streams, rivers, and lakes through urban runoff.
■ It reduces the amount of contaminated material entering aquifers and
affecting the quality of groundwater.
■ It reduces the number of abandoned buildings, which decreases urban
blight, thereby increasing property values and tax revenues.
■ It makes land available for businesses to expand or develop in new areas,
which creates jobs.
The reclamation of brownfields creates a range of questions that must be
answered before proceeding:
■ Will the cost and time to clean up a brownfield be prohibitive?
■ What does a city do with the contaminated material that is removed from
a brownfield?
■ How will workers who clean up the brownfield, as well as the people
living near the brownfield, be protected from the hazardous materials as
they are removed?
■ What short-term and long-term health effects are associated with cleaning
up brownfields?
The remediation of brownfields may include the following techniques:
■ BIOREACTORS—a device that supports a biologically-active environment
to hasten either aerobic or anaerobic decomposition.
■ BIOVENTING—microorganisms are used to biodegrade organic constituents
in the groundwater system.
■ COMPOSTING—the process of converting a mixture of various organic
vegetable matter, such as dead leaves or manure, for use as a fertilizer for
soil.
■ IN SITU OXIDATION—injecting or otherwise introducing strong chemical
oxidizers (e.g., ozone) directly into the contaminated soil or groundwater
to destroy chemical contaminants so as to remediate a variety of organic
compounds, including some that are resistant to natural degradation.
■ LAND-FARMING—contaminated soils, sediments, or sludges are
periodically turned over (tilled) to aerate the mixture.
■ PHYTOREMEDIATION—deep-rooted plants are used to soak up metals in
soils into the plant structure as the plant grows. After they reach maturity,