An environmental lawsuit can be more than just a legal headache; it can threaten the future of your business, your finances, and your reputation. Whether you’re facing allegations under CERCLA, the Clean Water Act, or state-level statutes like California’s Proposition 65, you need to know how businesses defend themselves in court.
Not every environmental lawsuit ends in a massive penalty. With the right defense, many companies successfully avoid liability, reduce fines, or resolve the matter through early settlement or arbitration.
A San Diego environmental lawyer can assess your legal exposure, prepare all required documentation, and build a tailored defense that protects your operations and long-term interests. Here we’ll look at the most common and effective defenses available to companies facing environmental litigation in the U.S.
Third-Party Defense: When Someone Else Is Responsible
In many environmental cases, liability hinges on who actually caused the contamination or violation. One of the strongest and most frequently used defenses is the third-party defense.
To succeed with this strategy, your legal team must show that:
- The environmental harm was caused solely by a third party;
- You had no contractual relationship with that party;
- You took appropriate steps to prevent such harm.
For example, if your property became contaminated due to actions by a prior tenant or neighboring facility, without your involvement or knowledge, this defense could relieve you of liability.
In California, this is especially important for commercial landowners or operators who purchase sites without knowing the full environmental history. Conducting due diligence before acquiring property can be critical to this defense.
Act of God and Act of War: Unpredictable Events
Sometimes, environmental damage results from events entirely outside of human control. If the contamination was caused by a natural disaster (like a flood, wildfire, or earthquake) or an act of war, your business may be shielded from liability under what’s known as the “act of God” or “act of war” defense.
This is a high bar to meet. The defense requires proof that:
- The event was truly unforeseeable;
- The damage was solely caused by that event;
- There were no contributing actions or omissions by your company.
In Southern California, for example, wildfires have caused environmental concerns such as ash runoff or chemical releases. If your operations were otherwise compliant and a fire triggered a hazardous release, this defense may apply.
Lack of Standing: When the Plaintiff Can’t Sue
Every plaintiff must have “standing” to bring a lawsuit. That means they must prove a direct, personal injury that’s traceable to the defendant’s actions—and that the court can fix that injury.
If the plaintiff cannot meet this standard, the case may be dismissed before it even begins.
This is often a successful tactic when lawsuits are brought by parties who claim generalized harm (like decreased water quality or a nuisance claim) but cannot link the damage directly to the accused business. In federal courts and many state courts, including California, standing is a fundamental legal requirement.
“Puffery” and Greenwashing Claims
In some cases, environmental lawsuits are based not on pollution or waste but on marketing language, alleging false environmental claims or deceptive practices.
Businesses have successfully defended these claims by arguing that the statements in question were merely “puffery”—subjective, non-specific opinions rather than false representations of fact.
For example, saying your product is “eco-friendly” or “green” without further promises or specific measurable claims may not rise to the level of fraud or misleading advertising.
This defense can be especially important in the age of greenwashing litigation, where plaintiffs challenge advertising as being misleading under state consumer protection laws like California’s Business and Professions Code §§ 17200 and 17500.
Federal Preemption: When Federal Law Overrides State Law
Another line of defense arises when federal law preempts state regulation. If a company is in full compliance with federal environmental standards, it may argue that additional state law claims are invalid.
This defense is particularly relevant in green marketing cases, where businesses argue that federal regulations govern labeling and advertising, limiting states’ ability to impose additional rules.
California businesses often face stricter state laws, but if the federal standard fully occupies the regulatory space, the court may dismiss state-level claims on constitutional grounds.
CERCLA Protections and Superfund Liability Defenses
Businesses accused of contamination under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) may have multiple avenues to defend against liability. These include not only the third-party defense and act of God/war, but also protections built into the law itself.
The CERCLA statute recognizes certain parties who should not bear the cost of environmental cleanup, particularly when they had no role in causing the contamination.
Some of the most important CERCLA-related defenses include:
Bona Fide Prospective Purchaser (BFPP) Defense
If you acquired a contaminated property after the pollution occurred, and you followed strict due diligence requirements, you may qualify as a bona fide prospective purchaser.
This protects you from liability as long as you:
- Conducted “all appropriate inquiries” before acquiring the property;
- Took reasonable steps to stop any ongoing releases;
- Cooperated with cleanup efforts.
This defense is commonly used in California real estate transactions where former industrial sites (such as dry cleaning businesses) are repurposed for commercial development. Failing to meet BFPP requirements, however, can expose you to penalties, lawsuits, and other adversarial actions.
Innocent Landowner and Contiguous Property Owner Defenses
These statutory defenses protect owners who can show:
- They did not know about contamination at the time of purchase (innocent landowner), or
- The pollution came from an adjacent property and migrated onto their property (contiguous property owner).
In both cases, documentation and environmental assessments are essential. California courts expect businesses to show they took reasonable steps to assess and manage potential risks.
Contractor, Lender, and Government Defenses
Certain categories of parties are protected from liability under CERCLA and related federal rules, including:
Cleanup Contractors
If your company was hired solely to perform environmental cleanup, you’re generally protected from Superfund liability—unless there was negligence or misconduct involved. This defense is intended to encourage participation in remediation efforts without punishing contractors for the contamination itself.
Lenders and Secured Creditors
Financial institutions are often exempt from environmental liability, even if they hold a mortgage or have foreclosed on a contaminated property, as long as they didn’t participate in the management of the facility. This protection is vital for maintaining access to commercial credit in California’s heavily regulated property markets.
Government Agencies
State and local governments are typically shielded from liability when:
- They act in an emergency capacity to prevent harm, or
- They acquire contaminated land through involuntary means (e.g., tax foreclosure or police powers).
This ensures public agencies can intervene when necessary without fear of costly litigation.
Statutory Exemptions for Recyclers and Service Stations
Certain businesses enjoy exemptions due to the nature of their operations:
- Recyclers may be protected under the Superfund Recycling Equity Act if they meet criteria related to the types of materials handled and how they were managed.
- Service station dealers who collect used motor oil from the public and send it to approved recyclers may qualify for an exemption under CERCLA § 114(c).
These defenses often hinge on following proper protocols and keeping detailed records. In California, where regulations governing waste oil and recycling are stringent, even minor procedural lapses can jeopardize these protections.
Voluntary Cleanup and the Good Samaritan Rule
Under Section 107(d) of CERCLA, parties who voluntarily render care or assistance during an environmental emergency, particularly under the direction of an EPA coordinator, may be protected from liability. This is known as the Good Samaritan rule.
This defense encourages community and nonprofit groups to help restore contaminated areas, including California’s many orphaned mine sites and brownfields.
Strategic Defense Starts with the Right Legal Partner
Environmental lawsuits don’t just go away. They require a thoughtful, evidence-based strategy and sometimes aggressive legal advocacy. Whether you’re a commercial landowner, manufacturer, developer, or contractor, the defenses available to you can make the difference between a multimillion-dollar cleanup order and a successful resolution.
You don’t need to know every technical detail of CERCLA or California environmental statutes, but you do need someone who does.
Contact Tropea McMillan LLP for Environmental Law Defense
If your business is being investigated or sued for an environmental issue, Tropea McMillan LLP offers comprehensive legal defense backed by decades of experience in environmental law, regulatory counsel, and litigation support. From Superfund liability to state enforcement actions and private lawsuits, we help businesses respond quickly and decisively with an emphasis on risk management and cost-efficient outcomes.
We serve clients in San Diego and Los Angeles and across Southern California, and we’re ready to assist you through any stage of your case, whether it’s regulatory compliance, negotiation, mediation, or trial defense.
Call us toll-free at 866-977-8921. You can also submit a contact form to request a confidential consultation today.