There are Elephants in the Room While We Talk About PFAS Contamination of Land and Water.

PFAS contamination of water systems and municipal sewage sludge is in the news across the nation. You know, those “forever chemicals.” Today the national news focus has shifted for a second time to Spokane County. First it was the massive 2017 contamination of drinking water wells in a residential area near the Spokane airport prompting on-going lawsuits and investigations and the handing out of free water filters and bottled water to hundreds of affected residents. Now, as the result of a first-of-its-kind nationwide study of the downstream consequences of wastewater treatment plants and fields where the sewage sludge is spread as fertilizer, Spokane County comes out as the location where the largest increase of PFAS in the country around a field on which sewage sludge was spread was found. It’s in the Dragoon Creek area where total PFAS levels jumped from about 0.63 ppt upstream from the site to about 33 ppt downstream from it– an increase of over 5,100%. It’s nowhere near the airport.

Image from the Waterkeeper Alliance report

The Environmental Protection Agency sets the baseline regulations for the states that administer the disposal of municipal sewage sludge. The EPA has evidence of the presence of 'contaminants of emerging concern' that are regularly found to be present in municipal sewage sludge intended for application to farmland. That is, when the sludge is tested for those substances. Normally, it isn't. Regulations governing the land application of sewage sludge do not require any testing for contaminants of emerging concern. As a result, no one knows whether or in what concentrations other contaminants of emerging concern might be present in any given batch of the stuff.

In Washington, the Department of Ecology regulates the disposal of municipal sewage sludge whether it’s applied to farmland or landfilled, but it must follow the federal rules set by the EPA.

For many years, the state of Washington has been home to a rag-tag team of agitators who have questioned the wisdom of spreading filth contaminated with toxic chemicals onto the soil in which we grow our food (not to mention what the errant practice does to the surrounding ecosystems and wildlife). See the Protect Mill Canyon Watershed website for a local example. The double whammy that Spokane is currently experiencing around PFAS will hopefully prompt loud demands from the public, effective actions by officials and a strong push for accountability to address the issue. What do the rag-tag agitators want to see as one outcomes of this effort? It would be for everyone to begin to see PFAS as an indicator chemical which, when found, should also trigger assessments of the other toxic contaminants that are known to be consistently present in sewage sludge but are, like PFAS has been until recently, simply ignored. There was never the political will to follow through with its own recommendations that EPA expand its testing and regulatory framework to include any of the other "emerging chemicals of concern." Not ever since the original handful of substances that are required to be tested for was adopted 50 years ago.

It's "good" that PFAS has brought attention to the risks involved when waste management is handled with more concern for dollars and cents than with common sense. No one wants to see the focus of activism diverted away from PFAS contamination, but we need to be quite done with everyone ignoring the other elephants in the room.

Here’s a list of the EPA’s 'contaminants of emerging concern’:

The U.S. Environmental Protection Agency (EPA) has identified several "contaminants of emerging concern" (CECs) in municipal sewage sludge (often referred to as biosolids when treated for land application). While the EPA recognizes a broad range of CECs, their primary focus and the highest level of concern regarding land-applied sewage sludge currently center on Per- and Polyfluoroalkyl Substances (PFAS).

Here's a breakdown of the contaminants and their attributed level of concern:

Highest Level of Concern:

• Per- and Polyfluoroalkyl Substances (PFAS):

• Specifically, Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS) are the two PFAS chemicals that the EPA has prioritized for risk assessment in sewage sludge.

• The EPA's draft risk assessment (released January 2025) indicates that acceptable risk thresholds may be exceeded when sewage sludge containing PFOA and PFOS is land-applied. These chemicals are known as "forever chemicals" due to their persistence in the environment and have been linked to various adverse human health effects, including cancer, liver and kidney issues, decreased birth weight, and diminished immune response. They can contaminate crops, livestock, and groundwater.

• While PFOA and PFOS manufacturing has been largely phased out, their persistence and the continued release of other PFAS precursors into wastewater streams mean they accumulate in sewage sludge.

PFAS are a leading concern for the EPA in biosolids, and a significant portion of these "forever chemicals" comes from industrial activities. PFAS have been widely used in manufacturing processes for products like:

• Non-stick coatings: (e.g., Teflon)

• Water and stain repellents: (e.g., in textiles, carpets, outdoor gear)
   

• Firefighting foams (AFFF): Used at military bases and industrial sites
   

• Industrial surfactants and emulsifiers: In various manufacturing processes
   

• Chrome plating, paper and packaging, and other industrial applications.

Wastewater treatment plants receive discharges from industrial facilities, and PFAS, due to their persistence, accumulate in the solid portion, which becomes biosolids. The EPA's ongoing risk assessment and potential future regulations for PFAS in biosolids directly address this industrial contribution.

The Washington State Department of Ecology has in recent years increased activity to address the PFAS contamination crisis. See a sampling of Ecology’s efforts.

Other Contaminants of Emerging Concern (with varying levels of current EPA-specific regulation/focus in sewage sludge for land application):

The EPA has acknowledged and conducted surveys for a wider range of CECs in sewage sludge, though they haven't yet reached the same level of regulatory action or explicit risk assessment for land application as PFOA and PFOS. This is a nice way of saying the EPA has not been given a political mandate (thanks to powerful lobbying from the waste management industry) to even lift a finger to establish any meaningful risk assessments or testing requirements when it comes to these other contaminants of emerging concern. These include:

• Pharmaceuticals and Personal Care Products (PPCPs): This broad category includes substances like:

• Antibiotics (e.g., tetracycline, sulfamethoxazole)

• Antidepressants (e.g., Prozac/fluoxetine)

• Hormones and steroids (e.g., estrogens, testosterone, progesterone)

• Antimicrobials/Disinfectants (e.g., triclosan, triclocarban)

• Anti-inflammatories, analgesics (e.g., ibuprofen, acetaminophen)

• Other consumer product chemicals (e.g., fragrances, detergents, plasticizers)

• Other Synthetic Chemicals:

• Brominated Diphenyl Ethers (PBDEs): Flame retardants.

• Pesticides: While generally regulated, some may be considered CECs in this context if found unexpectedly or at concerning levels in sludge.

 

Other Industrial Chemicals and Waste Products:

The EPA conducts regular "biennial reviews" and "national sewage sludge surveys" to identify additional pollutants present in biosolids. These reviews have detected a wide range of chemicals, many of which are associated with industrial activities. Examples of classes of chemicals that can originate from industrial sources and be found in biosolids include:

• Heavy Metals: While some metals are naturally occurring, industrial discharges (e.g., from electroplating, mining, battery manufacturing) can contribute to elevated levels of metals like lead, cadmium, mercury, chromium, arsenic, and nickel in biosolids. The EPA already has regulations for certain heavy metals in biosolids, but ongoing monitoring for emerging concerns continues at a snail’s pace.
   

• Polychlorinated Biphenyls (PCBs): These were widely used in electrical equipment, coolants, and other industrial applications before being phased out. They are persistent organic pollutants that can accumulate in biosolids. The EPA has conducted risk assessments for PCBs in sewage sludge.
   

• Dioxins and Furans: These are unintentional byproducts of various industrial processes, including combustion, chemical manufacturing (e.g., in pesticide production), and pulp and paper bleaching. They are highly toxic and persistent.
   

• Certain Solvents and Volatile Organic Compounds (VOCs): Industrial cleaning, manufacturing, and chemical production can contribute a variety of solvents (e.g., trichloroethylene, benzene, carbon tetrachloride, methylene chloride) to wastewater that can end up in biosolids.
   

• Brominated Flame Retardants (PBDEs): Used in plastics, textiles, and electronics, these can enter the waste stream from manufacturing and consumer product disposal.

The EPA also acknowledges some industrial chemicals and industrial waste products as contaminants of emerging concern in biosolids. In fact, many of the CECs found in biosolids originate from industrial sources, in addition to household and commercial sources.

 

EPA's Approach to Addressing Industrial Contributions:

• Clean Water Act (CWA) Pretreatment Program: The EPA tries to implement pretreatment programs under the CWA to control industrial discharges into municipal wastewater treatment plants. This program aims to prevent harmful pollutants, including industrial chemicals and waste products, from interfering with treatment plant operations or passing through into biosolids or receiving waters.
   

• Risk Assessments and Biennial Reviews: The EPA claims to regularly assess pollutants in biosolids to determine if they pose risks to human health or the environment. These assessments, if actually performed, would inform potential new regulations or management practices. Alas, there is neither the will nor the budget to back up their claim.
   

• PFAS Strategic Roadmap: As part of this roadmap, the EPA says it’s working to restrict PFAS from entering the environment, which includes focusing on industrial dischargers and encouraging states to use their Clean Water Act permitting authorities to address PFAS at the source. Unfortunately, the EPA is all rhetoric and its efforts to restrict PFAS from entering the environment are insignificant in relation to the problem.

In essence, the EPA recognizes that municipal sewage sludge is a sink for various substances from diverse sources, and industrial inputs are a significant component of the "contaminants of emerging concern," however, EPA is not actively investigating and seeking to manage much other than PFAS.

Micro-plastic as a contaminant of emerging concern

The EPA acknowledges microplastics as a contaminant of emerging concern (CEC). While PFAS have taken a more prominent and urgent regulatory focus in biosolids due to their direct toxicity and persistence, microplastics are a recognized and significant area of ongoing research and concern for the EPA, so says the agency.

Here's why and what the EPA is doing:

• Widespread Presence: Microplastics are ubiquitous in the environment, including in wastewater and subsequently in sewage sludge (biosolids). Wastewater treatment plants are effective at removing a large percentage of microplastics from the water phase, but this means these plastics accumulate in the solid sludge.
   

• Sources: Microplastics in wastewater come from a variety of sources, including:

• Synthetic textiles: Washing clothes made of synthetic fibers (e.g., polyester, nylon) releases microfibers.

• Personal care products: Some cosmetics and toothpastes used to contain microbeads (though these are largely phased out in the US now).
   

• Tire wear particles: From vehicle tires.
   

• Breakdown of larger plastics: Litter and other plastic waste in urban and industrial runoff break down into smaller pieces.5
   

• Industrial processes: Plastic manufacturing and recycling facilities can be direct sources.6
   

• Environmental and Health Concerns: The EPA and other scientific bodies are concerned about microplastics for several reasons:
   

• Persistence: Like PFAS, plastics are highly persistent in the environment and do not readily biodegrade.
   

• Physical impacts: Microplastics can be ingested by organisms, potentially causing physical harm, blockage, or altering digestive processes.
   

• Vector for other contaminants: Microplastics have a large surface area and can sorb (adhere to their surface) other hazardous chemicals, including heavy metals, PFAS, and persistent organic pollutants. This means they can act as carriers for these toxins, potentially facilitating their uptake into organisms and the food chain.
   

• Unknown long-term effects: The full ecological and human health impacts of chronic exposure to microplastics (especially nanoplastics, which are even smaller) are still being researched. There are concerns about their potential to enter cells, tissues, and organs.
   

• EPA's Research and Activities: The EPA claims to be actively engaged in addressing microplastics:
   

• Research: The EPA conducts and funds research on microplastics, focusing on:

• Developing and standardizing methods for collecting, extracting, quantifying, and identifying microplastics in various environmental matrices, including biosolids.15 This is a crucial step, as a lack of standardized methods makes it difficult to compare studies and establish consistent regulations.
   

• Understanding their sources, transport, and fate in the environment.

• Assessing their ecological and human health impacts, including potential toxicity and how they interact with other contaminants.
   

• Exploring solutions for their removal and degradation in wastewater treatment.
   

• Expert Workshops and Reports: The EPA has convened expert workshops and published reports (e.g., "Report on Priority Microplastics Research Needs") to identify information gaps and prioritize research efforts.
   

• Clean Water Act (CWA) Framework: While no federal regulations specifically for microplastics in biosolids exist yet, the EPA recognizes that microplastics pollution falls under the broader aims of the CWA, and future regulatory actions could be considered.
   

P3 Program: The EPA's P3 (People, Prosperity, and the Planet) student design competition has included projects focused on the biodegradation of microplastics in water treatment.