Skip to main content

PESA

Preliminary Environmental Site Assessments are required when a recognized environmental condition is identified in a project area.

PESA

Prior to acquisition of a right-of-way (ROW) or improvements to existing state-owned property, IDOT must conduct a Preliminary Environmental Site Assessment (PESA). The purpose of a PESA is to identify and assess environmental risks and liabilities of a property to protect worker and public safety, reduce IDOT liability, and minimize delays through efficient and cost-effective operating procedures.

Conducted by the Illinois State Geological Survey (ISGS) on behalf of IDOT, a PESA is triggered when an Environmental Survey Request (ESR) identifies the likelihood a Recognized Environmental Condition (REC), found in the BLRS Manual Ch.20-12(2), or other natural hazard associated with a property or ROW.

PESAs result in one of two findings1:

  • No REC Finding: If a PESA does not identify any RECs (other than de minimis) within the project area then no further action is necessary. New circumstances can trigger a reevaluation and are listed in the BDE Manual Ch.23-3.03(c).

  • REC Finding: If a PESA identifies a REC within the project area, then further consultation is necessary. A Preliminary Site Investigation may be necessary, which includes soil, sediment, and groundwater sampling.

Planners can reduce the need for a PESA, minimizing project delay, by identifying RECs or natural hazards and developing plans and alternatives that avoid them. Early identification saves a project time and money, and through the REF, planners can understand and take steps to avoid potentially hazardous sites.


  1. IDOT BDE Manual Chapter 27-3.03: Preliminary Environmental Site Assessment ↩︎