While EPA does not intend for innocent parties to pay, the Agency nonetheless maintains that a comprehensive liability scheme is critical for making truly polluting parties assume responsibility for their pollution. There are many factors that influence a decision to purchase property and redevelop it, but concern about environmental liability is often serious enough to preclude a real estate transaction from moving forward. Fear of liability for environmental contamination is only one factor among many that affects such development decisions. It is nearly impossible to determine the exact number of brownfields throughout the United States. EPA estimates that there are probably 500,000 sites or more with a high potential for some contamination, based on the sites' previous industrial or commercial use.
Many urban areas have thousands of abandoned and potentially contaminated properties.
The majority of these sites are located in urban areas where heavy manufacturing and other industrial activities have occurred. A brownfield might be found at an abandoned industrial yard or at a facility currently in operation. But brownfields also can be small residential or commercial lots where some form of contamination is suspected to exist even though there may be an information void. The law adopted a broad liability scheme to ensure that parties responsible for polluting would be held accountable for their actions. The over-arching characteristic associated with brownfields redevelopment is uncertainty.