NC0069841_Toxicity Test State Lab_20201118

Strickland, Bev
From: Henning, Lorimar S
Sent: Wednesday, November 18, 2020 12:03 PM
To: Basinger, Corey; Scheller, Roberto
Subject: NC0069841 /001
Attachments: MRO_Crooked Creek WWTP.pdf
Good afternoon,
Please see attached the report for the toxicity test performed for Crooked Creek WWTP (NC0069841/001) on November
2020. Please let me know if you have any questions.
Regards,
Lorimar S. Henning
Environmental Specialist II
Aquatic Toxicology Branch
NC Division of Water Resources
NC Department of Environmental Quality
919 743 8441 office
919 743 8517 fax
lorimar.henning(cDncdenr.gov
1621 Mail Service Center
Raleigh, NC 27699-1623
E Q
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.

Division of Water Resources
November 16, 2020
MEMORANDUM
To: Corey Basinger
Water Quality Regional Operations, MRO
Through: Cindy A. Moore 9lv
Supervisor, Aquatic Toxicology Branch (ATB)
From: Lorimar S. Henning 4:Rjf
Environmental Specialist II, Aquatic Toxicology Branch (ATB)
Subject: Whole effluent toxicity test results
Crooked Creek WWTP
NPDES Permit # NCO069841/001
Union County
The aquatic toxicity test using flow -proportional composite samples of effluent discharged from
the Crooked Creek WWTP has been completed. Crooked Creek WWTP has a permitted effluent
discharge of 1.9 million gallons per day (MGD) entering North Fork Crooked Creek. Whole
effluent samples were collected on November 3 and November 5 by Roberto Scheller for use in
a chronic Ceriodaphnia dubia pass -fail toxicity test. The test passed. Toxicity test information
follows.
Test Type 3-Broad Ceriodaphnia dubia chronic pass -fail
Test Result Pass
Test Concentrations 90%
Control Survival 100%
Control Mean Reproduction 20.9 neonates
Test Treatment Survival 91.7%
Treatment Mean Reproduction 21.8 neonates
First Sample pH 7.40 SU
First Sample Conductivity 339 micromhos/cm
First Sample Total Residual Chlorine 0.07 mg/L
Second Sample pH 7.07 SU
Second Sample Conductivity 610 micromhos/cm
Second Sample Total Residual Chlorine 0.07 mg/L
Test results for the above samples indicate that the effluent would not be predicted to have
water quality impacts. These samples were split and tested by ETT Environmental, Inc. The
chronic Ceriodaphnia dubia pass/fail test run by ETT resulted in a pass. Please contact us if you
have any questions or if further effluent toxicity monitoring is desired. We may be reached at
[phone].
Basin: Yadkin -Pee Dee
cc: Roberto Scheller (MRO)

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