Is there a better way to deal with household waste?
Some engineers are experimenting with “bioreactors,” in which leachate is collected and then, instead of being treated and discharged into nearby waterways, is repeatedly injected back into the dump. All this moisture accelerates decomposition, so that bacteria feeding off waste produce more gas more quickly. After the fermentation of waste has stopped, the dump contents are rinsed with freshwater, and the toxic runoff is collected and treated before final discharge. Because the garbage shrinks while it decomposes, the landfill settles and stabilizes faster than with the dry tomb method-while monitors are still keeping an eye on things, it is to be hoped. (The EPA requires landfill owners to monitor and maintain their properties for only 30 years after they’ve been filled up, covered, capped, and planted. After that, liability shifts back to taxpayers.) It’s too soon to say whether wet landfills are any safer than dry: None has yet been closed. Of course, we’d all be better off if most
