Acronyms | Meaning | Acronyms | Meaning |
| ADM | Administration | NOT | Notice of Termination |
| ADO | Associate Director's Office | NOV | Notice of Violations |
| AG | Attorney General | NPDES | National Pollutant Discharge Elimination System |
| AIR | Bureau of Air | NPL | National Priorities List |
| AMS | Air Monitoring Section | NPLU | National Priorities List Unit |
| AQPS | Air Quality Planning Section | NRC | National Response Center |
| ATU | Allotment Trading Units | NSPS | New Source Performance Standards |
| BACT | Best Available Control Technology | NSR | New Source Review |
| BCO | Bureau Chief's Office | O&M | Operations and Maintenance |
| CAAPP | Clean Air Act Permit Program | OBA | Office of Brownfield Assistance |
| CAFO | Concentrated Animal Feeding Operation | OCEPP | Office of Chemical Emergency Preparedness & Prevention |
| CASM | Compliance Systems and Management | OHR | Office of Human Resource |
| CDAP | Community Development Assistance Program | OPI | Office of Public Information |
| CERCLA | Comprehensive Environmental Response, Compensation & Liability Act | OPP | Office of Pollution Prevention |
| CERCLIS | Comprehensive Environmental Response, Compensation & Liability System | OSB | Office of Small Business |
| CES | Compliance Enforcement Section | OSFM | Office of the State Fire Marshal |
| CESQG | Conditionally Exempt Small Quantity Generator | P2 | Pollution Prevention |
| CFC | Chlorofluorocarbons | PCBs | Poly-Chlorinated Biphenyls |
| CFFP | Clean Fuel Fleet Program | PCS | Permit Compliance System |
| CR | Community Relations | PEID | Preliminary Environmental Impact Determination |
| CSO | Combined Sewer Overflow | PIMW | Potentially Infectious Medical Waste |
| DAPC | Division of Air Pollution Control | PM | Particulate Matter |
| DAU | Disposal Alternatives Unit | PS | Permit Section |
| DCEO | Department of Commerce and Economic Opportunity | PSD | Prevention of Significant Deterioration |
| DERTF | Drycleaner Environmental Response Trust Fund of Illinois | PSI | Pollutant Standards Index |
| DLC | Division of Legal Counsel | PWS | Public Water Supplies |
| DMRs | Discharge Monitoring Reports | QA | Quality Assurance |
| DMSP | Division of Mobile Source Programs | QAS | Quality Assurance Section |
| DO | Director's Office | QNCR | Quarterly Non-Compliance Reports |
| DOL | Division of Laboratories | RACT | Reasonable Available Control Technology |
| EAU | Engineering and Assessment Unit | RAP | Remedial Action Plan |
| EE | Environmental Education | RCRA | Resource Conservation & Recovery Act |
| EIS | Emission Inventory System | RFG | Reformulated Gasoline |
| EMFs | Electro-Magnetic Fields | RFP | Reasonable Further Progress |
| EOU | Emergency Operations Unit | RIPP | Regulatory Innovation Pilot Program |
| EPCRA | Emergency Planning & Community Right-To-Know Act | RMP | Risk Management Program |
| ERMS | Emissions Reduction Market System | RMP | Risk Management Programs |
| FESOP | Federally Enforceable State Operating Permit | ROP | Rate of Progress Plan |
| FFU | Federal Facilities Unit | RPMS | Remedial Project Management Section |
| FIP | Federal Implementation Act | RRT | Regional Response Team |
| FOIA | Freedom of Information Act | RVP | Reid Vapor Pressure |
| FOS | Field Operations Section | SARA | Superfund Amendments & Re-Authorization Act |
| FPA | Facility Planning Areas | SIC | Standard Industrial Codes |
| FSRS | Federal Site Remediation Section | SIP | State Implementation Plan |
| ICDB | Illinois Capital Development Board | SNC | Significant Non-Compliance |
| ICR | Information Collection Rule | SO2 | Sulfur Dioxide |
| IDA | Illinois Department of Agriculture | SOCs | Synthetic Organic Chemicals |
| IDNR | Illinois Department of Natural Resources | SPCC | Spill Prevention Contaminant Control Plans |
| IDNS | Illinois Department of Nuclear Safety | SQG | Small Quantity Generator |
| IDOT | Illinois Department of Transportation | SRF | State Revolving Fund |
| IDPH | Illinois Department of Public Health | SRP | Site Remediation Program |
| IEMA | Illinois Emergency Management Agency | SSU | State Site Unit |
| IFAS | Infrastructure Financial Assistance Section | SW | Solid Waste |
| IMES | Industrial Material Exchange Service | SWS | Surface Water Section |
| IOC | Inorganic Chemicals | TACO | Tiered Approach to Corrective Action Objectives |
| ION | Incident of Non-Compliance | TAU | Toxicity Assessment Unit |
| IPCB | Illinois Pollution Control Board | TMDL | Total Maximum Daily Load |
| ISOS | Illinois Secretary of State | TRI | Toxic Release Inventory |
| ITAC | Illinois Toxic Air Contaminant | TSCA | Toxic Substances Control Act |
| LAND | Bureau of Land | TTHM | Total Trihalomethane |
| LEAP | Lake Education Assistance Program | UIC | Underground Injection Control |
| LMOS | Lake Michigan Ozone Study | USEPA | United States Environmental Protection Agency |
| LPC | Land Pollution Control | UST | Underground Storage Tank |
| LQG | Large Quantity Generator | VIM | Vehicle Inspection and Maintenance |
| LUST | Leaking Underground Storage Tank | VMT | Vehicle Miles Traveled |
| MACT | Maximum Achievable Control Technology | VN | Violation Notice |
| MBE | Minority Business Enterprise | VOC | Volatile Organic Compound |
| MCM | Municipal Compliance Maintenance | WATER | Bureau of Water |
| NCA | Non-Compliance Advisory | WMS | Watershed Management Section |
| NESHAP | National Emission Standards for Hazardous Air Pollutants | WPC | Water Pollution Control |
| NFR | No Further Remediation | WQS | Water Quality Standards |
| NOI | Notice of Intent | WRAC | Waste Reduction and Compliance |
| NON | Notice of Non-Compliance | | |