Monsanto Poisoned San Diego Bay With Cancer-Causing PCBs for Decades
As the sole US manufacturer, Monsanto sold 1.4 billion pounds of PCBs despite knowing they caused cancer and contaminated water. San Diego Bay remains poisoned, fish are unsafe to eat, and taxpayers are paying millions for cleanup.
Monsanto manufactured and sold over 1.4 billion pounds of PCBs from 1935 to 1979, knowing these chemicals caused cancer, persisted in the environment indefinitely, and contaminated water supplies. The company gave customers disposal instructions it later admitted were inadequate, leading PCBs to flow into San Diego Bay through storm drains and landfills. Today, the Bay remains severely contaminated with some of the highest PCB levels ever recorded in California, fish are unsafe to eat, and San Diego taxpayers have spent over $17 million on cleanup while Monsanto fights liability in court.
This case shows how corporations externalize costs, profit from dangerous products, then leave communities to pay for the damage.
The Allegations: A Breakdown
| 01 | Monsanto was the sole US manufacturer of PCBs from 1935 to 1979, producing and selling 1.4 billion pounds of these cancer-causing chemicals that account for 99% of all PCBs used domestically. | high |
| 02 | The company knew PCBs presented health risks and were causing widespread environmental contamination, yet continued to promote their use and sale for decades. | high |
| 03 | A 1971 internal Monsanto memo acknowledged the company’s previous instructions telling customers to discard PCB products by dumping or burying them near water was no longer adequate due to the PCB pollution problem. | high |
| 04 | Monsanto advised customers that PCBs required incineration at 2,000 degrees Fahrenheit to be destroyed, but only after admitting its earlier disposal guidance led to water contamination. | high |
| 05 | PCBs are virtually indestructible, largely non-biodegradable, and persist in the environment for exceptionally long periods, readily binding to sediment and accumulating in living organisms. | high |
| 06 | San Diego Bay sediment contains some of the most severe PCB contamination on the California coast, with PCB concentrations in mussel tissue from Convair Lagoon measuring the highest ever recorded in the State Mussel Watch Program’s history. | critical |
| 07 | The Regional Water Quality Control Board declared parts of San Diego Bay polluted and issued multiple Cleanup and Abatement Orders for various contaminated sites. | high |
| 08 | San Diego Bay has been listed as impaired for PCBs under the Clean Water Act continuously since 2006 due to Monsanto’s chemical contamination. | high |
| 01 | Despite growing concerns about environmental persistence and health risks, comprehensive federal regulation of PCBs came 40 years after Monsanto began manufacturing them. | high |
| 02 | The EPA did not issue rules prohibiting future PCB production until 1979, allowing Monsanto to profit from sales for over four decades while contamination accumulated. | high |
| 03 | Monsanto only voluntarily restricted domestic PCB sales for certain uses in 1970, after public concern arose about environmental persistence, not out of proactive responsibility. | medium |
| 04 | The Toxic Substances Control Act providing for total PCB regulation was not enacted until 1976, decades after evidence of harm emerged. | high |
| 05 | Regulatory action lagged significantly behind industrial innovation and the discovery of associated harms, allowing harmful products to remain on the market and increase the scale of environmental problems. | high |
| 06 | PCBs were required in critical infrastructure like schools and hospitals due to fire-resistant properties, showing products with immediate benefits can be adopted without full accounting of long-term costs. | medium |
| 01 | Monsanto continued PCB production and sales for many years despite internal acknowledgments of pollution problems and the known persistence of these chemicals. | high |
| 02 | The sale of 1.4 billion pounds of PCBs generated substantial revenue for Monsanto and its shareholders over several decades. | high |
| 03 | Monsanto externalized the environmental cleanup and public health burdens onto society at large while privatizing profits from PCB sales. | high |
| 04 | The company’s voluntary 1970 sales restriction can be viewed as minimal action taken only when public pressure mounted, protecting market share while minimizing changes to profitable business lines. | medium |
| 05 | Monsanto’s behavior aligns with corporate ethics under systems that structurally incentivize maximizing shareholder value at the expense of public and environmental well-being. | high |
| 06 | The decades during which Monsanto endorsed less stringent disposal methods contributed significantly to environmental contamination forming the basis of public nuisance claims. | high |
| 01 | The City of San Diego spent $15.4 million investigating and cleaning up the Shipyard Sediment Site’s South and North Yards. | high |
| 02 | The City incurred $1,726,598.05 to investigate PCB and other pollutant contamination at the Chollas, TAMT, CMSD, and Campbell sites in the Bay. | medium |
| 03 | San Diego spent $159,463.97 to clean up the City’s storm drains adjacent to the former Shipyard Sediment Site. | medium |
| 04 | The San Diego Unified Port District funded construction of sediment caps at sites like Campbell Shipyard to contain pollutants Monsanto released. | medium |
| 05 | Resources spent on cleaning up pollution are diverted from other public goods and services, with taxpayers bearing burdens through public entities. | high |
| 06 | The Port District’s ongoing litigation seeks to shift future abatement costs back to Monsanto, the originator of the pollution, but outcomes remain uncertain. | medium |
| 07 | Potential costs for large-scale environmental remediation of San Diego Bay are immense, involving extensive study, dredging, and long-term monitoring. | high |
| 01 | Both the US EPA and California’s Office of Environmental Health Hazard Assessment classified PCBs as probable human carcinogens causing rare liver cancers and malignant melanoma. | critical |
| 02 | Studies of workers exposed to PCBs found increases in rare liver cancers and malignant melanoma, showing the risks manifested in serious illnesses among the most exposed. | high |
| 03 | The EPA warned that PCB types that bioaccumulate in fish and bind to sediment are the most carcinogenic components, meaning people eating contaminated Bay fish face even more toxic exposures than workers. | critical |
| 04 | PCBs cause damage to immune, reproductive, nervous, and endocrine systems, plus skin and eye problems, liver toxicity, and elevations in blood pressure and serum cholesterol. | high |
| 05 | The EPA stated animal studies could not identify any level of PCB exposure that did not cause effects on the immune system. | critical |
| 06 | California issued Fish Consumption Advisories for San Diego Bay in 2013 and again in 2018, making them more restrictive for women of childbearing age and children due to PCB and mercury levels. | high |
| 07 | Between 65% and 81% of all fish caught in San Diego Bay are now subject to do-not-eat advisories for women 45 and under and children. | critical |
| 08 | The 2018 advisory added Pacific chub mackerel, identified as the largest or most consumed fish in San Diego Bay, to the list of fish women and children should never consume. | high |
| 01 | Fish Consumption Advisories effectively declare a significant portion of San Diego Bay’s fish unsafe, eroding cultural practices and eliminating a free food resource for residents. | high |
| 02 | The County Health Department quarantined the Convair Lagoon area, entirely preventing the collection of shellfish for human consumption and obstructing free use of property. | high |
| 03 | Sediment caps in areas like Convair Lagoon and Campbell Shipyard curtail public use, with buoys warning DO NOT ANCHOR, NO FISHING ALLOWED, and DO NOT DISTURB. | medium |
| 04 | These necessary interventions to contain Monsanto’s pollution simultaneously shrink accessible areas of the Bay for boaters and anglers. | medium |
| 05 | The knowledge that waters and marine life are tainted with probable carcinogens breeds fear and diminishes overall quality of life for San Diego residents. | high |
| 06 | The comfortable enjoyment of the Bay is compromised when its use is fraught with health warnings and visible signs of pollution control. | medium |
| 07 | Health impacts disproportionately affect lower-income communities who have less healthcare access, rely more on subsistence fishing, or live closer to contaminated sites. | high |
| 01 | The court granted summary judgment in favor of Monsanto against the City of San Diego’s claims, concluding the City failed to prove its stormwater system suffered damage specifically from PCBs alone. | high |
| 02 | The City could not demonstrate cleanup expenditures were directly and exclusively attributable to Monsanto’s PCBs rather than multiple pollutants, closing its avenue for cost recovery. | high |
| 03 | The stringent burden of proof can shield polluters even when their products are known contributors to the overall environmental problem. | high |
| 04 | The San Diego Unified Port District’s purpresture claim was dismissed because PCBs as chemical contaminants do not fit the legal definition of physical obstruction. | medium |
| 05 | The Port District’s public nuisance claim survived, with the court finding sufficient evidence that PCBs polluted the Bay and caused substantial harm to human health and public use. | medium |
| 06 | The journey to this point has been long, with the case initiated in 2015 and key orders issued in 2020, underscoring the protracted nature of environmental litigation. | high |
| 07 | Such delays often benefit corporate defendants who leverage significant financial and legal resources, while accountability may come long after responsible individuals have moved on. | high |
| 08 | Limited outcomes like dismissal of the City’s claims reflect how legal standards can fall short of delivering what the public perceives as full justice for widespread environmental degradation. | high |
| 01 | Monsanto’s 1970 voluntary sales restriction came only after public concern arose about PCB persistence, representing a reactive measure under pressure rather than proactive responsibility. | medium |
| 02 | Voluntary actions taken under public or regulatory pressure are often part of a strategy to preempt stringent mandatory regulations or project an image of corporate social responsibility. | medium |
| 03 | The 1971 internal memo acknowledging previous disposal advice as no longer adequate represents an internal admission of prior inadequacy only after pollution became evident. | medium |
| 04 | Changing disposal advice after the problem emerged suggests a reactive rather than preventative stance focused on managing fallout rather than early assumption of responsibility. | medium |
| 05 | These actions can be seen as efforts to manage legal and reputational damage once harm becomes undeniable, a common pattern for industries with products proving long-term negative externalities. | medium |
| 01 | Monsanto reaped substantial profits from selling over 1.4 billion pounds of PCBs, with profits accruing to the corporation and its shareholders over several decades. | high |
| 02 | The immense costs associated with environmental damage and public health risks have been externalized, falling upon public entities, communities, and the environment itself. | high |
| 03 | Taxpayers through bodies like the City of San Diego and Port District have borne and will continue bearing the financial burden of investigation, remediation, and long-term abatement. | high |
| 04 | This dynamic where a corporation benefits financially while society pays for harmful consequences is a significant contributor to wealth disparity. | high |
| 05 | Resources diverted to pollution cleanup are resources taken from other public goods and services, entrenching socio-economic divides. | medium |
| 06 | The immense legal resources corporations deploy to defend against liability represent a power imbalance when pitted against public entities or affected individuals. | high |
| 01 | Monsanto manufactured and sold PCBs for over four decades from roughly 1935 to 1979 while contamination accumulated. | high |
| 02 | The environmental contamination PCBs caused is exceptionally long-lasting, with these chemicals persisting in the environment indefinitely. | high |
| 03 | Legal battles to address historical pollution are protracted, with lawsuits initiated in 2015 and key summary judgment orders issued only in 2020. | medium |
| 04 | This extended timeframe works to the advantage of the original polluter, as profits from the harmful product were realized and distributed long ago. | high |
| 05 | Over time, direct evidence of specific corporate decisions becomes harder to obtain and corporate entities may undergo restructuring, obscuring lines of responsibility. | medium |
| 06 | Understaffed regulatory agencies and overburdened court systems contribute to delays, allowing harm to continue while legal processes slowly unfold. | high |
| 07 | For affected communities and the environment, delay means prolonged exposure to harm and a longer wait for remediation and justice. | high |
| 01 | The PCB contamination of San Diego Bay is a predictable outcome of a system where profit generation is structurally prioritized over public and environmental health. | high |
| 02 | Under neoliberal capitalism with emphasis on deregulation and shareholder primacy, corporations are incentivized to maximize profits by externalizing environmental and health costs onto society. | high |
| 03 | Monsanto’s decades-long production of a profitable but hazardous chemical, inadequate disposal advice, and slow regulatory intervention are not surprising outcomes within this framework. | high |
| 04 | Legal and regulatory systems operate reactively and can be influenced by corporate power, leading to situations where significant harm persists before accountability is sought. | high |
| 05 | This case is less an anomaly and more a reflection of inherent tensions within a socio-economic system that struggles to reconcile private profit pursuit with protection of public goods. | high |
| 06 | The presence of persistent, cancer-causing chemicals in San Diego Bay serves as a reminder of long-term consequences when industrial activities are pursued without adequate accountability. | high |
| 07 | This legal battle illustrates deeper systemic failures in how modern economies prioritize corporate interests over community well-being, leaving a legacy of damage taking generations to address. | high |
Timeline of Events
Direct Quotes from the Legal Record
“Because of the advent of the PCB pollution problem, these instructions are no longer adequate… scrap askarel must not be allowed to contaminate a water supply. The material needs to be destroyed by proper incineration at 2,000°F.”
💡 Monsanto’s own 1971 internal memo proves the company knew its earlier advice to dump or bury PCBs near water caused pollution, yet continued profiting from sales for eight more years.
“PCBs are largely non-biodegradable and virtually indestructible, requiring incineration at 2,000 degrees Fahrenheit to be destroyed, and persist in the environment for exceptionally long periods.”
💡 The very properties that made PCBs profitable for Monsanto make them an enduring environmental menace that will threaten public health for generations.
“PCB concentrations in mussel tissue from Convair Lagoon were the highest ever measured in the history of the State Mussel Watch Program.”
💡 San Diego Bay contains record-breaking levels of Monsanto’s poison, demonstrating the severity of contamination the company caused.
“Between 65% and 81% of all fish caught in the Bay are now subject to a do-not-eat advisory for women 45 and under and children.”
💡 Monsanto’s PCBs have made the majority of San Diego Bay fish too dangerous for vulnerable populations to consume, eliminating a food source and cultural practice.
“The EPA stated that animal studies could not identify any level of PCB exposure that did not cause effects on the immune system.”
💡 Scientific evidence shows even minimal PCB exposure causes harm, yet Monsanto sold 1.4 billion pounds knowing there was no safe threshold.
“People who ingest PCB-contaminated fish or come into contact with contaminated sediment may be exposed to PCB mixtures even more toxic than those encountered by workers or initially released into the environment.”
💡 The PCBs bioaccumulating in Bay fish are more carcinogenic than what Monsanto originally sold, creating greater cancer risks for anyone eating contaminated seafood.
“Legal filings allege that Monsanto was aware that PCBs presented health risks and were causing widespread contamination of the environment, yet continued to promote their use and sale.”
💡 This was not an accident or oversight but a deliberate business decision to keep selling a product Monsanto knew was poisoning communities.
“The City of San Diego incurred $15.4 million for the investigation and cleanup of the Shipyard Sediment Site’s South and North Yards, $1,726,598.05 to investigate PCB contamination at multiple Bay sites, and $159,463.97 to clean up City storm drains.”
💡 Public funds that could have supported schools, healthcare, or infrastructure instead went to cleaning up Monsanto’s profitable poison.
“San Diego Bay has been consistently listed as impaired for PCBs under the Clean Water Act since 2006.”
💡 Federal law recognizes San Diego Bay as too polluted to meet water quality standards due to Monsanto’s contamination, a designation that persists nearly two decades later.
“The Regional Water Quality Control Board repeatedly identified elevated levels of PCBs in San Diego Bay sediments and aquatic life, leading the Board to declare parts of the Bay polluted and issue Cleanup and Abatement Orders for various sites.”
💡 State regulators have been forced to issue cleanup order after cleanup order, proving the contamination is widespread, severe, and ongoing.
“The court denied Monsanto’s motion for summary judgment on the Port District’s public nuisance claim, finding sufficient evidence for a reasonable trier of fact to conclude that PCBs have polluted the Bay and caused substantial harm to human health or the public’s use and enjoyment of the Bay.”
💡 Despite Monsanto’s legal challenges, the court found enough evidence of harm to allow the case seeking corporate accountability to proceed to trial.
“The court granted summary judgment to Monsanto against the City of San Diego’s claims, primarily because the City was found unable to definitively prove that its Municipal Separate Storm Sewer System suffered direct physical harm specifically from PCBs as distinct from other pollutants.”
💡 Legal technicalities allowed Monsanto to avoid paying San Diego back even though the City spent millions cleaning up contamination Monsanto caused, showing how the system protects polluters.
“The Surface Water Ambient Monitoring Program concluded in a 2012 report that the Bay suffers from some of the most severe PCB contamination on the California coast.”
💡 Independent scientific monitoring confirms San Diego Bay ranks among the worst PCB contamination sites in the entire state due to Monsanto’s chemicals.
“Monsanto stands as the sole manufacturer of PCBs in the United States from 1935 until their production was banned in 1979. Over this period, the company produced and sold an astounding 1.4 billion pounds of PCBs, accounting for approximately 99% of all PCBs used domestically.”
💡 There is no question about where San Diego Bay’s PCB contamination came from because Monsanto was the only company making this poison in America.
“The knowledge that the waters and marine life are tainted with probable carcinogens breeds fear and diminishes the overall quality of life for residents. The comfortable enjoyment of the Bay is compromised when its use is fraught with health warnings and visible signs of pollution control.”
💡 Monsanto’s contamination robbed San Diego residents of their right to safely enjoy a public waterway that belongs to the community, not the corporation.
Frequently Asked Questions
I’m contractually not allowed to post a PDF of the exact legal documents I used for this article, but they can be found here: https://www.law360.com/cases/550355ea80ea7013cd000001/articles
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