Solutions to environmental problems occasionally create unintended consequences, that is, solving one problem creates another. Scientists and engineers must carefully evaluate potential negative results before implementing new remediation programs. For example, burying wastes in landfills may cause groundwater contamination, incinerating wastes reduces waste volumes but can cause air pollution, and excavating abandoned waste sites as part of a remediation effort may expose workers to contamination. Recycling can have a net negative environmental impact if air pollution associated with transportation outweighs environmental benefits. Stimulating the biodegradation of trichloroethylene (TCE) in contaminated groundwater can lead to the formation of vinyl chloride, a more hazardous chemical. Two examples are described here: MTBE and disinfection by-products.

Mtbe

Methyl tertiary-butyl ether (MTBE) is a fuel additive that has improved air, but degraded groundwater. Its primary use in the United States began in the 1990s as a fuel oxygenate added to gasoline...