NC0024333_Monitoring (Information)_20240815

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR.
Director
Scott Clark, Water Resources Director
City of Monroe
Post Office Box 69
Monroe, NC 28111-0069
SUBJECT: Toxicity Test Results
City of Monroe WWTP
NPDES Permit No. NCO024333
Union County
Dear Mr. Clark:
NORTH CAROLINA
Environmental Quality
August 15, 2024
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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F161 F669A2D84A3...
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: Scott Clark, City of Monroe (via eCopy)
Kyle Edwards, City of Monroe (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: OE459795-E57B-4610-BD49-A81D1E16DB67
Q�p
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. Myerse
Environmental Specialist II, Aquatic Toxicology Branch (ATB)
Subject: Whole effluent toxicity test results
Monroe WWTP
NPDES Permit # NCO024333/001
Union County
The aquatic toxicity test using flow -proportional composite samples of effluent discharged from
the Monroe WWTP has been completed. Monroe WWTP has a permitted effluent discharge of
10.4 million gallons per day (MGD) entering Richardson Creek (7Q10 of 0.43 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 100%
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
10.2 neonates
6.73 SU
713 micromhos/cm
<0.1 mg/L
6.57 SU
748 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)