| The Gas System We are actually driving on garbage right now from 1990.We have a gas system on site. What we do is we drill down into the garbage and put a vacuum on the site to get the methane out of
it. Landfill gas is probably 50% methane and about 40% carbon dioxide. The rest of it would be nitrogen. We actually can burn the methane portion. You have to control methane. There was a house over on the West Side of Madison, probably, in the late '70s or early '80s. There was an old landfill over by Memorial high school and some of the methane in the landfill gas got out and into the basement. I think the guy was lighting a pipe and the methane blew
his house off the foundation. So, nowadays we have to make sure that we control any of the landfill gas from getting off the site. Then you have a choice. You can burn it in a foyer and generate electricity, and we chose to generate electricity at both of our sites. There's a whole network of wells connected to a header pipe and it's probably about 3,000 feet down to where the gas generators are located. The Creek
You can see where it looks almost like a little creek. That's the wetland that I mentioned that we built. It's kind of in a fan pattern and almost looks like a shell.That's been in place for just about three years. We have a regulatory requirement to monitor it for five years, but after three years now it's met the requirements that we've needed. One of the things that we found that we didn't realize was that there were fish in it after the first year. We
didn't stock it at all but the ducks would come in with eggs on their legs. So there's small fish in there as well. Long-term Effects We stay open in any weather condition. So, rain, sleet, snow, freezing temperatures, we'll be able to get where we need to go.We have to continuously monitor, there are monitoring wells that surround the site. There's basically 90 groundwater monitoring wells and probably 15
gas probes that measure to make sure that methane doesn't come off the site. We have to monitor this for probably 50 years once we finish putting al the garbage in and put a cap over the top of it. Those are things we'll watch over time. In general, the decomposition will last for 50 years, maybe a hundred years, depending on how quickly or how much moisture there is and how the biological part of it is cooking at the time. So we'll continue to watch that. For some
facilities, that 40 or 50-year mark ends and they can walk away from it. One of the things with the county is that we'll always be here and always watch to make sure that there isn't a problem with the facility. |
