PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate), or PFAS, are anthropogenic chemicals used in the manufacture of nonstick cookware coatings, breathable waterproof fabrics, carpet and textile finishes, treated food wrappers, wire coatings, aqueous film-forming foam, specialty dyes and paints, and other products.


The same properties that make PFAS durable and resistant also make them extremely persistent in the environment. Highly soluble in water, these chemicals do not degrade or bio-transform and do not precipitate or adhere to sediment. Even a small amount of PFAS can spread widely with groundwater flow and remain at detectable concentrations for years. Identifying a source can be difficult, and often there may be multiple sources.

The U.S. Environmental Protection Agency has determined that PFAS are suggestive of causing cancer in humans. In May 2016, the agency set a health advisory limit (HAL) of 70 parts per trillion (ppt) for the combined PFOA and PFOS level in drinking water. Michigan’s Department of Health and Human Services adopted using 70 ppt as the PFOA/PFOS limit in drinking water for decision making purposes. These levels are some of the lowest ever established for a contaminant. They represent a significant challenge for those who have used PFAS in manufacturing processes, who have used or are using firefighting foam, and who oversee water treatment and landfills because PFOA and PFOS have been found at low levels in many settings.

Informed decisions require reliable data

When measuring concentrations in parts per trillion, data quality and data reliability are critical. Barr has developed sample-collection best practices to avoid water-sample-and-blank cross contamination—and we’ve reduced or eliminated detectable concentrations of PFOA and PFOS in field blanks for over 10 years. We also work with laboratories to help them reduce or eliminate method blank cross contamination that may occur during sample handling and analysis, enabling our clients to make informed decisions based on reliable data. 

At Barr, we work with clients and regulators to help develop a clear understanding of PFAS fate and transport and hone the scope of data-collection efforts to focus on providing accurate information and developing long-term solutions. 

Project: multi-site PFAS remedial investigation and remediation

Barr is part of a collaborative consulting team conducting remedial investigations and feasibility studies for PFAS at multiple active and former manufacturing facilities in the eastern United States.

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Project: environmental support for post-fire cleanup at industrial facility

After a fire at a large industrial facility, Barr was hired to provide emergency response services and longer-term environmental monitoring activities to address PFAS contamination from fire-fighting foams.

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Project: preliminary feasibility study for PFAS-related water quality concerns

Barr evaluated the city of Bemidji's ability to provide drinking water that meets updated health-based advisory values for PFAS due to the use of aqueous film-forming foam for fire-suppression training at the Bemidji airport.

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Emerging challenges in biosolids management

Wastewater treatment plants, by separating solids from water, generate a residual organic material known as “biosolids.” For roughly half of the major municipal wastewater treatment plants (WTPs), disposal consists of providing biosolids for application to cropland, which beneficially increases the nutrient and organic content of the soil.

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Contact an expert

Ward Swanson

Chief Executive Officer, President

Adam Driscoll

Environmental Engineer

Tim Russell

Vice President, Senior Chemical Engineer