On January 4, 2024, the Board adopted amendments to keep Illinois’ definition of “volatile organic material” (VOM) “identical in substance” to the federal definition of “volatile organic compound” (VOC). The amendments reflect one action taken by the United States Environmental Protection Agency (USEPA) during the first half of 2023. Specifically, USEPA excluded HFO–1336mzz(E) from its VOC definition (40 C.F.R. § 51.100(s)) after determining that the compound makes a negligible contribution to the formation of tropospheric ozone, commonly known as “smog.” The Board also made a few non-substantive changes to its VOM definition (35 Ill. Adm. Code 211.7150).

On January 4, 2024, the Board proposed non-substantive amendments to its agriculture-related water pollution rules for second-notice review by the Joint Committee on Administrative Rules (JCAR). These proposed amendments are part of a larger undertaking by the Board to update its rules across multiple media and subject areas. The proposal will remove unnecessary language, replace outdated text, update statutory references, and reorganize provisions for clarity.

On February 15, 2024, the Board adopted non-substantive amendments to its agriculture-related water pollution rules. These final amendments are part of a larger undertaking by the Board to update its rules across multiple media and subject areas. The amendments include removing unnecessary language, replacing outdated text, updating statutory references, and reorganizing provisions for clarity. All four Parts of the Board’s Subtitle E rules are affected, i.e., Parts 501, 502, 503, and 506 of Title 35 of the Illinois Administrative Code.

On March 7, 2024, for public comment, the Board proposed amendments to keep Illinois’ hazardous waste regulations “identical in substance” to the federal regulations. The proposal reflects action taken by the United States Environmental Protection Agency (USEPA) during the second half of calendar years 2020 and 2021, as well as the first half of calendar year 2023. During these timeframes, USEPA updated its regulations for identifying ignitable hazardous waste, modernized test methods that currently require the use of mercury thermometers, harmonized its regulations on hazardous waste import-export recovery and disposal operations with new Canadian disposal code numbers and descriptions, and revised Method 23.

On March 7, 2024, for public comment, the Board proposed amendments to Illinois’ wastewater pretreatment regulations. The proposed amendments are “identical in substance” to rule amendments adopted by the United States Environmental Protection Agency (USEPA) during the second half of 2023. Specifically, on August 9, 2023, USEPA updated the reporting and recordkeeping requirements for dental offices as a point source category (40 C.F.R. § 441.50).

On March 7, 2024, the Board proposed amendments to keep Illinois’ ambient air quality standards “identical in substance” to the National Ambient Air Quality Standards (NAAQS). The amendments reflect two actions taken by the United States Environmental Protection Agency (USEPA) during the second half of 2023. First, USEPA updated the current ozone absorption cross-section to the recommended consensus-based cross-section value. Second, USEPA updated its List of Designated Reference and Equivalent Method. This update modified existing method designations and designated a new Federal Equivalent Method (FEM) for measuring concentrations of fine particulate matter (PM10) in ambient air.

On March 7, 2024, the Board proposed first-notice amendments to update its groundwater quality rules in 35 Ill. Adm. Code 620. The proposed changes will uphold the policy of the Illinois Groundwater Protection Act “to restore, protect, and enhance the groundwaters of the State, as a natural and public resource.” 415 ILCS 55/2(b) (2022). Among the amendments, the Board proposes adding groundwater quality standards for ten new chemicals detected in Illinois groundwater, including six per- and polyfluoroalkyl substances or “PFAS.”

On April 18, 2024, the Board proposed first-notice amendments to update its air pollution rules on permitting for the construction and modification of major stationary sources in non-attainment areas. The changes will make the Board’s Non-Attainment New Source Review (NA NSR) permitting rules consistent with the federal Clean Air Act and the United States Environmental Protection Agency’s underlying NA NSR permitting program. The Board also proposed related changes to its rules on Prevention of Significant Deterioration (PSD) permitting, as well as its rules on toxic air contaminants.

On June 6, 2024, the Board issued an order proposing, for public comment, non-substantive amendments to Illinois’ air pollution rules. The proposed amendments are part of a larger undertaking by the Board to update its rules across multiple media and subject areas. The proposal will remove unnecessary language, replace outdated language, update statutory references, and reorganize provisions for clarity. The proposed amendments include revisions submitted by the Illinois Environmental Protection Agency to delete obsolete provisions and make other non-substantive updates and corrections.

On May 16, 2024, the Board adopted amendments to keep Illinois’ wastewater pretreatment regulations “identical in substance” to the federal regulations. The amendments reflect action taken by the United States Environmental Protection Agency (USEPA) during the first half of calendar year 2023. USEPA amended a provision of the steam electric power generating point source category within the effluent limitation guidelines. Specifically, USEPA extended the date by which existing coal-fired power plants must submit a notice if they plan to participate in a subcategory of electric generating units permanently ceasing coal combustion by December 31, 2028. The Board added the extended deadline to the Illinois sewer discharge criteria rules for steam electric power generating.

On May 16, 2024, the Board adopted amendments to keep Illinois’ ambient air quality standards identical in substance to the National Ambient Air Quality Standards (NAAQS). The amendments reflect two actions taken by the United States Environmental Protection Agency (USEPA) during the second half of 2023. First, USEPA updated the current ozone absorption cross-section to the recommended consensus-based cross-section value. Second, USEPA designated two new equivalent methods for monitoring ambient air quality, one for measuring concentrations of lead (pb) and the other for measuring concentrations of particulate matter (PM10). The Board’s final amendments account for these USEPA updates.

In 2023, the Board adopted new rules (35 Ill. Adm. Code 1501) on licensing drycleaning facilities, overseeing their environmental insurance coverage, and administering State fund reimbursement for the costs of cleaning up drycleaning solvent releases. In that rulemaking (docket R21-19), the Board also opened a sub-docket (R21-19(A)) to further consider the issues of continuing education and compliance program requirements for owners and operators of active drycleaning facilities.

On June 20, 2024, the Board adopted amendments to keep Illinois’ hazardous waste regulations “identical in substance” to the federal regulations. The amendments reflect actions taken by the United States Environmental Protection Agency (USEPA) during the second half of calendar years 2020 and 2021, as well as the first half of calendar year 2023. During these timeframes, USEPA updated its regulations for identifying ignitable hazardous waste, modernized test methods that currently require the use of mercury thermometers, harmonized its regulations on hazardous waste import-export recovery and disposal operations with new Canadian disposal code numbers and descriptions, and revised Method 23.

On June 20, 2024, the Board adopted amendments to Illinois’ wastewater pretreatment regulations. The amendments to 35 Ill. Adm. Code 307 are “identical in substance” to rule amendments adopted by the United States Environmental Protection Agency (USEPA) during the second half of 2023. Specifically, on August 9, 2023, USEPA updated the reporting and recordkeeping requirements for dental offices as a point source category (40 C.F.R. § 441.50).

On July 11, 2024, for public comment, the Board proposed amendments to keep Illinois’ hazardous waste regulations “identical in substance” to the federal regulations. The proposed amendments reflect actions taken by the United States Environmental Protection Agency (USEPA) in the second half of calendar year 2023. During this timeframe, USEPA made technical revisions to correct or clarify regulations adopted as part of the Hazardous Waste Generator Improvements rule, the Hazardous Waste Pharmaceuticals rule, and the Definition of Solid Waste rule. USEPA also made other minor corrections, clarifications, and updates to its hazardous waste regulations.

On July 11, 2024, for review by the Joint Committee on Administrative Rules (JCAR), the Board proposed second-notice amendments to establish alternative emission limits for periods of startup, shutdown, breakdown, and malfunction. The proposal would amend four Parts of the Board’s air pollution rules, i.e., Parts 212, 215, 216, and 217 (35 Ill. Adm. Code 212, 215, 216, 217).

On August 22, 2024, the Board issued an order proposing amendments to 35 Ill. Adm. Code 845 for first notice. The Board had opened this sub-docket when it adopted new Part 845, Illinois’ first Statewide standards for the disposal of coal combustion residuals (CCR) in surface impoundments. The sub-docket was established to further explore four issues: (1) historic, unconsolidated coal ash fill in the State; (2) the use of temporary storage piles of coal ash, including time and volume limits; (3) fugitive dust monitoring plans for areas surrounding CCR surface impoundments; and (4) the use of environmental justice screening tools.

On September 5, 2024, for public comment, the Board proposed amendments to Illinois’ wastewater pretreatment regulations. The proposed amendments are “identical in substance” to rule amendments adopted by the United States Environmental Protection Agency (USEPA) during the first half of 2024. Specifically, on May 9, 2024, USEPA updated the effluent limitations guidelines and standards (ELGs) for the steam electric power generating point source category.

On September 5, 2024, the Board proposed amendments to keep Illinois’ ambient air quality standards “identical in substance” to the National Ambient Air Quality Standards (NAAQS). The amendments reflect two actions taken by the United States Environmental Protection Agency (USEPA) during the first half of 2024. First, USEPA revised the primary annual NAAQS for fine particulate matter (PM2.5) from 12.0 micrograms per cubic meter of air (12.0 µg/m3) to 9.0 µg/m3. USEPA set the more stringent standard due to human health effects associated with long- and short-term exposures to PM2.5 in ambient air. Second, USEPA updated its List of Designated Reference and Equivalent Methods. This update modified existing method designations and designated a new Federal Equivalent Method (FEM) for measuring concentrations of ozone (O3) in ambient air.

On September 5, 2024, the Board adopted amendments to its administrative rules at Part 2175 of Title 2 of the Illinois Administrative Code. The Board amended the rules to reflect, among other things, a recent change to the Open Meetings Act (5 ILCS 120/7(a) (2022)). The Open Meetings Act was amended so that a member of a public body could attend a meeting of that body by video or audio conference when the member is unable to physically attend the meeting because of “unexpected childcare obligations.” The Board added corresponding language to its rule that specifies the circumstances under which a Board Member may telephonically attend an open meeting of the Board.