(Beyond Pesticides, October 7, 2021) The state Arizona State Auditor General reports a lack of groundwater monitoring for pesticides and other contaminants by the Arizona Department of Environmental Quality (ADEQ). For over six years, the agency failed to monitor groundwater and soil for agricultural pesticide contamination. Furthermore, the agency did not implement key groundwater monitoring processes over four years, despite law requirements. This lack of waterway monitoring resulted in an increased number of impaired surface waters across the state.
Pesticide contamination in waterways is historically commonplace and widespread throughout U.S. rivers and streams, with at least five or more different pesticides present in 90 percent of water samples. Thousands of tons of pesticides enter waterways (e.g., rivers, streams, lakes, oceans) around the U.S. from agricultural and nonagricultural sources, contaminating essential drinking water sources, such as surface water and groundwater. Reports like these are essential in determining appropriate regulatory action to protect human, animal, and environmental health from chemical toxicant contamination. The report states, “[The] Department has not developed all required aquifer water quality standards, conducted key ongoing groundwater monitoring of the State’s aquifers, monitored for agricultural pesticides in groundwater and surrounding soil, or reduced the number of impaired surface waters in the State, limiting its ability to keep these waters safe from pollution.”
Arizona’s state Auditor General established this report to determine whether the ADEQ upheld the responsibility to develop aquifer water quality standards (AWQS). ADEQ’s Water Quality Division is responsible for waterway protection and improvement systems, including developing an AWQS to protect Arizona groundwater. These standards include conducting ambient groundwater monitoring, monitoring agricultural pesticides in groundwater and the surrounding soil, and reducing impaired surface waters in Arizona. Moreover, the report investigates whether ADEQ provided information related to per- and polyfluroralkyl substance (PFAS) contamination in waterways. To determine if ADEQ upheld its responsibility to protect groundwater, the auditors reviewed state and federal water laws, ADEQ website information, and documentation (i.e., policies, procedures, finances, annual reports, and staff interviews).
The report finds ADEQ did not develop the required AWQS for eight different toxicants, including arsenic, uranium, coliform bacteria, chlorite, chlorobenzene, haloacetic acid, bromate, and trihalomethane (e.g., chloroform). Therefore, aquifers that transmit liquid to groundwater tables lack protection from these contaminants, decreasing drinking water safety, especially for private well users. Additionally, the report finds that ADEQ did not fulfill AWQS development objectives for these eight contaminants for the past seven to 29 years. Since 2017, ADEQ evaded monitoring ambient groundwater responsible for detecting and evaluating the impact of chemical contamination. Furthermore, the Department failed to conduct state-required monitoring of groundwater and adjacent soil for agricultural pesticides. The ADEQ established a goal to reduce the total amount of impaired or contaminated surface water to meet federal surface water quality standards. However, between 2014 and 2020, the number of impaired surface waters in Arizona increased from 136 to 155. Lastly, although the Department aims to address the issue through various steps (i.e., monitorization, investigation, remediation), PFAS continues to contaminate Arizona’s (and the nation’s) waterways.
Pesticide contamination of surface and groundwater raises another issue of deficient waterway monitoring and regulations that allow pesticides to accumulate in waterways. One of the ways the U.S. Environmental Protection Agency (EPA) protects human and environmental health is by regulating pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and point source pollution in waterways as regulated by the Clean Water Act and Safe Drinking Water Act. However, EPA under the previous administration rolled back waterway regulations, which do little to protect aquatic ecosystem health that marine, and terrestrial species, including humans, require. Previously, U.S. Geological Survey (USGS)-National Water-Quality Assessment (NAWQA) has criticized EPA for not establishing sufficient water quality benchmarks for pesticides. According to NAWQA, “Current standards and guidelines do not completely eliminate risks posed by pesticides in waterways because: (1) values are not established for many pesticides, (2) mixtures and breakdown products are not considered, (3) the effects of seasonal exposure to high concentrations have not been evaluated, and (4) some types of potential effects, such as endocrine disruption and unique responses of sensitive individuals, have not yet been assessed.”
According to advocates, this report represents an all too familiar pattern of government and state agencies failing to uphold their responsibility to protect the public from toxic pollutants. Aquatic environments continuously encounter environmental pollutants, and this study demonstrates that certain unmonitored toxic compounds exceed federal drinking water standards. All eight contaminants lacking adequate AWQS have links to severe health problems, especially among vulnerable individuals such as infants/children, pregnant individuals, and the elderly or immunocompromised. These health issues range from kidney problems to an increase in various cancers. However, the ubiquity and persistence of certain compounds make it difficult to limit the number of toxicants that enter waterways. Many of the most commonly used pesticides in the U.S. are detectable in both surface and groundwater, which serve as drinking water sources for half of the U.S. population. As the number of pesticides in waterways increases, it has detrimental impacts on aquatic ecosystem health, especially as some chemicals work synergistically (together) with others to increase the severity of the effect. In addition to adverse health effects on marine organisms, these chemicals harm terrestrial organisms relying on surface or groundwater. The report, “Human Health and Ocean Pollution,” finds that the combination of nonpoint source chemical contamination from pesticide runoff can have an adverse synergistic effect on species’ health and ecosystem. Many of these chemicals cause endocrine disruption, reproductive defects, neurotoxicity, and cancer in humans and animals while being highly toxic to aquatic species.
Between 2009 and 2013, preceding this report, pesticide monitoring data show that ten pesticides have the potential to contaminate groundwater, including those containing active ingredients like chlorpyrifos, diuron, and quaternary ammonium compounds (quats). However, ADEQ states the Department halted pesticide groundwater monitoring owing to a lack of funding and staff. Although these pesticides were not present at concentrations polluting groundwater, these compounds can accumulate in soil and water, increasing concentrations over time. Furthermore, these pesticides cause adverse health effects: chlorpyrifos is neurotoxic, diuron is carcinogenic, and quats sensitize and irritate the respiratory system. Groundwater pollution is a significant issue, especially in the Southwestern United States. For the first time, the U.S. government announced a Colorado River water shortage. The river supplies water to nearly 40 percent of Arizona residents, in addition to other adjacent states. This announcement follows a 2020 groundwater model update from the Arizona Department of Water Resources that reveals there is not enough groundwater to legally meet dozens of developmental requirements and ensure a water supply for 100 years.
All aquatic environments are essential to human health and well-being, feeding billions, supporting millions of jobs, and supplying medicinal materials. Therefore, this report recommends ADEQ adopt legislation for AWQS to match that of federal drinking water standards or establish AWQS for the eight contaminants. The report recommends the following:
- “Conduct statutorily required ambient groundwater monitoring and agricultural pesticide monitoring in groundwater and soil.
- Perform a workload analysis to assess its costs for developing AWQS and conduct ambient groundwater and agricultural pesticide monitoring and then work with the Legislature to obtain the needed resources.
- Reduce the number of impaired surface waters in the State by developing and reviewing implementation plans for reducing impaired surface waters in a timely manner.”
Government and health officials must address chemical pollution to safeguard human general health, fitness, and well-being. Furthermore, climate crisis implications like melting glaciers present a new concern over the levels of chemical concentrations in waterways from pesticides and other persistent organic pollutants trapped in ice. Beyond Pesticides has long advocated for healthier and more environmentally friendly pest management practices to protect the environment and wildlife, particularly water resources. Therefore, pesticide use should be phased out and ultimately eliminated to protect the nation’s and world’s waterways and reduce the number of pesticides that make their way into drinking water. Replacing pesticides with organic regenerative systems conserves water, nurtures soil fertility, reduces surface runoff and erosion, and reduces the need for nutrient input (i.e., fertilizers). Most critically, organic systems eliminate the use of toxic chemicals that threaten so many aspects of human and ecosystem life, including water resources. For more information about pesticide contamination in water, see Beyond Pesticides’ article Pesticides in My Drinking Water? Individual Precautionary Measures and Community Action, where Beyond Pesticides states: “This problem requires individual precautionary measures and preventive, community-based action to protect [individual and public health] and ultimately, stop ongoing pesticide use that ends up in drinking water from numerous agricultural, public land, and home and garden use. Beyond Pesticides urges a solution that keeps pesticides out of the water, rather than trying to clean them up after they enter our waterways and drinking water supply.”
All unattributed positions and opinions in this piece are those of Beyond Pesticides.