If you are an industrial facility operator in California, there is a legal reality about the Clean Water Act that catches many facility operators off guard: liability under the CWA is strict. That means your good faith, your reasonable efforts, and your lack of intent to pollute are all irrelevant to the question of whether you violated the law.
What Strict Liability Means
The Clean Water Act prohibits the discharge of any pollutant from a point source into waters of the United States unless authorized by an NPDES permit. A violation occurs the moment a permit condition is not met. As the Ninth Circuit put it in Sierra Club v. Union Oil Co. of California, the CWA is a strict liability statute: "A defendant's knowledge and intent are irrelevant, and there is no exception for de minimis violations." The Supreme Court has reinforced this framework, describing the CWA as imposing "a regime of strict liability, backed by criminal penalties and steep civil fines," with "consequences for even inadvertent violations."
This means it does not matter that you trained your employees, hired a consultant, invested in BMPs, or genuinely tried to comply. If your SWPPP was not updated on time or a required visual observation was missed, the plaintiff will argue the violation exists as a matter of law.
That said, not every allegation in a 60-Day Notice is as strong as it may first appear. Plaintiffs sometimes allege more than the permit requires, and many such claims are defensible. A common example: plaintiffs frequently cite exceedances of Numeric Action Levels as permit violations, but NAL exceedances are not themselves violations of the Industrial General Permit. They are triggers for further evaluation of whether BMPs are adequate, an important distinction that affects both the legal analysis and the appropriate response. Understanding which allegations carry real liability and which may be overstated is essential to mounting an effective defense.
Why This Matters in Litigation
Strict liability significantly reshapes how citizen suit litigation plays out. Because plaintiffs do not need to prove negligence, recklessness, or intent, they need only establish that a permit condition was not met. That includes far more than elevated pollutant concentrations in your sampling results. A failure to collect required samples, submit annual reports, conduct visual observations, or update your SWPPP on time may itself constitute a permit violation, regardless of your facility's actual discharge quality. And because much of the evidence comes from your own self-reported data in SMARTS or CIWQS, the plaintiff's burden of proof is often substantially met early in the case.
This makes early dismissal difficult. Traditional defenses, such as “we acted reasonably," "we made good faith efforts," or "we did not intend to violate,” do not defeat liability. They may factor into penalty calculations, where courts consider a defendant's good-faith compliance efforts as one of several statutory factors. But on the threshold question of whether you violated the CWA, they are legally irrelevant.
The practical consequence is that defendants often face significant pressure to settle rather than litigate. When liability is largely established, the remaining questions are typically the size of the penalty, the scope of injunctive relief, and the amount of the plaintiff's attorney's fees, each of which tends to favor the plaintiff’s negotiating position.
What You Can Do
Strict liability cannot be negotiated away, but exposure can be managed. The most effective defense is the one you build before the 60-Day Notice arrives: rigorous, documented compliance with every procedural and substantive requirement of the Industrial General Permit. If your records show consistent sampling, timely reporting, updated SWPPPs, and implemented BMPs, you deny plaintiffs the readily available evidence they rely on, and you put yourself in a far stronger position if litigation ever comes.
If you have questions about your facility's compliance posture or have received a 60-Day Notice, contact the Allen Matkins environmental team.
California Stormwater Defense is published by Allen Matkins Leck Gamble Mallory & Natsis LLP. Nothing in this post constitutes legal advice. Contact us for a consultation specific to your facility or needs.