Limited Area Ordinance Caution Statement

Agency Statement Concerning Groundwater Ordinances Reviewed for Institutional Controls Using Radii/Circles to Define Limited Area Prohibitions

(December 28, 2010)

Limited area groundwater ordinance prohibitions reviewed for use as environmental institutional controls and defined entirely or in part by radii and circles recently have received additional scrutiny by the Division of Legal Counsel reviewers. Limited area prohibitions are those that do not apply throughout the entire jurisdiction of the adopting unit of local government. Illinois Pollution Control Board rules require limited area prohibitions to be easily identifiable and clearly defined. Any prohibition defined entirely or in part by a radius and circle must have a single, clearly identifiable, permanent (i.e., fixed and unchanging) point of reference from which the radius of the circle can be measured throughout the life of the institutional control.

Radii purporting to extend from any descriptor other than a clearly identifiable, permanent point of reference cannot be determined with acceptable precision (e.g., radii purporting to extend from an area or multiple points such as "a property", a common address, or the "boundary" of a property). In the absence of a single, identifiable, permanent point of departure for the measurement of the radius, outer boundaries of the prohibition area could vary significantly in a context where a relatively few feet may make the difference between compliance and noncompliance with regulatory requirements.

Ordinances using the radius/circle approach to define all or part of an area of prohibition will be evaluated and approved or rejected on a site-specific basis. However, if the point of departure for determining the radius is not clearly identifiable and permanent, approval of the ordinance is unlikely. Questions concerning ordinances used as institutional controls may be directed to the Agency's Division of Legal Counsel at (217) 782-5544.