Tiered Approach to Corrective Action Objectives (TACO)

In Illinois, the Tiered Approach to Corrective Action Objectives (TACO), 35 Ill. Adm. Code Part 742, is a method for developing remediation objectives for soil and groundwater; the Illinois Environmental Protection Agency (Illinois EPA) says site owners use it to set the objectives for their site. Illinois EPA describes it as protecting health while weighing the conditions at the site and the use of the land. Under TACO the site owner chooses the approach, and the intended land use, residential or industrial and commercial, decides how much cleanup is needed.

In a Phase I ESA

TACO is not a list. Illinois EPA's fact sheet on NFR letters says a site qualifies for a No Further Remediation (NFR) letter once it meets its program's requirements and the TACO objectives that apply, and TACO explains the controls such a letter can carry. When a property's letter rests on TACO, read which tier and which land use it relied on.

• Three tiers. Tier 1 objectives allow for the land use but nothing else about the site, and so rest on the most cautious assumptions about how contamination moves and how much people take in. Tier 2 and Tier 3 objectives come from site-specific data and risk assessment, and Illinois EPA says they are usually less strict than Tier 1 while being as protective. An owner may then treat or remove contamination, block exposure with barriers or institutional controls, do nothing where Tier 1 is not exceeded, or combine these.
• Some objectives bring controls. Illinois EPA's fact sheet on institutional controls says a control is needed when objectives are based on industrial or commercial use, an engineered barrier, an excluded exposure pathway, or a point of exposure away from the source, and not when the site meets residential objectives. A control can limit the land to industrial or commercial use, bar potable wells, require three feet of clean cover over contamination, require a safety plan for digging in a contaminated area, or require a parking lot or other barrier to be kept up. Illinois EPA says owners must keep engineered barriers in good repair, so look at the barrier's condition at the site visit.
• Zoning is not a control. Illinois EPA says commercial zoning does not necessarily bar residential use, as a TACO control does. TACO's residential category takes in, besides homes, places such as educational, health care and child care facilities and playgrounds where children could be exposed.
• Neighbors must agree. Illinois EPA will not issue a letter that puts controls on off-site property without that owner's consent; without it the off-site contamination must be cleaned to residential objectives.

The controls come in several forms. The fact sheet lists restrictive covenants and deed restrictions, negative easements, local ordinances, and agreements with a highway authority, since a road can serve as a barrier. An Environmental Land Use Control (ELUC), under Section 742.1010, is one kind of institutional control, and takes effect only once Illinois EPA approves it. A local ordinance that in effect bans private drinking water wells can serve as a control if Section 742.1015's procedures are met. The fact sheet counts an agreement between Illinois EPA and the city, a Memorandum of Understanding, among those procedures; the model ordinance page says one is needed where the ordinance does not expressly bar the local government itself from installing and using potable wells.

Where to look a site up

• Illinois EPA's Groundwater Ordinance Chart. Its table has columns for municipality, county, review complete, DLC reference number, citation, ordinance, comments and the ordinance document. Its rows load by script and did not reach the copy this handbook saved.
• Illinois EPA's Institutional Control Model Documents page links models for, among others, a highway authority agreement, a groundwater ordinance, a Memorandum of Understanding, an ELUC and an off-site notification letter.
• The rule is linked from Illinois EPA's Tiered Approach to Corrective Action Objectives page, which also links the agency's toxicity values for Tier 2 and Tier 3 and a memo on background concentrations of polynuclear aromatic hydrocarbons in Chicago soil.

Getting the file

The controls on a closed site are in its NFR letter and the reports behind it, in the program file. Illinois EPA takes requests under the Illinois Freedom of Information Act through its online FOIA Request Web Form, which needs an account, or by fax, U.S. mail or special carrier. Fees, reply times and the options for large files are on the FOIA requests page.

Sources

Illinois Environmental Protection Agency pages, read October 13, 2026:

• Tiered Approach to Corrective Action Objectives, last modified April 29, 2026.
• Fact Sheet 3: No Further Remediation Letters - Fact Sheets, last modified February 1, 2023.
• Fact Sheet 4: Institutional Controls, last modified January 6, 2023.
• Institutional Control Model Documents, last modified January 17, 2023.
• Model Environmental Land Use Control, last modified January 6, 2023.
• Model Groundwater Ordinance, last modified December 4, 2025.
• Groundwater Ordinance Status, last modified September 11, 2023.
• Freedom of Information Act, last modified May 2, 2024.