Municipal sewage compost found in fertilizers

[Cole_Robbie]

Study: Potentially harmful 'forever chemicals' found in popular garden fertilizers

https://www.freep.com/story/news/local/ ... 418828002/

[rossomendblot]

I've always been a bit suspicious of the sewage sludge fertilisers. In the UK I don't think they are in any products available to the public, but farmers do spread the sludge on their fields. I'm all for more of a closed loop system but no doubt there's a lot of micro/nano plastics in there too.

[Cole_Robbie]

My uncle just retired from the local sewage treatment plant. He says the sludge is full of heavy metals and pharmaceutical drug residues, largely estrogen from birth control pills. Oh, and lots of tomato seeds that end up growing around the treatment plant wherever they spill any of the sludge.

[Donnyboy]

Milwaukee has produced and sold Milorginite fertilizer from their treatment plant sludge for many years. I've never used it, but I've never heard of any problems experienced by folks who do use it.

I grew up with two Chinese families who fled chairman Mao's new China. They had always saved and used their "night soils" in China and continued to do so in the United States. They always had the most beautiful and productive gardens I've ever seen.

[MissS]

I have used Milorginite which is from Milwaukee. It does contain heavy metals as well as medical residues. I would never use it on a food crop as some farmers do because it is cheap. But I have used in in my flower gardens because it is a wonderful deer deterrent. Many people around here use it on their lawns.

[Paquebot]

Have used Milorganite for many years and now andthen contributed to it. I have not heard of it containing anything harmful in recent years. Great side-dressing for alliums.

Martin

[bower]

I have always distrusted anything with a NPK formula that doesn't list all its ingredients. Instead they have a cute name, or fluff about "organically sourced" or "natural" which can mean anything at all.
It's bad enough we have to wonder about residues in a plain bag of composted sheep or cow manure.
Cole you are lucky to have your own cows. No mysteries.

[worth1]

Wasn't there an old movie called The grass is always greener over the septic tank?

[Whwoz]

I can recall a poster along those lines [mention]worth1[/mention].

The very processes used to treat sewage is always going to lead to a build up of heavy metals and other chemicals that are not readily biodegradable in any remaining solids which equals your sludge component. A city of a million might generate a couple of cubic metres a day, but that would include everything washed down drains, from roads etc. Not as bad as in leaded petrol days fortunately.

[Paquebot]

One factor which determines what chemicals and metals are in the product is the heat used to make it. All of those have a boiling point and beyond that they evaporate. I always wondered why Milorganite listed no potassium when every other manure in the world has plenty. The process used is hotter than it can remain solid so it evaporates.

Martin

[Growing Coastal]

All those chemicals and metals evaporate into the air? Is that better?

[rossomendblot]

Milorganite does contain heavy metals, just at acceptable levels if the product is used according to instructions. https://www.milorganite.com/index.php?cID=177

[Paquebot]

All so-called heavy metals are present naturally. Some exist in soils higher than what is considered safe. Some of them exist in living animals including humans. If one wanted to garden in soil containing no heavy metals it would be possible only with a sterile medium. Because of their presence there is a minimum acceptable limit. Milorganite complies with that.

Martin

[rossomendblot]

Yes, other organic fertilisers also contain some heavy metals. The micro/nano plastics in products like Milorganite are more of an issue for me.

[zendog]

I think studies like this are a reminder that so much that we buy and use is contaminated with other chemicals, but they are often not tested for them. Unfortunately, it is very limited, since it only targeted biosolids products not examining the full range of fertilizers available. I can remember being surprised, then realizing maybe I shouldn't be, when I saw the studies about Roundup residues found in organic food products.

We should definitely be suspicious of any fertilizer with biosolids or other uncontrollable inputs that may have things in them we don't want in our veggies, but it is interesting that Milorganite, which is getting most of the discussion here, had the lowest levels of the other products, several of which had "natural" and "eco" in their names. I'd also like to see many of the organic options tested so we could confirm that they are lower, particularly if they are using local water supplies in their production that might have such compounds in them.

This article had the actual results: https://bestlifeonline.com/harmful-fertilizers-news/

Here is a study of PFAS compounds in the water supplies in my area: https://www.ewg.org/research/nova-pfas-testing/

For fertilizing I would think the really important test would be the transmission of the various chemicals of concern into the actual veggies being grown. I know there are PFAS compounds in the water I'm drinking, since they found them in every water supply they tested in my area and that goes straight into my body unless I pre-filter it in some way. But if there is estrogen, heavy metals or PFAS or whatever in a fertilizer I use, what is the uptake in the plants themselves and what levels do they have at harvest?

I mostly cover crop, get composted manure from a local horse farm and use wood mulch that composts down. But mid-summer those tomatoes definitely need a boost. I remain suspicious of anything you can buy in a bag...

[Paquebot]

Years ago on Garden Web's Soil Forum there was a thread where one could name any organic matter and someone could report on why it should not be used. Regardless of what anyone came up with, someone could find a valid reason to not us it. Plant life as we know it has developed to use manure of every animal, humans included. They depend on recycling every part of the plant one way or another. One can only take so much out of the soil without replacing it. Previous societies knew this and human manure was collected for fertilizer. Somewhere along the way new societies didn't trust whatever came out of their own bodies. Something that was perfectly natural became wrong. If whatever comes out of one;s body is bad, then what is going in must be equally bad. Think of that.

Martin

[brownrexx]

We have to do the best we can to keep these chemicals out of our bodies and our soil.

Past generations did not have exposures to the products of "modern" societies such as plastic food packaging, factory farming of animals such as cows for beef, chemical sprays for lawns and gardens and large amounts of industrial wastes poured into the nation's oceans and waterways. Mining and smelting to provide for the needs of modern societies also spews heavy metals and other contaminants into the air which falls to earth and contaminates the soil.

Part of the problem stems from overpopulation. More people leads to more depletion of natural resources and more habitat destruction. Less trees and plants to help cleanse the environment and prevent erosion. More people equals lots more waste and the associated problems with getting rid of it. This would include solid wastes, aka garbage as well as more sewage being generated. More people equals more pollution generating vehicles on the roads.

When I was a child, my parents did not spray their lawn or use purchased mulch on their flower beds. They did not use chemical herbicides, they pulled weeds. We had one car until I was an adult and got my own.

In many ways, life seems much easier now but it is also highly dependent on chemicals which end up in our bodies and our soils.

[worth1]

In the old days before commercial fertilizer folks would wear the soil out and just move on if they could.
In a natural environment mushrooms and fungi play a very important role in the breaking down of material for living plants to benefit from.
A field would have a vast network of this fungi living underground.
Plowing and spreading of chemicals will disrupt and kill the fungi.
You end up with a dead soil that is dependent on outside unnatural sources to grow and survive.
I personally don't have any problem eating food grown above my own sewer system closed off from every one else.
The plants I grow there thrive.

[Kurt]

We tried the poop,great stuff,maybe your area has large zoos for the cause.We gather bout 5 neighbors,rent a truck,do not use yours!Great for lawns,compost piles.Just like manures.

https://www.zoomiami.org/zoo-doo

[zeuspaul]

I don't have a problem with biosolids depending on where they come from. My own septic system is fine but I am going to open the lid to harvest them. Municipal biosolids have everything our friends and neighbors flush down their toilets.