31
Oct
Pesticide-Contaminated Water Wells Documented, Representing Widespread Poisoning
(Beyond Pesticides, October 31, 2024) Approximately four in ten private wells in the state of Wisconsin contain toxic pesticides and pesticide metabolites, according to findings released earlier this year from a 2023 survey, entitled Wisconsin Agricultural Chemicals in Wisconsin Groundwater, conducted by the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP) in partnership with U.S. Department of Agriculture’s (USDA) National Agricultural Statistics Service (NASS). An analysis of the survey findings from Wisconsin Public Radio determined that “more than half of 29 pesticide compounds detected are unregulated in groundwater.†Pesticides detected in this study include toxic herbicides atrazine, dacthal, metolachlor, and alachlor, commonly used by chemical-intensive corn and soybean growers throughout the United States, but they are particularly concentrated for use in Corn Belt states such as Wisconsin. Various neonicotinoid insecticides were also detected. Pesticide leaching into both surface water and groundwater continues to impose adverse health and environmental impacts on communities across the nation, leading to advocates pushing for organic land management principles and practices to avoid the continuous use of toxic pesticides.
Methods and Findings
“Of the 29 compounds detected, [Carla] Romano [groundwater specialist at DATCP] said 13 have established groundwater standards,†based on an interview conducted by Wisconsin Public Radio. “Nine pesticide compounds lacked any groundwater limits or health advisory levels. Seven only have health advisory levels.†A primary obstacle to establishing standards that state officials pinpoint is an insufficient amount of peer-reviewed research on the health and ecological impacts of various specific pesticides.
This survey is conducted on a five-year rotation basis, beginning in 1996, and has resulted in surveys in 1996, 2001, 2007, 2016, and 2023 to “assess the presence of agrichemicals in Wisconsin’s groundwater.†In each survey following the initial study, 50% of wells surveyed were already tested in the previous cycle with the other 50% newly selected, with state and national officials reporting that “[t]his rotation strategy enabled the identification of new areas with agricultural chemical presence within the state and allowed for tracking changes in pesticide concentrations over time.†The researchers used “a stratified random sampling†including NASS Land Use Strata for previously untested wells, providing data on the intensity of agricultural production on targeted land areas. Researchers describe the benefits of this research strategy as twofold:
- “First, samples were allocated proportional to agricultural intensity throughout the state.
- “Second, the current method allows for comparisons of water quality to agricultural intensity in addition to location within the state.â€
The topline statistic worrying public health and environmental advocates, as well as regenerative organic and organic farmers and landowners in the state, is that the “percentage of wells that contained a detectable concentration of a pesticide or pesticide metabolite was 43.1%, up from 41.7% of 2016 and 33.5% in 2007.†When comparing pesticide levels in waterways across different assessment years, DATCP arrives at some of the following additional conclusions:
- “Alachlor ESA [ethane sulfonic acid], a metabolite of alachlor — an active ingredient historically employed in herbicides targeting grass and broadleaf control — was identified in 97 samples from the same survey, despite the absence of currently registered alachlor products in Wisconsin.â€
- “The increase in the estimated detection rates for metolachlor ESA and atrazine TCR since 2007 may be partially attributed to the reduction of laboratory reporting limits, initiated in 2016, for a range of tested compounds, including metolachlor ESA, atrazine, and atrazine metabolites.â€
- “Between 2016 and 2023, the statewide detection rate for neonicotinoids increased by approximately 5%.â€
Regarding the detectability of pesticides and pesticide metabolites, a concentration is considered detected if it is reported as greater than the “respective reporting limit,†which is set by Wisconsin regulators. More than half of the detected pesticides do not have groundwater or health advisory levels, which demonstrates the pervasiveness of pesticide use and the lack of data tracking to assess short- and long-term health impacts.
The framing of these surveys regarding the statistical insignificance of changes in pesticide levels found in private waterways is viewed by advocates as an implicit acceptance by state and federal government officials of contamination and a failure to address the problem at its source: the continuous registration and use of toxic pesticides that ultimately breakdown in, and spread widely throughout waterways.
Pesticides, Waterways, and SCOTUS
Wisconsinites, as well as researchers, farmers, and advocates across the country, have spoken out against state inaction on pesticide contamination in groundwater.
In 2016, a Wisconsin family spoke out against groundwater contamination after their son was diagnosed with juvenile dermatomyositis, a rare inflammatory skin disease with unknown causes. Test results from the Wisconsin State Laboratory of Hygiene showed that their well-contained atrazine levels at twice the state and federal drinking water health standards; follow-up testing by DATCP found it was closer to triple the state health standard. While there are no conclusive studies linking pesticide exposure to this rare disease, atrazine exposure has been linked to serious respiratory and skin diseases. (See here for Daily News.)
During the Trump Administration, the U.S. Environmental Protection Agency (EPA) waived its requirement for Syngenta to monitor Midwest waterways for atrazine presence, alarming public health and environmental advocates across the region. This weakening of policies was consistent with the establishment of Navigable Waters Protection Rule in the Trump Administration, a precursor to the eventual SCOTUS decision in Sackett v. EPA (2023) in which Clean Water Act protections are only applied to contiguous “Waters of the United States†(WOTUS), excluding groundwater, ephemeral streams, and critical wetland ecosystems that do not connect directly to waterbodies that are not clearly defined under the WOTUS definition.
Recent research conducted by Yale University and the University of Massachusetts determined that the Sackett decision “endangered the drinking water sources of at least 117 million Americans by stripping protections from over half of the nation’s wetlands, as well as up to nearly 5 million miles of rain-dependent and seasonal streams that feed into rivers, lakes, and estuaries.â€
Further analysis of allowable groundwater levels for herbicides in Wisconsin specifically can be found in this Daily News here.
Pesticide Contamination, Biodiversity, and Public Health
Pesticide movement into waterways is a national and international reality for which there has been testing and numerous research efforts.
In 2021, a study published by the U.S. Geological Survey (USGS) determined that millions of people are drinking from groundwater reserves riddled with pesticide and pesticide metabolites or breakdown chemicals. More specifically, USGS researchers found that 41% of public drinking water supply wells are contaminated with pesticides. USGS, in a 2023 study published in Environment International, found that nearly half (45%) of U.S. tap water is contaminated with PFAS chemicals. Researchers note that USGS can only detect 32 of the more than 12,000 different types of PFAS and PFAS breakdown chemicals, thus indicating the number is most likely higher.
According to a Portland State University study in 2021, pesticide contamination is a threat to biodiversity considering the continuous use of pesticides in forest management practices on public lands threatens marine organisms along the West Coast of the United States, including indicator species such as clams, mussels, and bivalves (oysters). A 2024 study published in Aquatic Toxicology reviewed over 150 peer-reviewed studies that found pesticide contamination (including glyphosate, atrazine, bifenthrin, and imidacloprid) in algae populations disrupts the aquatic food web. In a study published in Science of the Total Environment, chemicals of concern, including pesticides, were identified as leaching into groundwater reserves in the Grombalia shallow aquifer feeding into the Wadi El Bay watershed in northeast Tunisia. The researchers determine their findings to be relevant for watershed management beyond this specific regional context, including relevance in areas with “high population density [with] intensive agricultural activity.â€
What are states doing to respond to pesticide movement and subsequent contamination? In Arizona, the state’s Auditor General reported the systemic failure of Arizona’s Department of Environmental Quality (ADEQ) to monitor groundwater reserves and soil for pesticides and other environmental contaminants in a 2021 investigation. Between 2013 and 2021, ADEQ 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. There have been some instances of government leadership, including in 2018 when the Vermont Department of Environmental Conservation denied a permit to apply toxic pesticides (Fluridone) to Lake Iroquois, a 237-acre spring-fed body of water used for public recreation.
This problem of pesticide contamination and government inaction is not limited to the state level but is a broader national regulatory system issue. On the topic of EPA regulation of PFAS, Public Employees for Environmental Responsibility (PEER) filed a lawsuit against EPA in June 2024 on behalf of Texas farmers impacted by PFAS-contaminated biosolid fertilizers, alleging EPA’s failure to live up to its statutory obligation under Clean Water Act Section 405(d) and 40 CFR Part 504 to identify and regulate toxic pollutants. (See Daily News here.) Beyond Pesticides joined a petition submitted by the Center for Food Safety and numerous other environmental, farmer, and grassroots organizations to hold EPA accountable in updating their regulatory approach to PFAS contamination. (See Daily News here.) On October 9, EPA issued the fifth Test Order pursuant to the Toxic Substances Control Act requiring Innovative Chemical Technologies, The Chemours Company, Daikin America, Inc., Sumitomo Corporation of Americas, and E.I. Du Pont de Nemours and Company to conduct testing on certain PFAS chemicals in their products as a part of the National PFAS Testing Strategy.
Considering recent major settlements—including a $1.185 billion dollar settlement in 2023 from pesticide manufacturers DuPont, Chemours, and Corteva to major cities across the U.S. for PFAS remediation and monitoring in public drinking water systems—advocates continue to mount public pressure for the federal government to take action.
Call to Action
Public health and environmental advocates see the persistent infiltration of toxic pesticides into common areas, including public drinking wells and waterways, as a failure of local, state, and national governments to adequately address the ongoing biodiversity and health crises compounded by the climate crisis. The National Organic Program prevents the use of toxic pesticides on certified land; however, advocates, farmworkers, and farmers acknowledge that the movement of pesticides off their target site poses an existential threat to safeguarding agroecological food systems.
See Actions of the Week for opportunities to pressure EPA to suspend the registration of atrazine and paraquat using the criteria established under The Dacthal Standard. See Beyond Pesticides’ ongoing campaign, Keeping Organic Strong, to ensure the integrity of organic standards and enforcement.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources: Wisconsin Public Radio, Wisconsin Department of Agriculture, Trade, and Consumer Protection
