At ALG we stay informed with new and changing regulations so that we can best assist our clients: develop strategies to implement regulatory requirements, find permitting solutions that maintain operational flexibility within the parameters defined by the regulations, and prepare compliance and training plans to assist operators with implementing changes.


Industrial General Permit TMDL Amendment

FAQs to Understand the IGP Amendments

California Storm Water - Industrial General Permit TMDL Amendment

Printable FAQ Summary: ALG IGP TMDL Amendments.

What are TMDLs, TNALs, & NELs?

TMDLs are additional, waterbody/shed-specific pollutant requirements that have been incorporated into the IGP. If your site discharges to a waterbody/shed with a TMDL, your SW may need to meet additional discharge TMDL numeric action levels (TNALs) and/or numeric effluent limitations (NELs) for specific pollutant parameters.

Why are NELs and TNALs important?

An NEL exceedance is a permit violation and can be subject to mandatory minimum penalties of at least $3,000 per violation per day. A TNAL exceedance triggers response actions, but is not a permit violation.

Do TMDL requirements apply to me?

TMDLs are adopted for specific waterbodies/sheds and include areas of coastal Southern CA and Napa/Sonoma. Use the Water Board's map tool or call ALG for help to determine whether TMDLs apply to your site.

What do I have to do to meet TMDL requirements?

Affected sites must be prepared to meet any new TNALs/NELs and update their SWPPPs as necessary by the effective date of July 1, 2020. Even sites in baseline must assess compliance with TMDL requirements.

My facility is a No Exposure Certification (NEC) site. Do TMDLs apply?

No, TMDL requirements do not apply to facilities under NEC Certification.

Does SMARTS inform me of these requirements?

No, SMARTS does not inform facilities of additional requirements or calculate TNAL or NEL exceedances. It is your responsibility to update SMARTS reporting for any new TMDL requirements.

If I get a high sample, can I achieve compliance by averaging?

No, TNALs and NELs are instantaneous maximums only (2 or more exceedances per pollutant at any monitoring location) and are not evaluated based on averaging.

What if I can't meet these NELs by July 1, 2020?

If your facility can't meet these requirements in time, you can request additional time through a Time Schedule Order (TSO) that states a schedule of actions to be taken to achieve compliance and may include interim effluent limitations. There are also other compliance options available in Attachment I of the IGP.


For a summary of the IGP TMDL Amendments, please see: ALG IGP TMDL Amendments.


ALG has Qualified Industrial Stormwater Practitioners (QISP) available to assist with evaluating whether a facility is subject to the new TMDLs, assist with developing a stormwater sampling program, and assess necessary BMPs to come into compliance with the TMDLs before the July 2020 compliance deadline.

Please call Jayme Dryden at 805-764-6005 or Elliott Ripley at 805-764-6004 to discuss how ALGs team of QISPs can help your business take the next step to insure continued compliance with the requirements of the Industrial General Permit.