NC0085553_NOV-2021-LV-0560 Response_20210810

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The Village of Bald Head Island
v
ZLAr��• August 10, 2021
Morella Sanchez -King, Regional Supervisor
Water Quality Regional Operations Section
Wilmington Regional Office
Division of Water Resources, NCDEQ
Subject:NOV Letter Response —Tracking Number NOV-2021-LV-0560
Permit No. NC0085553
Village of Bald Head Island WTP
Brunswick County
Ms. Sanchez -King:
The Village of Bald Head Island has received your Notice of Violation (NOV) and Intent to Assess Civil Penalty letter
(tracking number NOV-2021-LV-0560) regarding reported exceedances of the Daily and Monthly effluent limit's
associated with the Village's reverse osmosis (RO) water treatment plant (WTP) processing effluent discharge at sample
location 001 Effluent fortune 15, 2021, and June 30, 2021, under the current NPDES permit number NCO85553. Per your
letter, the Village is providing additional information with -in the 10-bussiness day window of opportunity to request that
no fine be assessed due to the good faith efforts under way by the Village to resolve this compliance problem.
When I talked with you yesterday afternoon, you directed me to document when I received this notification to
demonstrate that we are responding in a timely manner. The NOV letter is dated July 27, 2021.1 received notice, by
text, of the letter on August 2, 2021, from the Village Manager. I physically received the NOV letter on August 3, 2021.
Based on previous correspondence and meetings between the Division of Water Resources (DWR) and Village staff, I
believe that you are already aware that we have been working with a consulting team, Tony Boahn of McKim and Creed
and Trevor Clements, Tetra Tech Incorporated. The team has been in correspondence with David A. Hill, Environmental
Specialist 11, of your Division's Industrial Permitting Unit and his office since the Fall of 2021 to plan and conduct a mixing
zone analysis for the WTP discharge. In February 2021 the team submitted a Mixing Zone Analysis Report which provides
a scientific bases for estimating acute and chronic dilution ratios that would resolve the issue of periodic non-
compliance with the existing total Arsenic limit in the Village's current NPDES Permit (NC0085553). This submittal
included a request for consideration of modifying the instream waste concentrations for toxicant limits and whole
effluent toxicity requirements in the WTP's reverse osmosis concentrate discharge. The effort followed a Modeling Plan
discussed and approved by DEQ during a virtual meeting on November 19,2021. During that meeting, the Tetra Tech
modeling team agreed to refine their approach and documented the results as requested by David Hill. In addition,
background metals monitoring information was collected during the Spring of 2021 for DWR to conduct a Reasonable
Potential Analysis (RPA) that would support new effluent limits and monitoring requirement decisions for specific
parameters including Total Arsenic, Total Copper, and Total Zinc. David Hill indicated in his July 30 email (copy attached)
that the DEQ Permitting Unit concurs with Tetra Tech's recommendations for mixing zone dilution factors of 10:1 for
human health and chronic criteria and 6.5:1 for acute criteria which when applied will bring the WTP effluent discharge
into compliance.
P.D. Box 3009 BALD HEAD ISLAND, NC 28461 [phone] FAX [phone]
E-MAIL: villageCq illugehhi.or,; WEBSITE http.Z'ww)v.villa;;ebhi.org

The Village of Bald Head Island has invested monies and is working to resolve this related reporting exceedance of Total
Arsenic. The mixing zone analyses and the results indicate our efforts to resolve the problem and the Village requests
not to be fined or found in violation since the current limits are not based on the most current and scientifically
defensible information. The current arsenic (and other toxicant) chronic limits should be multiplied by a factor of 10, and
the acute limits by a factor of 6.5, based on these decisions by the DEQ Permitting Unit. both the Village's and DEQ's
determinations of appropriate limits. The current arsenic limit should be multiplied by a factor of 10 based on these
decisions by the DEQ Permitting Unit. Also at his time, the Village of Bald Head Island requests your assistance in
modifying the permit effluent limits to the correct values if that is what is needed to stop the NOV's. This should not just
be for arsenic, but for all toxic limits and our chronic WET test should also be adjusted to a 10 percent instream waste
concentration (IWC) using ceriodaphnia or an appropriate test species.
The Village looks forward to hearing from you soon to resolve this matter. Thank you.
Sincerely,
JP McCann
Public Services Director
Village of Bald Head Island
P.O. Brxr 3009 BALD HEAD ISLAND, NC 28461 (910) 45 7- 9700 FAX [phone]
E N-IAIL: village(uvillagebKorg WEBSITE http://iviviv.vill(tl;ebhi.orr;

JP McCann
From: Clements, Trevor <[e-mail]>
Sent: Thursday, August 05, 2021 8.47 AM
To: Hill, David A; Young, Brianna A
Cc: Schmidt, Michelle; JP McCann; Tony Boahn ([e-mail])
Subject: RE: [External] RE: Follow up to Request RE: Bald Head Island WTP Discharge Mixing
Zone Analysis Report Submittal
David,
Thank you for sending your decision so that the Village can move forward. A Village representative or their designee will
be back in touch with the Division to find out next steps regarding incorporation of these results into their NPDES permit
for compliance.
We appreciate you sharing these results.
Trevor
Trevor Clements I Principal/Program Manager
Direct: 919.485.2058 1 Main: 919.485.82781 Cell: 919,328.0175
[e-mail]
Tetra Tech Engineering P.C. I Complex World, Clear Solutions
P.O. Box 14409 11 Park Drive. Suite 2001 Research Triangle Park, NC 277091 www.tetratech.com
PLEASE NOTE: This message, including any attachments, may include privileged, confidential and/or inside information. Any distribution or use of this
communication by anyone other than the intended recipient is strictly prohibited and may be unlawful. If you are not the intended recipient, please notify
the sender by replying to this message and then delete It from your system.
From: Hill, David A <[e-mail]>
Sent: Friday, July 30, 20216:50 PM
To: Clements, Trevor<[e-mail]>; Young, Brianna A <[e-mail]>
Cc: Schmidt, Michelle <[e-mail]>; JP McCann <[e-mail]>; Tony Boahn
([e-mail]) <[e-mail]>
Subject: Re: [External] RE: Fallow up to Request RE: Bald Head Island WTP Discharge Mixing Zone Analysis Report
Submittal
Hello Trevor,
After reviewing the model results, sensitivity analyses, and stream sampling, the Division concurs with your
assessment with using an average 10:1 dilution for human health and aquatic life chronic criteria. A dilution of
6.5:1 for acute criteria is also acceptable. These dilution ratios only apply to the parameters that were
sampled for (arsenic, copper, and zinc) and WET testing.
Sincerely,
David Hill
Environmental Specialist 11

We'll have a response by the 30th.
Thanks,
David Hill
Environmental Specialist II
Industrial Permitting Unit
**Email preferred during this time*
NC DELI / Division of Water Resources / Water Quality Permitting Section
NPDES Industrial Permitting Unit
919 707 3612 office
919 707 9000 main office
[e-mail]
Physical Address: 512 North Salisbury St.,Raleigh, NC, 27604
Mailing Address: 1617 Mail Service Center, Raleigh, NC, 27699-1617
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Clements, Trevor <[e-mail]>
Sent: Wednesday, July 21, 2021 10:45 AM
To: Hill, David A <[e-mail]>; Young, Brianna A <[e-mail]>
Cc: Schmidt, Michelle <[e-mail]>; JP McCann <imccannCcDvillaRebhi.org>; Tony Boahn
([e-mail]) <[e-mail]>
Subject: [External] RE: Follow up to Request RE: Bald Head Island WTP Discharge Mixing Zone Analysis Report Submittal
CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
Report Spam.
Hello David and Brianna,
I'm circling back to you to see if you've had a chance to calculate the revised permit limits for the Bald Head Island RO
concentrate discharge. Would you please update us regarding the status and your anticipated schedule?
Thank you,
Trevor

From: Clements, Trevor
Sent: Thursday, June 10, 20213:36 PM
To:'Hill, David A' <[e-mail]>;'Young, Brianna A' <[e-mail]>
Cc: Schmidt, Michelle <[e-mail]>;'JP McCann' <[e-mail]>; Tony Boahn
([e-mail]) <[e-mail]>
Subject: RE: Follow up to Request RE: Bald Head Island WTP Discharge Mixing Zone Analysis Report Submittal
David and Brianna,
Good news ... the monitoring and lab analysis for background concentrations of the identified metals (As, Cu, Zn) was
completed by Environmental Chemists and we received the final of the a data sets this week (collected between April 14
and May 21) at the two monitoring locations (river and marina, map attached with lat/long coordinates). The lab reports
are attached for verification, and we summarized the data in the attached Excel file with high or low tide time provided
for referencing to the timing of both sets of data collection for each sampling day.
As you will note, all samples were found to be below detection levels, which is also good news. This indicates that
observable build-up of metals concentrations in the marina associated with the discharge of WTP concentrate from the
Village is unlikely which I think everyone is glad to see.
Please use this information along with the previous submittals to calculate your revised NPDES limits for the facility. We
look forward to reviewing the proposed limits and discussing any of our previous analyses and recommendations further
with you as needed.
Thank you,
Trevor
Trevor Clements I PrincipallProgram Manager
Direct: 919.485 2058 1 Main: 919.485 8278 1 C _11 919. � �8.0175
trevor.clements 0 tetratech.com
Tetra Tech Engineering P.C. I Complex World. Clear Solutions
P O. Box 14.109 1 1 Park Drive, Suile 200 Research Triangle Park. NC 27709 1 www.tetratech.com
PLEASE NOTE: This message, includu-g any attachments, may include privileged, confidential andlor inside information. Any distribution or use of this
communication by anyone :)ther than the mended recipient is strictly prohibited and may be unlawful. If you are not the intended recipient. please notdy
the sender by replying to this message and then delete it from your system
From: Clements, Trevor
Sent: Wednesday, March 17, 2021 3:10 PM
To: Hill, David A <[e-mail]>; Young, Brianna A <[e-mail]>
Cc: Schmidt, Michelle<[e-mail]>; JP McCann <[e-mail]>; Tony Boahn
([e-mail]) <tboahn mckimcreed.com>
Subject: RE: Follow up to Request RE: Bald Head Island WTP Discharge Mixing Zone Analysis Report Submittal
David and Brianna,
This email is to follow up on our previous email and conversation on 3/15/21. The attached tables show the sensitivity
to a 25 percent change in either direction for ambient temperature, ambient salinity, and effluent temperature. The first
table indicates the impact on the dilution ratio under high tidal variation observed in December, and the second shows
the results in terms of percent change from the original output. As we might expect, the output is slightly more

Industrial Permitting Unit
"Email preferred during this time`
NC DEC) f Division of Water Resources / Water Quality Permitting Section
NPDES Industrial Permitting Unit
919 707 3612 office
919 707 9000 main office
[e-mail]
Physical Address: 512 North Salisbury St.,Raleigh, NC, 27604
Mailing Address: 1617 Mail Service Center, Raleigh, NC, 27699-1617
Email correspondence to and from this address is subject to the
Noilh Carolina Public Records Lau, and may be disclosed to third parties.
From: Clements, Trevor <[e-mail]>
Sent: Wednesday, July 21, 2021 10:48 AM
To: Hill, David A <[e-mail]>; Young, Brianna A <[e-mail]>
Cc: Schmidt, Michelle <[e-mail]>; JP McCann <[e-mail] >; Tony Boahn
(TBOAHN mckimcreed.com) <TBOAHN mckimcreed.com>
Subject: RE: [External] RE: Follow up to Request RE: Bald Head Island WTP Discharge Mixing Zone Analysis Report
Submittal
CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
Report t Sim.
David,
Thank you for the rapid response. We'll look forward to reviewing that with you at that time.
Much appreciated,
Trevor
From: Hill, David A <[e-mail]>
Sent: Wednesday, July 21, 2021 10:47 AM
To: Clements, Trevor <Trevor.Clements tetratech.com>; Young, Brianna A <Brianna.Youn ncdenr. ov>
Cc: Schmidt, Michelle <[e-mail]>; JP McCann <j_mccann@village_bhi.ors>; Tony Boahn
(TBOAHN mckimcreed.com) <[e-mail]>
Subject: Re: [External] RE: Fallow up to Request RE: Bald Head Island WTP Discharge Mixing Zone Analysis Report
Submittal
Hi Trevor,