Pull my finger...

The idea of harnessing methane from the county landfill has been batted around for several years, but it wasn't until Chris Merdon proposed using it to fuel county facilities and vehicles during his campaign that the idea reached a wider auidience.

On paper, capturing methane – a powerful greenhouse gas, though one with a relatively short atmospheric residence time – sounds like a good idea. After all, it's a naturally-occuring byproduct of our rotting waste that we can convert into energy (the county currently burns it off, releasing carbon dioxide, a larger threat to the atmosphere).

But what about in the real – that is, non-paper – world, where we have to consider whether it's actually worth it?

Today's Examiner, er, examines this issue, which came up during a recent meeting involving County Executive Ken Ulman and a local group, Transportation Advocates.

"The question is if there are cost savings," County Executive Ken Ulman said this week at a Transportation Advocates meeting.

The possibility of converting methane gas, a landfill waste byproduct, into fuel for the county's bus fleet was raised at the forum.

During the campaign, County Executive candidate Chris Merdon proposed using the methane gas for heat and electricity.

Ulman said he had asked the Department of Public Works to look into harnessing the methane gas to power the nearby public safety academy.

Howard would still need backup power and have to build the infrastructure to support the conversion, Ulman said. Because the Alpha Ridge landfill is small, it may not be producing enough methane gas to make it a worthwhile investment.

Meanwhile, from yesterday's Sun we get this:

Ulman said he would like to do that but has been advised by public works officials that not enough gases are produced at the old New Cut Landfill or at Alpha Ridge to make fuel conversion practical.

(I'm not sure why there's a discrepancy in reporting between the two papers, but that's beside the point.)

David Keelan is disappointed by Ulman's seeming unwillingness to aggressively entertain this idea, suggesting that the county executive is making assertions that run counter to "EPA studies." Although he doesn't include them on his blog, Keelan provided links to some EPA documents on the Howard County Citizens Association email group.

The links, however, do not lead to studies showing that Alpha Ridge is a really a viable source of energy, but rather to a site for the 7th annual conference of the Environmental Protection Agency's Landfill Methane Outreach Program, an event that included a presentation by Evelyn Tomlin of the Howard County Environmental Services Department.

Tomlin's presentation is more marketing piece for the businesses attending the conference than study demonstrating that methane extraction is completely feasible in Howard County. Indeed, of the eight slides, only two address potential "recovery" and none address whether the landfill's emmissions are significant enough to yield returns.

Although Alpha Ridge is listed by EPA as a "candidate" site for methane recovery, the only necessary qualification for inclusion as such appears to be existance as a landfill. But with the data available (links to an Excel spreadsheet from EPA's site) we can compare Alpha Ridge to other landfills in the state that are producing methane for energy and get a rough idea of whether it should really be considered a candidate.

First, below is a graph from Tomlin's presentation showing recovery potential over time. Note that Alpha Ridge now operates mainly as a waste transfer station -- that is, it buries only a "small portion of Howard County trash."

As you can see above, the recovery potential is projected to steadily decline, and in 2007 is likely yielding only 500 standard cubic feet per minute (scfm). After converting this number to millions of standard cubic feet per day (mmscfd), we can see how Howard's potential flow stacks up to that of four Maryland energy producing landfills (there are two other such sites listed in the EPA database but neither has data on methane flow).

Alpha Ridge generates significantly less methane each day than the others, and this discrepency will only grow as its emissions diminish over time.

Now, this analysis is not meant to imply that capturing methane from our landfill is a foolish or wasteful endeavor, as it would generate additional benefits besides energy production -- namely, a reduction in greenhouse gas emissions.

I think it does show, however, that Howard County is not the optimal site for this, but a cost-benefit analysis would be necessary to gain a complete understanding of the issue. (And because I'm a tree hugger and wanna-be economist, I would include environmental benefits as a line item in any feasibilty calculations.)

Certainly, Ulman shouldn't hastily write-off this idea because it started as a campaign pledge from another candidate, but I'd also urge caution to others when claiming that EPA attests to Alpha Ridge's viability. If anything, I would point to the lack of a corporate partner as an argument to the contrary.

Now, if we believe that there are larger benefits to methane capture and choose to make it a priority, we could send our trash to landfills where it exists. Our current disposal site is King George County Landfill in Virginia, and, no, it doesn't practice methane capture. Actually, if this story from The Nation is to be believed, it appears our dump is on the leading edge of any increasingly environmentally destructive industry.

Seems to me that if we want to do what's right for the environment and our budget, shipping our trash to a "greener" landfill is probably our best option.