What is in Organic Potting Soil?

What is in organic potting soils most people are buying?

I just read an article that suggests it’s not what we think, and it’s bad.

As gross as it may sound, we recycle human waste and much of it winds up in organic potting soils and other agricultural uses. Treated human waste is used around the world this way and is likely the most sustainable method to dispose of the millions of tons  produced every day in every city around the world.

According to the EPA, “after treatment and processing, biosolids can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth. The controlled land application of biosolids completes a natural cycle in the environment. By treating sewage sludge, it becomes biosolids which can be used as valuable fertilizer, instead of taking up space in a landfill or other disposal facility.” EPA

The problem, Dr. Lewis highlights in this article, is the concentration of heavy metals mixed in with the treated sewage. Extremely high levels of  lead, cadmium, mercury, arsenic, toxic organic chemicals, pesticides, and pharmaceuticals. Most of these toxins are introduced when industrial waste is combined with sewage for treatment.

There are no warnings on the labels and no way to know what levels are in the bag you buy for your garden. If the bag lists “milorganite” on the label, don’t buy it. Milorgranit is a brand name used by the City of Milwaukee and distributed nationally. The name is a derivative from MILwaukee ORGAnicNITroEn.  It is sold as a natural fertilizer with a formulation of 6-2-0 (N-P-K). On their web page, they tell us how Milorgranit is made. “The District captures wastewater from the metropolitan Milwaukee area, including local industries such as MillerCoors.  This water is then treated with microbes to digest nutrients that are found in it, and cleaned water is returned to Lake Michigan.  The resulting microbes are then dried, becoming Milorganite fertilizers.”

What exactly are you buying

There is one benefit to using Milorganit in your garden. Apparently it is a very effective deer repellent. It’s even marketed that way here. Funny how animals instinctively know to stay away from industrial waste.

Using the Mittleider Gardening method avoids the use of the potentially dangerous products. Read more about the Mittleider Gardening Method here

The link to read about Milorgranit is


The link to the entire article by Dr. Lewis is