Section 704.129  Transitioning from a Class II Injection Well to a Class VI Injection Well

a)         The owner or operator of a Class II injection well that is injecting carbon dioxide into an oil and gas reservoir for the primary purpose of long-term storage must apply for and obtain a Class VI injection well geologic sequestration permit when there is an increased risk to a USDW compared to usual Class II injection well operations.  In determining if there is an increased risk to a USDW, the owner or operator must consider the factors specified for Agency consideration in subsection (b).

b)         The Agency must determine when there is an increased risk to a USDW from injecting carbon dioxide into an oil and gas reservoir for the primary purpose of long-term storage compared to usual Class II injection well operations and that a Class VI injection well permit is required.  In order to make this determination, the Agency must consider the following factors:

1)         Any increase in reservoir pressure within the injection zones;

2)         Any increase in carbon dioxide injection rates;

3)         Any decrease in reservoir production rates;

4)         The distance between the injection zones and USDWs;

5)         The suitability of the Class II injection well area of review delineation;

6)         The quality of abandoned well plugs within the area of review;

7)         The owner's or operator's plan for recovery of carbon dioxide after the cessation of injection;

8)         The source and properties of injected carbon dioxide; and

9)         Any additional site-specific factors that the Agency determines are necessary to determine whether the injection poses greater risk than usual Class II operations.

BOARD NOTE:  Derived from 40 CFR 144.19 (2017).

(Source:  Amended at 42 Ill. Reg. 21095, effective November 19, 2018)