NC0046728_Monitoring (Report)_20240815

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR.
Director
NORTH CAROLINA
Environmental Quality
August 15, 2024
Allison Kraft, Public Utilities Director
Town of Mooresville
Post Office Box 878
Mooresville, NC 28115
SUBJECT: Toxicity Test Results
Town of Mooresville/Rocky River WWTP
NPDES Permit No. NCO046728
Iredell County
Dear Ms. Kraft:
Enclosed is a copy of the toxicity test results relative to the samples collected at the subject facility on July 30 and August
1, 2024, by Mr. Wes Bell of this Office. Effluent samples were collected for use in a chronic Ceriodaphnia dubia pass -fail
toxicity test. The test Passed utilizing these samples.
Should you have any questions concerning this report, please do not hesitate to contact Mr. Bell at [phone] or at
wes.bellkdeq.nc. gov.
Sincerely,
EA
DocuSigned by:
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Andrew H. Pitner, P.G.
Regional Supervisor
Water Quality Regional Operations Section
Mooresville Regional Office
Division of Water Resources, NCDEQ
Enclosure: Toxicity Test Results
Cc: Allison Kraft, Town of Mooresville (via eCopy)
Jamie Levis, Town of Mooresville (eCopy)
NPDES Program Files - Laserfiche
D_E Q�� North Carolina Department of Environmental quality I Divisionof Water Resources
Mooresville Regional Office 1 610 East Center Avenue, Suite 301 1 Mooresville, North Carolina 28115
a;k c-u+ci
704.6631699

Docusign Envelope ID: 470AE662-563A-4E81-829C-OE971C4C86AO
pEQ` DWR
Division of Wt., Resources
August 14, 2024
MEMORANDUM
To: Andrew Pitner
Water Quality Regional Operations, MRO
Through: Cindy A. Moore
Supervisor, Aquatic Toxicology Branch (ATB)
From: Madison E. Myers
Environmental Specialist II, Aquatic Toxicology Branch (ATB)
Subject: Whole effluent toxicity test results
Mooresville — Rocky River WWTP
NPDES Permit # NCO046728/001
Iredell County
The aquatic toxicity test using flow -proportional composite samples of effluent discharged from
the Mooresville WWTP has been completed. Mooresville WWTP has a permitted effluent
discharge of 5.5 million gallons per day (MGD) entering Dye Creek (7Q10 of 0.5 CFS). Whole
effluent samples were collected on July 30 and August 1 by Wes Bell for use in a chronic
Ceriodaphnia dubia pass -fail toxicity test. The test passed. Toxicity test information follows.
Test Type 3-Brood Ceriodaphnia dubia chronic pass -fail
Test Result Pass
Test Concentrations 90%
Control Survival 100%
Control Mean Reproduction 15.7 neonates
Test Treatment Survival 83.3%
Treatment Mean Reproduction
First Sample pH
First Sample Conductivity
First Sample Total Residual Chlorine
Second Sample pH
Second Sample Conductivity
Second Sample Total Residual Chlorine
21.4 neonates
7.56 SU
503 micromhos/cm
<0.1 mg/L
7.56 SU
511 micromhos/cm
<0.1 mg/L
Test results for the above samples indicate that the effluent would not be predicted to have
water quality impacts. Please contact us if you have any questions or if further effluent toxicity
monitoring is desired. We may be reached at [e-mail] or
[e-mail].
Basin: Yadkin -Pee Dee
cc: Wes Bell (MRO)