22
Oct
Studies Confirm Contaminants, Including PFAS, in Biosolids (Sewage Sludge) Fertilizer, Subject of Lawsuits
(Beyond Pesticides, October 22, 2025) The release of scientific studies on contaminants in sewage sludge (biosolids) used as fertilizers coincides with two lawsuits filed by Beyond Pesticides against ScottsMiracle-Gro and GreenTechnologies, LLC, in which the organization alleged that each defendant engaged in false and deceptive marketing and sale of fertilizer products that were marketed as environmentally friendly, despite containing per- and polyfluoroalkyl substances (“PFAS”). PFAS have been linked to cancer and other adverse effects. (See settlement statement recently reached with ScottsMiracle-Gro.) Biosolids are widely used in agricultural production and nonagricultural land management, including parks and playing fields, but prohibited from use in certified organic agriculture under the Organic Foods Production Act.
Two recent studies raise serious concerns about a range of contaminants in treated sewage sludge. While widely advanced as supplementing organic matter with macro- and micro-nutrients, treated sludge “harbor[s] a concentrated presence of contaminants that have adsorbed onto the soil post-wastewater treatment,” according to a literature review published in Frontiers in Environmental Chemistry. The researchers identify 414 contaminants of emerging concern (CECs) in soils, untreated and treated sewage sludge (biosolids), and dust, across 151 peer-reviewed studies released between 2018 and 2023—emphasizing the range of potential exposure pathways across various products, including classes of pesticides like neonicotinoid insecticides. In Scientific Reports, researchers report their test results of biosolids-treated farmland in southeastern Pennsylvania that detected 14 different PFAS (per- and polyfluoroalkyl substances) above the limit of quantification (LOQ). This means that not only were they detectable, but also high enough in concentration to confirm contamination at a significant concentration.
PFAS are a group of synthetic chemicals that are extremely resistant to degradation, persist indefinitely in the environment, bioaccumulate in blood and body tissues, and can be harmful to humans and the environment, even at very low levels.
Biosolids (Sewage Sludge) Lawsuits
Beyond Pesticides filed two consumer protection lawsuits in Washington, DC Superior Court in October, 2024, in which it alleges that both companies market their sewage sludge-containing fertilizer products “as eco-friendly and “sustainable,” when, in fact, the products contain hazardous substances. The Scotts Miracle-Gro Product, EcoScraps, was advertised as having a mission “to make sustainable living easy.” The Greentechnologies, LLC product, GreenEdge, is advertised as an “eco-Friendly product[] for a healthier planet,” and a “sustainable fertilizer that enhances environmental quality.” Beyond Pesticides alleged in the lawsuits that reasonable consumers encountering representations emphasizing that these products are “eco-friendly” and “sustainable” do not expect the products to contain environmentally damaging, unsustainable chemicals.” The complaint cites test results showing PFAS residues in the companies’ products and numerous scientific studies on the adverse effects of PFAS to public health, wildlife, and pollinators.
“Companies that market hazardous substances while claiming environmental and health benefits are misleading consumers who seek out products to protect themselves, their families, and the ecosystems in which they live,” said Jay Feldman, executive director of Beyond Pesticides. “Our litigation seeks to put a stop to this deceptive practice in the marketplace, where there are products and practices that are truly healthful and protective of nature,” Mr. Feldman continued. (The action was brought under the District of Columbia Consumer Protection Procedures Act (“CPPA”), D.C. Code §§ 28-3901–13. Beyond Pesticides was represented by Richman Law and Policy.
Contaminants of Emerging Concern (CEC) Study Results
Despite these dramatic findings of contaminants, the U.S. Environmental Protection Agency (EPA), the authors of the CEC review explain, classify the biosolids typically used by gardeners, municipalities, golf courses, and farmers as Class A, which are “virtually free of pathogens and can be applied without any site-specific restrictions.” The authors explain that Class B biosolids, used in agriculture and land reclamation, may contain pathogens and stipulates restrictions on use.
The study authors conducted a literature search strategy using databases like Web of Science, Scopus, PubMed, and Google Scholar. They utilized combinations of keywords including contaminants of emerging concern, biosolids, sewage sludge, soil, wastewater, pharmaceuticals, hormones, bisphenols, phthalates, parabens, neonicotinoids, etc.). They then screened and selected 151 articles to include studies reporting quantifiable data on CECs in sewage sludge or soils and relevant information on transport mechanisms or compound properties. The researchers included field and laboratory studies. CECs were grouped into several major categories, including pharmaceutical products, personal care products, hormones, plastic-related compounds, polymer additives and antioxidants, and insecticides (neonicotinoids).
Once the studies were identified, researchers analyzed data on quantifiable concentrations of the listed CECs. They were summarized as median and mean values for each category in sewage sludge, biosolids (treated sewage sludge), and soils. The top fifty most prevalent compounds were identified by frequency and degree of concentration; the relative contribution of CEC by mass was also determined. Qualitative data on transport mechanisms like adsorption, leaching, degradation, and plant uptake was considered in their analysis as well. The researchers did note that there are knowledge gaps in their review, including the fact that various CECs fall below quantification levels in soil, metabolites have limited data, and the lack of standardized methods across the scientific literature.
Phthalates (PAEs) dominated the balance of CECs, representing more than 97 percent of the total mass of CECs in sewage sludge and biosolids. Phthalates are hydrophobic compounds that lend themselves to strong retention in sewage sludge or soil. Meanwhile, conventional wastewater treatment processes only partially remove CECs, with many portioned into both treated and untreated sludge.
This literature review finds that neonicotinoid insecticides are also detectable in biosolids, sewage sludge, and soils across the globe, including China, Belize, and the Philippines (see subsection 8.3 for specific citations), indicating widespread environmental contamination even at low concentrations. The authors attribute the high-water solubility of neonicotinoids as a major contributor to its widespread runoff and leachability. Matched with poor plant absorption, the continuous use of neonicotinoids can lead to persistent residues in the soil.
This CEC study was published by researchers in the Department of Chemistry at Université de Montréal. The lead scholar is Sébastien Sauvé, PhD, professor of Environmental Chemistry with expertise in environmental analysis of CECs, including pesticides and PFAS. The authors declared that there were no competing commercial or financial conflicts of interest in conducting this study; they also “declare that no Generative AI was used in the creation of this manuscript.” The research was funded in part by Ministry of the Environment, Climate Change, Wildlife and Parks (MELCCFP) of Quebec (Canada).
PFAS, known as “forever chemicals” due to their ability to persist in the environment, are endocrine disruptors linked to developmental issues, cancers, metabolic, cardiovascular and reproductive harm, damage to the liver, kidneys, and the respiratory system, as well increased chances of disease infection and severity. The chemicals’ immunotoxic effects threaten human health.
PFAS in Farmland Soil
Biosolids contaminated with PFAS as become an increasingly prevalent issue for farmers grappling with reliance on synthetic inputs. This study was conducted by researchers at Stroud Water Research Center and Center for PFAS Solutions, independent nonprofit research organizations based in Pennsylvania and Delaware, respectively. The study focused on 10 farms in southern and central Pennsylvania (Berks, Lancaster, Bedford, and Chester counties). The field design included pairings of treated and control fields (history of biosolid treatment and no biosolid treatment), with all fields no-till or reduced-till in terms of cultural practices. For treated fields, most had been covered with biosolids between two to 26 years, with some farms not keeping historical records. Six farms used biosolids from private applicators while four sourced from municipal sewage treatment facilities, which will often distribute the biosolids as “fertilizer” or “compost” free of charge. Biosolids can also be purchased from commercial companies at local nurseries or hardware stores under different trade names with environmental claims.
PFAS is conventionally known as a legacy contaminant in firefighting foam, nonstick cookware, and other commercial and consumer products; however, there is less public awareness on the dangers of PFAS and agrichemical products (i.e., pesticides) that share its fluorinated chemistry. Concern among safety advocates continues to mount this year as EPA escalated registration approvals for four new active ingredients – Cyclobutrifluram, Diflufenican, Isocycloseram, and Trifludimoxazin – that “qualify as PFAS.”
The researchers collected ten soil samples (called “cores”) from each field. Biosolids were collected from storage piles at Farms #2 and #10 and stream water (duplicate samples) were collected downstream of treated fields. Cornell Soil Health Laboratory tested the soil chemistry for a standard analysis for nutrients, pH, organic matter, organic carbon, total carbon, and total nitrogen.
The researchers used “USEPA Method 1633” to target 40 PFAS, including:
- 11 PFCAs (perfluoroalkyl carboxylic acids)
- 8 PFSAs (perfluoroalkane sulfonic acids)
- 3 FTSAs (fluorotelometer sulfonic acids)
- 3 perfluorooctane sulfonamides
- 2 perfluorooctane sulfonamidoacetic acids
- 2 perfluorooctane sulfonamide ethanols
- 5 per- and polyfluoroether carboxylic acids
- 3 ether sulfonic acids
- 3 FTCA (fluorotelomer carboxylic acids)
For further details on PFAS analysis, quality control, and additional methodological background, see page nine of the study.
Researchers concluded that biosolids are a demonstrable source of PFAS contamination in agricultural soils, affected by soil properties, depth, and the source of the biosolid-based fertilizer. PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate), forms of PFAS, franged 1-24 ng/g, which is much higher than reported background levels in forest soils (less than 0.01 ng/g). PFAS concentrations in surface soils shared positive correlation with increased zinc, copper, and sulfur levels; conversely, PFAS concentrations correlated negatively with pH (6.1-7.5 range), with lower pH favoring PFAS partitioning (or distributing) into soil systems rather than water. The majority of farms found PFAS in the surface (0-15 cm) and subsurface (15-30 cm) soil samples, but the researchers reported detectable migration between surface levels.
Fields treated with biosolids had significantly higher PFAS concentrations than non-treated fields at most farms. Soils with biosolids sourced from private applicators were higher in median PFAS concentrations than those from municipal applicators, which the authors indicate is an effect of private applicators sourcing from multiple waste streams to create biosolid products that increases contamination risks.
A Total Oxidizable Precursor (TOP) Assay was conducted to confirm preexisting PFAS levels that may not be captured in the study analysis; after oxidation, the sum of the concentrations of 40 PFAS increased across water, soil, and biosolid samples.
In farms #2 and #10, concentrations of PFAS in biosolids, soil, and water samples were below EPA’s proposed draft acute and chronic water quality criteria; however, the lower detection of PFAS in soils relative to biosolids coupled with PFAS levels in nearby stream water documented at higher than typical levels for regional streams—975 ng/L (Farm #2) and 158 ng/L (Farm #10) relative to the typical reported environmental levels (0.8-112 ng/L).
Environmental and public health advocates emphasize the importance of identifying how chemicals of concerns, like PFAS, move between mediums (soil, water, fertilizer product, etc.). They say that this understanding should inform regulatory agencies’ efforts to protect the public and ecosystems from further harm.
Previous Daily News Reporting
There are numerous peer-reviewed studies that associate PFAS contamination through contaminants of concern detected in sewage sludge and biosolids. One contaminant of concern that was not explored in either of the highlighted studies is microplastic. A literature review of over 90 scientific articles in Agriculture documents microplastics’ (MPs) increase in the bioavailability, persistence, and toxicity of pesticides used in agriculture. The interactions between MPs and pesticides exacerbate the impact of pesticide exposure to nontarget organisms, perpetuate the cycle of toxic chemical use, and decreases soil health that is vital for productivity. (See Daily News here.)
Biosolid-based fertilizer products like Milorganite, often sold to consumers as “organic,” are contaminated with dangerous PFAS chemicals, according to a report published by Sierra Club and Ecology Center. (See Daily News here.) Community concerns mounted during the early stages of the Covid-19 pandemic when SARS-CoV-2 was being detected in wastewater, sewage sludge, and biosolids. (See Daily News here.)
For additional analysis on biosolid sewage sludge and potential toxic contamination, see this previous Pesticides and You article, Biosolids or Biohazards?
For discussion of eco-sensitive, health protective practices that are cost effective, consider attending Beyond Pesticides’ 42nd National Forum Series, The Pesticide Threat to Environmental Health: Advancing Holistic Solutions Aligned with Nature, which is scheduled to begin on October 29, 2025, 1:00-3:30pm (Eastern time, US) with a focus on aligning land management with nature in response to current chemical-intensive practices that pose a threat to health, biodiversity, and climate. The virtual Forum is free to all participants. 
Register here.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source
Beyond Pesticides v. The ScottsMiracle-Gro Company
Beyond Pesticides v. GreenTechnologies, LLC
