A recent study by environmental groups found that you were unwittingly spreading “chemicals forever” on your lawn and garden in the form of fertilizer.

And that sounds scary, especially because one of the fertilizers tested was the famous Milorganite from Milwaukee.

But PFAS in fertilizers is not only a problem for those who grow their own fruits and vegetables. Experts said the PFAS found in wastewater treatment plants likely came from elsewhere, meaning industrial users are still not properly filtering harmful compounds from their waste streams before releasing them into the system. sanitation.

Here’s what you need to know about Milorganite, study, and what to do:

What is Milorganite?

Milorganite – the name is derived from Milwaukee organic nitrogen – is made up of heat-dried microbes that digest organic matter in wastewater, made by the Milwaukee Metropolitan Sewerage District, according to MMSD captures the wastewater that flows through it and uses natural microbes to digest nutrients commonly found in waste, such as nitrogen, phosphorus, and potassium.

Once the organic material is consumed, the clean water is then returned to Lake Michigan and the resulting material is dried and sold as fertilizer.

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Why do people like it?

Users generally prefer Milorganite because it is considered an organic fertilizer. According to the company, the fertilizer works with nature and can help build healthy soil.

Where is it made?

Milorganite is manufactured in Milwaukee by MMSD. The Sanitation District provides services to approximately 1.1 million people in 28 communities in the Milwaukee area.

MMSD has been producing the fertilizer since 1926 and selling it in the United States and Canada. It is billed as “one of the oldest recycling efforts in the country”.

What did the Sierra Club study find about fertilizers?

The study, which was carried out by both the Sierra Club and Michigan Ecology center, found that several fertilizers purchased across the country contained PFAS. All fertilizers contained at least 50% biosolids.

The study tested nine common fertilizers:

  • ProCare Natural Fertilizer, purchased from Lowes, made from 85% to 91% biosolids from several locations in Georgia.
  • EcoScraps Slow Release Fertilizer, purchased from Home Depot, made with 100% biosolids from unknown sources.
  • Milorganite Fertilizer 6-4-0, purchased from Home Depot, 100% Biosolids from the Milwaukee Metropolitan Sewerage District.
  • Dried Bloom Conditioner, purchased from a store in Washington, DC, made with 100% biosolids from the Blue Plains Advanced Wastewater Treatment Plant in Washington, DC
  • Menards Premium Natural Fertilizer, purchased from Menards, made from 100% biosolids from unknown sources.
  • GreenEdge Slow Release Fertilizer, purchased from Home Depot, made with 100% biosolids from the JEA Sewer Collection System in Jacksonville, Florida.
  • Earthlife Natural Fertilizer, purchased from a store in Eliot, Maine, made with 100% biosolids from the New England Fertilizer Company in Quincy, Massachusetts.
  • Synagro Granulite fertilizer granules, purchased in Sacramento, Calif., made with 100% biosolids from the regional Sacramento wastewater treatment plant.
  • TAGRO mix, purchased from Ace Hardware, which is 50% biosolids from the central wastewater treatment plant in Tacoma, Wash.

What are PFAS?

PFAS, known as “forever chemicals” are per- and polyfluoroalkylated substances. This is a group of man-made chemicals used for their water and stain resistance qualities in products such as clothing and rugs, non-stick cookware, packaging, and fire-fighting foam. .

The chemicals are persistent and remain both in the environment and in the human body over time. The build-up of chemicals in the body has been linked to cancer, according to studies, or to other adverse health effects.

Are there PFASs in Milorganite?

Yes a bit PFAS were found in the popular fertilizer. PFOA and PFOS, two of the most studied forms of the chemicals, have both been detected.

PFOA was detected at 0.67 parts per billion, below the 2.5 parts per billion limit for the chemical in Maine, which was used as a standard for the study because it has the most stringent requirements. for PFAS in biosolids.

PFOS, however, was detected at 8.66 parts per billion in milorganite, above the Maine standard of 5.2 parts per billion.

The study found that some PFAS precursors were also contained in the Milwaukee fertilizer, which degraded over time to form true PFAS.

The fertilizer tests verified 33 common PFAS compounds, as well as precursor compounds and synthetic fluorine compounds.

Where does PFAS come from?

To be clear, MMSD does not create PFAS. The chemicals come from the waste stream, probably released as a by-product of manufacturing. The district is currently encouraging state leaders to set standards for chemicals so that releases of PFAS to wastewater treatment plants are regulated to lower levels.

Tom Nowicki, staff attorney for MMSD, said the fact that the chemicals were found in Milorganite is not surprising. He said the biggest question to be answered following the results of this study is what levels of PFAS in fertilizers are unsafe. Studies are underway, he said, to examine the transport of PFAS from biosolids.

Are there any states in which Milorganite cannot be sold?

No state bans Milorganite, Nowicki said, not even Maine.

Besides Maine, Vermont, New Hampshire and Michigan have also started testing biosolids for PFAS, the study found, and Colorado has implemented PFAS standards that will likely lead to permit restrictions for sources. industrial chemicals. It is important to test biosolids because not only are they put into fertilizers, but they are also systematically spread on farmland, including crops and the grass on which cows graze.

What should I do to fertilize my lawn or garden?

While the study suggests gardeners should find a new fertilizer without biosolids, the MMSD insists that Milorganite is safe to use.

“We have to remember that the presence does not mean a risk of something,” Nowicki said.

If you decide that biosolids fertilizers are not something you want to use, check the “Analysis Guaranteed” label on the back of the bag. Terms like “residues” or “municipal waste” generally indicate that biosolids are present in the product at some level.

How could we remove PFAS from wastewater and biosolids?

The study suggested a number of solutions, including further testing of water discharged by industrial users to treatment plants and reducing the use of biosolids fertilizers. But the most important steps to regulate chemicals in biosolids would be legislation at state and national levels.

The researchers also hope the fertilizer study will spur action by state lawmakers across the country.

Sonya Lunder, senior toxic substances policy adviser for the Sierra Club, said without legislation, the burden is on ordinary people to choose different fertilizers or figure out how to treat PFAS already in their soil or water. But that shouldn’t be the case, and if governments embrace some of the report’s suggestions, it could be a good first step.

“People are really stuck with the exposure,” she said. “And these solutions are not just for one agency. Several things will have to happen to contain this crisis.”

Laura Schulte can be reached at and on Twitter at @SchulteLaura.

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