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Sewage treatment plant compost, how safe?

17 years ago

The town i live in has free compost available from the sewage treatment plant, iam curious as to how safe this compost in general, might be? iam particularly interested in using it to start a new bed in to which i would like to plant garlic, onions, leeks etc. Ive heard in the past that this type of compost may have an unacceptable level of heavy metals etc. any thoughts?

Comments (26)

  • 17 years ago

    The treatment plant has to test its sludge to let you know how much, if any, contaminants are in it. Ask them for their test results.

    What industry is in your town that would contribute heavy metals to the treatment plant?

    A small town with no industry should have a very clean product.

  • 17 years ago

    I agree with joeyeweed, if the sewage is tested and there is not heavy industry that dumps poisons into the sewer and they test for it, you should be in good shape. I use "biosolids" everywhere in my garden with no ill effects. I even use a product called Milorganite on my vegetables. Check out my website for the results.

    Here is a link that might be useful: Panama John's Tropical Zone

  • 17 years ago

    I use Milorganite and biosolids compost too, but only on the lawn and flowers.

    Frankly, in this case I'd personally be a little bit cautious. Others are right that the sewage from a small bedroom community town is probably less likely to contain heavy metals. But if the plant is doing their own composting, I would be a little bit skeptical about the quality control processes the have in place. As a former wastewater treatment plant inspector, I can tell you that often the smaller the operation, the worse the quality control practices. If they have it monitored and tested, then sure, fine. But if they are just doing the small-town thing and piling it in a corner of the municipal dump along with the leaves that the highway crew collected, the spoiled silage from Farmer Brown's barn, the sawdust from the local sawmill, and the bags and bags of Heaven knows what that residents brought to the curb, then it's kinda hard to ensure consistent quality.

    I'm not saying don't use it - I'm just saying "Ask."

    -Diggity

  • 17 years ago

    WOW! Thanks for the prompt responses, although we were a "mill town" most, if not all of the heavy industry has been gone for several years. i didnt really realize they might test the resulting product for the heavy metals i may be speaking of.Thanks again, i'll look forward to what others might think, but you folks may have answered my questions. Lets see!

  • 17 years ago

    Just think of all the household cleaning products that go down the drain and into the sewage treatment plant: bleach, liquid plumber, plus many other poisons: paint thinner, paint, and whatnot.

    I would never use the "treatment plant compost," nor Milorganite, which is supposed to contain heavy metals.

  • 17 years ago

    I know a company which is pretty good at soil diagnostics (bodemverbetering). It is a dutch company, though they can probably give you some advice on this.

  • 17 years ago

    Thanks again! I wasnt sure just how much of that "stuff" that was mentioned was neutralized or whatever the term might be, and just how "pure" the compost might be.......I'll be contacting them in person probably in the beginning of next wee just to see what they say about any testing they may have done...

  • 17 years ago

    Living near Milwaukee where Milorganite is made I would never use it on any edibles. It is fine for the lawn and ornamentals, but every now and then, like this past summer, a sewer gets cleaned for the first time in decades and PCBs get released. Now they claim none made it to their retail product but PCBs did make it to county parks. If your town was a mill town, such things could lurk in your sewers for years.

    tj

  • 17 years ago

    This is why they test to make sure the product that is released to the public meets or exceeds EPA standards for biosolids. The levels of minerals, metals etc is less than most drinking water standards in the US, so watering your lawn with tap water can have more contaminats in it than Milorganite. The PCBs were released when they cleaned out an old sewage pipe that was being reactivated after years of sitting idil, and being connected to the newer sewer system. They caught the mistake, none was shipped to consumers and they are disposing of the bad batch in an approved landfill.

  • 17 years ago

    Although it is tempting offer, as in getting the sewage treatment compost for free, i think iam going to pass on it, at least for my vegetable gardens, new beds etc etc . Thanks for all of your input..if anyone else has any other comments, lets hear 'em!

  • 17 years ago

    *they test to make sure the product that is released to the public meets or exceeds EPA standards for biosolids. The levels of minerals, metals etc is less than most drinking water standards in the US,*

    Sure. We have seen how dependable the EPA testing and standards are when it comes down to the economics of pollutants. The EPA claimed that the air at ground zero in 2001 did not exceed certain levels, and that the air was ok to breathe. Now, after many, many youngish/middle aged people have died of respiratory illnesses as a direct result of breathing the G.Z. air, we find out that the EPA was not truthful.

    Please use common sense. Sludge could never be ok to put on the soil that produces foods. By the way, who'd be eating the foods that you were thinking of growing using sludge compost? Would the vegetables be sold at a market? ---or be given away to friends/neighbors?

    I almost never accept home-grown foods, because unhealthy growing practices abound.

  • 17 years ago

    Sludge would be fine from a small town that has no industry.

    WWTP are required to monitor and control how much bad stuff industry puts into the sewer. So there is some control on what is in the sewer, even in those towns that have industries. Industries must provide some preliminary treatment to remove lots of the bad stuff before it gets into the sewer.

    And of course, we can always doubt any information provided. It wouldn't hurt to develop a good relationship the operator of your WWTP to develop a comfort level for the type of information he is providing.

    Truly sustainable living should mean that we provide a demand for the waste products that we generate. Similar to buying products made out of recycled paper, as long as we continue to flush the toilet, we should provide a use for clean sludge, rather than shoving it into a landfill.

  • 17 years ago

    This is a great reason not to contaminate your humanure with everything else that goes into the sewage systems. Also, flush toilets are very wasteful of water and even if you have a septic system, it is very possible for it to leach nitrates, phosphates and other things back into the drinking water supplies. That is what leach fields are designed to do, leach the liquid back down into the ground. Just hoping that the ground water supplies are large enough to dilute everything back to safe levels.

    Compost is the answer even though most people are too uncomfortable with the idea.

    Here is a link that might be useful: Read Humanure Handbook Online

  • 17 years ago

    That is the key, no industrial input and a good monitoring system and testing like they have for Milorganite. Even our drinking water can be contaminated to a degree if someone slips up. I have confidence in the source I use, but others should be investigated before using their biosolids. I am a big fan of humanure, but my wife still won't let me get started in using the methods in my home. I do use my urine to help heat up my compost pile though.

  • 17 years ago

    The Organic Materials Review Institute and every organic standard I've seen forbids the use of sewage sludge on organic crops.

    The OMRI states, "All organic ingredients must be produced without the use of volatile synthetic solvents, genetic engineering, ionizing radiation, or sewage sludge."

    If you're concerned about the fact that sewage, a potential fertilizer, is polluting the environment instead of being put to good use, why not start at home with poop you can trust? The Humanure Handbook, available online, is a great read and a real eye-opener. Also pretty funny at times.

  • 17 years ago

    Milorganite contains heavy metals and should never be used near food crops. This is the typical dilemma: Public safety, versus industry's economic interests.

  • 17 years ago

    I use compost from the local water treatment plant, and I did it after I asked around.

    One of the people I checked with was an organic farmer. This farmer told me that the compost from a government controlled facility was going to be better then the compost he was making on site. When I asked him if me meant to say safer, he said yes. He stated it was safer then his own compost because he doesn't check for any pathogens or anything else in his compost, where the treatment plant's compost has to be tested before sale and while it was being composted. He said if he had a source like I did, he would purchase it, rather then composting his own.

    Here's what I also found out about the waste that my local treatment plant uses for compost. I was told they had 3 different grades of waste. One was just to toxic, it gets shipped off to a landfill that handles toxic materials. The next grade has to much bacteria/pathogens to use at the time... I was told it was trucked at their cost to farms and was spread on to the fields. The catch was that the fields were not to be used for any edibles for one year. This was to allow whatever was in it to break down to a safe level. The last grade of waste was for composting. This waste was mixed with wood chips and hot composted. I think it took them 2 weeks, with testing every couple days, to get it made and ready for the public. The testing wasn't just for themselves, they had to submit the test results to the state health agency too.

  • 17 years ago

    crabjoe, just to clarify, is that the water treatment plant or the wastewater treatment plant. I've worked on sludge processing for both types and was just wondering which you were using.

    And your post is an good example of learning about what is available and how safe it is. Every treatment facility is required to test their sludge. But each facility has different quality sludges. Doing a little background work on your specific facility is about the only way one will know if they feel comfortable using the sludge or not.

  • 17 years ago

    Joe,

    It's a small town so the plant is setup to do both and they make a lot of compost all year round. When I asked them what they do with all the compost, they told me they sell most of it to local nurseries.

    Wouldn't it be funny if some fool was to scared to purchase it directly from the WW treatment plant for $7 a yard but end up getting that same compost from the local nursery for around $30 a yard? It probably happens way more then most people think.

  • 17 years ago

    It probably happens way more then most people think.

    I am sure it happens all the time.

  • 17 years ago

    The anti-biosoild zealots are long on "it might be a risk" or Europe's standards are lower,yet they still fail to produce real hard data. For example, what they leave out is the load limit of some of these metals, such as copper and lead in class A and even class B biosoilds. You would need to apply Milorganite EVERY year or some other biosolid like it for 345 years for lead and 278 years for copper for it to reach its EPA load limit. That doesn't even account for organic binding, mineralization and leaching/migration of the metals harmlessly in the soil. I don't know about you, but even with long life in my family, I doubt I will be around that long to worry about it. I use Milorganite on everything and I have even seen the independent report and have spoken with an independent scientist who tested it for a bioremediation project for the DoD. She indicated it was lower in metals and other contaminants than the tap water and virgin soil they were going to use in the project. Compare class A biosoilds to Scott's or Ironite sometime and decide which will be better to put down as fertilizer for your kids or pets to play around. BTW, the National Science Foundation did an independent study and risk assessment in 1995 of EPA biosolids regulations and found they were far below any levels that would possibly pose any threat to humans, wildlife, soil or water and agriculture. The zealots seem to overlook this fact as well in their quest to malign well managed practices of biosolid use. There has NEVER been a documented case of the regulated use of biosolids causing harm to people, animals or plants in over 35 years of use in our environment-yet the myth and junk science persists. I will continue to use and benefit from Milorganite on my lawn, veggies, ornamentals like temperate tropicals and palm trees.

  • 17 years ago

    Not really unfair when you compare what they say and the facts. Some facts are timeless and there really aren't "two" sides to a fact, unless someone is bent on believing the World is flat.

  • 17 years ago

    Until somebody can convince me that biosolids are not made from human bodies I will not be using them. That is disgusting. A little bit of heavy metals is okay, if they help keep my mulch from blowing away. Lead expecially.

  • 17 years ago

    LOL, Human bodies, like Soylent Green! Heavy metal levels are so low you would have to be an immortal to live to see them come close to their load levels.

  • 17 years ago

    I'd have to live that long to see the end of this post.

    tj