Bloom-How to contaminate your yard with PFAS

DC Water is marketing its EPA-certified “Exceptional Quality” Class A Biosolids as a retail soil additive called Bloom. Biosolids are merely the sludge that comes out of a wastewater treatment plant. DC Water is not the first wastewater utility or DC area utility to turn its wastewater biosolids into a soil additive for home gardeners and crops for human consumption. AlexRenew sells their Class A Exceptional Quality bio-solids to farmers in Virginia; and some of the Class A Biosolids are combined with wood fines, creating a soil amendment product that they are calling “George’s Old Town Blend.”

At DC Water’s  Blue Plains and other sewer treatment plants primary treatment uses screens to remove large solids from wastewater which then sits in settling tanks, which are designed to hold the wastewater for several hours. During that time, most of the heavier solids fall to the bottom of the tank, where they become a thick slurry known as primary sludge.

The sludge is separated from the wastewater during the primary treatment is further screened and gravity is allowed to thicken the sludge in a tank. Then the sludge is mixed with the solids collected from the secondary and denitrification units. The combined solids are pumped to tanks where they are heated to destroy pathogens and further reduce the volume of solids. With treatment sludge is transformed (at least in name) to Biosolids.

In 2015 DC Water unveiled the newly completed and operational sludge treatment system. Blue Plaines now has Cambi thermal hydrolysis trains, four digesters, dewatering equipment and a combined heat and power plant that cost $470 million. The new digestor system uses thermal hydrolysis (heating to over 160 degrees under high pressure) followed by anaerobic digestors. This takes care of the pathogens.

Bloom is an “EPA approved Exceptional Quality Class A biosolids.” This means that Bloom has been tested for a limited list of contaminants.   Class A biosolids can provide essential plant nutrients, including slow-release nitrogen, and organic matter, by slowly add nutrients to the soil by naturally breaking down and decomposing into a plant-available form which is helpful in building healthy soil. However, we do not actually know what other contaminants are in the biosolids and  there are other ways to build healthy soil. The real need addressed is disposing of the biosolids. DC Water encourages the use of Bloom for water holding capacity, improving and establishing lawns, remediating poor soils, planting trees and shrubs, and establishing flower and vegetable gardens. I don’t think this is a good idea.

U.S. EPA regulations limit metals and pathogens in biosolids intended for land applications, but no organic contaminants are currently regulated under 40 CFR Part 503 Rule created in 1989 and still in effect today. Only metals and pathogens are tested for. It categorizes Biosolids as Class A or B, depending on the level of fecal coliform and salmonella bacteria in the material and restricts the use based on classification. There turns out to be many more contaminants in sewage sludge. Over the years controversy associated with potential impacts of Biosolids and the land disposal or reuse of Class B and even Class A Biosolids have grown.

The presence of other contaminants in the Biosolids has not been tracked, but has become an emerging area of concern. Previously, research at the University of Virginia found that organic chemicals persist in Biosolids and can be introduced into the food chain. Land application of biosolids is a widespread practice across the US and remains an approved method by the US EPA. This practice is now being questioned.

In April 2024, the EPA announced the final national primary drinking water standards for six poly- and perfluoroalkyl substances (PFAS). Public water systems have five years (by 2029) to implement solutions that reduce these PFAS if monitoring shows that drinking water levels exceed the maximum contaminant levels (MCLs). The limit for PFOA and PFOS at or near the MCL of 4.0 parts per trillion (ppt) individually. For PFNA, PFHxS, and HFPO-DA (GenX Chemicals), EPA is setting MCLs of 10 parts per trillion combined. Per- and Polyfluoroalkyl Substances (PFAS) do not occur in nature, they are an entirely synthetic substance and are highly stable which is how they got their nickname “forever chemicals.”

DC Water reports that they have tested Bloom for various PFAS chemicals. They have found concentrations of PFOS and PFOA within ranges of 4.60 to 16.1 parts per billion (ppb) and 1.7 to 3.7 ppb respectively – a thousand of times higher than the primary drinking water standard, but lower than than in food packaging materials; and cosmetics; and lower than the levels measured in dust. Bloom’s total combined PFAS levels average 130 ppb. Though very water soluble, PFAS are resistant to degradation and simply flow through the wastewater treatment plant. PFAS remains in the biosolids and effluent.

Though PFOS and PFOA have been eliminated from production, exposure to them is still occurring. Almost all of the PFOS and PFOA ever manufactured is out there still circulating in the hydrologic cycle. According to the National Institute of Environmental Health Sciences (part of the NIH): “People are most likely exposed to these chemicals by consuming PFAS-contaminated water or food, using products made with PFAS, or breathing air containing PFAS. Because PFAS break down slowly, if at all, people and animals are repeatedly exposed to them, and blood levels of some PFAS can build up over time.”

One report by the Centers for Disease Control and Prevention, using data from the National Health and Nutrition Examination Survey (NHANES), found PFAS in the blood of 97% of Americans. Even when/ or if the source of exposure is removed, measurable levels of PFASs may be detected in humans due to the relatively long half-life of these chemicals. The estimated half-life for PFOS, PFOA, and PFHxS in humans ranges from 3.8 to 8.5 years.  

Practically everyone has been exposed to PFAS and DC Water seems to want to assure that the PFAS out in the environment continues to spread. There are thousands of PFAS chemicals, and they are found in many different consumer, commercial, and industrial products.  PFOS and PFOA were used in Scotch Guard, the manufacture of Teflon and traditional Aqueous Film-Forming Foam (AFFF) - the Class B firefighting foam used to fight aviation and other chemical.

After AFFF is deployed in an emergency or training exercise, it can seep into the ground, or flow to the storm drain system and contaminate soil, surface water and groundwater. Then there was the wastewater from the manufacture of flame retardants, Teflon, Gortex, Scotch guard and other coating that was buried, ponded or simply released into streams. PFAS began to spread in the environment.

Then onto consumer products. Coatings were sprayed onto cans and food packaging. Wash water from light manufacturing or processing. Treatments for fabrics. The companies that applied the stain resistant and flame resistant treatments to carpeting, upholstery, clothing sent their wastewater to the wastewater treatment plants which cannot remove PFAS. PFAS containing packaging picked up traces of PFAS and it was passed onto people that way, too.

The PFAS ended up in the effluent and the biosolids. The reach and spread of PFAS was increased because effluent from wastewater treatment is released to rivers and used as source water for drinking water. Out it went to rivers and streams ultimately to the oceans. Fish and seafood were exposed to PFAS through the wastewater effluent as are we. The wastewater effluent is often upstream of drinking water plant intakes or intentionally reused. The Occoquan receives up to 40 million gallons a day of treated wastewater from UOSA.

Wastewater treatment plants generate biosolids which also are contaminated with PFAS. Biosolids were land applied in agriculture (cheap "natural" fertilizer in Maine) and buried in landfills. Animals grazed on the land, food grown on the land picked up some of the PFAS and passed traces into food. People passed it onto other wastewater treatment plants and the circle widened.

When our analytical methods were less precise and PFAS had less time to permeate our environments, we used to think that only people living near the industrial manufactures of PFAS, their industrial waste disposal sites or airports were exposed. The ability to measure parts per trillion disabused us of that belief and allowed us to understand we have helped spread PFAS almost everywhere .

We discovered that we are all exposed to PFAS in everyday life. Stain-resistant carpeting, nonstick cookware, grease- and water-proof food packaging, fabric softeners, waterproof clothing, cosmetics, and through our diet and water. PFAS- forever chemicals -are washed out of our clothing, carpeting, pans, skin and end up in our wastewater. There are numerous sources of exposure including: industrial emissions, PFAS-containing consumer products, contaminated drinking and surface water, house dust and food. I do not think it is appropriate to sell this product to spread it on our lawns (my pets lie on the lawn and eat the grass) and use it to grow the vegetables in my garden. We need to begin to extinguish the contaminants from the environment, and that should start by not spreading it further.