If your facility handles industrial materials outdoors in California, the rules that govern your stormwater come from a single document: the California Industrial General Permit. Most people call it the IGP. It is the permit that decides whether you have to sample your runoff, what you have to write down, what you report to the state, and what happens when a sample comes back high. This guide explains what the permit is, who it covers, and what it asks of you, so you can tell where your facility stands before anyone walks your site.
For the broader picture of what a stormwater plan is and how the whole program fits together, start with our SWPPP and stormwater compliance overview. This page goes a level deeper on the permit itself.
What the Industrial General Permit Is
The IGP is a statewide permit issued by the State Water Resources Control Board. Its formal name is Water Quality Order 2014-0057-DWQ, as amended by later orders, and it carries National Pollutant Discharge Elimination System number CAS000001. NPDES is the federal permit system, created under the Clean Water Act, that controls what gets discharged into rivers, creeks, bays, and the ocean. The IGP is California’s version of that permit for industrial stormwater. Instead of issuing a separate permit to every factory and warehouse in the state, the Water Board wrote one general permit and lets covered facilities enroll under it.
Enforcement runs through two levels. The State Water Board writes the permit. Your local Regional Water Quality Control Board, one of nine across California, oversees the facilities in its area. Reporting happens through SMARTS, the state’s online stormwater portal where you register, upload sampling data, and file your annual report.
The permit is not optional and it is not federal paperwork you can handle the federal way. California’s IGP includes state-specific implementation details: mandatory electronic reporting through SMARTS, a structured exceedance response process with escalating levels, Total Maximum Daily Load (TMDL)-specific requirements, and NEC provisions. These go beyond generic federal stormwater assumptions. Facilities with locations in other states often find that their out-of-state process does not satisfy the Water Board here.
Who the Permit Applies To
The IGP covers facilities by Standard Industrial Classification (SIC) code. The permit lists the categories it regulates: manufacturing across most sectors, transportation with vehicle maintenance or fueling, recycling and scrap operations, hazardous waste facilities, and others. If your SIC code is on the list and you have industrial materials or activities exposed to rain, the permit applies.
The exposure part matters as much as the code. A covered facility that keeps everything indoors or under cover may qualify for a lighter path rather than the full permit. We do not rebuild the full applicability test here. If your first question is whether you are covered at all, read do I need a SWPPP, which walks through SIC codes and the exposure question with a decision table.
What the Permit Requires of You
Once the permit applies and you have industrial exposure, you take on a set of recurring obligations. They run on California’s stormwater year, which starts July 1 and ends June 30. The table below lays out the core requirements.
| Obligation | Frequency | Deadline | What’s Involved |
|---|---|---|---|
| Permit registration | Once, at coverage | Before you begin discharging | File a Notice of Intent and permit registration documents through SMARTS; you receive a Waste Discharger Identification (WDID) number |
| SWPPP | Develop once, keep current | In place at coverage; update when conditions change | A multi-section plan with site maps, pollutant source assessment, a minimum of seven Best Management Practices (BMPs), and a monitoring plan, The facility develops and implements the plan. The permit requires QISP involvement when a facility enters Level 1 or Level 2 Exceedance Response Action (ERA) status. |
| Visual observations | Monthly, plus each sampling event | Logged as you go | Walk the site, document conditions, check for non-stormwater discharges |
| Stormwater sampling | A set number of qualifying storm events each year (generally four, two per half of the year) | During qualifying storms in the July–June season | Collect samples, send them to a lab, compare results to action levels |
| Data upload to SMARTS | Each sampling event | Within 30 days of receiving lab results | Enter your analytical results into the state portal |
| Annual facility evaluation | Once per reporting year | During the reporting year | A structured inspection of every industrial area, drainage point, and BMP |
| Annual Report (SWAR, the Stormwater Annual Report) | Once per year | July 15 | Submit the evaluation and the year’s monitoring data through SMARTS |
A qualifying storm event is a storm that produces a discharge and follows at least 48 hours with no discharge from the facility. You sample during those events, not on a fixed calendar. The sampling mechanics, including which parameters apply and how the kit-based collection works, are covered in detail in SWPPP sampling in California.
One detail that surprises new permit holders: the state requires your facility’s Legally Responsible Person to log in to SMARTS and click submit. A consultant can prepare every document, but the LRP has to be the one who files it. Build that into your annual calendar so a July 15 deadline does not slip because the right person was traveling.
Trying to figure out which of these obligations apply to your facility? Call (925) 551-7300 or request a consultation. Tell us your SIC code and what sits outside on your property, and we will map out exactly what the Industrial General Permit requires of you.
The No Exposure Certification Alternative
Not every covered facility runs the full program. If your SIC code is on the list but nothing industrial is actually exposed to rain, you may qualify for a No Exposure Certification (NEC) instead of a full SWPPP. The NEC carries lighter obligations: no routine sampling, but still a state filing, an annual facility evaluation, and a recertification due each October 1.
A majority of the facilities we enroll qualify for an NEC. That number surprises people who assumed they were stuck with full sampling. It is worth checking before you commit to a season of monitoring you may not need. The catch is that “no exposure” is a specific determination, not a judgment call. The Water Board expects you to certify it honestly and back it up at the annual evaluation.
What Happens When a Sample Exceeds a Numeric Action Level
The permit sets Numeric Action Levels (NALs) for the pollutants it tracks. An NAL is not a hard limit you get fined for crossing. It is a trigger. When your sampling results exceed an NAL, the permit moves your facility up a tiered response ladder, from baseline monitoring to a Level 1 evaluation, then to Level 2 if exceedances continue. Each level asks for more: a closer look at your pollutant sources, additional BMPs, and formal reports.
This is where the permit requires specialized help. A Level 1 or Level 2 response has to involve a Qualified Industrial Stormwater Practitioner (QISP), a person certified by the State Water Board to evaluate exceedances and direct the response. We keep QISPs on staff and handle this work for clients. If your results have already come back high, stormwater exceedance response explains the Level 1 and Level 2 process in full.
Common Compliance Gaps We See
When we walk a facility for the first time, the same gaps show up again and again.
The most common one is a SWPPP that no longer matches the site. The document describes a layout, a chemical inventory, or a set of BMPs that changed two renovations ago. On paper the facility looks compliant. On the ground, the plan and the site have drifted apart, and an inspector notices the difference fast.
The second is missed or incomplete sampling. A facility collects one storm event and assumes it is covered, or never confirms that the lab results made it into SMARTS within the 30-day window. The third is relying on the SMARTS portal’s automated determinations. The system sometimes reports that no further action is needed when the sample data says otherwise. We verify requirements against the actual results rather than trusting the automated readout.
None of these are exotic. They are the predictable result of a permit that runs year-round while the person responsible for it changes jobs, gets busy, or inherits the file with no handoff. The fix is rarely complicated once someone with permit experience looks at the whole picture.
Want a clear read on where your facility stands under the Industrial General Permit? Call (925) 551-7300 or request a consultation. Tell us what you do on site and what triggered the question, and we will walk you through your obligations and provide a fixed-price quote to handle them.
