A stormwater BMP, or Best Management Practice, is anything your facility does to keep pollutants out of the rain that leaves your property. Some BMPs are physical: a berm around a storage area, a cover over a dumpster, a drain insert. Most are habits: sweeping the yard, closing lids, training the crew, fixing leaks before they spread. Your SWPPP lists them. The Industrial General Permit requires them. And when someone reviews your facility, the BMPs are where the conversation starts.
The gap that gets facilities in trouble is the one between what the SWPPP says and what is actually happening on the ground. A plan can list a dozen well-written BMPs. If the yard is dirty and the lids are open, the plan does not help you. This piece covers what BMPs the permit requires, what a reviewer checks against the written plan, and the deficiencies we find most often when we walk a site for the first time. For the full program picture, see our SWPPP and stormwater compliance services in California overview.
The Seven Minimum BMPs Every Facility Needs
The Industrial General Permit (the statewide stormwater permit that covers most California industrial facilities, WQ Order 2014-0057-DWQ) sets a baseline. Every covered facility has to implement seven minimum BMPs, regardless of size or industry. These are mostly operational, not structural:
- Good housekeeping. Keep work areas, yards, and storage zones clean and orderly.
- Preventive maintenance. Inspect and maintain equipment before it leaks or fails.
- Spill and leak prevention and response. Have materials and procedures ready before a spill happens.
- Material handling and waste management. Store, move, and dispose of materials so they do not reach a storm drain.
- Erosion and sediment controls. Keep exposed soil from washing off site.
- Employee training. Make sure the people on the floor know the procedures.
- Quality assurance and recordkeeping. Document inspections, observations, and corrective actions.
If those seven are not enough to control your pollutant sources, the permit requires advanced BMPs on top of them. Advanced BMPs are where the structural controls usually come in: moving an activity indoors, building containment, covering an outdoor process, or installing treatment before water leaves the site. A facility that keeps exceeding benchmark values almost always ends up adding advanced BMPs.
Written Plan Versus What’s on the Ground
A reviewer, whether a Regional Water Quality Control Board inspector or an attorney working a citizen-suit notice, does not just read your SWPPP. They walk your site with it in hand and compare the two.
When we walk a facility for the first time, that comparison is the first thing we run ourselves. We take the BMP section of the existing SWPPP outside and check it against reality. The most common finding is not a missing BMP. It is a BMP that exists on paper but is not being done, or was done once and then quietly stopped. The drain insert that was never cleaned. The spill kit that was used and never restocked. The training log that ends two years ago. None of these are exotic problems. They are what happens when the person responsible for stormwater leaves, gets busy, or inherits the file with no handoff.
Inspectors typically start by asking for your records: your monthly visual observation logs, your training documentation, your BMP inspection checklists. Records are the fastest way for a reviewer to see whether a program is real or just written. A clean binder with current dates says the program is running. Gaps in the log say it is not.
BMP Checklist: What Gets Checked and Where Facilities Fall Short
This is the comparison we run on every site. Use it as a self-assessment before anyone else does.
| BMP Category | What a Reviewer Checks | Common Deficiencies We Find |
|---|---|---|
| Good housekeeping | Yard, loading docks, and storage areas clean; no accumulated debris near drains | Sweepings, sawdust, or pallets piling up near a storm drain; outdoor clutter that traps pollutants |
| Preventive maintenance | Equipment inspected on schedule; leaks repaired and documented | Slow leaks under forklifts or compressors; no maintenance log tying repairs to inspections |
| Spill prevention and response | Spill kits stocked, accessible, and matched to the materials on site | Empty or expired kits; staff who cannot say where the nearest kit is |
| Material handling and waste | Materials covered or indoors; dumpsters closed; drums sealed and bermed | Open dumpster lids; uncovered raw material; drums staged outside without containment |
| Erosion and sediment control | Exposed soil stabilized; sediment kept on site | Bare graded areas with no cover; sediment tracking toward the property line |
| Employee training | Current training records naming current staff | Logs that end years ago or list employees who left |
| Recordkeeping | Monthly visual observations and inspections logged and current | Missing months; observations never written down; no corrective-action notes |
Want to know how your BMPs would hold up before a reviewer walks the site? Call (925) 551-7300 or request a consultation. Tell us what you do on site, and we will compare your current BMPs against what the Industrial General Permit requires and flag the gaps.
When Pollutants Come From Outside Your Fence
Not every benchmark exceedance starts on your property. We see facilities post high results for metals, sediment, or oil and grease that trace back to sources they do not control. Tire and brake dust blowing off a nearby freeway. Exhaust settling from a neighbor’s bag-house. Runoff from a roof or an adjacent lot draining across your site. These external sources are common, and they matter because the permit still holds you responsible for what leaves your discharge point.
The practical response is the same: BMPs. A facility that documents external contributions and adds controls (sweeping, filtration, redirecting roof runoff) builds the record it needs to explain the result. This is exactly the kind of analysis that happens during exceedance response. When sampling comes back high and a facility moves into an Exceedance Response Action plan, the BMPs almost always get revised, and the reasoning behind those revisions is what a stormwater exceedance and ERA Level 1 and Level 2 response is built on. Weak BMPs lead to exceedances. Documented, working BMPs are how you get back to baseline.
How CDMS Handles BMPs
When CDMS develops or updates a SWPPP, we build the BMP section around what your facility actually does, not a generic list copied between plans. Our team walks the site, identifies the real pollutant sources, and writes BMPs your crew can follow. When results come back high, our QISPs (Qualified Industrial Stormwater Practitioners certified by the State Water Board) evaluate which BMPs need to change and document the reasoning. BMPs are not a one-time task. They are an ongoing requirement under the permit, and they are the part of your program a reviewer can see with their own eyes.
Ready to make sure your stormwater BMPs match what the permit requires and what’s happening on your site? Call (925) 551-7300 or request a consultation. We will review your current BMPs, walk your facility, and give you a fixed-price quote to close any gaps. BMPs are one requirement of the broader California Industrial General Permit; we handle the whole program.
