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Developing long-term PFAS solutions

August 15, 2022

Barr helped the City of Bemidji provide drinking water that met updated PFAS values from the Minnesota Department of Health.

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 may lead to an increased risk of some cancers, as well as other adverse health outcomes. 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.

Emerging challenges in biosolids management

By separating solids from water, wastewater treatment plants 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. However, public concerns over the presence of PFAS in wastewater have recently led to increased scrutiny over the use of biosolids. Losing the ability to land-apply biosolids would result in significant cost increases to both WTPs and farmers.

In addition to vegetables and other crops accumulating PFAS when fields are irrigated with contaminated water, the land application of biosolids can also add PFAS to the food supply. The extent of PFAS accumulation in crops, livestock, and dairy cow milk can be measured by established analytical techniques and characterized by recently developed mathematical models.

For the past 15 years, Barr has helped clients assess the fate and transport of PFAS; evaluate, permit, and design PFAS treatment and disposal options; sample and characterize wastes; and identify and reduce sources. For additional information, contact our team of PFAS experts.