The ultimate goal of TACO is to reduce environmental risk to humans by managing one or more of these components. If an exposure route can be limited or cut off, then the health risk from the contamination is also limited. In the TACO rules this is called pathway exclusion. A site owner using pathway exclusion needs to demonstrate that the exposure route will be properly blocked, and that the contaminants cannot move into new exposure routes. The primary means of pathway exclusion are institutional controls and engineered barriers.
Institutional controls are ways of regulating the use of a property.
Institutional controls may also be used to prevent exposure to contaminated groundwater. If a property has contaminated groundwater, the owner does not necessarily need to clean the groundwater. If the property is sold, the purchaser must either accept these restrictions as part of the deed transfer or clean up the groundwater. Another option is the use of engineered barriers. A structure, such as a parking lot, could be used to cover contaminated soil.