How much methane seeps out of Oregon landfills?

Earlier this year, the Washington state Department of Ecology wrote new rules to regulate methane emissions from landfills that surpass federal emission regulations set by the U.S. Environmental Protection Agency. Oregon’s Department of Environmental Quality wrote its own rules in 2021 and has been collecting data from landfills for the last two years. About 30% of today’s global warming is driven by methane. Heather Kuoppamaki, senior environmental engineer at DEQ, joins us to share what we know about methane emissions from Oregon’s landfills.

Note: The following transcript was created by a computer and edited by a volunteer.

Dave Miller: This is Think Out Loud on OPB. I’m Dave Miller. We talk a lot about CO2 as a greenhouse gas and for good reason. Billions of metric tons of it go into the atmosphere every year, creating an ever hotter, ever more chaotic world. Less methane ends up in the atmosphere, but it’s much more of a problem when it gets there. It is 80 times more potent at trapping heat. The Washington state Department of Ecology recently put out new rules to regulate methane emissions from landfills. Meanwhile, Oregon has had methane rules in place since 2021 and has been collecting data from landfills for the last two years. Heather Kuoppamaki is a senior environmental engineer at Oregon’s Department of Environmental Quality. She joins us to talk about what we know now about methane emissions from Oregon’s landfills. Heather, it’s great to have you on the show.

Heather Kuoppamaki: Hi, thanks for having me.

Miller: Can you explain the basics of the methane emission landfill rules that Oregon’s DEQ – I should say Oregon’s Environmental Quality Commission – adopted in 2021?

Kuoppamaki: Sure. Before 2021, there were some rules already in place that came down from EPA and they focused on the really large landfills. So those are landfills that maybe took or had over 2.5 million tons of waste in the landfill. So those are really big ones.

In our rules, we wanted to look at another size of landfills, maybe not quite as big, that are still making methane and still a potential issue. And we also wanted to expand the requirements for what landfills are doing to assess how much methane they are making, how much is being released from their landfill and what they do with it. California had rules in place for over a decade, so we started with their rules, saw it was working and tried to push a little bit farther where we could.

Miller: Have these new rules been in place long enough to have a measurable impact?

Kuoppamaki: That is what we’re trying to find out. Like I said, we’re regulating probably twice as many landfills now as we were before. And those landfills, we didn’t have a good baseline for it. We didn’t know, really, where we were starting to see what the impact is. So we’re gathering the data to see, I think, kind of qualitatively, anecdotally. I would say yes, because landfills are having to fine tune how they’re controlling their methane, what they’re doing with it. They’re having to fine tune how they’re assessing what’s coming out of their landfills. I can’t really give you a firm number yet, but I would be confident to say that it is being effective.

Miller: How do landfill operators capture the methane that otherwise would just rise up in the air?

Kuoppamaki: So it’s kind of an interesting thing. When you think of landfill, a lot of people just think of these big piles of trash. There’s a lot more going on with landfills. They have a lot of engineered structures that are helping the landfill work how it needs to work. So one of those structures that landfills can have is what’s called landfill gas wells. They look fairly similar to a drinking water well. It’s a pipe that’s drilled into that pile of waste, there’s holes in the pipe and the methane can literally just be pulled out of the landfill using those. Then those wells are connected to piping that’s taken to a different location where they do something with that methane.

Miller: What might they do with it? I mean, if a landfill operator captures methane, then what next?

Kuoppamaki: Yeah, it depends. We leave that up to the landfill operator somewhat, with the caveat that they have to really destroy 99% of the methane that’s in that gas that they capture. So we are requiring that they get rid of those emissions, to a high percentage. If it’s just a small amount of methane, they might just burn it off. If you burn methane, it breaks down into carbon dioxide and some other constituents that aren’t as harmful. But if you have enough, a lot of landfills actually can use that landfill gas, that methane, as a fuel to literally put into engines or turbines and make electricity. Some landfills around different parts of the country can turn that gas into natural gas and it can go right into the natural gas pipeline.

Miller: Why is that better? I mean, because as I mentioned at the beginning, methane is 80 times more potent at trapping heat than CO2. But CO2, which you get when you burn methane, or natural gas which is largely methane, my understanding is it lasts in the atmosphere hundreds or maybe thousands of times longer than methane. So the math here, it doesn’t seem like a slam dunk. Why is it better to burn methane than just to let it go up into the atmosphere?

Kuoppamaki: Yeah, because you’re getting a similar amount of carbon dioxide, or even less than you had of the methane. You have that methane being 80 times as potent, so you have a less potent greenhouse gas going into the atmosphere. It is just one step in the right direction. I think the ideal thing to do with the gas is to use it for electricity, so you’re replacing some other fuel that might be used to make that electricity or putting it into the natural gas pipeline. You’re then replacing natural gas that would be used.

Miller: But I suppose that the better situation for us as a species would be to have less methane to begin with. What would that take?

Kuoppamaki: Sure. So methane in landfills is made from the breakdown of organic material, anything that you can think of that decomposes. So really, if you want to decrease the amount of methane that a landfill is making, we really need to look at, focus at decreasing the organics that are going to a landfill. One big place that some coworkers of mine – it’s called the DEQs Food Waste Prevention Program – are focusing on is reducing food waste, reducing the food itself that goes into landfills, because that is a large, large part of the methane emissions from landfills.

Miller: Portland has had curbside food waste composting for more than a dozen years now. Salem and Kaiser started a year earlier. Does composting reduce overall methane emissions?

Kuoppamaki: Yeah, absolutely. Composting is a good step in the right direction. It’s definitely an improvement over sending that waste to the landfill. But really reducing the food waste overall, not even having to compost it, that’s six to seven times more effective than composting. So while composting is a good step, really trying to reduce that food waste is an even better step.

Miller: Oh, because composting is further along in the process. The idea is just only grow and prepare as much food as we or, say, animals, are actually going to eat.

Kuoppamaki: Absolutely. Yeah. And composting itself makes some methane, not nearly as much as landfills. It depends on the method of composting, but there is some methane that’s happening from there. So, yeah, because of what you said in the methane emissions from composting. Absolutely.

Miller: Just briefly, you mentioned that you went further a couple of years ago than federal requirements. What would you like to see at the federal level? And we have about 40 seconds left.

Kuoppamaki: I think they should really see what other states have been doing. It’s not just Oregon and Washington. I know Maryland’s been looking at the rules and other states have sort of been looking at where they can see improvements. I think they should see what the states have been doing, see what’s been working and push as far as we have been doing. There’s a lot more methane emissions from landfills that could be, I think, mitigated or regulated that would be helpful.

Miller: Heather, thanks very much.

Kuoppamaki: Yeah. Thank you.

Miller: Heather Kuoppamaki is a senior environmental engineer with the Oregon Department of Environmental Quality. She joined us to talk about Oregon’s, and now Washington’s, efforts to reduce methane emissions from landfills.

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