Section 1600.210  Procedures for Potable Water Supply Well Surveys

a)         When Board rules require a well survey to determine the existence and location of potable water supply wells, the following must be identified:

1)         All private, semi-private, and non-community water system wells located at the property where the release occurred or within 200 feet of the property where the release occurred;

2)         All community water system (CWS) wells located at the property where the release occurred or within 2,500 feet of the property where the release occurred; and

3)         All setback zones and regulated recharge areas in which all or any portion of the property where the release occurred is located.

b)         The person performing the well survey must take action to identify the wells and associated protected areas, including the following:

1)         Contacting the Agency's Division of Public Water Supplies to identify community water system wells and associated setback zones and regulated recharge areas;

2)         Using current information from the Illinois State Geological Survey, the Illinois State Water Survey, and the Illinois Department of Public Health (or the county or local health department delegated by the Illinois Department of Public Health to permit potable water supply wells) to identify potable water supply wells, other than community water system wells, and their setback zones; and

3)         Contacting the local public water supply entities to identify properties that receive potable water from a public water supply.

c)         In addition to  subsections (a) and (b), persons subject to Subpart B may be required to expand the area of the potable water supply well survey.

1)         An expanded well survey is required if measured or modeled groundwater contamination extends beyond a boundary of the property where the release occurred in concentrations exceeding the remediation objectives of 35 Ill. Adm. Code 742.Appendix B: Table E for the groundwater ingestion exposure route or the groundwater quality standards at 35 Ill. Adm. Code 620 (e.g., Class I, Class III). 

A)        If there is no Table E objective or Part 620 standard, the Agency will determine or approve an objective according to 35 Ill. Adm. Code 620.Subpart F. 

B)        The extent of modeled groundwater contamination must be determined using the procedures of 35 Ill. Adm. Code 742 or another model approved by the Agency.  When modeling the extent of groundwater contamination, the modeling must include the impact from soil contamination in concentrations exceeding the remediation objectives for the soil component of the groundwater ingestion exposure route.

2)         At a minimum, the expanded well survey must identify the following:

A)        All private, semi-private, and non-community water system wells located within 200 feet, and all community water system wells located within 2,500 feet, of the measured or modeled groundwater contamination exceeding the remediation objectives of Part 742 for the groundwater ingestion exposure route or Part 620 groundwater quality standards; and

B)        All setback zones and regulated recharge areas in which any portion of the measured or modeled groundwater contamination exceeding the remediation objectives of Part 742 for the groundwater ingestion exposure route or Part 620 remediation objectives is located.

d)         The Agency may, based on site-specific circumstances or information collection deficiencies (e.g., incomplete, conflicting or imprecise information, information assembled from unverified sources), require additional investigation to determine the existence or location of potable water supply wells, setback zones or regulated recharge areas.  The additional investigation may include physical well surveys (e.g., interviewing property owners, investigating individual properties for wellheads, distributing door hangers or other materials requesting information about the existence of potable water supply wells).

e)         Documentation of a potable water supply well survey conducted under this Section must include the following:

1)         One or more maps to a scale depicting the following:

A)        The locations of the community water system wells and other potable water supply wells identified under this Section;

B)        The location and extent of setback zones and regulated recharge areas identified under this Section; and

C)        The areas identified in subsections (A) and (B) in relation to the measured or modeled groundwater contamination exceeding the remediation objectives of Part 742 for the groundwater ingestion exposure route or Part 620 groundwater quality standards;

2)         One or more tables listing the setback zones and regulated recharge areas for each community water system well and other potable water supply wells identified under this Section; and

3)         A narrative that, at a minimum, lists each entity contacted to identify potable water supply wells and protected areas, the name and title of each person contacted, and any field observations while identifying and locating potable water supply wells.

(Source:  Amended at 43 Ill. Reg. 11637, effective September 25, 2019)