NC, to determine their ability to support more
frequent WET testing (as often as weekly). They have suggested also testing for ionic imbalance,
which may be done by our own in-house laboratory.
Thank you for your consideration of this information and any guidance you can provide to
ensure ONWASA remains compliant with NPDES requirements. Please feel free to contact me
directly at [phone] or dmohr(d)onwasa.com you have any additional questions.
Sincerely,
(�2b I P�
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• David M. Mohr, P.E.
Chief Operations Officer
C: Seth Brown, Treatment Facilities Administrator
Carter Hubard, PE, W.K. Dickson and Company