rghorto
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Grass Clippings from Septic Leach Feild for composting?

Is it safe to use Grass Clippings from Septic Leach Field for composting? This grass is much greener than other areas in my yard for obvious reasons, but I have never used it in my compost pile because I have never been sure if it would be safe to do so. We use our finished compost dirt for our vegetable garden. Anyone know the answer?

rghorto

firstimegardener
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I have known people who actually plant their veggie garden over their septic. I have no clue if it's safe, but they had pretty plants. However, I myself, didn't eat their veggies...couldn't quite bring myself too.

Last year, I was given some strawberry plants that looked awesome, but was told that they were grown in sewer sludge. After doing some research, I found that although most places test for some heavy metals and bacterial issues, they don't test for medications or a very wide variety of metals and such. The fruit, there fore, has all of these toxins in it. I chose to throw them away as I have kiddos and didn't want to chance it. I'm not sure if the same concept would hold true to septic systems. And, there is some debate over if I was right or wrong not to use them as some people feel sewer sludge is perficatlly safe.

Sorry I'm not alot of help

firstimegardener
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Went back and looked through my posts. Here is the threads I had going at the time about it

https://www.helpfulgardener.com/forum/viewtopic.php?p=154665&highlight=#154665

and

https://www.helpfulgardener.com/forum/viewtopic.php?p=153548&highlight=#153548

hope it helps!

toxcrusadr
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The main risk from household sewage is microbial pathogens. These tend to survive best in the gut and not well in aerobic conditions outside the body, such as a compost pile. I would have no problem at all putting those grass clippings into the compost.

I would have used firstimegardener's strawberry plants, since 1) toxins in soil are not necessarily taken up by plants, 2) it is unlikely a tiny strawberry plant could carry enough 'load' of toxins to make later fruits risky, and 3) in fact the composition of *fruit* is going to be primarily based on what the plants are growing in when they fruit, and since they would be transplanted to my garden and growing in good clean soil, the fruit should be fine. JMHO, YMMV.

A gardener once posted on a composting forum that he had used Milorganite (compost from Milwaukee's sewage plants) on all their flower beds and had tomatoes sprouting all over. His wife didn't get it till he explained that the seeds can survive not only the human digestive system but the sewage plant. She would not touch the tomatoes! It's all semantics I think, it's not like that tiny seed, having been through 3 decomposition steps, is going to contribute more than a gnat fart to the tomatoes. :wink:

BTW, much of the produce sold in the US comes from places where they *do* use sewage sludge. Given the choice between storebought and home grown from a plant started in sludge compost, I'd take the home grown!

Dixana
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I work for a friends septic company off and on. They spread septic waste on fields used for growing "food" that ends up used for animal feed in the spring and fall. Those fields must not be used for food for human consumption for at least 12 months after spreading.
Given those standards I would think there would be no problem using grass grown in a septic area in a compost pile, especially if it's hot. Anything nasty in the grass (if there even is anything) will be killed off by the microbes in the compost. Very different than actually planting in the leach field (which people aren't supposed to do anyway!!)

firstimegardener
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toxcrusadr wrote:The main risk from household sewage is microbial pathogens. These tend to survive best in the gut and not well in aerobic conditions outside the body, such as a compost pile. I would have no problem at all putting those grass clippings into the compost.

I would have used firstimegardener's strawberry plants, since 1) toxins in soil are not necessarily taken up by plants, 2) it is unlikely a tiny strawberry plant could carry enough 'load' of toxins to make later fruits risky, and 3) in fact the composition of *fruit* is going to be primarily based on what the plants are growing in when they fruit, and since they would be transplanted to my garden and growing in good clean soil, the fruit should be fine. JMHO, YMMV.

A gardener once posted on a composting forum that he had used Milorganite (compost from Milwaukee's sewage plants) on all their flower beds and had tomatoes sprouting all over. His wife didn't get it till he explained that the seeds can survive not only the human digestive system but the sewage plant. She would not touch the tomatoes! It's all semantics I think, it's not like that tiny seed, having been through 3 decomposition steps, is going to contribute more than a gnat fart to the tomatoes. :wink:

BTW, much of the produce sold in the US comes from places where they *do* use sewage sludge. Given the choice between storebought and home grown from a plant started in sludge compost, I'd take the home grown!
Wish I would have known you would have used them...I'd have shipped them to you!! :lol:

rghorto
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Thank you all for your replies. Good information. I hope that others will add their thoughts, especially some of you scientist. lol

toxcrusadr
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It's funny that we're grossed out by the concept of human poop as fertilizer, even after it's composted, but we seek out all kinds of animal poop to compost and put on our gardens. It's really no different, even with respect to most pathogens (cow and horse poo have e coli too), but the Poop Taboo is deeply ingrained. It is formed at a very early age.

Dixana
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I have to disagree on that one tox. Humans, dogs, and cats eat things that livestock animals don't. Horses won't kill the lawn if they pee in the same spot everyday, dogs and people will. Because of the meat and fats we eat there are things in our gut and our feces that you don't find in the grain and grass eaters. Grazers poo also usually doesn't smell too much whereas omnivore poo will make you gag.
I'll keep seeking out cow and horse manure to put on the garden, but it will never be acceptable to me to put human or dog poo out there.

Odd Duck
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Horses are nearly as likely to carry salmonella as chickens and certainly can carry bad E. coli strains (E. coli is a normal component of their gut flora). Does that stop me from putting horse manure in my compost? Not on your life, I'm happy to use it. I don't use my doggy poo - that's currently going in a worm digester out in the yard that will hopefully feed my future blueberry bushes that are planned for nearby. But the doggy poo thing is really more of an ick factor than a medical opinion.

Theoretically, omnivore and carnivore poo is more likely to carry pathogens, but I doubt it's an issue with my healthy dogs and cats. I would never even consider it with unknown carnivore poo. I know it's always recommended against, but I really haven't seen studies about if it's truly an issue.

firstimegardener
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I don't use horse, chicken or cow either...I do use worms though. And I wonder if people quit using poo that contained e coli and such to fertilize the fields where they grow their animals feed if it would be an issue??? I honestly DON'T know...it's just a passing thought....

toxcrusadr
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irsttime, not sure what you mean by that last - can you clarify the question?

Just to be clear, I was not advocating using human sewage in our gardens, no matter how composted it may be. Just ruminating on cultural attitudes and taboos.

Given the opportunity, I and many others would be willing to shift over to composting toilets and use that compost out in the forest or on ornamentals, etc. That is how mother nature cares for the planet, and if it was that dangerous we'd all have died millions of years ago. Sewage treatment was the right thing when it was invented, because the rivers were dying and people were getting sick from sewage. But we need to start thinking in new terms, because there are too many of us and too many nutrients going down the drain.

Dixana
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I think that's something most of us can agree on! I've actually been ruminating over the idea of bokashi composting my cats feces. If I switch him to that natural corn husk litter it should be pretty simple. Then I could dig the finished product into my flower beds in the spring and fall.
Composting toilets need to become way more user friendly and less expensive to be a viable option though.

firstimegardener
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Tox

I guess what I mean is, if we put something on the ground that is contaminated, then grow grain on it, can the grain become contaminated? (or with the OP original question, the grass clippings)

And if the grain is contaminated, then can the animal we feed the grain to become sick?

And if we use the manure from said animal and put it back on the ground, are we just re contaminating it???

Like I said, I have NO CLUE! Sadly, I failed pretty much every science class I ever took with the exception of computer science. I'm not stupid, just not a "science minded" person. Which is why gardening is so hard for me. I feel like I'm missing basic information to make connections! I need to find a way to take basic science and build from there I guess...

OP Sorry, I"m not trying to hijack your thread! I'll be quiet now! :)

toxcrusadr
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A very relevant question and not a simple one. I don't have all the answers myself. I'm on the chemical toxin side of environmental science, not the biological side, and if I know anything about compost it's only as a hobby.

Yes there is e coli in fresh manure, for example, and yes, if the animals poop on the field they are adding more, but in the aerobic conditions outside the gut, the numbers drop rapidly. It's when we do 'un-natural' things like using large amounts in one place (like the garden) that hasn't been thoroughly composted or put down and allowed to become aerobic for a sufficient time. In nature animals probably wouldn't eat around their own or others' fresh poo, and that's how nature protected us. We start short-circuiting those processes and we can get in trouble.

One thing we haven't even gotten into is those nasty prions and such - the ones that can survive heat and all kinds of decomposition of their surroundings. I think mad cow is in that category and there are possibly others. But it's not in the cow poop, mostly the brain tissue and bones, so I think the issue is feeding offal to other cattle, rather than composting.

It does make you think about human waste though. I suspect those studies have been done on municipal sewage sludge, but I don't know the results. I would not be surprised to find that municipal sludge used on leafy crops like spinach etc. could spread some awful diseases in spite of the prior processing.

Complicated stuff, and an evolving science.



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