Engineered barriers must be kept in good working order by site owners. One more way to reduce risk is to reduce the amount of chemicals present to safe levels through removal or treatment. This is often the tactic used by site owners, and it is frequently combined with institutional controls and engineered barriers to make the risk acceptable. TACO is a risk-based method for developing corrective action objectives. Any work to remediate a contaminated site can be called a corrective action.
Objectives refers to the goals of that corrective action.
The final goal of any cleanup action is to protect human health. Site owners can establish their own remediation objectives by conducting risk assessments. To accurately assess the health risk posed by the contamination, site owners must collect data on soil and groundwater conditions at the site and evaluate how long and how often people might be exposed to the chemicals. These site specific remediation objectives, called Tier 2 and Tier 3, are usually less stringent than baseline remediation objectives but are just as protective of human health. Baseline remediation objectives, also called Tier 1 objectives, take into account the intended land use of the property, but do not consider other conditions specific to the site.