NC0047384_NOV-2021-TX-0028_20210614

June 14, 2021

CERTIFIED MAIL: 7019 0140 0000 2844 3005
RETURN RECEIPT REQUESTED

Michael Borchers, EP
City of Greensboro
PO Box 3136
Greensboro, NC 27402-3136
SUBJECT: NOTICE OF VIOLATION: NC NOV-2021-TX-0028
Whole Effluent Toxicity (WET) Testing
NPDES Permit No. NC0047384/001
T.Z. Osborne WWTP
Guilford County

Dear Mr. Borchers:

This is to inform you that a review of your toxicity self-monitoring report forms for April 2021 indicate a
violation of the toxicity limitation specified in your NPDES Permit.

You should take whatever remedial actions are necessary to eliminate the conditions causing the effluent
toxicity violation(s). Your efforts may include conducting a Toxicity Reduction Evaluation (TRE), a site-
specific study designed to identify the causative agents of effluent toxicity, isolating the sources of
toxicity, evaluating the effectiveness of toxicity control options, and confirming reductions in effluent
toxicity. Please be aware that North Carolina General Statutes provide for assessment of civil penalties
for violations of NPDES permit limitations and requirements.

The reverse side of this Notice contains important information concerning your Whole Effluent Toxicity
Monitoring and Reporting Requirements. Please note the appropriate mailing addresses for submitting
your Discharge Monitoring Reports (DMRs) and Aquatic Toxicity (AT) Test Forms. Also, the Aquatic
Toxicology Branch now accepts AT forms via email ([e-mail]); if an AT form is
submitted via email, we do not require that a hard copy is mailed. We encourage you to review this
information; if it would be helpful to discuss this situation or possible solutions to resolve effluent
toxicity noncompliance, please contact Zach Thomas at [phone] or [e-mail].

Sincerely,

Cindy Moore, Supervisor Aquatic Toxicology Branch
Division of Water Resources, NCDEQ

cc: Martie Groome (via email: [e-mail])
Jenny Graznak, WSRO (via email: [e-mail])
ATB Enforcement File & Laserfiche __________





 
 


WHOLE EFFLUENT TOXICITY MONITORING AND REPORTING INFORMATION

¾ The following items are provided in an effort to assist you with identifying critical and sometimes overlooked toxicity testing and
reporting information. Please take time to review this information. The items below do not address or include all the toxicity
testing and reporting requirements contained in your NPDES permit. If you should have any questions about your toxicity
testing requirement, please contact Zach Thomas with the Aquatic Toxicology Branch at [phone] or Cindy Moore at (919)
743-8442.

¾ The permittee is responsible for ensuring that toxicity testing is conducted according to the permit requirement and that toxicity
report forms are appropriately filed.

¾ The reporting of whole effluent toxicity testing data is a dual requirement. All toxicity test results must be entered (with the
appropriate parameter code) on your monthly Discharge Monitoring Report which is submitted to:

North Carolina Division of Water Resources
Central Files
1617 Mail Service Center
Raleigh, NC 27699-1617

IN ADDITION

Toxicity test data (“AT” form) must be submitted to the following address:

North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicity Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
or
Email to: [e-mail]

¾ Toxicity test results shall be filed with the Water Sciences Section no later than 30 days after the end of the reporting
period (eg, January test result is due by the end of February).

¾ Toxicity test condition language contained in your NPDES permit may require use of multiple concentration toxicity testing upon
failure of any single quarterly toxicity test. If the initial pass/fail test fails or if the chronic value is lower than the permit limit, then
at least two multiple concentration toxicity tests (one per month) will be conducted over the following two months. As many
analyses as can be completed will be accepted. If your NPDES permit does not require use of multiple concentration toxicity testing
upon failure of any single quarterly test, you may choose to conduct either single concentration toxicity testing or multiple
concentration toxicity testing per the Division’s WET enforcement initiatives effective July 1, 1999. Follow-up multiple
concentration toxicity testing will influence the Division’s enforcement response.

¾ Toxicity testing months are specified by the NPDES Permit, except for NPDES Permits which contain episodic toxicity monitoring
requirements (eg, if the testing months specified in your NPDES permit are March, June, September, and December, then toxicity
testing must be conducted during these months).

¾ If your NPDES Permit specifies episodic monitoring and your facility does not have a discharge from January 1-June 30, then you
must provide written notification to the Water Sciences Section by June 30 that a discharge did not occur during the first six months
of the calendar year.

¾ If you receive notification from your contract laboratory that a test was invalidated, you should immediately notify the Water
Sciences Section at [phone] and provide written documentation indicating why the test was invalidated and the date when
follow-up testing will occur.

¾ If your facility is required to conduct toxicity testing during a month in which no discharge occurs, you should complete the
information block located at the top of the AT form indicating the facility name, permit number, pipe number, county and the
month/year of the subject report. You should also write “No Flow” on the AT form, sign the form and submit following normal
procedures.

¾ The Aquatic Toxicity Test forms shall be signed by the facility’s Operator in Responsible Charge (ORC) except for facilities which
have not received a facility classification. In these cases, a duly authorized facility representative must sign the AT form. The AT
form must also be signed by the performing lab supervisor.

¾ To determine if your AT test forms were received on time by the Division of Water Resources, you may consider submitting your
toxicity test results certified mail, return receipt requested to the Water Sciences Section or email to the above address, receiving e-
confirmation.