Do you remember this thread: Is Recycling BS? Well, I present to you the sequel.
So my fair city of Seattle has been making a lot noise lately about trying to increase the proportion of trash not hauled off to a landfill. One method they’ve proposed is gathering kitchen scraps and processing them in some sort of municipal composting facility. As I understand, this program has already started for businesses and single-family residences, and will probably be extended to apartments in condos in the near future. Naturally, it’s being marketed as the best thing ever for the environment, bringing urban folks back to the bosom of mother nature and solving global warming at the same time.
But is it BS? They always point to a few pros to a municipal composting program: produces compost, saves room in a landfill, and saves the effort of transporting garbage (it’s transported twice here - once by truck to a transfer facility, then by train to it’s final resting place several hundred miles away). Also, apparently to the degree that the waste is ‘processed’ in the landfill, it produces methane, a potent greenhouse gas. Though it seems that this is easily mitigated (and perhaps turned into a positive by capturing that methane and using it as fuel.)
But as we established in the earlier thread, landfill space isn’t particularly limited, and even waste being composted has to be trucked around, though not as far as waste being landfilled. And I think it misses a huge plus of landfilling the material: since it largely doesn’t break down in modern, sanitary landfills, it effectively sequesters a large amount of carbon in a stable environment.
So, how do the tradeoffs shake out? Is composting worthwhile?
(If you want to debate whether or not global warming is real, or bad, or whatever, start your own thread. The rules of this debate presuppose that we want to avoid AGW.)
Someone probably ouight to compost some of that bullshit, I mean if the bulls aren’t just using the meadow and all, where it would kinda get composted automatically, I mean you’ve seen how dandelions just take off thru that stuff, right?
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OK seriously… I would think that anything buried in a landfill that happens to be organic waste is going to rot and is therefore going to get as composted as it would anywhere else.
Now, as to whether you can utilize resultant methane, etc, by composting it specifically in a dedicated environment, and is it cost-effective, and does it save space in the landfill, and is it worth the wear and tear on the citizenry to separate this mess out, and the civic gov to deal with it separately… lots of indeterminate variables in there, even if I lived in Seattle I doubt I’d be able to answer that w/o a fairly involved study.
On the plus side, you didn’t list the fact that you end up with a lot of compost, which can be used by the public and by the city for their landscaping projects. If they would already be buying compost or something of that equivalent, that cost should be extracted from the cost of making the compost, which makes it more cost-effective.
OTOH, if they’re just composting and making a big, smelly pile of (more compact) trash right outside of town, then, no, not so helpful.
Farming in general depletes the soil of nutrients. Those nutrients are stripped out by the plants that grow in the soil. Compost is the waste byproduct of those plants. Compost is meant to help return nutrients to the soil, and thereby keep soil as soil rather than rendering it merely dirt.
The big problem people have in understanding ecological issues is that they don’t recognize that life is all about proportions. As AHunter said, it rots regardless of where it is. However, where it rots is important. When compost rots in a compost bin, it can be used to mulch parks, gardens and various other places where we are trying to grow plants. When it rots in a landfill, it rots mixed in with battery acid and mercury, and degenerating styrofoam, and chlorine bleech, and ammonia, and disposed of pharmaceuticals. Basically, that renders it a toxic melange of what COULD be useful organic material rendering it useless.
An animal has a waste cycle that works very well. We consume food, we digest it use it for fuel and shit out the byproduct. Our shit then feeds bacteria which break it down into constituent proteins, aminos and raw elements that are then sucked up by the roots of trees, grass, wheat, etc… Sanitation in it’s current form has removed a lot of the nutrient rich waste product from the lifecycle by consigning it to landfills filled with other toxic chemicals that render its nutritive organic value inert.
So no, composting is not at all a waste of time. As long as we are depleting the soil, we should be returning as much back to that soil as we can. That way the soil will remain rich and hearty longer and can be used to grow our crops more efficiently.
Is this really true over any kind of human timescale? There are all manners of stories - urban legends - that in the depths of landfills lie decades-old newspapers as readable as they day they were printed, hotdogs as appetizing as the day they were cooked, animal scat as smelly as the day it was shat, etc.
They do that around here. I don’t know how much it has changed since then, but two years ago landfill gas generators around Perth were producing a total of 24 MW this way.
There is a Prof. at ASU that researches Trash degradation. He’s the one who burried a carrot and 7 years later dug it up, bit into it and it snapped like it was freshly cut. Don’t have time to dig up the cite, but it 's out there…
Dr. William Rathje is the guy you are talking about, and his Garbage Project (which turned into Garbology, some info here: Garbology - Wikipedia) really changed the way we think about landfills and garbage. His work started as an archeology / sociology oriented study, but also ended up telling us about how waste behaves in landfills. If you have a chance to read about his work, it’s really interesting.
As I understand it, the way landfills are designed and managed create an anaerobic environment. This means that while decomposition does happen in landfills, it happens much more slowly than we previously believed.
Speaking to large-scale composting programs, the biggest environmental benefit probably comes from not have to truck that tonnage to some remote landfill (in those areas that might have to send their trash a hundred miles or more away.) Then there’s the “conserving expensive landfill space” issue. Also, reducing organics in the landfill should also reduce leachate (trash juice) that needs to be treated as it comes out of the landfill. Putting those nutrients back in the soil is a good thing as well.
FYI - most of the environmental benefits of any recycling program are turning out to be the upstream impacts of reducing the energy needed to refine raw materials into manufacturing inputs. This isn’t really an issue with organics, but I suppose replacing at least some chemical-based manufactured fertilizers with compost has a positive impact.
It should be noted that “kitchen scraps” amount to a small percentage of overall waste. Most waste food from the home either goes down the toilet after some basic human processing or down the garbage disposal in the sink. Either of those ends up going to the sewage plant that does indeed filter off methane for power (it helps to power the plant) and create compost to be sold to farms.
The amount of kitchen scraps which doesn’t end up that way is probably somewhere around 5% of the total food mass. I’d also guess–and someone correct me if I’m wrong–that the food which gets discarded, like egg shells and orange rinds, generally have fewer nutrients in them. That’s why they taste bad or cardboard-like to us. So making that assumption, the value of that 5% might be significantly decreased.
Overall I wouldn’t take it as a given that it is worth it unless I had farmers complaining that their soil wasn’t able to keep up with what they’re already getting.
How many homes have garbage disposal units? And of those, how many of them use them so much? I haven’t had one since my parent’s house, and they stopped using it in around 1982…
Something else to consider is that if you have the space (eg a back yard or a balcony) you can do your own composting and eliminate the fossil fuels consumed to haul your organic waste around. In Toronto, we’ve had to be aggressive about waste management because of our lack of landfill space, but it has been successful from all accounts. Here is a rather self-congratulatory article from the Toronto Solid Waste Management site.
I’ve lived in two houses, a condo, and two apartments in and around the Seattle area. All of them had a garbage disposal unit built into the sink. Perhaps it’s uncommon in other areas of the country or perhaps I had good luck, I couldn’t honestly say.
I’d still venture to guess that the majority of food sold ends up as poop.
Which still is irrelevant. As I said in the last sentence of my prior post, if our current level of composting is meeting demand, driving trucks around to get more is rather pointless.
As an environmental engineer, I will tell you unequivocally that this point is not at all established and that landfill space is certainly limited, especially here in the Northeast. And wherever you live, there are fundamental issues about landfills:
[ol]
[li]Modern fully lined, capped, and monitored landfills are expensive.[/li][li]Even modern landfills are capable of impacting aquifers upon which they are situated.[/li][li]Nobody wants landfills near where they live (NIMBY argument).[/li][li]Also, while some have argued that the U.S. has millions of acres of unused land that could be used for landfills, most of this land is not where people live, or is land that we would like to preserve.[/li][li]However, landfills are needed where people live, or you end up with transportation problems (expense and emissions).[/li][/ol]
In short, any environmental engineer will tell you that anything that reduces the waste stream going to landfills is a good thing.
This is no urban legend. In my basement, I have a half-sheet of a September 1941 New York Sun newspaper that I picked out of a old dump in 2006, while observing some excavating. It was completely readable–in fact I took a number of photos of it in case it deteriorated after removing it from its former resting place. I saw it last night–yellowed but still readable.
The solid material that must be disposed of from wastewater treatment plants is rarely (almost never) composted. It is virtually always disposed of as solid waste (i.e. landfilled or incinerated).
This is because of all of the contaminants that go down the waste stream besides human waste, including heavy metals (especially mercury waste from dentists), pharmaceutical waste (such as from discarded and excreted medicine), industrial pollutants, household hazardous waste, trash (cigarette butts, tampons, condoms, razor blades), etc., etc.
The people who run wastewater treatment plants would actually prefer that people not send their garbage down the sewer pipes.
I compost at home - even better since there is no cost in bringing it out to my compost bin. We probably fill up a small bathroom sized trash can a day with scraps - especially vegetable peels, bits of onions or jalapenos you cut off and discard, any rotted food. I don’t know if it 5% or what. The big advantage is that composting dramatically reduces the volume of the waste. Even so, I get about 30 cubic feet of new soil every year or so, and given the increase in soil quality, the compost seems to be of good quality.
Our waste disposal people let you put compost in your green can, but I prefer to keep it. Our green can (grass clippings and such) and our recycling can (newspapers, cans, etc.) have a lot more volume every week than our trash can. I trust that the recycling actually gets recycled, but we get 2 bags back of soil from the composted stuff a year.
I compost at home too, but I don’t use the compost: it’s just a way of reducing my landfill waste. Being a Brit, I don’t have a waste disposal unit.
I have two bins of about ~100 litres each in my garden, and I alternate between them, and alternate layers of kitchen waste with grass clippings. The bacteria and insects and so on that live in the bins just get rid of all the waste I produce, slowly but surely, reducing the height of the bin’s contents by about 6" a week.
Since I send so little to landfill anyway, it also stops my regular trash from smelling of rotten food, and allows me to go much longer before empting (two trash bags, collected every two weeks).
I guess there’s lots of valuable compost there at the bottom of the bins, but I’m such a bad gardener that I never bother removing it.