Your lab results came back, a number was high, and now SMARTS is telling you that you owe an “ERA.” If that is why you are here, start with the part that matters most: a stormwater exceedance is a manageable, defined process, not a violation and not a fine. Plenty of compliant facilities go through it. The permit anticipates exceedances and lays out exactly what to do about them.
This guide explains what an exceedance triggers under the Industrial General Permit, the difference between an ERA Level 1 and an ERA Level 2, and the deadlines that come with each. For the full picture of the program, see our SWPPP and stormwater compliance services in California overview. This piece stays focused on what happens after a result comes back high.
What Counts as an Exceedance
Every facility under the Industrial General Permit (the IGP, the statewide stormwater permit run by the State Water Board) samples its stormwater and compares the results against permit thresholds called Numeric Action Levels, or NALs. An exceedance means a sample came back above an NAL. That is it. The word sounds alarming, but it is a measurement, not a citation.
NALs come in two forms, and a result can trip either one:
| Parameter (example) | Annual NAL | Instantaneous maximum NAL |
|---|---|---|
| Total Suspended Solids (TSS) | 100 mg/L | 400 mg/L |
| Oil and Grease | 15 mg/L | 25 mg/L |
| pH | (none) | 6.0 – 9.0 (range) |
The annual NAL is the average of your samples across the year. The instantaneous NAL is a single sample. You can exceed one without the other, and the level you land in depends on which parameter exceeded and how many times.
One detail that surprises facilities: NALs are tracked per parameter. You can sit at Baseline for pH, Level 1 for copper, and Level 2 for zinc at the same time. The permit does not roll everything into one status. Each pollutant carries its own escalation track.
Baseline, Level 1, Level 2: The Escalation Ladder
The IGP organizes exceedance response into a ladder. You move up a rung when the same parameter exceeds again, and you move back toward Baseline when it stops.
| Status | What puts you here | What you file | Deadline | Certified by |
|---|---|---|---|---|
| Baseline | No NAL exceedances | Routine sampling, twice per qualifying season | Ongoing | None |
| Level 1 | An NAL exceedance in the prior year | ERA Evaluation, then a Level 1 ERA Report | Evaluation Oct 1; Report Jan 1 | QISP |
| Level 2 | A second exceedance of the same parameter | Level 2 ERA Action Plan, then a Level 2 ERA Technical Report | Action Plan Jan 1; Technical Report Jan 1 of the following year | QISP |
QISP: Qualified Industrial Stormwater Practitioner, a state-registered credential.
A Level 1 ERA is an evaluation. A registered Qualified Industrial Stormwater Practitioner (QISP) reviews your SWPPP, looks at where the pollutant is coming from, evaluates your existing Best Management Practices, and recommends additional ones. The deliverable is a report that documents the source and the response. It is analytical work, not a penalty.
A Level 2 ERA is heavier. The Action Plan commits you to demonstrations for each exceeded parameter, on a schedule, with implementation on the schedule the permit requires. The follow-up Technical Report then has to explain the exceedances. It separates industrial sources, non-industrial sources, and natural background, because not every pollutant in your runoff comes from your operations. Freeway tire dust, particulate from a neighbor’s stack, and ordinary roof runoff can all push a number up. Documenting that distinction is a large part of what a Level 2 Technical Report does.
Got a Level 1 or Level 2 notice and not sure what it actually requires of you? Call (925) 551-7300 or request a consultation. Tell us which parameter exceeded and we will tell you where you stand on the ladder and what comes next.
Two Things That Catch Facilities Off Guard
Level status is parameter-specific, and repeat exceedances carry consequences. If you clear a parameter and return to Baseline, then exceed that same parameter again, the permit may move you directly back to Level 2 rather than starting over at Level 1, depending on the facility’s current status, reporting timing, and whether return-to-baseline conditions were fully met. The safer assumption is that a repeat exceedance for the same parameter picks up where you left off.
A pH exceedance changes how you sample, permanently. Once you go to Level 1 for pH, you can no longer use pH test strips. You have to switch to a calibrated pH meter, and that requirement stays even if you return to Baseline. When we walk a facility into ERA work for pH, this is one of the first things we set up, because it affects every sampling event from then on.
Don’t Trust the SMARTS Auto-Determination Alone
SMARTS (the State Water Board’s online stormwater portal) tries to determine your level automatically from your uploaded data. It is not reliable. We have seen it report “no Level 1 needed” when the sample data clearly says otherwise, and we have seen it flag levels that a closer read does not support. The automated status is a starting point, not an answer. When we take on ERA work, we verify your requirements independently against your actual results rather than relying on what the portal calculated. An exceedance is one place where trusting the wrong number can cost you a missed deadline.
This is also where location-specific requirements can change the picture. The statewide NALs in the permit use EPA benchmark values, such as a pH range of 6.0 to 9.0. But facilities in watersheds with approved Total Maximum Daily Loads (TMDLs) may face stricter numeric limits for specific pollutants. For example, a TMDL-specific limit for copper can be significantly lower than the statewide NAL. The practical result: a facility can read as compliant against the statewide number and still be in exceedance under TMDL requirements that apply to its receiving water. Which standard applies depends on the facility’s location and the water body it discharges to.
Your SWPPP Almost Always Changes
ERA work rarely ends with a report and nothing else. A Level 1 evaluation that identifies a new pollutant source usually means new or revised Best Management Practices, and those have to go into your plan. The monitoring section often changes too. In practice, a SWPPP update is part of nearly every ERA engagement we handle. If the exceedance points back to a control measure that is missing or not working, fixing the plan is the actual fix. Our guide to the stormwater BMPs inspectors actually look for covers the control measures that most often need revision after an exceedance.
How CDMS Handles ERA Work
When a client comes to us mid-exceedance, the first thing we do is confirm where they actually stand, not where SMARTS says they stand. We review the sampling results that triggered the level, identify the parameter and the likely source, and lay out the deadlines you are working against. From there our QISP prepares the Level 1 or Level 2 deliverables, revises the SWPPP and BMPs as needed, and gets everything staged in SMARTS for submission.
One requirement we cannot remove: the Water Board makes your Legally Responsible Person log in and click submit. We prepare and line up every document, but the final certification has to come from your LRP. We tell clients that up front so nothing stalls at the deadline.
Because exceedances start with sampling, the cleanest way to avoid surprise ERA work is a sampling program that catches problems early and reads the right benchmarks. Our guide to SWPPP sampling in California and how it works covers that side of the program.
Facing a Level 1 or Level 2 deadline and want it handled before it slips? Call (925) 551-7300 or request a consultation. We will confirm your real status, prepare the QISP-certified reports, and update your SWPPP so the exceedance gets resolved, not just documented.
