“Let’s move fast to stop non-essential uses of PFAS. Then let’s work carefully and more slowly on research and balanced regulation.”
— Dr. Linda Lee, Professor of Agronomy, Purdue University, MI WEA Biosolids Conference, Aug. 2020


PFAS in Biosolids (“sludge”) and Residuals

Recycling organic “wastes” benefits society and the environment.

Throughout the U. S. and Canada, biosolids (treated and tested sewage sludge), septage, paper mill residuals, composts, and other organic residuals are commonly recycled to soils. This recycling does amazing things:

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  • enhances soil health

  • recycles nutrients

  • sequesters carbon (mitigating climate change)

  • reduces fertilizer & pesticide use

  • strengthens farm economies (thousands of farmers choose to use biosolids, because they work)

  • restores vitality to degraded lands

  • puts to productive use residuals that every community has to manage.
    (Wastewater treatment is a vital public health service, and it creates residual solids that have to be managed!)

Sustainability & healthy soils require recycling organic residuals. Explore our website to see why.

Best Resources:

Water Environment Federation’s PFAS Website

Response to Maine’s proposed biosolids ban - Op Ed, Portland Press Herald, 15 March 2022.

CASA PFAS & Biosolids Info & Fact Sheet (2021)

Excellent approach to addressing PFAS in biosolids: Madison, WI Fact Sheet, Dec. 2020

PFAS & Biosolids & Septage on NE Farms
May 2020, updated December 2021


Michigan’s biosolids PFAS interim strategy is recommended:

Madison Metropolitan Sewerage District PFAS Initiative website

PFAS in Agriculture: USDA NRCS Webinar

Feb. 19, 2021
Dr. Linda Lee (Purdue Univ.) & Ned Beecher (NEBRA)

Evaluation of Current Alternatives and Estimated Cost Curves for PFAS Removal and Destruction from Municipal Wastewater, Biosolids, Landfill Leachate, and Compost Contact Water by Minnesota Pollution Control Agency (May 2023)

Minnesota Pollution Control Agency’s PFAS Studies and Reports


The Impact of PFAS on Municipal Utilities and Biosolids Management: A Cost Analysis
by CDM Smith, October 2020 (rev. Jan 2021)

EPA PFAS Science Webinar Slides, Sept. 2020, includes PFAS and biosolids…

PFAS Regulatory Limits in Drinking Water & Other Media, v.6, August 20, 2020

Minnesota’s PFAS Blue Print (report)
PFAS Blue Print (additional information)
February 2021

ITRC Interstate Council PFAS Resources, including April 2020 Technical/Regulatory Guidance

See News for additional PFAS developments.

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NEBRA’s Letter to the Editor of the Globe, 12/4/19:

“Group is on the front line of water quality protection...

The article “From sludge to fertilizer to growing fears” (Page A1, Dec. 2) focused on a relatively minor aspect of the PFAS issue. Per- and polyfluoroalkyl chemicals unfortunately are widespread in the environment from decades of consumer use in myriad products. This includes detectable levels in soils and human blood. PFAS levels in Massachusetts Water Resources Authority fertilizer are not much different from levels in food waste compost or septic systems. Levels in household dust are four times higher and a more likely source of exposure.

Using biosolids makes soils healthier, reduces irrigation requirements, and reduces atmospheric carbon by storing it in the soil. Stopping the use of biosolids would cause disruption of important public health and environmental programs and increase costs to communities, without necessarily making a significant difference in levels of PFAS in the environment.”
— Janine Burke-Wells, Executive Director, NEBRA

PFAS are in biosolids, septage, paper mill residuals, digestates, composts, & soils.

Of course they are, usually in trace amounts. Because these materials reflect the chemistry of our daily lives. PFAS are a family of chemical compounds commonly used in many different products we encounter in our daily lives, which is how we are exposed to them and how they end up in trace amounts (parts per billion or less) in wastewater and biosolids and other residuals. Fortunately, PFOA and PFOS, the most concerning and most-researched PFAS, have been mostly phased out, reducing potential risk. Such source reduction is the most efficient action to reduce risk - and it reduces potential concerns related to PFAS in recycled biosolids and residuals.

See InfoGraphic on PFAS in everyday products versus various composts.

See Bar Graph from CASA on the relative concentrations of PFAS from various sources in our environment.

PFAS Concentrations and Exposure Fact Sheet from the National Waste and Recycling Association and the Solid Waste Association of North America

Data Sources for PFAS in Various Media:

GeoTracker PFAS Map (ca.gov) — California. For biosolids data, uncheck everything but wastewater facilities and at the bottom check “solid” for the matrix.

Massachusetts: Energy & Environmental Affairs Data Portal (state.ma.us)
Also see: Review of PFAS data collected for the Massachusetts Department of Environmental Protection Biosolids and Residuals Program, 2020-2021 (Data Summary and Quality Control Report)

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General information about PFAS:

Interstate Council Fact Sheets
U. S. EPA PFAS webpage
U. S. CDC PFAS health info
Australian Health Expert Panel Report

Common products containing PFAS:

Textile treatments • Paper coatings • Paints • Surfactants • Pesticides • Fire-fighting foam • Floor/Ski polish • Photographic film • Denture cleaner • Mining fluids • Polymers • Non-stick cookware • Adhesives • Caulks • Lubricant additive • Carpets • Food wrappers See more.

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Industry, military uses, & fire-fighting are the sources of high levels* of PFAS contamination in the environment.

Almost all of the known sites (e.g. see EWG map) with high levels* of water and soil contamination by PFAS are directly related to:
a) industrial uses of significant volumes of PFAS with direct discharges to land or air, or
b) firefighting and fire training sites, including military sites and airports.

These are the sites that deserve and are getting the highest level of federal Department of Defense (DoD), U. S. EPA, Health Canada, and state and provincial environmental agency attention.

Example: Pease International Tradeport drinking water well impacted by fire-fighting foam: 2,500 ppt PFOS in 2014.

*”high levels” means well above - often far above - EPA’s 70 ppt public health advisory level for drinking water - in the 1000s or 10,000s parts per trillion

In contrast, wastewater, septage, & biosolids are usually part of low-level “ambient background” levels (Figure 1).

Wastewater, septage, and biosolids are not “sources” of PFAS.

Figure 1: Point sources vs. ‘ambient background’ PFAS. Source: Dr. Bradley Clarke, RMIT, Per- and polyfluoroalkyl substances (PFAS) in Australia, Dec. 2017 slide presentation to Water Research Australia

Figure 1: Point sources vs. ‘ambient background’ PFAS.
Source: Dr. Bradley Clarke, RMIT, Per- and polyfluoroalkyl substances (PFAS) in Australia, Dec. 2017 slide presentation to Water Research Australia

Wastewater treatment processes do not utilize PFAS chemicals. Wastewater, septage, and biosolids receive and convey traces of PFAS that we use and encounter in our daily lives. Only in a few worst-case scenarios have wastewater and biosolids been implicated in PFAS water contamination at levels of concern (e.g. near or above 70 ppt in water). These rare cases are where there has been ongoing discharges to the sewers from industrial facilities or fire-fighting using significant volumes of PFAS. In response to these rare situations, PFAS levels in wastewater and biosolids have been reduced efficiently by investigating industries discharging to the sewer system and stopping their discharges through industrial pretreatment requirements and other source controls.

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Levels compared to biosolids:

Foundation cosmetic: up to 2,370 ppb PFOA (1)
Pork liver in Taiwan: up to 283 ppb PFOA (2)
Dust in daycare center: 142 ppb PFOA median (3)
Household food waste: 6 ppb all PFAS mean (4)
U. S. human blood serum: 2 ppb PFOA mean (5)
Control garden soil: .36 ppb PFOA median (6)

NH biosolids, 2018 (n = 20): 2.3 ppb PFOA mean
ME biosolids, 2019 (n = 55): 3.8 ppb PFOA median
ME biosolids field soils (n = 29): 3.1 PFOA mean
(after decades of annual biosolids use)
ME cow feed & milk from those fields: Non-detect

When biosolids are applied to soil, they are diluted ~200 times. So a typical NH biosolids application will result in soil levels at 0.012 ppb PFOA, for example. Compare that to control (background) garden soil, above.

(1) Danish study, Oct. 2018
(2) Chen et al., 2018
(3) Strynar and Lindstrom, 2008
(4) Brandli et al., 2006
(5) NHANES, 2012
(6) MN Dept. of Health, 2005

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What is a part per trillion (ppt)?

PFAS in drinking water and other waters is usually reported in ppts.

1 ppt = 1 second in ~31,700 years

OR

1 ppt = 1 drop of water in 20 Olympic-sized pools

(assuming ~590 drops / oz. and ~660,000 gallons in an Olympic-sized swimming pool)

OR

1 ppt = 1 drop of water in a pool of water the size of a football field and 30.7 feet deep.

(a U. S. football field is 160 x 360 feet)

What is a part per billion (ppb)?

A ppb is 1000 times more than a ppt. It is 1 second in 31.7 years. PFAS in soils, sediments, biosolids, and residuals are usually reported in ppbs.

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PFAS in our daily lives:

PFAS exposure from biosolids/residuals is unlikely & minimal.

Risk assessments by states (ME, NH, NY, VT, etc.) have determined that direct contact, inhalation, or ingestion of typical biosolids and other recycled residuals pose no significant health risk, including from the traces of PFAS they contain. Typical levels of PFAS in modern residuals are ~10 times less than the most stringent direct contact standard for soils, which is 300 ppb (ME, VT). And, when biosolids/ residuals are applied to soils, they are diluted (typically 200 times), further reducing potential exposure.

Can PFAS leach from soils amended with biosolids & residuals and affect ground- & surface water?

This is the one concern that has been raised regarding PFAS in biosolids and residuals. Research shows this is a possibility. But that research and investigations by state regulators indicate that typical biosolids with no direct large industrial inputs are unlikely to impact ground- and surface waters at levels above U. S. EPA’s health advisory level for drinking water (70 ppt), even with repeated applications. Therefore, the PFAS conveyed in modern wastewater, septage, biosolids, and other residuals are similar to numerous other incidental, minor releases of PFAS to the environment and are no greater risk to public health than those other releases from daily activities. (See all the ways we use PFAS.)

Common use of many different PFAS chemicals means that there are many releases of traces of PFAS to the environment from daily living. PFOA and PFOS, the most concerning PFAS, have been mostly phased out, reducing potential risk. Such source reducti…

Common use of many different PFAS chemicals means that there are many releases of traces of PFAS to the environment from daily living. PFOA and PFOS, the most concerning PFAS, have been mostly phased out, reducing potential risk. Such source reduction is the most efficient action to reduce risk - and it reduces any potential concerns related to PFAS in recycled biosolids and residuals.

What can be done?
Steps we are taking to reduce potential risk

Wastewater treatment facilities and biosolids and residuals managers - who serve public health 24/7/365 - are taking proactive measures to address potential risks from PFAS in wastewater, biosolids, septage, and other residuals.

And we are proactively advancing further research on the one important concern - the potential leaching of PFAS into ground- and/or surface waters.

In the meantime, we have published Interim Best Management Practices for PFAS in Biosolids & Residuals (January 2019).

The most significant action we can all take is to support removal from commerce of chemicals of high risk. That reduces risks to human health - and it also reduces potential concerns related to wastewater, biosolids, septage, and other residuals.

We support source reduction and pollution prevention in the case of the most concerning PFAS, just as we have with regards to other trace chemicals of high concern in the past. The two most prominent PFAS - PFOA and PFOS - have been phased out of commerce, and this has been the most important reduction in potential PFAS risk of any action in the past 15 years (see details at bottom of page).

You can help: think about what you buy and what you use.

More details:

PFAS, the Clean Water Sector and Advocacy Asks, NACWA & WEF, Fall 2021 Update, Sept. 2021

ITRC Interstate Council PFAS Resources, including April 2020 Technical/Regulatory Guidance

PFAS Regulatory Limits in Drinking Water & Other Media, v.6, August 20, 2020

WEF PFAS Position Statement, April 7, 2020

Dr. Linda Lee, Purdue Univ., discusses the science and data of PFAS in biosolids, Words On Water, WEF, Feb. 3, 2020.

Managing PFAS Chemicals in Composting and Anaerobic Digestion, BioCycle CONNECT, Jan. 21, 2020

National Water Quality Groups’ Letter to Congress, Jan. 8, 2020, regarding H. R. 535, The PFAS Action Act

National PFAS Fact Sheet, Jan. 2020, by the “receivers” coalition - NACWA, WEF, AWWA, SWANA, etc.

Green Mountain WEA’s PFAS Fact Sheet, January 2020

NEBRA Comments to NH Senate ENR Committee re PFAS drinking water standards & cost-benefit analysis:
January 14, 2020 and January 21, 2020

Beecher/NEBRA, 2019: Emerging regulatory controls on PFAS, NEWEA Journal, Vol. 53, No. 4, Winter 2019

Data: PFAS in Biosolids & Related Media, NEBRA compilations of representative data, with context, November 1, 2019.

The Cost to Your Community of Chasing Background Levels of PFAS, Nov. 25, 2019, Bloomberg Environment (commentary)

Maine Farm PFAS Concern - Information Update - March 26, 2019 (This addresses the original Maine farm; in 2021, a second Maine farm was in the news; investigation ongoing.)

PFAS and Recycling: Putting Them in Perspective (March 2018)

Interim Best Management Practices for PFAS in Biosolids & Residuals (January 2019)

NEWEA Position Statement on PFAS & Wastewater/Biosolids, April 2019

Concerns regarding regulation of PFAS, expressed in a collaborative letter to U. S. EPA (July 2018)

PFAS news in our “News Archives”

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December 2019: The Boston Globe Raised Concerns About PFAS in Boston/MWRA Bay State Fertilizer

NEBRA provided the following to the Globe reporter in advance of publication in response to his question:
Should Boston’s Bay State Fertilizer continue to be recycled when it contains PFAS (and considering the Precautionary Principle)?
—Here is the paper cited in NEBRA’s response: Marc Hébert: Biosolids Application and the Precautionary Principle, 2011 (English version)
—Additional comment on the Globe story.
—MWRA presentation about PFAS in Boston wastewater, Oct. 2019.

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Additional NEBRA PFAS & Biosolids References & Resources

Contact NEBRA at info@nebiosolids.org or 603-323-7654 for further info & assistance.

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What works:

Phasing out use of concerning chemicals, such as PFOA and PFOS, leads to reduced human exposure. The voluntary reductions in use of PFOA and PFOS in consumer products and businesses has yielded lower levels in humans, according the U. S. Centers of Disease Control. It has also resulted in lower levels in biosolids.

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