For over 35 years, Proposition 65 has limited and restricted harmful contaminants that can threaten California’s water safety. Although about 900 substances are currently regulated, several toxic herbicides have eluded California’s Environmental Protection Agency (CalEPA) and can still be applied legally.

As a California resident and a professional evaluating toxic tort claims eligibility, I have witnessed firsthand the dreadful consequences of exposure to hazardous pesticides on farmers, agricultural workers, and their respective families.

California’s Department of Pesticide Regulation’s most recent report indicates that 209 million pounds of pesticides are sprayed annually across the state. This represents almost 20% of all pesticides used in the U.S., even though California accounts for only about 3% of all U.S. cropland.

Harmful Herbicides Not Regulated by Proposition 65

The Office of Environmental Health Hazards Assessment (OEHHA) updates Proposition 65’s regulated substances. The law requires Californian authorities to publish a list of chemicals known to cause cancer, congenital disabilities, and reproductive harm. However, even though Proposition 65 protects Californians from a plethora of health hazards, it fails to regulate harmful substances like paraquat, a widely used herbicide in the state’s thriving agricultural sector.

Paraquat has been linked to a host of debilitating afflictions. It has been clinically documented to lead to reproductive issues in laboratory rodent models, as well as affecting kidney and lung function in humans, and holding a high correlation with Parkinson’s disease. Although a growing body of clinical literature indicates its high toxicity to humans, paraquat’s registration was renewed with the EPA’s approval in August 2021 until 2035. Moreover, it can now be applied to crops with only a small 50 to 75-feet buffer zone protecting residential areas.

The EPA’s decision came under scrutiny from environmental, health, and farmworker rights groups who initiated legal action against the Agency, citing its disregard for the safety of farming communities and workers in light of paraquat’s neurotoxic effects. The petitioners accuse the EPA of violating its own risk assessment standards and continually dismissing overwhelming proof that chronic exposure to paraquat is linked to Parkinson’s disease. In September 2022, the Agency filed a motion for voluntary remand, stating it will review its decision and provide an addendum in a year’s time.

Until further developments occur in the ongoing litigation, California should exert its broad regulatory authority to limit the risk of toxic herbicide exposure. OEHHA can easily accomplish this goal by increasing the narrow range of Proposition 65 qualifying criteria to include other types of harm, such as renal, respiratory and neurologic. Doing so would allow concrete safety standards to be established, regulating paraquat and other unsafe herbicides that can impact the lives of many.

Water Quality Affected by Unsustainable Agricultural Practices

The Golden State’s continually-dwindling water supplies directly result from the mega-drought affecting the American Southwest for the past two decades, the most severe regional event since around 800 AD. Although man-driven climate change and California’s unique geography influence precipitation levels, the state’s diminishing water resources are further affected by the unsustainable exploitation of groundwater aquifers.

Around 80% of the state’s water is used for agriculture, most notably in the fertile San Joaquin Valley. The problem arises when toxic pesticides used in the cultivation of high-value crops (almonds, pistachios, cotton, alfalfa) threaten the remaining 20%, mostly intended for human consumption.

With approximately 1.3 million pounds used in the San Joaquin Valley in 2018, paraquat represents a severe contamination risk to one of California’s vital drinking water sources. The level of contamination that could end up endangering public health depends on the substances’ toxicity, the amount registered in the water, and the degree of exposure that occurs daily when using the tainted water.

Past precedence justifies current concerns; in 2002, the EPA reported that agricultural pesticides compromised 635 miles of San Joaquin Valley waterways, rendering the water unsafe for consumption or recreation. Pesticide runoff from cultivated land can reach the San Joaquin and Sacramento rivers contaminating the drinking water of major population centers like Los Angeles, San Francisco, and San Diego.

Despite environmental safety groups’ efforts to advance policy proposals that would ensure water safety by mitigating discharge from agricultural waste, progress is stunted due to the lack of efficient monitoring abilities and enforceable standards.

Attempts to Ensure California’s Water Safety

In August 2021, the Infrastructure Investment and Jobs Act was passed to improve California’s vital water infrastructure in the face of worsening climate conditions. However, the state’s extensive use of agricultural pesticides continues to raise concerns over the strained water reserves’ quality, especially since toxic herbicides like paraquat remain unregulated. For individuals like my clients who work in agriculture or reside in farming communities, this often incurs higher exposure risks that can lead to costly medical expenses that many aren’t able to afford.

Even if the EPA remains unconvinced of paraquat’s status as a neurologic hazard, the Agency is still responsible for addressing the risks of pesticide water contamination and the harm it can produce to humans and the environment. To help states prevent extensive pesticide pollution from agricultural runoff, the EPA has taken steps to develop improved on-site monitoring and rapid detection solutions.

The Agency’s 2021 Water Toxicity Sensor Challenge aims to gather innovative designs and ideas for cost-effective electrochemical biosensors that can rapidly detect toxins in aqueous environments. In early October 2022, the EPA announced the 1st phase winners, along with several honorable mentions who will be invited to submit prototype models during the challenge’s second phase, which is expected to commence in late 2022.

Ensuring California’s water quality in the critical context of its scarcity will require extensive water management reforms and increased regulation for substances used in economically-vital agricultural practices. CalEPA should take the first step and reevaluate its toxic pesticide qualifying criteria to limit and prevent the contamination of the state’s water sources. Concurrently, along with its efforts of developing timely detection methods for contaminants, the EPA could help ensure water quality more efficiently by reconsidering the questionable reapproval of herbicides with adverse neurological effects.