NODI Codes Explained

What are NODI Codes?

A permittee may not always have a result to report on their discharge monitoring report (DMR). ADEQ’s permitting portal, myDEQ, does not allow partial submissions of DMRs. Either numeric results must be reported or a reason must be provided describing why no data exists—for either the entire DMR or certain parameters. NODI codes allow the permittee to easily provide a reason that is understood by ADEQ and EPA compliance databases.

Will I get a violation if I use a NODI code?

It depends. If a permittee has no discharge to report and has no required monitoring, reporting NODI C will not indicate a violation on the DMR. However, if a sample is lost, or not all required monitoring was completed, permittees may receive a notification of potential deficiency, alerting them of the missed monitoring.

How does ADEQ verify proper usage?

ADEQ uses the laboratory reports and any additional comments submitted via the myDEQ portal to verify that NODI codes are used appropriately. If ADEQ has questions, they may contact you and ask for more information.

Commonly Used NODI Codes

To ensure you are entering the proper NODI code, refer to the following list (updated for all reporting periods after April 1, 2021):

NODI Code	What does it mean?	When is it used?	Examples
2	Operation Shutdown	When there is an operation shutdown.	The operation was shut down.
9	Conditional Monitoring — Not Required This Period	Parameter must only be monitored in certain conditions. This can also be used for parameters with no approved laboratory method.	• Total residual chlorine was not required because UV was used for disinfection • No approved laboratory method exists (Tribulin).
B	Below Detection Limit/No Detection	When the result is less than the laboratory’s LOD/MDL.	Chlorine result is less than the method detection limit.
C	No Discharge (entire facility or entire monitoring point)	No discharge occurred during the reporting period. NOTE: You can enter NODI C only as part of the No Data reporting for the entire facility or an entire monitoring point.	All discharge was sent to reuse.
E	Failed to Sample/Required Analysis Not Conducted	Laboratory did not complete all of the required analyses.	• Omission of a parameter from the laboratory analysis. • Sample or laboratory analysis was not conducted.
N	Not Constructed	When the facility is not constructed.	Facility not constructed.
P	Laboratory Error or Invalid Test	There was a laboratory error or invalid test.	The laboratory sample was contaminated.
Q	Not Quantifiable	The result is greater than the LOD but less than the LOQ.	Laboratory reports cyanide result above the MDL but below the RL and uses an E4 data laboratory data qualifier indicated the results is estimated.
T	Environmental Conditions – Monitoring Not Possible	Environmental conditions prevent monitoring.	Weather event like flooding or snow.

Other NODI codes include:

3 – Special report attached
7 – No Influent
A – General permit exemption
F – Insufficient flow for sampling
I – Land Applied
R – Administratively resolved
W – Dry iysimeter/well
X – Parameter/value not reported